園田 洋史

PURPOSE: To propose a new and improved surveillance schedule for colorectal cancer (CRC) patients by focusing on the recurrence rate, resectability, and especially, the tumor doubling time (DT) of recurrent tumors. METHODS: The subjects of this retrospective review were 1774 consecutive patients who underwent radical surgery for stage I-III CRC between January, 2004 and December, 2015. We calculated the DT by measuring the tumor diameter using computed tomography (CT). RESULTS: The median DT for recurrences in the liver, lung, peritoneum, and other locations were 35, 72, 85, and 36 days, respectively, (p < 0.001) and tumor growth rates differed according to the organs where recurrence developed. Multiple linear regression analysis showed that the DT was strongly associated with the relapse-free interval from primary surgery (p < 0.001), and that the DT in patients with recurrence detected ≥ 3 years after primary surgery was longer by 151.1 days than that in patients with recurrence detected within 1 year after primary surgery. We proposed a less intensive surveillance, which achieved an average cost reduction of 32.5% compared with conventional surveillance in Japan. CONCLUSION: We propose a new and more cost-efficient surveillance schedule for CRC surgery patients in the clinical setting.

ABSTRACT: One-stage resections of primary colorectal cancer and liver metastases have been reported to be feasible and safe. Minimally invasive approaches have become more common for both colorectal and hepatic surgeries. This study aimed to investigate outcomes of these combined surgical procedures among different approaches.We retrospectively analyzed patients diagnosed as having primary colorectal cancer with synchronous liver metastases and who underwent 1-stage primary resection and hepatectomy with curative intent in our hospital. According to the surgical approach for the primary tumor and hepatic lesions, namely open laparotomy (Op) or laparoscopic approach (Lap), patients were classified into Op-Op, Lap-Op (laparoscopic colorectal resection plus open hepatectomy), and Lap-Lap groups, respectively. Clinicopathological factors were reviewed, and short- and long-term outcomes were compared among the groups.The Op-Op, Lap-Op, and Lap-Lap groups comprised 36, 18, and 17 patients, respectively. The superior/posterior hepatic segments were more frequently resected via an open approach. There was no laparoscopic major hepatectomy. The median volume of intraoperative blood loss was smaller in the Lap-Lap and Lap-Op groups (290 and 270 mL) than in the Op-Op group (575 mL, P = .008). The hospital stay after surgery was shorter in the Lap-Lap and Lap-Op groups (median: 17 days and 15 days, vs 19 days for the Op-Op group, P = .033). The postoperative complication rates and survivals were similar among the groups.Application of laparoscopy to 1-stage resections of primary colorectal cancer and liver metastases may offer advantages of enhanced recovery from surgical treatment, given appropriate patient selection.

BACKGROUND AND OBJECTIVES: An optimal postoperative surveillance protocol for colorectal cancer (CRC) is dependent on understanding the time line of recurrence. By hazard function analysis, this study aimed at evaluating the time of occurrence of metastasis. METHODS: A total of 21,671 Stage I-III colon cancer patients were retrospectively included from the Japanese study group for postoperative follow-up of colorectal cancer database. RESULTS: The 5-year incidence by metastasized organ was 6.3% for liver (right:left = 5.5%:7.0%, p = .0067), 6.0% for lung (right:left:rectum = 3.7%:4.4%:8.8%, p = 7.05E-45), and 2.0% for peritoneal (right:left:rectum = 3.1%:2.0%:1.2%, p = 1.29E-12). The peak of liver metastasis hazard rate (HR) (0.67 years) was earlier and higher than those of other metastases. The peak HR tended to be delayed in early stage CRCs (0.91, 0.76, and 0.52 years; for Stages I, II, and III, respectively). When analyzed as per the primary tumor location (right-sided, left-sided, and rectum), the peak HR for lung metastasis was twice as high for rectal cancer than for colon cancer, and peritoneal metastasis had a high HR in right-sided colon cancers. CONCLUSION: The time course for the risk of recurrence in various metastatic organs based on the primary tumor site was clearly visualized in this study. This will aid in individualizing postoperative surveillance schedules.

