鈴木 浩一

Nivolumab monotherapy is a standard treatment of metastatic gastric cancer, and this type of cancer involves vascular endothelial growth factor (VEGF) signaling in the tumor immunological environment. The subgroup analysis of the ATTRACTION-2 trial revealed that prior treatment with ramucirumab (RAM), a VEGF inhibitor, affected the therapeutic effect of nivolumab. The present retrospective study aimed to review patients with metastatic gastric cancer who were treated with paclitaxel (PTX) and RAM followed by nivolumab. A total of 29 patients with metastatic gastric cancer were treated with PTX + RAM as second-line treatment, followed by nivolumab monotherapy as third-line treatment. The therapeutic efficacy of nivolumab was compared in 13 patients with progression-free survival (PFS) of <5 months and 16 patients with PFS ≥5 months after PTX + RAM therapy. The present study included 22 male and seven female patients, with a median age of 68 years (range, 45-82 years). Human epidermal growth factor receptor 2 positivity was observed in six patients. The disease control rate was 62.1%. The PFS and overall survival (OS) were 4.4 and 11.9 months, respectively. Patients with PFS ≥5 months after PTX + RAM therapy showed better outcome in both PFS (5.3 months vs. 2.8 months, P=0.039) and OS (6.9 months vs. 15.2 months, P=0.066) after nivolumab treatment than patients with PFS of <5 months after PTX + RAM therapy. However, no significant relationship was observed between the outcome of first-line treatment and nivolumab. The therapeutic effect of nivolumab was associated with prior PTX + RAM treatment in advanced gastric cancer.

Molecular assessment using circulating tumor DNA (ctDNA) has not been well-defined. We recruited 61 pancreatic cancer (PC) patients who underwent initial computed tomography (CT) imaging study during first-line chemotherapy. Initial molecular assessment was performed using droplet digital PCR and defined as the change in KRAS-mutated ctDNA before and after treatments, which was classified into five categories: mNT, molecular negative; mCR, complete response; mPR, partial response; mSD, stable disease; mPD, progressive disease. Of 61 patients, 14 diagnosed with PD after initial CT imaging showed significantly worse therapeutic outcomes than 47 patients with disease control. In these 47 patients, initial molecular assessment exhibited significant differences in therapeutic outcomes between patients with and without ctDNA (mPD + mSD vs. mCR + mNT; 13.2 M vs. 21.7 M, P = 0.0029) but no difference between those with mPD and mSD + mCR + mNT, suggesting that the presence of ctDNA had more impact on the therapeutic outcomes than change in its number. Multivariate analysis revealed that it was the only independent prognostic factor (P = 0.0405). The presence of ctDNA in initial molecular assessment predicted early tumor progression and identified PC patients more likely to benefit from chemotherapy.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most cancers. Its 5-year survival rate is very low. The recent induction of neoadjuvant chemotherapy and improvements in chemotherapy for patients with pancreatic cancer have resulted in improved survival outcomes. However, the prognosis of pancreatic cancer is still poor. To dramatically improve the prognosis, we need to develop more tools for early diagnosis, treatment selection, disease monitoring, and response rate evaluation. Recently, liquid biopsy (circulating free DNA, circulating tumor DNA, circulating tumor cells, exosomes, and microRNAs) has caught the attention of many researchers as a new biomarker that is minimally invasive, confers low-risk, and displays an overall state of the tumor. Thus, liquid biopsy does not employ the traditional difficulties of obtaining tumor samples from patients with advanced PDAC to investigate their molecular biological status. In addition, it allows for long-term monitoring of the molecular profile of tumor progression. These could help in identifying tumor-specific alterations that use the target structure for tailor-made therapy. Through this review, we highlighted the latest discoveries and advances in liquid biopsy technology in pancreatic cancer research and showed how it can be applied in clinical practice.

Gastric and bile acid reflux leads to chronic inflammation, resulting in methylation alterations in Barrett's esophagus (BE) together with chromosomal instability (CIN). We investigated DNA hypomethylation following acid exposure and confirmed its significance in BE-related carcinogenesis by inducing CIN in vitro. OACP4C, an esophageal cancer cell line, and CP-A, a non-dysplastic cell line originating from BE, were exposed to acidic conditions using deoxycholic acid. CP-A exhibited substantially increased DNA hypomethylation of alpha satellite sequences in the centromere region, as well as increased levels of alpha satellite transcripts, but no changes were observed in the long interspersed nucleotide element-1 sequences distributed throughout the entire genome. These changes were not clearly found in OACP4C. Copy number changes at specific chromosomes were identified in CP-A, along with an increased number of cells exhibiting abnormal segregations, whereas these changes were rarely observed in OACP4C. The changes were maintained after several cell divisions. These findings suggest that alpha satellites are likely targets of DNA hypomethylation induced by acid exposure. CP-A was more sensitive to acid exposure than OACP4C, indicating that acid-induced DNA hypomethylation is involved in cancer development rather than progression, which could be involved in the underlying mechanism of esophagogastric junction carcinoma development.

IκBζ is a transcriptional regulator that augments inflammatory responses from the Toll-like receptor or interleukin signaling. These innate immune responses contribute to the progression of nonalcoholic fatty liver disease (NAFLD); however, the role of IκBζ in the pathogenesis of NAFLD remains elusive. We investigated whether IκBζ was involved in the progression of NAFLD in mice. We generated hepatocyte-specific IκBζ-deficient mice (Alb-Cre; Nfkbizfl/fl) by crossing Nfkbizfl/fl mice with Alb-Cre transgenic mice. NAFLD was induced by feeding the mice a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD). CDAHFD-induced IκBζ expression in the liver was observed in Nfkbizfl/fl mice, but not in Alb-Cre; Nfkbizfl/fl mice. Contrary to our initial expectation, IκBζ deletion in hepatocytes accelerated the progression of NAFLD after CDAHFD treatment. Although the increased expression of inflammatory cytokines and apoptosis-related proteins by CDAHFD remained unchanged between Nfkbizfl/fl and Alb-Cre; Nfkbizfl/fl mice, early-stage steatosis of the liver was significantly augmented in Alb-Cre; Nfkbizfl/fl mice. Overexpression of IκBζ in hepatocytes via the adeno-associated virus vector attenuated liver steatosis caused by the CDAHFD in wild-type C57BL/6 mice. This preventive effect of IκBζ overexpression on steatosis was not observed without transcriptional activity. Microarray analysis revealed a correlation between IκBζ expression and the changes of factors related to triglyceride biosynthesis and lipoprotein uptake. Our data suggest that hepatic IκBζ attenuates the progression of NAFLD possibly through the regulation of the factors related to triglyceride metabolism.

Overexpression of satellite RNAs in heterochromatin induces chromosomal instability (CIN) through the DNA damage response and cell cycle checkpoint activation. Although satellite RNAs may be therapeutic targets, the associated mechanisms underlying drug sensitivity are unknown. Here, we determined whether satellite RNAs reflect drug sensitivity to the topoisomerase I inhibitor camptothecin (CPT) via CIN induction. We constructed retroviral vectors expressing major satellite and control viruses, infected microsatellite stable mouse colon cancer cells (CT26) and MC38 cells harboring microsatellite instability, and assessed drug sensitivity after 48 h. Cells overexpressing satellite RNAs showed clear features of abnormal segregation, including micronuclei and anaphase bridging, and elevated levels of the DNA damage marker γH2AX relative to controls. Additionally, overexpression of satellite RNAs enhanced MC38 cell susceptibility to CPT [half-maximal inhibitory concentration: 0.814 μM (control) vs. 0.332 μM (MC38 cells with a major satellite), p = 0.003] but not that of CT26. These findings imply that MC38 cells, which are unlikely to harbor CIN, are more susceptible to CIN-induced CPT sensitivity than CT26 cells, which are characterized by CIN. Furthermore, CPT administration upregulated p53 levels but not those of p21, indicating that overexpression of major satellite transcripts likely induces CPT-responsive cell death rather than cellular senescence.

Genome‑wide DNA hypomethylation is the most common molecular feature in human cancers associated with chromosomal instability (CIN), which is involved in the mechanisms that regulate pancreatic cancer (PC) metastasis. It was investigated whether genome‑wide DNA hypomethylation affects the phenotype in PC via CIN in vitro, and its significance on the biological behavior of PC was verified. The relative demethylation level (RDL) of long interspersed nucleotide element‑1 (LINE‑1) in human PC cell lines was used to characterize DNA hypomethylation using methylation‑specific quantitative (q)PCR. CIN was estimated by changes in chromosomal copy number using comparative genomic hybridization analysis. Abnormal segregation of chromosomes was assessed by immunocytochemistry, and the DNA damage response was evaluated using the number of anti‑γH2AX positive cells. Invasion ability was assessed using a Matrigel invasion assay. Clinical specimens from 49 patients with PC who underwent curative surgery were evaluated for a correlation of DNA hypomethylation with clinical outcome. Successful induction of genome‑wide DNA hypomethylation in PC cells led to copy number changes in specific chromosomal regions. The number of cells with abnormal segregation of chromosomes significantly increased with the number of anti‑γH2AX positive cells. The invasive potential of these cells also significantly increased. The occurrence of occult distant metastasis in the clinical specimens and receiver operating characteristic analysis clearly identified those who were and were not likely to have occult distant metastasis, with high LINE‑1 RDL significantly correlated with the presence of occult distant metastasis (P=0.035) and poor prognosis (P=0.048). The significance of genome‑wide DNA hypomethylation on the biological behavior of PC, which promotes a more invasive phenotype via CIN in vitro and predicts the susceptibility to occult distant metastasis and poor prognosis in patients with PC was revealed.

Combined treatment with bevacizumab and trifluridine/tipiracil (TAS-102) leads to an increased chance of survival in patients with refractory metastatic colorectal cancer (mCRC); however, this treatment is associated with an increased frequency of severe neutropenia (number of neutrophils <1,000), which should ideally be managed without dose delays. The present study provided a retrospective review of 35 patients with mCRC, and aimed to elucidate the benefits of prophylactic pegfilgrastim for the treatment of severe neutropenia. Patients received TAS-102 (35 mg/m2) orally twice daily on days 1-5 and 8-12 of each 28-day treatment cycle, along with intravenous bevacizumab (5 mg/kg) on days 1 and 15. Moreover, the patients received 3.6 mg pegfilgrastim on day 15 of each cycle. The incidence of adverse events (AEs), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS) were assessed. In the first and subsequent cycles, 23 and 12 patients, respectively, received pegfilgrastim. The most common AE experienced was grade 3/4 neutropenia (8 patients; 22.9%). Among these 8 patients, 6 (17.1%) and 3 (8.6%) exhibited neutropenia prior to receiving pegfilgrastim or following discontinuation of pegfilgrastim administration, respectively. Moreover, 1 individual among these 8 patients (2.9%) demonstrated grade 3 neutropenia both prior to receiving pegfilgrastim and following discontinuation of pegfilgrastim. A total of 2 patients (5.7%) exhibited grade 3 bone pain, which prevented sustainable administration of pegfilgrastim and resulted in grade 3 neutropenia. Dose delays and dose reduction of TAS-102 due to neutropenia were required in 5 (14.3%) and 2 (5.7%) patients, respectively, during the treatment period. None of the patients exhibited severe neutropenia during chemotherapy after pegfilgrastim administration, thereby preventing dose delays and dose reduction of TAS-102. The relative dose intensity was 96.8% (65.0-100.0%), and the DCR was 54.3%. The median PFS and median OS were 4.4 and 14.9 months, respectively. In conclusion, prophylactic pegfilgrastim may facilitate the management of severe neutropenia without dose delays in patients with mCRC treated with TAS-102 plus bevacizumab.

INTRODUCTION: and importance: We report a case of a patient who developed early peritoneal metastasis after laparoscopic incisional hernia repair secondary to curative colon cancer resection. CASE PRESENTATION: A 77-year-old woman underwent ileocecal resection with open laparotomy for locally advanced cecal cancer. The pathological diagnosis was adenocarcinoma with T3N2aM0. Three months after the surgery, she developed incisional hernia at the midline incision site. After the completion of adjuvant chemotherapy, surveillance computed tomography (CT) showed no cancer recurrence. Her abdominal discomfort persisted because of incisional hernia, and thus we performed laparoscopic incisional hernia repair using the intraperitoneal onlay mesh technique at 11 months after the initial surgery.Five months after incisional hernia repair, CT showed multiple liver and peritoneal metastases. She was started on systemic chemotherapy. Two days after the first therapeutic infusion, she developed small bowel obstruction. We decided to perform palliative surgery with intestinal bypass. Exploratory laparoscopy revealed that the implanted mesh for incisional hernia repair was completely covered with multiple nodules of peritoneal metastasis. Two months after the bypass surgery, she resumed her chemotherapy, but CT showed significant progression of all recurrent lesions. She did not wish to continue further chemotherapy and decided to receive the best supportive care. CLINICAL DISCUSSION: This case may raise important clinical questions regarding the indication and timing of incisional hernia repair for patients who are at high risk of cancer recurrence. CONCLUSION: Incisional hernia repair must be performed in the absence of any possibility of cancer recurrence, particularly in the earlier follow-up period.

Despite the acceptance of carbohydrate antigen 19-9 (CA19-9) as a valuable predictor for the prognosis of pancreatic ductal adenocarcinoma (PDAC), its cutoff value remains controversial. Our previous study showed a significant correlation between CA19-9 levels and the presence of KRAS-mutated ctDNA in the blood of patients with PDAC. Based on this correlation, we investigated the optimal cutoff value of CA19-9 before surgery. Continuous CA19-9 values and KRAS-mutated ctDNAs were monitored in 22 patients with unresectable PDAC who underwent chemotherapy between 2015 and 2017. Receiver operating characteristic curve analysis identified 949.7 U/mL of CA19-9 as the cutoff value corresponding to the presence of KRAS-mutated ctDNA. The median value of CA19-9 was 221.1 U/mL. Subsequently, these values were verified for their prognostic values of recurrence-free survival (RFS) and overall survival (OS) in 60 patients who underwent surgery between 2005 and 2013. Multivariate analysis revealed that 949.7 U/mL of CA19-9 was an independent risk factor for OS and RFS in these patients (P = 0.001 and P = 0.010, respectively), along with lymph node metastasis (P = 0.008 and P = 0.017), unlike the median CA19-9 level (P = 0.150 and P = 0.210). The optimal CA19-9 level contributes to the prediction of prognosis in patients with PDAC before surgery.

Background/Aim: The impact of diverting ileostomy on the feasibility of adjuvant chemotherapy (ACT) remains unclear. We retrospectively investigated the tolerability and adverse events of ACT for rectal cancer in patients with diverting ileostomy. Patients and Methods: Thirty-three patients who received ACT after curative resection with ileostomy construction for rectal cancer were analyzed. We assessed completion rate, the mean relative dose intensities, and the factors affecting the tolerability of ACT. Results: The completion rate of each chemotherapy regimen was 10 out of 16 patients in oral uracil-tegafur plus leucovorin (UFT/LV), 1 out of 3 patients in oral capecitabine (Capecitabine) and 2 out of 14 patients in capecitabine plus oxaliplatin (CAPOX). The mean relative dose intensities were 77% in UFT/LV, 48% in Capecitabine, and 57% of capecitabine and 42% of oxaliplatin in CAPOX. In multivariate analysis, laparoscopic surgery (Odds ratio=11.6, p=0.021) and receiving preoperative chemoradiotherapy (Odds ratio=32.4, p=0.021) were associated with treatment completion. Conclusion: Completion rate of ACT in patients with diverting ileostomy was lower than that of colorectal cancer patients in the previous studies. UFT/LV may be a more tolerable regimen than Capecitabine or CAPOX in colorectal cancer patients with diverting ileostomy.

Antiangiogenic agents, such as ramucirumab, should be cautiously administered along with radiotherapy because of the enhanced risk of adverse events.

BACKGROUND: Anti-epidermal growth factor receptor (EGFR) antibody is widely used for the treatment of patients with metastatic colorectal cancer. Hypomagnesemia is a comparatively frequent adverse event of this drug, which is likely overlooked because it occurs later in treatment without symptoms. Furthermore, hypomagnesemia and hypomagnesemia-induced corrected QT (QTc) prolongation may lead to loss of consciousness (LOC), the onset of which is not generally considered associated with the treatment of anti-EGFR antibody because of its rare occurrence. Here, we present a colorectal cancer patient treated with anti-EGFR antibody, who suffered LOC during treatment while severe hypomagnesemia or QTc prolongation was not observed. CASE PRESENTATION: A 69-year-old man with metastatic colon cancer was treated with cetuximab (anti-EGFR antibody) plus irinotecan as third-line chemotherapy. His serum magnesium level gradually decreased, and grade 2 hypomagnesemia (a serum magnesium level of 0.9 mg/dL) was observed at the 12th administration of cetuximab. In light of this development, intravenous supplementation of 20 mEq magnesium sulfate began with careful blood monitoring despite the lack of clinical symptoms. Electrocardiogram (ECG) showed prolonged QT or corrected QT (QTc) intervals (grade 1). His serum magnesium level remained at 0.9 mg/dL, and no hypomagnesemia symptoms were observed by the 17th administration of cetuximab. After the treatment, however, he suddenly lost consciousness without symptoms related to infusion or allergic reactions. Circulatory collapse following dermatological reactions and respiratory events were not evident. Intravenous supplementation of magnesium sulfate was administered again. He awakened 2 min after the onset of temporary LOC without any other symptoms related to hypomagnesemia, such as lethargy, tremor, tetany, and seizures. No other etiology outside of the low level of serum magnesium was confirmed in further examinations. Cetuximab was discontinued, and his serum magnesium level returned to a level within the normal range after 6 weeks. Because of tumor progression, regorafenib and TAS-102 (trifluridine tipiracil hydrochloride) were introduced sequentially for 6 months. Five months after the final treatment of TAS-102, he died of his primary disease, which reflected a survival period of 4 years and 6 months since the beginning of treatment. CONCLUSIONS: This case report reminds clinicians that LOC can be induced without severe hypomagnesemia or QTc prolongation, during anti-EGFR antibody treatment for metastatic colorectal cancer even while under carefully monitored magnesium supplementation.