PURPOSE: A diverting stoma is created to prevent anastomotic leakage and related complications impairing sphincteric function in rectal surgery. However, diverting stoma may be left unclosed. This study is aimed to analyze preoperative factors including anorectal manometric data associated with diverting stoma non-reversal before rectal surgery. We also addressed complications related to diverting stoma in patients undergoing surgery for rectal malignant tumor. METHODS: A total of 203 patients with rectal malignant tumor who underwent sphincter-preserving surgery with diverting stoma were retrospectively evaluated. The risk factors for non-reversal of diverting stoma were identified by univariate and multivariate analyses. For these analyses, anorectal manometric data were measured before rectal surgery. The association between stoma-related complications and other clinicopathological features was also analyzed. RESULTS: During the median follow-up of 46.4 months, 24% (49 patients) did not undergo stoma reversal. Among parameters that were available before rectal surgery, age ≥ 75 years, albumin < 3.5 g/dl, tumor size ≥ 30 mm, tumor distance from the anal verge < 4 cm, and maximum squeezing pressure (MSP) < 130 mmHg measured by anorectal manometry (ARM) were independent factors associated with stoma non-reversal. The most common stoma-related complication was peristomal skin irritation (25%). Ileostomy was the only factor associated with peristomal skin irritation. CONCLUSION: The current study demonstrated that low preoperative MSP evaluated by ARM, old age, hypoalbuminemia, and a large tumor close to the anus were predictive of diverting stoma non-reversal. Stoma site should be well deliberated when patients have the aforementioned risk factors for diverting stoma non-reversal.

Although CD133 is a representative cancer stem cell marker, its function in tumor aggressiveness under hypoxia remains unclear. Therefore, the present study aimed to investigate the associations between CD133, the epithelial-mesenchymal transition and distant metastasis in colorectal cancer. CD133+ and CD133- cells were isolated from a single colorectal cancer cell line LoVo, and their adhesive and migratory properties were compared under hypoxic conditions. Immunostaining analysis was performed to determine CD133 expression in clinical samples of primary tumors, as well as liver and peritoneal metastases. Under hypoxia, the expression levels of hypoxia-inducible factor (HIF)-1α and the epithelial-mesenchymal transition markers N-cadherin and vimentin were significantly higher in the CD133+ compared with those in the CD133- cells. Furthermore, the migratory ability of the CD133+ cells was higher compared with that of the CD133- cells under hypoxia. By contrast, the expression levels of β1 integrin were significantly lower in the CD133+ cells under hypoxia compared with those in the CD133- cells. Immunohistochemical analysis of clinical samples revealed that the levels of CD133 expression in metastatic tissues from the liver were significantly higher compared with those in the corresponding primary tumors, whereas CD133 expression levels in peritoneal metastatic tissues were significantly lower compared with those in the corresponding primary tumors. In conclusion, compared with the CD133- cells, the CD133+ colorectal cancer cells exhibited enhanced levels of HIF-1α expression and tumor cell migration during hypoxia. This was associated with an increased ability of epithelial-mesenchymal transition, possibly leading to the acquisition of an increased hematogenous metastatic potential and eventually resulting in liver metastasis. High β1 integrin expression levels in the CD133- cells under hypoxia may serve a key role in cell adhesion to the peritoneum, resulting in peritoneal metastasis.

The Deloyers procedure is performed after extended left colectomy, enabling the reach of the proximal colon to the rectum for anastomosis while preserving sufficient blood supply. We report a case of the Deloyers procedure performed safely under indocyanine green (ICG) fluorescence guidance. A 50-year-old man with obesity (body mass index, 35.7 kg/m2) and a history of diabetes underwent an extended left hemicolectomy and ultralow anterior resection of the rectum as radical resection for transverse and sigmoid colon cancers and a lower rectal neuroendocrine tumor. Reconstruction was performed by the Deloyers procedure. A necessary length of the transverse colon with reduced blood flow was additionally resected under ICG fluorescence guidance, and a transanal hand-sewn coloanal anastomosis was performed. This is the first report in which the Deloyers procedure was performed successfully with the ICG fluorescence method. ICG fluorescence may be useful when combined with the Deloyers procedure.

INTRODUCTION: Multiple primary malignancies (MPMs) are likely to develop in patients with colorectal cancer (CRC); however, their prognoses are unclear. This study aims to investigate the prognostic impacts and clinicopathological features of multiple CRCs and extracolorectal malignancies (EMs) with CRC. METHODS: We retrospectively evaluated a total of 22,628 patients with stage I-III CRC who underwent curative resection at 24 referral institutes in Japan between January 2004 and December 2012. MPMs were classified as synchronous CRCs (SCRCs), metachronous CRCs, synchronous EMs (SEMs), and metachronous EMs. RESULTS: The presence of SCRCs (odds ratio 1.54, p < 0.001) was independently associated with SEMs in the multivariate analyses. SEMs were the strongest poor prognostic factor for OS (hazard ratio [HR] 2.21, p < 0.001) and RFS (HR 1.69, p < 0.001) compared with age, sex, and primary T and N factors. The incidence of stomach cancer was the highest in EMs, followed by lung, breast, and prostate cancers. Multiple CRCs were evenly distributed throughout the right-side colon to the rectum. DISCUSSION/CONCLUSION: SEMs were a strong poor prognostic factor for patients with stage I-III CRC. Patients with CRC, particularly those with SCRCs, should be surveyed for SEMs, especially for stomach and lung cancers.

Background/Aim: It remains unclear whether rectal cancers down-staged by preoperative chemoradiotherapy (CRT) have similar prognoses to those of the same stage without preoperative CRT. We compared prognoses of pT1 rectal cancer patients stratified by preoperative CRT. Patients and Methods: We retrieved data of patients with pathological T1 rectal cancer between 2003 and 2020. Patients were divided into the "ypT1 group" who received preoperative CRT following surgery and the "pT1 group" who underwent surgery alone. Factors associated with relapse-free survival (RFS) were investigated. Results: Among 86 patients, ypT1 and pT1 groups comprised 18 and 68 patients, respectively. There was no significant difference in RFS between the groups (p=0.19). Tumor location within 5 cm from the anal verge was associated with recurrence (hazard ratio: 0.13, p=0.034). Conclusion: The prognosis of patients with ypT1 rectal cancer was similar to that of patients with pT1. Low tumor location was a poor prognostic factor.

PURPOSE: To identify the incidence of and risk factors for postoperative bleeding after ileocolic end-to-side anastomosis using a circular stapler. METHODS: We analyzed, retrospectively, the risk factors for postoperative anastomotic bleeding in patients who underwent right-sided colectomy with end-to-side anastomosis done using a circular stapler during colon tumor surgery at our institute between January 2015 and March 2019. RESULTS: Anastomotic bleeding developed in 10 (3.6%) of the total 279 patients. Univariate analysis revealed that age ≥ 80 years (8.8% vs. 1.9%; P = 0.008) and Eastern Cooperative Oncology Group performance status (ECOG PS) ≥ 1 (12.5% vs. 2.8%; P = 0.014) were significant risk factors for anastomotic bleeding. Postoperative anticoagulation therapy was not a risk factor for anastomotic bleeding. Multivariate analysis revealed that only age ≥ 80 years was an independent risk factor (odds ratio 4.12, 95% confidence interval 1.02-16.68, P = 0.047). Six of the ten patients with anastomotic bleeding were treated conservatively, three were treated by colonoscopic clipping, and one required surgery. CONCLUSION: End-to-side anastomosis is safe and feasible, but must be performed carefully in the elderly, who are at higher risk of anastomotic bleeding.