Patients with breast cancer who undergo surgery have a risk of developing multiple cancers in the contralateral breast and other organs. We previously reported that overexpression of satellite alpha transcripts (SAT) facilitates chromosomal instability, which is involved in the development of multiple tumors in patients with colorectal and gastric cancer. In this study, we elucidated the significance of SAT in the development of multiple tumors in patients with breast cancer. Relative expression of SAT (rSAT) was calculated in normal and tumor tissues from 167 patients. In total, 27 patients developed bilateral breast cancer (BBC) and 27 patients showed multiple primary cancer (MPC), with patients with BBC and MPC showing higher rSAT levels in tumor tissues than those in patients with single breast cancer (SBC) (P=0.0312 and P=0.0420, respectively). Additionally, higher rSAT levels in tumor tissues from patients with BBC were a significant factor according to univariate analysis, and multivariate analysis showed that rSAT >1.5 was a significant predictor of MPC [hazard ratio (HR): 2.96; P=0.0243); however, we did not clarify the involvement of SAT in normal tissues. Excluding 71 patients with BRCA‑related clinical features, rSAT levels were higher in patients with BBC and MPC than in patients with SBC in tumor tissues and normal tissues (P<0.05). Significant predictors according to univariate analysis included rSAT >1.5 in tumor tissues, rSAT >2.4 in normal tissues, and T <2, whereas those for multivariate analysis included rSAT >2.4 in normal tissues for BBC (HR: 22.7; P=0.00120) and MPC (HR: 13.0; P=0.00601). Our data indicated that patients with breast cancer and high rSAT levels in their breast tissues exhibit a 10‑ to 20‑fold increased risk for the development of multiple cancers when harboring no BRCA‑related clinical features.

As a result of recent advances in diagnostic techniques and treatment modalities, the number of patients diagnosed with multiple primary malignancies has been increasing. We report the case of a 79-year-old male with multiple primary malignancies of three histological types in six different organs: Stomach, prostate, colon, urinary bladder, facial skin and pancreas, in chronological order. The first malignancy was upper gastric cancer diagnosed in 1998. The second and third malignancies were prostate cancer and ascending colon cancer, which were diagnosed in 2010. The fourth malignancy was bladder cancer diagnosed in 2011. The fifth and sixth malignancies were squamous cell skin cancer of the right cheek and intraductal papillary mucinous carcinoma (IPMC), respectively, diagnosed in 2014. The gastric cancer, colon cancer, bladder cancer, skin cancer and IPMC were surgically resected. The prostate cancer was treated by anti-androgen therapy. The patient died of local recurrence of IPMC in August 2016. Although multiple primary malignancies are not uncommon, diagnosis of six primary malignancies in a single patient, as reported in the present study, is extremely rare. It is important to understand the characteristics of multiple primary malignancies in order to administer suitable treatment and determine relevant follow-up plans for patients with cancer.

Introduction: We herein present three cases of locally advanced colon cancer (LACC) invading the urinary bladder, in whom combined neoadjuvant chemotherapy with surgical intervention was effective in disease control and preserving urinary function. Case Presentation: Before neoadjuvant chemotherapy, all three cases underwent loop transverse colostomy for symptomatic colonic obstruction. Case 1: after 6 courses of capecitabine plus oxaliplatin (CAPOX), we performed sigmoid colectomy and partial resection of the bladder. The histological examination revealed pathological complete response (pCR). The final diagnosis was ypStage 0 (ypT0ypN0M0). Case 2: after 13 courses of CAPOX plus bevacizumab, we performed Hartmann's operation with partial resection of the bladder. The histological examination revealed pCR. The final diagnosis was ypStage 0 (ypT0ypN0M0). Case 3: after 6 courses of chemotherapy with CAPOX plus bevacizumab, we performed sigmoid colectomy and partial resection of the bladder. The pathological response was grade 1a according to the Japanese Classification of Colorectal Carcinoma. The final diagnosis was ypStage IIC (ypT4bypN0M0). All three cases underwent capecitabine-based adjuvant chemotherapy after radical surgery and patients are alive without recurrence. Conclusion: Neoadjuvant chemotherapy with CAPOX with or without bevacizumab followed by radical surgery could be an effective treatment option for LACC invading the urinary bladder.

BACKGROUND: Liquid biopsies enable the detection of circulating tumor DNA (ctDNA). However, the clinical significance of KRAS-mutated ctDNA for pancreatic cancer has been inconsistent with respect to its prognostic and predictive potential. METHODS AND FINDINGS: A total of 422 blood samples were collected from 78 patients undergoing treatments for localized and metastatic pancreatic ductal adenocarcinoma. KRAS mutation in tissues and KRAS ctDNA levels in plasma were determined by RASKET and droplet digital polymerase chain reaction. Longitudinal monitoring of KRAS ctDNA was performed to assess its significance for predicting recurrence and prognosis and for evaluating therapeutic responses to chemotherapy compared with carbohydrate antigen 19-9 (CA19-9). In 67 tumor tissues, discrepancies in point mutations of KRAS were rarely observed among individual patients, implying that one targeted point mutation of KRAS can be determined in tumor tissues prior to longitudinal blood monitoring. One-time blood assessment of KRAS-mutated ctDNA before surgery or chemotherapy was not clearly associated with recurrence and prognosis. Sequential blood monitoring was performed in 39 patients who underwent surgery for potentially resectable tumors. Increased CA19-9 levels were significantly associated with recurrence, but not prognosis (P<0.001, P = 1.0, respectively), whereas emergence of KRAS ctDNA was significantly associated with prognosis (P<0.001) regardless of recurrence. Furthermore, in 39 patients who did not undergo surgery, detection of KRAS ctDNA was a predictive factor for prognosis (P = 0.005). Multivariate analysis revealed that detection of KRAS ctDNA was the only independent prognostic factor regardless of tumor resection (hazard ratios = 54.5 for patients who underwent surgery and 10.1 for patients who did not undergo surgery; P<0.001 for both). Patients without emergence of KRAS ctDNA within 1 year after surgery showed significantly better prognosis irrespective of recurrence (P<0.001). No detection or disappearance of KRAS ctDNA within 6 months of treatment was significantly correlated with therapeutic responses to first-line chemotherapy (P<0.001). Changes in KRAS status provided critical information for the prediction of therapeutic responses. CONCLUSIONS: Our study showed for the first time that detection of KRAS ctDNA levels within a short period enables the prediction of prognosis and therapeutic responses in patients with pancreatic cancer.

KRAS mutated circulating tumor DNA (MctDNA) can be monitored in the blood of patients with metastatic colorectal cancer (mCRC), but dynamic changes have not been determined. Four hundred and fifty-seven plasma samples were collected prospectively from 85 mCRC patients who underwent chemotherapy. MctDNA in plasma was detected by droplet digital PCR, and the percentage of MctDNA in total circulating cell-free DNA was calculated. KRAS assessment in tumor tissues showed 29 patients with the mutant-type (MT) and 56 patients with the wild-type (WT). Twenty-three of 29 MT patients (79.3%) and 28 of 56 WT patients (50.0%) showed MctDNA. Emergence of MctDNA was recognized during treatments with various drugs. Regardless of KRAS status in tumor tissues, patients with MctDNA in blood showed poor progression-free survival with first-line treatment. Median percentage of MctDNA accounted for 10.10% in MT patients and 0.22% in WT patients. These differences between MT and WT likely affected patterns of changes in MctDNA. KRAS monitoring identified dynamic changes in MctDNA, such as continuous, intermittent, and transient changes (quick elevation and disappearance). Emergence of MctDNA involved drug resistance, except for transient changes, which were seen in WT patients and likely corresponded with the drug response. Transient changes could be involved in recovery of sensitivity to anti-EGFR antibody in WT patients. Monitoring MctDNA during various treatments showed dynamic changes in KRAS status and could provide useful information for determining treatments for patients with mCRC.

The impairment of the stability of the chromosomal structure facilitates the abnormal segregation of chromosomes, thus increasing the risk of carcinogenesis. Chromosomal stability during segregation is managed by appropriate methylation at the centromere of chromosomes. Insufficient methylation, or hypomethylation, results in chromosomal instability. The centromere consists of satellite alpha repetitive sequences, which are ideal targets for DNA hypomethylation, resulting in the overexpression of satellite alpha transcript (SAT). The overexpression of SAT has been reported to induce the abnormal segregation of chromosomes. In this study, we verified the oncogenic pathway via chromosomal instability involving DNA hypomethylation and the overexpression of SAT. For this purpose, we constructed lentiviral vectors expressing SAT and control viruses and then infected human mammary epithelial cells with these vectors. The copy number alterations and segregation errors of chromosomes were evaluated by microarray-based comparative genomic hybridization (array CGH) and immunocytochemistry, respectively. The levels of hypomethylation of satellite alpha sequences were determined by MethyLight polymerase chain reaction. Clinical specimens from 45 patients with breast cancer were recruited to verify the data in vitro. The results of immunocytochemistry revealed that the incidence of segregation errors was significantly higher in the cells overexpressing SAT than in the controls. An array CGH identified the specific chromosomes of 8q and 20q as frequent sites of copy number alterations in cells with SAT overexpression, although no such sites were noted in the controls, which was consistent with the data from clinical specimens. A regression analysis revealed that the expression of SAT was significantly associated with the levels of hypomethylation of satellite alpha sequences. On the whole, the overexpression of SAT led to chromosomal instability via segregation errors at specific chromosomes in connection with DNA hypomethylation, which was also recognized in clinical specimens of patients with breast cancer. Thus, this oncogenic pathway may be involved in the development of breast cancer.

BACKGROUND: To evaluate the clinical significance of a CT-based evaluation of abdominal aortic calcification (AAC) in the postoperative outcomes after pancreaticoduodenectomy (PD) in elderly patients. METHODS: Patients 70 years of age and older who were randomly assigned to Group A were compared with those younger than 70 who were assigned to Group B in terms of preoperative and intraoperative variables and postoperative outcomes. We compared the patients with clinically relevant postoperative pancreatic fistula (CR-POPF) (Group C) to those without CR-POPF (Group D), and especially Group A. We also compared the patients with CR-POPF (Group E) to those without CR-POPF (Group E) to clarify the risk factors for POPF, in each of the analyses. The AAC score was determined using the methods of Agatston et al. RESULTS: Group A more often had frequent atherosclerosis-related comorbidities (62.2%), low serum albumin (55.9%), and a high AAC score (66.1%). There were no significant differences in the postoperative variables. The comparisons between Groups C and D identified four independent risk factors for CR-POPF: BMI ≥ 25 (OR 8.54, 95% CI 3.15-23.1), male gender (OR 3.17, 95% CI 1.28-7.85), soft pancreatic parenchyma (OR 3.43, 95% CI 1.34-8.81), and the absence of MPD dilatation (OR 5.70, 95% CI 2.13-15.3). Comparisons between Groups E and F identified two independent risk factors for CR-POPF: BMI ≥ 25 (OR 29.4, 95% CI 5.77-150) and a high ACC score (OR 10.8, 95% CI 2.08-56.6). CONCLUSIONS: We demonstrated, for the first time, that a high AAC score is a risk factor of CR-POPF in elderly patients who underwent PD.

Somatic, and in a minor scale also germ line, epigenetic aberrations are fundamental to carcinogenesis, cancer progression, and tumor phenotype. DNA methylation is the most extensively studied and arguably the best understood epigenetic mechanisms that become altered in cancer. Both somatic loss of methylation (hypomethylation) and gain of methylation (hypermethylation) are found in the genome of malignant cells. In general, the cancer cell epigenome is globally hypomethylated, while some regions-typically gene-associated CpG islands-become hypermethylated. Given the profound impact that DNA methylation exerts on the transcriptional profile and genomic stability of cancer cells, its characterization is essential to fully understand the complexity of cancer biology, improve tumor classification, and ultimately advance cancer patient management and treatment. A plethora of methods have been devised to analyze and quantify DNA methylation alterations. Several of the early-developed methods relied on the use of methylation-sensitive restriction enzymes, whose activity depends on the methylation status of their recognition sequences. Among these techniques, methylation-sensitive amplification length polymorphism (MS-AFLP) was developed in the early 2000s, and successfully adapted from its original gel electrophoresis fingerprinting format to a microarray format that notably increased its throughput and allowed the quantification of the methylation changes. This array-based platform interrogates over 9500 independent loci putatively amplified by the MS-AFLP technique, corresponding to the NotI sites mapped throughout the human genome.

Recent advancements in multimodal therapy can provide oncologic benefits for patients with recurrent colorectal cancer. This report presents a case of locoregionally recurrent appendiceal cancer treated with neoadjuvant chemotherapy followed by surgical resection with vascular reconstruction. A 68-year-old Japanese woman was diagnosed with appendiceal cancer and underwent ileocecal resection. The pathological evaluation revealed KRAS-mutant adenocarcinoma with the final stage of T4bN1M0. She received oral fluorouracil-based adjuvant chemotherapy. One year later, she was found to have peritoneal dissemination in the pelvic cavity and vaginal metastasis. She received an oxaliplatin-based chemotherapy followed by surgical resection. One year after the second surgery, she developed a locoregional recurrence involving the right external iliac vessels and small intestine. She received an irinotecan-based regimen with bevacizumab as neoadjuvant chemotherapy, followed by surgical resection. At first, a femoro-femoral bypass was made to secure the blood supply to the right lower extremities. Subsequently, an en bloc resection including the recurrent tumor and the external iliac vessels was completed. Surgical resection for recurrent colorectal cancer is often technically challenging because of the tumor location and invasion to adjacent organs. In this case, a surgical approach with persistent chemotherapy achieved oncologic resection of locoregionally recurrent appendiceal cancer.

KRAS mutations have been recognized as predictive markers of primary resistance to anti-EGFR-antibodies in colorectal cancer patients. In addition, newly detected KRAS mutations have been reported to be related with acquired resistance to chemotherapy containing anti-EGFR antibody. Considering this evidence, monitoring of KRAS mutations is indispensable for making treatment decisions, and the method should be non-invasive allowing repeated examinations. Recently, we established a novel automated sensitive detection system for KRAS mutations, named mutation-biased PCR quenching probe system (MBP-QP). The goal of our study was to investigate the potential for monitoring KRAS mutations during treatment with anti-EGFR antibodies. The detection limit of MBP-QP using a control plasmid containing KRAS mutations was 1-9 copies, and 0.05-0.3% mutant plasmid was detectable in a mixture of wild type and mutants. One-hundred twenty colorectal cancer patients were genotyped for KRAS mutations with MBP-QP as well as polymerase chain reaction reverse sequence-specific oligonucleotide (PCR-rSSO), which has already been applied to cancer tissue samples in the clinical setting. Concordance rates between plasma DNA and cancer tissues were 68% with MBP-QP and 66% with PCR-rSSO, indicating that these systems are equivalent in terms of detecting KRAS mutations with plasma DNA. KRAS mutations in plasma DNA were frequently observed in systemic metastatic cancer patients, and in three patients KRAS mutations appeared after chemotherapy containing anti-EGFR antibody. A prospective study is needed for clarifying whether KRAS mutations detected in plasma DNA are predictive markers of treatment efficacy with anti-EGFR antibody.

AIM: To assess the usefulness of en bloc right hemicolectomy with pancreaticoduodenectomy (RHCPD) for locally advanced right-sided colon cancer (LARCC). METHODS: We retrospectively reviewed the database of Saitama Medical Center, Jichi Medical University, between January 2009 and December 2016. During this time, 299 patients underwent radical right hemicolectomy for right-sided colon cancer. Among them, 5 underwent RHCPD for LARCC with tumor infiltration to adjacent organs. Preoperative computed tomography (CT) was routinely performed to evaluate local tumor infiltration into adjacent organs. During the operation, we evaluated the resectability and the amount of infiltration into the adjacent organs without dissecting the adherent organs from the cancer. When we confirmed that radical resection was feasible and could lead to R0 resection, we performed RHCPD. The clinical data were carefully reviewed, and the demographic variables, intraoperative data, and postoperative parameters were recorded. RESULTS: The median age of the 5 patients who underwent RHCPD for LARCC was 70 years. The tumors were located in the ascending colon (three patients) and transverse colon (two patients). Preoperative CT revealed infiltration of the tumor into the duodenum in all patients, the pancreas in four patients, the superior mesenteric vein (SMV) in two patients, and tumor thrombosis in the SMV in one patient. We performed RHCPD plus SMV resection in three patients. Major postoperative complications occurred in 3 patients (60%) as pancreatic fistula (grade B and grade C, according to International Study Group on Pancreatic Fistula Definition) and delayed gastric empty. None of the patients died during their hospital stay. A histological examination confirmed malignant infiltration into the duodenum and/or pancreas in 4 patients (80%), and no patients showed any malignant infiltration into the SMV. Two patients were histologically confirmed to have tumor thrombosis in the SMV. All of the tumors had clear resection margins (R0). The median follow-up time was 77 mo. During this period, two patients with tumor thrombosis died from liver metastasis. The overall survival rates were 80% at 1 year and 60% at 5 years. All patients with node-negative status (n = 2) survived for more than seven years. CONCLUSION: This study showed that the long-term survival is possible for patients with LARCC if RHCPD is performed successfully, particularly in those with node-negative status.