PURPOSE: Prognosis after peritoneal metastases in colorectal cancer is worse than that after lung or liver metastases. Previously, we demonstrated the safety of intraperitoneal (ip) administration of paclitaxel (PTX) combined with mFOLFOX6/CapeOX plus bevacizumab for colorectal cancer with peritoneal metastasis in a phase-I trial. Here, we evaluated the efficacy of this chemotherapy. METHODS: We enrolled six patients with histologically confirmed peritoneal metastases secondary to colorectal cancer. PTX was administered through a peritoneal access port, in combination with oxaliplatin-based systematic chemotherapy. Response rate, progression-free survival, 1-year survival rate, frequency of improvement in peritoneal cancer index (PCI), and cytology in peritoneal lavage were evaluated. This study was registered in the University Hospital Medical Information Network Clinical Trial Registry on July 1, 2016 (UNIN000022924). RESULTS: Three patients received the mFOLFOX6-bevacizumab regimen, whereas the other three received the CapeOX-bevacizumab regimen. The response rate was 25%. PCI score improved in 50% of the cases. Peritoneal lavage cytology that was positive in five patients before initiating the chemotherapy turned negative during chemotherapy in all patients. One-year survival rate was 100%, progression-free survival was 8.8 months (range, 6.8-12 months), and median survival time was 29.3 months. CONCLUSION: The ip administration of PTX with systemic chemotherapy can potentially control peritoneal metastases in colorectal cancer.

Isolated para-aortic lymph node recurrence (PALNR) after curative surgery for colorectal cancer (CRC) is rare and its optimal management is not defined clearly. This review investigates the best outcomes among published studies on the management of PALNR in the field of CRC. We searched the PubMed database for studies reporting on the management of isolated PALNR in CRC, published in English or Japanese from January, 2000 to December, 2018. Studies including patients with other metastases were excluded. A total of 24 retrospective studies including 227 patients with PALNR were evaluated. The 3-year overall survival (OS) ranged from 60 to 100%, with a median OS of 34-80 months for patients who underwent PALNR dissection, and 14-42 months for patients who received non-surgical treatment. No surgery-related mortality was reported and the incidence of surgical, mainly low-grade, complications ranged from 33 to 52%. The predictors of improved survival outcome included R0 resection margins. Dissection for PALNR from CRC is considered a feasible treatment option that may yield a better prognosis than non-surgical treatment alone. Preoperative chemotherapy or CRT should be considered for their potential benefits, including a reduction in cancer volume and improved R0 resection rates.

Background: Several previous studies have shown that laparoscopic resection of rectal cancer is a feasible option. However, its safety and efficacy in patients receiving long-term anti-thrombotic therapy (AT) remain unclear.Material and methods: We retrospectively reviewed 364 patients who underwent elective resection for rectal cancer via a laparoscopic approach between 2007 and 2018 in our institute. Patients were classified according to the long-term use of AT. AT was interrupted perioperatively with or without heparin bridging therapy in all anti-thrombotic users. Clinicopathological factors and surgical outcomes were analyzed between patient groups.Results: Thirty-two patients (9%) receiving AT were older and had lower albumin and hemoglobin levels than those not receiving AT (the non-AT group), and were predominantly male. Estimated blood loss and operative time in the AT group (median: 50 mL and 294 min) did not differ from those in the non-AT group (median: 20 mL and 295 min). There were no intergroup differences in the frequencies of other postoperative complications and oncological outcomes.Conclusions: Our results at the very least can support that laparoscopic surgery for rectal cancer is a safe and feasible option for patients taking long-term AT discontinued perioperatively.

Perianal Paget's disease is a rare condition, which is not usually accompanied by cancer. Here, a case of anal canal carcinoma with pagetoid spread and inguinal lymph node metastasis, which exhibited a significant response to preoperative chemoradiotherapy (CRT), is presented. A 58-year-old woman was admitted to The University of Tokyo Hospital with a complaint of discomfort around the anus. Physical examination revealed an erythematous inflamed skin lesion in the perianal region and a tumor of 15 mm in diameter detected on palpation in the left inguinal region, which was diagnosed as metastatic adenocarcinoma by excisional biopsy. Colonoscopy revealed moderately differentiated adenocarcinoma of 15 mm in diameter in the anal canal. Skin biopsy of the perianal region revealed an infiltration of pagetoid cells, which were positive for cytokeratin 7, and negative for cytokeratin 20 and gross cystic disease fluid protein 15. Based on these results, the patient was diagnosed as having anal canal adenocarcinoma with pagetoid spread. The patient received preoperative CRT including the bilateral inguinal region. After CRT, robotic-assisted laparoscopic abdominoperineal resection was performed. The macroscopic findings of the surgical specimen confirmed the formation of a scar as a result of the preoperative CRT. Microscopic examination of the anal tumor revealed no residual carcinoma or lymph node metastasis. In conclusion, this case may suggest the potential applicability of preoperative CRT for the local control of anal canal carcinoma with pagetoid spread.