Morphological response is considered an improved surrogate to the Response Evaluation Criteria in Solid Tumors (RECIST) model with regard to predicting the prognosis for patients with colorectal liver metastases. However, its use as a decision-making tool for surgical intervention has not been examined. The present study assessed the morphological response in 50 patients who underwent chemotherapy with or without bevacizumab for initially un-resectable colorectal liver metastases. Changes in tumor morphology between heterogeneous with uncertain borders and homogeneous with clear borders were defined as an optimal response (OR). Patients were also assessed as having an incomplete response (IR), and an absence of marked changes was assessed as no response (NR). No significant difference was observed in progression-free survival (PFS) between complete response/partial response (CR/PR) and stable disease/progressive disease (SD/PD), according to RECIST. By contrast, PFS for OR/IR patients was significantly improved compared with that for NR patients (13.2 vs. 8.7 months; P=0.0426). Exclusion of PD enhanced the difference in PFS between OR/IR and NR patients (15.1 vs. 9.3 months; P<0.0001), whereas no difference was observed between CR/PR and SD. The rate of OR and IR in patients treated with bevacizumab was 47.4% (9/19), but only 19.4% (6/31) for patients that were not administered bevacizumab. Comparison of the survival curves between OR/IR and NR patients revealed similar survival rates at 6 months after chemotherapy, but the groups exhibited different survival rates subsequent to this period of time. Patients showing OR/IR within 6 months appeared to be oncologically stable and could be considered as candidates for surgical intervention, including rescue liver resection. Comparing the pathological and morphological features of the tumor with representative optimal response, living tumor cells were revealed to be distributed within the area of vascular reconstruction induced by bevacizumab, resulting in a predictive value for prognosis in the patients treated with bevacizumab. The present findings provided the evidence for physicians to consider patients with previously un-resectable metastatic colorectal cancer as candidates for surgical treatment. Morphological response is a useful decision-making tool for evaluating these patients for rescue liver resection following chemotherapy.

Sequential administration of the chemotherapy regimes capecitabine and oxaliplatin (XELOX) and capecitabine and irinotecan (XELIRI) in the first- to second-line treatment setting would allow patients to be managed more easily in an outpatient unit. However, a small number of studies have raised concerns of cumulative adverse events as a consequence of the continuous use of capecitabine. To investigate this, the present study conducted a retrospective review of 81 consecutive metastatic colorectal cancer (mCRC) patients treated with the oxaliplatin, fluorouracil and leucovorin-irinotecan, fluorouracil and leucovorin (FOLFOX-FOFIRI/F-F) regimen (n=40) or the XELOX-XELIRI (X-X) regimen (n=41) in first- to second-line chemotherapy in Saitama Medical Center between 2006 and 2012. The disease control rate (DCR), the progression free survival (PFS), the overall survival (OS) and the time to failure of strategy (TFS) from first to second-line chemotherapy, as well as adverse events, were assessed and compared between patients receiving X-X or F-F. A total of 10 and 20 patients were additionally treated with bevacizumab in the F-F and X-X regimens, respectively, during first or second-line chemotherapy. There was no significant difference in DCR and the median PFS between the two regimens for first or second-line chemotherapy. There was no significant difference in the median OS and TFS between the two regimens (OS=24.5 and TFS=14 months in the F-F vs. 23.2 and 12.0 months in the X-X). Regarding adverse events, 45.0% of patients (18/40) exhibited grade 3-4 neutropenia throughout treatment with F-F. Whilst, 15.0% of patients (6/41) exhibited grade 3 hypertension throughout treatment with X-X, which was effectively controlled by a single antihypertensive drug. The results show that sequential administration of X-X is as effective and feasible as F-F treatment, while additionally reducing the frequency of infusion visits and eliminating the need for a central venous access device or home infusion pump, thereby offering a more convenient treatment option to patients with mCRC.

Approximately 1.6% of tumors metastatic to the ovary of nongynecologic origin are from a small bowel adenocarcinoma (SBA). However, the incidence of SBA is extremely rare (0.23 cases/100,000 people), which suggests a high frequency of ovarian metastasis, although the reason is unknown. To identify the characteristics of ovarian tumor metastasis from SBA, we reviewed 72 cases reported in the English literature, including the case presented in this report. The mean age of the patients was 46.7 yr. Solitary ovarian metastasis was observed in 67% of the cases, and ovarian metastasis was accompanied by peritoneal dissemination in 33% of the cases. Although duodenal adenocarcinoma has the highest incidence among the SBAs, jejunal adenocarcinoma, particularly that at the proximal end, is the type of SBA that most frequently metastasizes to the ovary. Among the cases of ovarian metastasis from SBA, 51% were bilateral, 33% were unilateral to the right ovary, and 16% were unilateral to the left ovary.

Regorafenib has shown survival benefits in metastatic colorectal cancer patients who were exacerbated after all standard therapies. Some patients, however, exhibit severe adverse events (AEs) resulting in treatment discontinuation. Therefore, the selection of patients likely to benefit from regorafenib is crucial. Twenty patients were treated with regorafenib for metastatic colorectal cancer; 122 plasma samples were taken from 16 of these patients for monitoring of circulating tumor DNA (ctDNA) in the blood. The treatment response, AEs, overall survival (OS), progression-free survival (PFS) and tumor morphologic changes on CT images were evaluated. KRAS mutant ctDNA was determined using digital PCR. Median PFS and OS were 2.5 and 5.9 months, respectively. Treatment was discontinued because of disease progression (PD) in 10 patients, and AEs in another 10 patients. AEs included hyperbilirubinemia, severe fatigue and skin rash. Hyperbilirubinemia was seen in two patients with multiple bilateral liver metastases, and severe fatigue in another 2 patients with poor performance status (PS). These severe AEs resulted in treatment discontinuation. Ten patients had a median PFS of 2.1 months with AE related discontinuation; PD occurred at 3.5 months (p=0.00334). Four patients exhibited a morphologic response, achieving better PFS times of 3.5, 5.3, 5.6 and 14.2 months. Emergence of the KRAS mutation in ctDNA was observed during anti-EGFR antibody treatment in 3 patients among 11 with KRAS wild-type tumors; it was detectable in the blood prior to radiographic detection of PD. Moreover, the KRAS mutation declined in two patients during regorafenib monotherapy. These patients were re-challenged with anti-EGFR antibody. Patients with extensive multiple liver metastases or poor PS are unlikely to benefit from regorafenib. Patients with a morphologic response will probably benefit from regorafenib with adequate management of other AEs. KRAS monitoring in ctDNA could be useful regarding treatment response and in determining treatment strategy.

BACKGROUND: Incidence and clinical characteristics of synchronous colorectal cancer (sCRC) patients significantly vary among studies, likely due to differences in surveillance methodology. If remain undetected, sCRC can progress to more advanced stages seriously aggravating patient prognosis. We studied the incidence and clinicopathological characteristics of Japanese patients with sCRCs who underwent surgery for primary CRC and received exhaustive perioperative surveillance. METHODS: We recruited 1005 patients with surgically resected CRCs between January 2007 and December 2011. The associations of clinical and pathological factors with sCRC development were assessed by univariate and multivariate logistic regression. RESULTS: Eighty-four patients (8.4 %) developed sCRCs, 16 of them (19.0 %) harboring three or more cancers. Companion sCRCs were smaller and earlier stage than the index lesion (P < 0.0001). In multivariate analysis, advanced age (odds ratio (OR) 1.03 per year; P = 0.009) and left colon tumor location (OR 1.78; P = 0.013) are associated with higher risk of sCRCs, particularly in females. Overall survival did not differ between solitary CRC and sCRC (P = 0.62). CONCLUSIONS: Our results highlight the importance of perioperative colonoscopy examination to ensure the absence of sCRCs that, being small and early staged, are more difficult to detect. The incidence of sCRC, and notably of triple or more sCRCs, was higher than previously recognized. Because they are also significantly higher than expected by merely stochastic accumulation of individual cancerous lesions, we suggest that the occurrence of many sCRC reflects a hitherto uncharacterized predisposition condition.

Although epithelial-mesenchymal transition (EMT) has been implicated as the pivotal event in metastasis, there is insufficient evidence related to EMT in clinical settings. Intratumor heterogeneity may lead to underestimation of gene expression representing EMT. In the present study, we investigated the expression of EMT-associated genes and microRNAs in primary colorectal cancer while considering intratumor heterogeneity. One-hundred and thirty-three multiple spatially separated samples were obtained from 8 patients with metastatic colorectal cancers and 8 with non-metastatic colorectal cancers, from the tumor center (TC), invasive front (IF) and metastasis. Differences in gene and microRNA expression were investigated by microarray and quantitative reverse-transcription PCR. Gene expression microarray analysis detected 7920 sites showing differing levels of gene expression among the TC, IF and metastasis. Expression of the EMT-associated gene zinc-finger E-box-binding homeobox 1 (ZEB1) significantly increased in the IF (p<0.01). To exclude individual differences, the expression ratio between TC and IF in each tumor was applied to analysis. This approach enabled recognition of the activation of the VEGF and Wnt signaling pathways, which were involved in metastasis via promotion of EMT. While no activation of these pathways was seen at the TC, regardless of whether tumors were metastatic or non-metastatic, they were preferentially activated at the IF in metastatic tumors, where high ZEB1 expression was seen in connection with decreased miR-200c expression. Multiple sampling in a tumor revealed that heterogeneous ZEB1 expression induced by EMT-associated signaling pathways played a pivotal role in metastasis via regulation of miR-200c.

BACKGROUND: Improvement in the prognosis of colorectal cancer (CRC) patients has led to increasing occurrences of multiple primary malignancies (MPMs) alongside CRC but little is known about their characteristics. This study was undertaken to clarify the clinical and pathological features of MPMs, especially those at extra colonic sites, in patients with CRC. METHODS: We reviewed 1,111 patients who underwent operations for primary sporadic CRC in Saitama Medical Center, Jichi Medical University between April 2007 and March 2012. Two patients with familial adenomatous polyposis, one with hereditary non-polyposis colorectal cancer, two with colitic cancer, and any patients with metastasis from CRC were excluded. We compared the clinicopathological features of CRC patients with and without MPMs. As a control, we used a database compiled of patients with gastric cancer (GC) detected by mass screening performed in the Saitama Prefecture in Japan 2010 and compared these with CRC patients with synchronous GC. RESULTS: Multiple primary malignancies at extracolonic sites were identified in 117 of 1,111 CRC patients (10.5%). The median age was 68 (range, 29 to 96) versus 71 (50 to 92) (P < 0.001). The incidence of GC (44.4% (52 of 117)) was the highest of all MPMs. All CRC patients with GC were older than 57 years. Synchronous GC was detected in 26 patients. By contrast, out of 200,007 screened people, 225 people were diagnosed as having GC in the Saitama Prefecture. The age-standardized incidence of synchronous GC in CRC patients was significantly higher (0.53%) than in the control group (0.03%) (odds ratio, 18.8; 95% confidence interval, 18.6 to 19.0; P < 0.001). CONCLUSION: Patients with CRC who were older than 50 years preferentially developed GC synchronously and metachronously. Thus, this patient group should undergo careful perioperative screening for GC.

Tumor suppressor protein p19(ARF) (Arf; p14(ARF) in humans) functions in both p53-dependent and -independent modes to counteract hyper-proliferative signals caused by proto-oncogene activation, but its p53-independent activities remain poorly understood. Using the tandem affinity purification-tag technique, we purified Arf-containing protein complexes and identified p68 DEAD-box protein (DDX5) as a novel interacting protein of Arf. In this study, we found that DDX5 interacts with c-Myc, and harbors essential roles for c-Myc-mediated transcription and its transforming activity. Furthermore, when c-Myc was forcibly expressed, the expression level of DDX5 protein was drastically increased through the acceleration of protein synthesis of DDX5, suggesting the presence of an oncogenic positive feedback loop including c-Myc and DDX5. Strikingly, Arf blocked the physical interaction between DDX5 and c-Myc, and drove away DDX5 from the promoter of c-Myc target genes. These observations most likely indicate the mechanism by which Arf causes p53-independent tumor-suppressive activity.

BACKGROUND: ADAMTS19 encodes a member of the ADAMTS (a disintegrin and metalloproteinase domain with thrombospondin motifs) protein family with emerging roles in carcinogenesis and metastasis. ADAMTS shares several distinct protein modules including a propeptide region, a metalloproteinase domain, a disintegrin-like domain, and a thrombospondin type 1 (TS) motif. In a previous work, we found ADAMTS19 frequently hypermethylated in colorectal cancer (CRC). We explored the association of methylation with tumor genotype and phenotype. RESULTS: The methylation status of the CpG island in the promoter of ADAMTS19 was determined in 252 colorectal, 65 pancreatic, 33 breast and 169 ovarian primary tumors, 70 CRC metastases, and 10 CRC cell lines. Tumor-specific methylation of ADAMTS19 was significantly more frequent in gastrointestinal than in gynecological cancers (odds ratio (OR) = 2.9, confidence interval (CI) = (1.9-4.7), p = 5.2 × 10(-7)) and was independent of the methylation of adjacent loci in CRC. Hypermethylation associated with CRC with mutated BRAF oncogene (OR = 10.1, CI = (3.1-42.9), p = 6.3 × 10(-6)) and with the mucinous phenotype in CRC (OR = 2.1, CI = (1.1-4.1), p = 0.023) and ovarian cancer (OR = 60, CI = (16-346), p = 4 × 10(-16)). Methylation was significantly more frequent in CRC metastases homing to the ovary and omentum than in those homing to the liver and lung (OR = 6.1, CI = (1.8-22.2), p = 0.001). Differentiating local from distant metastatic spread, methylation negatively associated with tumor progression (p = 0.031) but positively with depth of invasion (p = 0.030). Hypermethylation associated with transcriptional repression in CRC cell lines, and treatment with 5'-AZA-2'-deoxycytidine led to reactivation of mRNA expression. shRNA-mediated silencing of ADAMTS19 had no effect on the in vitro proliferation rate of CRC cells but significantly diminished their collective migration speed (56 %, p = 3.3 × 10(-4)) and potential to migrate in collagen I (64 %, p = 4.3 × 10(-10)). CONCLUSIONS: Our results highlight the frequent involvement of ADAMTS19 epigenetic silencing in CRC and mucinous ovarian cancer. The mechanistic preferences for the target organ of metastatic spread may lead to the development of diagnostic CRC biomarkers. The association with the mucinous phenotype also may have diagnostic applications for ovarian cancer.

BACKGROUND: The standard treatment for stage IV gastric cancer is chemotherapy, but outcomes remain poor. The effectiveness of induction chemotherapy followed by surgery in selected patients who had a good response to chemotherapy is unclear. METHODS: A total of 59 patients with stage IV gastric cancer received induction chemotherapy with S-1 and cisplatin. In each cycle, oral S-1 (80 mg/m2) was administered for 3 weeks, followed by a 2-week drug holiday. Intravenous cisplatin (60 mg/m2) was administered on day 8 after adequate premedication and hydration. If unresectable features resolved after chemotherapy, patients underwent curative (R0) resection. The safety and outcomes of this treatment combination were evaluated, and predictive factors for survival were determined. RESULTS: Thirteen of 59 patients (22%) were eligible for R0 resection after induction chemotherapy. Kaplan-Meier analysis showed an overall median survival time of 13 months and a 3-year survival rate of 18.2%. Among patients who underwent R0 resection, the median survival time was 53 months and the 3-year survival rate was 53.8%. Multivariate analyses showed that negative para-aortic lymph nodes and undergoing R0 resection were independent predictors of survival. CONCLUSIONS: Treatment of stage IV gastric cancer with S-1 and cisplatin induction chemotherapy followed by R0 resection is safe and may improve survival compared with chemotherapy alone. Further study of this dual-modality therapy is warranted.

The aim of the present study was to present a retrospective review of 42 metastatic colorectal cancer (mCRC) patients treated using the XELIRI regimen as second-line chemotherapy during the period between 2010 and 2012. Patients were treated with capecitabine, 1,600 (≥65 years) or 2,000 mg/m2 (<65 years), on days 1-15, 200 mg/m2 irinotecan (CPT-11) on day 1, with or without 7.5 mg/kg bevacizumab on day 1 and every 21 days. A total of 21 patients underwent XELIRI and 21 underwent XELIRI plus bevacizumab treatment. Fifteen patients received continuous administration of bevacizumab in the first- and second-line settings [bevacizumab beyond progression (BBP)+], whereas 27 patients did not receive the treatment (BBP-). Forty patients (95.2%), including all the patients in the BBP+ group, received sequentially administered XELOX and XELIRI regimens from the first- to the second-line setting. The disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and adverse events were compared between the BBP- and BBP+ groups. The median relative dose intensity was similar (93.9% for capecitabine and 96.3% for CPT-11 in the BBP- group vs. 94.8% for capecitabine and 91.5% for CPT-11 in the BBP+ group). The DCR was 25.9% in the BBP- and 66.6% in the BBP+ groups (P=0.020). The median PFS was 3.5 months in the BBP- and 7.2 months in the BBP+ groups (P=0.028). The BBP+ group exhibited a higher median OS time compared to the BBP- group (12.5 months in the BBP- group vs. not reached in the BBP+ group; P=0.0267). The most common grade 3/4 adverse event (n≥20) was hypertension observed in the BBP+ group [three patients (20%)]: these three patients were well-controlled with a single antihypertensive drug. Treatment with sequentially administered XELOX and XELIRI regimens did not aggravate adverse events in the 40 patients. The results showed that the XELIRI regimen, involving continuous treatment with bevacizumab, was well-tolerated and effective as a second-line chemotherapy and sequentially administering XELOX and XELIRI was feasible and manageable for patients with mCRC.