Postoperative distant metastasis dramatically affects rectal cancer patients who have undergone neoadjuvant chemoradiotherapy (NACRT). Here, we clarified the association between NACRT-mediated mammalian target of rapamycin (mTOR) signaling pathway activation and rectal cancer metastatic potential. We performed immunohistochemistry for phosphorylated mTOR (p-mTOR) and phosphorylated S6 (p-S6) on surgical specimen blocks from 98 rectal cancer patients after NACRT (cohort 1) and 80 colorectal cancer patients without NACRT (cohort 2). In addition, we investigated the association between mTOR pathway activity, affected by irradiation, and the migration ability of colorectal cancer cells in vitro. Based on the results of the clinical study, p-mTOR was significantly overexpressed in cohort 1 (with NACRT) as compared to levels in cohort 2 (without NACRT) (P < .001). High p-mTOR and p-S6 levels correlated with the development of distant metastasis only in cohort 1. Specifically, high p-S6 expression (HR 4.51, P = .002) and high pathological T-stage (HR 3.73, P = .020) after NACRT were independent predictors of the development of distant metastasis. In vitro, p-S6 levels and migration ability increased after irradiation in SW480 cells (TP53 mutation-type) but decreased in LoVo cells (TP53 wild-type), suggesting that irradiation modulates mTOR signaling and migration through cell type-dependent mechanisms. We next assessed the expression level of p53 by immunostaining in cohort 1 and demonstrated that p-S6 was overexpressed in samples with high p53 expression as compared to levels in samples with low p53 expression (P = .008). In conclusion, p-S6 levels after NACRT correlate with postoperative distant metastasis in rectal cancer patients, suggesting that chemoradiotherapy might modulate the mTOR signaling pathway, promoting metastasis.

PURPOSE: This study aimed to clarify predictors and therapeutic significance of inguinal lymph node metastasis (ILNM) in patients with rectal cancer. METHODS: Patients with rectal adenocarcinoma invading the anal canal who underwent curative surgery between 2003 and 2019 were retrospectively reviewed. Synchronous and metachronous lymph node (LN) metastasis were collectively defined as final nodal metastasis (f-LNM). Factors associated with f-LNM were analyzed. Moreover, the "modified therapeutic value index," defined by multiplication of the frequency of f-LNM by the 5-year overall survival rate for patients who received treatment for f-LNM, was calculated for each LN area. RESULTS: A total of 145 patients were enrolled (16 patients with f-ILNM). To predict f-ILNM, the cutoff of the inguinal lymph node (ILN) diameter of 8.5 mm gave an area under the curve of 0.889. Dentate line involvement (odds ratio 33.4) and ILN larger than the cutoff of 8 mm (odds ratio 11.9) were independently associated with f-ILNM. The modified therapeutic value indices of the inguinal, lateral pelvic, and mesorectal LNs in the entire population were 6.1, 8.2, and 20.3 points, respectively. In patients with dentate line invasion by cancer, the index of the ILN increased to 11.7 points. In patients with an ILN > 8 mm, the index further increased to 21.1 points. CONCLUSION: Dentate line involvement and ILN > 8 mm predicted the development of ILNM in patients with rectal cancer invading the anal canal. Treatment of the ILN should be considered for patients with the above predictors given the significant therapeutic outcomes.