BACKGROUND: Recent work led to recognize sessile serrated adenomas (SSA) as precursor to many of the sporadic colorectal cancers with microsatellite instability (MSI). However, comprehensive analyses of DNA methylation in SSA and MSI cancer have not been conducted. METHODS: With an array-based methylation sensitive amplified fragment length polymorphism (MS-AFLP) method we analyzed 8 tubular (TA) and 19 serrated (SSA) adenomas, and 14 carcinomas with (MSI) and 12 without (MSS) microsatellite instability. MS-AFLP array can survey relative differences in methylation between normal and tumor tissues of 9,654 DNA fragments containing all NotI sequences in the human genome. RESULTS: Unsupervised clustering analysis of the genome-wide hypermethylation alterations revealed no major differences between or within these groups of benign and malignant tumors regardless of their location in intergenic, intragenic, promoter, or 3' end regions. Hypomethylation was less frequent in SSAs compared with MSI or MSS carcinomas. Analysis of variance of DNA methylation between these four subgroups identified 56 probes differentially altered. The hierarchical tree of this subset of probes revealed two distinct clusters: Group 1, mostly composed by TAs and MSS cancers with KRAS mutations; and Group 2 with BRAF mutations, which consisted of cancers with MSI and MLH1 methylation (Group 2A), and SSAs without MLH1 methylation (Group 2B). AXIN2, which cooperates with APC and β-catenin in Wnt signaling, had more methylation alterations in Group 2, and its expression levels negatively correlated with methylation determined by bisulfite sequencing. Within group 2B, low and high AXIN2 expression levels correlated significantly with differences in size (P = 0.01) location (P = 0.05) and crypt architecture (P = 0.01). CONCLUSIONS: Somatic methylation alterations of AXIN2, associated with changes in its expression, stratify SSAs according to some clinico-pathological differences. We conclude that hypermethylation of MLH1, when occurs in an adenoma cell with BRAF oncogenic mutational activation, drives the pathway for MSI cancer by providing the cells with a mutator phenotype. AXIN2 inactivation may contribute to this tumorigenic pathway either by mutator phenotype driven frameshift mutations or by epigenetic deregulation contemporary with the unfolding of the mutator phenotype.

Some colon cancer (CC) patients present synchronous cancers at diagnosis and others develop metachronous neoplasms, but the risk factors are unclear for non-hereditary CC. We showed previously that global DNA demethylation increased with aging and correlated with genomic damage in CC, and we show now that preferentially associates to CCs with wild-type p53. This study aimed to elucidate the extent of DNA hypomethylation in patients with single and multiple CC, its relationship with aging, and its potential as predictive tool. We compared by real-time methylation-specific PCR the relative demethylation level (RDL) of long interspersed nucleotide element-1 (LINE-1) sequences in matched cancer tissues and non-cancerous colonic mucosa (NCM) from patients with single and multiple right-sided CCs. Although no RDL difference was found in NCM from single CC patients and healthy volunteers (P=0.5), there was more demethylation (higher RDL) in NCM from synchronous cancer patients (P=1.1 × 10(-5)) multiple CCs also were more demethylated than single CCs (P=0.0014). High NCM demethylation was predictive for metachronous neoplasms (P=0.003). In multivariate logistic regression analyses RDL was the only independent predictor for metachronous (P=0.02) and multiple (P=4.9 × 10(-5)) tumors. The higher LINE-1 demethylation in NCM from patients with multiple (synchronous and metachronous) tumors (P=9.6 × 10(-7)) was also very significant in patients with tumors without (P=3.8 × 10(-6)), but not with (P=0.16) microsatellite instability. NCM demethylation increased with aging in patients with single tumors, but decreased in those with multiple tumors. Moreover, the demethylation difference between patients with single vs multiple tumors appeared higher in younger (P=3.6 × 10(-4)) than in older (P=0.0016) patients. These results predict that LINE-1 hypomethylation in NCM can be used as an epigenetic predictive biomarker for multiple CC risk. The stronger association of demethylation in NCM with multiple CC risk from younger patients also suggests an inherited predisposition for the apparent field cancerization effect of somatic demethylation.

Helicobacter pylori (HP) infection is widely recognized as a risk factor for gastric cancer, but only a minority of infected individuals develop gastric cancer. The aim of this study was to determine whether DNA demethylation in non-cancerous gastric mucosa (NGM) significantly enhances susceptibility to gastric cancer. A total of 165 healthy volunteers, including 83 HP-positive and 82-negative individuals, as well as 83 patients with single and 18 with synchronous double gastric cancer (GC) were enrolled in this study. The relative demethylation levels (RDLs) of repetitive sequences, including Alu, LINE-1 and Sat α, were quantified by real-time methylation-specific polymerase chain reaction. The Alu RDL did not exhibit any differences within each respective group, whereas LINE-1 RDL was significantly elevated in cancer tissues compared with the NGM in the other groups (P<0.001). Our results indicated that a gradual increase in Sat α RDL correlated with HP infection and cancer development. Sat α RDL was significantly elevated in the NGM in HP-positive compared with HP-negative (P<0.001), and significantly elevated in cancer tissues (P<0.001). Although the Sat α RDL of the NGM in the total population increased in an age-dependent manner, it was significantly increased in a fraction of younger GC patients (<45 years) compared with all of the others (45 years or older, P=0.0391). In addition, double GC exhibited a significantly higher Sat α RDL in the NGM compared with single GC (P=0.0014). In these two fractions, Sat α RDL in the NGM exhibited an inverse correlation with age. In conclusion, the present study demonstrated that the accumulation of DNA demethylation in Sat α RDL in the NGM with HP infection potentially renders susceptibility to gastric cancer in a fraction of GC patients younger than 45 years or in patients with multiple cancers.

Patients with long-standing ulcerative colitis (UC) have higher risk of developing colorectal cancer. Albeit the causes remain to be understood, epigenetic alterations have been suggested to play a role in the long-term cancer risk of these patients. In this work, we developed a novel microarray platform based on methylation-sensitive amplified fragment length polymorphism (MS-AFLP) DNA fingerprinting. The over 10,000 NotI sites of the human genome were used to generate synthetic primers covering these loci that are equally distributed into CpG rich regions (promoters and CpG islands) and outside the CpG islands, providing a panoramic view of the methylation alterations in the genome. The arrays were first tested using the colon cancer cell line CW-2 showing the reproducibility and sensitivity of the approach. We next investigated DNA methylation alterations in the colonic mucosa of 14 UC patients. We identified epigenetic alterations affecting genes putatively involved in UC disease, and in susceptibility to develop colorectal cancer. There was a strong concordance of methylation alterations (both hypermethylation and hypomethylation) shared by the cancer cells of the CW-2 cell line and the non-cancer UC samples. To the best of our knowledge, this work defines the first high-throughput aberrant DNA methylation profiles of the colonic mucosa of UC patients. These epigenetic profiles provide novel and relevant knowledge on the molecular alterations associated to the UC pathology. Some of the detected alterations could be exploited as cancer risk predictors underlying a field defect for cancerization in UC-associated carcinogenesis.

We previously reported that the Pleckstrin and Sec7 domain-containing (PSD) gene is preferentially methylated in patients with ulcerative colitis (UC) who developed colorectal cancer (CRC), and is implicated in UC-associated carcinogenesis through its inhibition of apoptosis. This study aimed to determine the potential effect of PSD methylation on its downstream molecule, Ras-related C3 botulinum toxin substrate 1 (Rac1), which governs neutrophil chemotaxis and apoptosis signaling. PSD was knocked down in a normal human fibroblast cell line (HNDF) and a neutrophil-like cell line (HL-60). Both NHDF and HL-60 cells exhibited numerous filamentous-actin (F-actin) rich membrane extensions, resulting in the activation of Rac1; this activation was hampered by PSD silencing. Lipopolysaccharide, a reactive oxygen species (ROS) inducer, stimulated NHDF cells to release ROS and activated caspase‑3/7 in the presence of neutrophils, which was inhibited by PSD knockdown. Migration assays demonstrated that chemotaxis of HL-60 cells was affected by PSD silencing in NHDF cells. Tissue sections from 6 UC patients with CRC and 15 UC patients without CRC were examined. To verify Rac1-mediated chemotaxis in tissue sections, we evaluated the grade of neutrophil infiltration by histological assessment and assessed F-actin and PSD expression by immunohistochemistry. Neutrophil infiltration, F-actin and PSD expression were significantly decreased in specimens from UC patients with PSD methylation compared with those without. Decreased levels of F-actin expression were observed in colorectal mucosa, as well as in infiltrating cells with PSD methylation. PSD expression was preferentially inhibited in colorectal mucosa by PSD methylation, whereas PSD expression was rarely observed in infiltrating cells, regardless of PSD methylation status. These data indicate that aberrant methylation of PSD occurs in UC-associated colorectal mucosa, enabling circumvention of Rac1-mediated immune responses governing neutrophil chemotaxis and apoptosis, and thus plays a pivotal role in the mechanisms underlying UC-associated carcinogenesis.

The Pleckstrin and Sec7 domain-containing (PSD) gene, which regulates skeletal rearrangements, has been found to be more frequently methylated both in ulcerative colitis (UC)-associated colorectal cancer tissues (5 of 7; 71.4%) and matched normal epithelia (4 of 7; 57.1%) compared to non-neoplastic UC epithelia (6 of 22; 27.3%) and sporadic colorectal cancer tissues (6 of 32; 18.8%). The levels of PSD mRNA were positively correlated with the methylation status of PSD, as shown by both MSP and bisulfite sequencing. To determine the potential role of PSD silencing in the mechanisms underlying UC-associated carcinogenesis, the levels of senescence, proliferation and apoptosis were evaluated in a normal human fibroblast cell line (NHDF) in which 93% of PSD expression was knocked down by a small-interfering RNA (si-RNA). Although there were no significant differences in the levels of senescence and proliferation caused by PSD knockdown, the level of apoptosis was significantly decreased by PSD knockdown (5.3% in siControl-treated cells vs. 0.67% in siPSD-treated cells, p=0.0001). In addition, reactive oxygen species inducers accelerated apoptosis in NHDF and a neutrophil-like cell line, which was significantly reduced by PSD knockdown. To verify the effect of PSD methylation in tissue sections including 21 samples from UC patients with or without tumors, we elucidated PSD promoting accumulation of filamentous-actin (F-actin) and apoptosis by immunohistochemistry and TUNEL assay, respectively. Both levels of accumulation of F-actin and apoptosis were significantly decreased in specimens from UC patients with PSD methylation compared to those without PSD methylation (F-actin: 0.69±0.86 with vs. 1.57±0.51 without, p=0.0031, apoptotic index: 0.31±0.63 with vs. 1.0±0.88 without, p=0.0277). In conclusion, our results indicate that PSD methylation plays a significant role in the mechanisms underlying UC-associated carcinogenesis through its inhibitory effect on apoptosis in the interaction between colorectal mucosa and neutrophils.

Drug resistance remains a major obstacle to successful cancer treatment. Genome-wide comprehensive analysis identified a novel gene, glucocorticoid-induced protein-coding gene (DEXI), which was frequently methylated in colorectal (CRC; 36 of 73 patients; 49%) and gastric (28 of 89 patients; 31%) cancer patients. Here, we show that DEXI methylation is implicated in mechanisms facilitating resistance to camptothecin (CPT) via inhibition of apoptosis. Silencing of DEXI by siRNA significantly reduced CPT-induced apoptosis in a fibroblast cell line (1/6-fold; p<0.01) originally expressing endogenous DEXI. Restored expression of DEXI by 5-aza-2'-deoxycytidine (DAC) significantly enhanced susceptibility to CPT (3-fold; p<0.01) in a colon cancer cell line originally suppressing endogenous DEXI due to almost complete methylation. Exogenous induction of DEXI confirmed that DEXI per se contributed to enhanced susceptibility to CPT. 5-Fluorouracil (5-FU) did not exhibit these synergistic effects by DEXI restoration. Further, to estimate the clinical usefulness of DEXI methylation status as biomarker for drug resistance to irinotecan (CPT-11), 16 CRC patients who underwent FOLFIRI (5-FU + CPT-11) therapy because they were refractory to FOLFOX (5-FU + oxaliplatin) were analyzed. Significantly poor response and outcome were observed in 8 CRC patients harboring DEXI methylation. In 8 CRC patients harboring DEXI methylation disease control rate, progression-free survival and overall survival were 25.0%, 2 and 11.8 months, respectively, whereas in 8 CRC patients without DEXI methylation they were 62.5%, 5.3 and 15 months, respectively (p<0.01). These significant differences were not observed in patients undergoing treatment with FOLFOX. In conclusion, silencing of DEXI leads to resistance, but restored expression enhances susceptibility to CPT in vitro and DEXI methylation results in poor response and outcome to CPT-11-based chemotherapy, suggesting that DEXI is a potent therapeutic target and an epigenetic biomarker for the selection of patients more likely to benefit from CPT-11-based chemotherapy.

Genetic and epigenetic features of sessile serrated adenoma (SSA), a precursor lesion to colon cancer with microsatellite instability (MSI), were investigated. The aim of this study was to clarify whether there are location-dependent genetic and epigenetic features in SSA. Twenty-two patients with proximal SSAs and 8 with distal SSAs were recruited. Twenty-two patients with tubular adenoma (TA) and 66 with proximal colon cancer were studied for comparison. Genetic and epigenetic features were evaluated as BRAF and KRAS mutations, MSI, hMLH1 methylation and CpG island methylator phenotype (CIMP). BRAF mutation (p=0.007) and CIMP (p=0.012) were more frequently found in proximal than in distal SSAs. Furthermore, the KRAS mutation was found only in distal SSAs. In TAs, no location-related molecular features were observed. All SSAs, TAs and 42 colon cancer lesions were microsatellite stable (MSS). Twenty-four colon cancer lesions exhibited MSI and had more frequent BRAF mutations (p<0.001), hMLH1 methylation (p<0.001) and CIMP (p<0.001). BRAF mutation occurred in only 9.5% of MSS cancers (p=0.01). In MSI cancers with the BRAF mutation, a higher correlation with CIMP (p=0.032) was observed. We demonstrated the distinct genetic and epigenetic features between proximal and distal SSAs. Similar genetic and epigenetic features were shared between proximal SSAs and proximal MSI cancers harboring the BRAF mutation. By contrast, our results allow the possibility of carcinogenesis in SSAs leading to MSS cancer with the BRAF mutation.

This article critically discusses the current evidence for adjuvant chemotherapy in elderly patients (> or =70 years of age) with stage III colon cancer. The authors emphasize that current evidence is inconclusive, and surgeons should be aware of this fact when making informed decisions and recommendations.

BACKGROUND AND OBJECTIVES: The predictive value of free cancer cells in the peritoneal fluid of patients with colorectal cancer (CRC) remain to be elucidated. The aim of this study was to determine the prognostic relevance of the methylation of tumor-related genes detected in the peritoneal lavage fluid (PLF) of patients undergoing a resection for CRC. METHODS: The promoter methylation pattern of four target genes, CDH1, CDKN2A (p16), MGMT, and APC, was examined in 51 primary CRC and corresponding matched PLF DNA. The relative methylation levels of these genes in primary CRC tissue and paired PLF were assessed by quantitative methylation-specific polymerase chain reaction (QMSP). RESULTS: An aberrant methylation of at least one gene was found in 45 of 51 (88%) primary tumors. In matched PLF specimens, the frequencies of aberrant promoter methylation detected for each marker were 16% for CDH1, 2% for p16, 4% for MGMT and 24% for APC. Patients with PLF demonstrating the methylation of more than one of these four target genes demonstrated significantly shorter relapse-free survival. CONCLUSIONS: These findings suggest that disseminated tumor cells in PLF detected by QMSP may correlate with the postoperative clinical course of patients undergoing curative surgery for CRC.

The PCR-based DNA fingerprinting method called the methylation-sensitive amplified fragment length polymorphism (MS-AFLP) analysis is used for genome-wide scanning of methylation status. In this study, we developed a method of fluorescence-labeled MS-AFLP (FL-MS-AFLP) analysis by applying a fluorescence-labeled primer and fluorescence-detecting electrophoresis apparatus to the existing method of MS-AFLP analysis. The FL-MS-AFLP analysis enables quantitative evaluation of more than 350 random CpG loci per run. It was shown to allow evaluation of the differences in methylation level of blood DNA of gastric cancer patients and evaluation of hypermethylation and hypomethylation in DNA from gastric cancer tissue in comparison with adjacent non-cancerous tissue.

BACKGROUND: Recently, the right gastroepiploic artery (RGEA) has been used in coronary artery bypass grafting (CABG) as an alternative arterial graft. Unfortunately, an increased incidence of gastric cancers has been reported after CABG using the RGEA. Handling of the RGEA during gastrectomy in these patients may cause lethal complications, which sometimes reduces the feasibility of curative dissection of lymph nodes at the base of the graft. CASE PRESENTATIONS: We describe two cases of gastric cancer undergoing gastrectomy after CABG with the use of RGEA. To avoid the potentially fatal coronary event during gastrectomy, safe handling of the conduit including preparations for injuries and prevention of vessel spasm was performed in both cases, accompanied by an adequate monitoring of the systemic circulation. Intraoperative frozen section examination showed no lymph node metastasis around the graft in any of the cases; therefore, complete lymph node dissection at the base of the graft was not undertaken. No complications occurred during the operation. In addition to these two cases, twenty-four cases reported in the literatures were reviewed (a total of 26 cases). Ten early and 16 advanced gastric cancers were included. Among the 16 advanced gastric cancer cases, an alternative graft was employed in 8 due to the resection of an original graft to complete lymph node dissection. Mere handling of a graft often caused lethal complications suggesting that the operation should be completed by isolation of the graft. A pedicled graft harvesting via the ante-gastric route was popular. However, a skeletonized harvesting with resection of the pyloric branches of the RGEA would be better because this would interrupt the original lymph flow, which could eliminate the need for lymph node dissection and graft isolation. Among the 10 cases having early gastric cancers, 6 were found within 1.5 years after CABG. Early detection in these 6 cases was possible due to the use of gastric fiberscopic examination before and after CABG, which gave them opportunities to receive a less extensive operation such as endoscopic mucosal resection. CONCLUSION: Adequate intraoperative care as well as an optimal lymph node dissection considering the graft harvesting method at the first CABG leads to successful gastrectomy after CABG using the RGEA graft. Therefore, this operation should be carried out with careful management by both gastrointestinal and cardiovascular surgeons.