BACKGROUND/AIM: To date, there is no clear understanding whether preoperative long-course chemoradiotherapy combined with surgery for rectal cancer is detrimental to anorectal function. The purpose of this study was to clarify the influence of preoperative chemoradiotherapy and surgery for middle and lower rectal cancer on postoperative anorectal function. PATIENTS AND METHODS: Data of 113 patients with middle or lower rectal cancer treated with preoperative chemoradiotherapy plus surgery or surgery alone between January 2013 and December 2016 were analyzed. A total of 84 and 29 patients underwent low anterior resection and intersphincteric resection, respectively. In patients with T3 or deeper and with any N stage cancer below peritoneal reflection, surgery plus lateral lymph node dissection or preoperative radiation (total: 50.4 Gy/28 fractions) to the pelvis with chemoradiotherapy plus surgery was treated. Anorectal function was assessed prior to treatment and 6 and 12 months postoperatively. Specifically, maximum resting pressure and maximum squeezing pressures were measured. The Wexner score was recorded prior to treatment and 12 months postoperatively. RESULTS: maximum resting pressure and maximum squeezing pressure decreased post-surgery in both groups. Maximum resting pressure and maximum squeezing pressure at 12 months and the Wexner score at 12 months post-surgery were comparable among patients treated with chemoradiotherapy plus surgery and those treated with surgery alone. CONCLUSION: Preoperative chemoradiotherapy did not clearly impair postoperative anorectal function in patients who underwent low anterior resection and intersphincteric resection.

BACKGROUND/AIM: The clinical significance of surgery for secondary small intestinal non-Hodgkin's lymphomas (NHL) remains unknown. This study aimed to investigate the efficacy of resection for both primary and secondary small intestinal NHL. PATIENTS AND METHODS: Twenty patients with small intestinal lymphoma who underwent surgical resection at our Institute between 2009 and 2017 were retrospectively evaluated. The clinicopathological and surgery-related factors were reviewed. We also analyzed their surgical outcomes such as postoperative complications, perforation rate, and overall survival (OS). RESULTS: In total, 13 (65%) and 7 (35%) patients had primary and secondary lymphomas, respectively. A total of 70% of patients were diagnosed with aggressive-type lymphomas. A total of 15 (75%) patients had Lugano system stage IV. Only one (5%) patient experienced postoperative grade II deep vein thrombosis and pulmonary embolism. The 3-year OS rate after surgery was 59.6%. CONCLUSION: Surgical resection prior to chemotherapy is a feasible and safe therapeutic strategy for small intestinal NHL.

PURPOSE: Advances in systemic chemotherapy have increased the resectability in colorectal cancer (CRC) associated with metastases even if it was initially unresectable. However, what determines the prognosis of stage IV CRC patients treated by preoperative therapy and surgery remains unclear. We attempted to identify prognostic factors in such CRC patients. METHODS: We reviewed stage IV CRC patients who underwent curative resection between December 2007 and May 2019. The patients who underwent conversion chemotherapy for initially unresectable disease and those who received neoadjuvant chemotherapy (NAC) for resectable synchronous metastases or neoadjuvant chemoradiotherapy (NACRT) for advanced lower rectal cancer with resectable metastases were included. Recurrence-free survival (RFS) and overall survival (OS) were examined by multivariate analyses using Cox proportional hazard models. The RFS and OS curves were analyzed according to postoperative adjuvant chemotherapy (AC). RESULTS: Among 70 patients who underwent curative surgery (34 men, mean age: 60 years old), 33 had initially unresectable disease, 23 received NAC, and 14 NACRT. By multivariate analyses, AC was an independent predictor for improved RFS and OS (hazard ratio = 0.29, p = 0.0002, and hazard ratio = 0.37, p = 0.025). Patients treated with AC showed improved RFS and OS than those without AC (2-year RFS rate = 30% vs 19%, p = 0.031, and 3-year OS rate = 87% vs 67%, p = 0.045). CONCLUSION: Because of its association with improved prognosis, AC should be considered for stage IV CRC patients after curative resection regardless of initial resectability status and preoperative therapy.

BACKGROUND: Systemic therapy can cause loss of skeletal muscle mass in colorectal cancer (CRC) patients in the neoadjuvant and palliative settings. However, it is unknown how the body composition is changed by chemotherapy rendering unresectable CRC to resectable disease or how it affects the prognosis. This study aimed at elucidating the effects of systemic therapy on skeletal muscles and survival in stage IV CRC patients who underwent conversion therapy. METHODS: We reviewed 98 stage IV CRC patients who received systemic therapy in our hospital. According to the treatment setting, patients were divided into the conversion, neoadjuvant chemotherapy (NAC), and palliation groups. The cross-sectional area of skeletal muscles at the third lumbar level and changes in the skeletal muscle index (SMI), defined as the area divided by height squared, during systemic therapy were compared among patient groups. The effects of these parameters on prognosis were analyzed in the conversion group. RESULTS: The mean SMI increased by 9.4% during systemic therapy in the conversion group (n = 38), whereas it decreased by 5.9% in the NAC group (n = 18) and 3.7% in the palliation group (n = 42, p < 0.0001). Moreover, patients with increased SMI during systemic therapy had a better overall survival (OS) than those whose SMI decreased in the conversion group (p = 0.025). The increase in SMI was an independent predictor of favorable OS on multivariate analysis (hazard ratio 0.25). CONCLUSIONS: Stage IV CRC patients who underwent conversion to resection often had an increased SMI. On the other hand, a decrease in the SMI during systemic therapy was a negative prognostic factor in such patients.

Perineural invasion (PNI) is a prognostic factor in patients with colorectal cancer. Neurotrophic factors, molecular determinants of PNI, are altered in their expression levels in patients with ulcerative colitis. In this study, we evaluated the frequency of PNI in colitis-associated cancer (CAC) and sporadic cancer.We retrospectively reviewed 778 colorectal cancers with pathological T3-T4 in 761 patients all of whom were surgically resected without preoperative treatment. The lesions were classified into either CAC or sporadic cancer based on the clinical information. Clinicopathological findings including PNI were compared between CACs and sporadic cancers. Moreover, we analyzed the risk factors for positive PNI by multivariate analysis using a logistic regression model.Ten of the cancers (1.3%) were diagnosed as CACs, and the remaining 768 as sporadic cancers. CACs were characterized by being nonobstructive and predominantly located in the rectum. The CACs had a larger size and more frequent undifferentiated histology than sporadic cancers. PNI was observed more frequently in CACs (90%) than in sporadic cancers without obstruction (45%, P = .007). On multivariate analysis, CAC was one of the significant factors associated with PNI (odds ratio: 9.05, P = .040).Our results suggest that CAC was more likely to exhibit PNI than sporadic colorectal cancer.

PURPOSE: Most elderly patients with colorectal cancer have comorbidities and reduced functional reserve, which may increase their risks of postoperative morbidity and mortality, and subsequently influence the treatment choice. Therefore, this study aimed to investigate the treatment choice and compare laparoscopic and open surgery in this setting. METHODS: This retrospective study evaluated 118 patients with colorectal cancer (≥ 85 years old between January 2007 and February 2018) to determine the influence of comorbidities on treatment choice, as well as the safety and feasibility of laparoscopic surgery for these patients. RESULTS: The patients included 42 men (35.6%) and 106 patients (89.8%) with comorbidities. The treatments were curative resection for 90 patients and palliative surgery for 16 patients, including 5 cases of colostomy/ileostomy because of the difficulty of primary cancer resection, pneumonia, or pulmonary hypertension. Twelve patients received non-surgical treatment, including 7 patients with decreased respiratory function because of chronic obstructive pulmonary disease or pneumonia. Forty-three patients underwent open curative resection and 47 patients underwent laparoscopic curative resection, which was associated with a significantly shorter hospital stay (14 days vs. 19days, P < 0.01), a lower morbidity rate (17.0% vs. 37.2%, P = 0.035), and less blood loss (10 mL vs. 140 mL, P < 0.01). One patient in each group died during the postoperative period because of worsened pre-existing pneumonia. CONCLUSION: Laparoscopic surgery was safer and less invasive than open surgery for colorectal cancer among ≥ 85-year-old patients. Pulmonary comorbidities affected the choice of non-curative surgery and may be related to the risk of postoperative mortality.

The PI3K/AKT/mTOR pathway and autophagy are known to play important roles in cancer radioresistance. The aim of the present study was to investigate whether the combination of temsirolimus (TEM), an mTOR inhibitor, and chloroquine (CQ), an autophagy inhibitor, can increase radiosensitivity in colorectal cancer (CRC) cells. The efficacies of TEM and/or CQ as radiosensitizers were examined using clonogenic assays in CRC cell lines SW480 and HT‑29. The expression levels of the phosphorylated isoforms of S6 and 4E‑BP1, downstream proteins of mTOR, as well as the expression levels of p62 and LC3, autophagy‑related proteins, were assessed by western blot analysis. The formation of acidic organelles was detected in acridine orange‑stained cells. Apoptosis and caspase activity were assessed using flow cytometry. The results revealed that ionizing radiation (IR) activated the downstream proteins of mTOR and induced autophagy. In the clonogenic assays, neither TEM nor CQ influenced the efficacy of IR, whereas their combination significantly increased the dose‑dependent efficacy of IR. TEM inhibited phosphorylation of the downstream proteins of mTOR and induced autophagy. CQ inhibited autophagy in the late phase and did not influence the downstream proteins of mTOR. TEM and CQ inhibited both the phosphorylation of downstream proteins of mTOR and autophagy. Cell death analysis revealed that the combination of TEM and CQ strongly induced apoptosis in cells exposed to IR. In conclusion, the combination of TEM and CQ increased radiosensitivity in CRC cells through co‑inhibition of mTOR and autophagy.

Rectal gastrointestinal stromal tumor (GIST) is a rare entity. Thus, its clinical features have not been well documented, and optimal treatment strategies have not been established. Surgery for rectal GISTs may be difficult because they are often large in size. In addition, rectal GISTs were found to be associated with high rates of local recurrence, regardless of the surgical procedure, before imatinib was introduced in the early 2000s. Since the introduction of imatinib therapy, accumulating evidence suggests that neoadjuvant imatinib therapy may improve the outcomes of rectal GIST treatment. Neoadjuvant imatinib therapy for rectal GISTs offers a number of potential benefits, including tumor downsizing, reduction in mitotic activity, reduced morbidity, and a reduced risk of recurrence. Less radical procedures may allow for the preservation of the anal sphincter and avoidance of a permanent colostomy. This review summarizes the current status and future perspectives of neoadjuvant imatinib therapy for the treatment of rectal GISTs.

Although lysophospholipids are known to play an important role in the development and progression of several kinds of cancers, their role in human colorectal cancer is as yet unclear. In this study, we aim to investigate lysophospholipid levels in colorectal cancer tissues to identify lysophospholipids, the levels of which change specifically in colorectal cancers. We used liquid chromatography-tandem mass spectrometry to measure lysophospholipid levels in cancerous and normal tissues from 11 surgical specimens of sigmoid colon cancers, since recent advances in this field have improved detection sensitivities for lysophospholipids. Our results indicate that, in colon cancer tissues, levels of lysophosphatidylinositol and lysophosphatidylserine were significantly higher ( p = 0.025 and p = 0.01, respectively), whereas levels of lysophosphatidic acid were significantly lower ( p = 0.0019) than in normal tissues. Although levels of lysophosphatidylglycerol were higher in colon cancer tissues than in normal tissues, this difference was not found to be significant ( p = 0.11). Fatty acid analysis further showed that 18:0 lysophosphatidylinositol and 18:0 lysophosphatidylserine were the predominant species of lysophospholipids in colon cancer tissues. These components may be potentially involved in colorectal carcinogenesis.

BACKGROUND: We aimed to investigate the molecular features of synchronous colorectal cancer (CRC). MATERIALS AND METHODS: Out of 1,262 patients with CRC, 130 lesions in 59 patients with synchronous CRC were retrospectively analyzed. Microsatellite, v-Ki-Ras2 Kristen rat sarcoma viral oncogene homolog (KRAS), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), tumor protein 53 (TP53) and β-catenin status were evaluated and compared between synchronous CRC lesions in each patient. RESULTS: The subtypes of instability, BRAF and β-catenin subtypes was significant but low. Patients with discordant KRAS and TP53 were not concordant between lesions in the same patient, and concordance of microsatellite KRAS/BRAF subtypes comprised 50.8% of those with synchronous CRC. The rate of patients with lesions containing both mutL homolog 1 (MLH1) methylation and microsatellite stable status was 66.7% in those with synchronous CRC, with at least one lesion with high microsatellite instability. CONCLUSION: The present study on synchronous CRC demonstrated a low concordance of molecular subtypes between lesions in the same patient. A molecular analysis of metastatic lesions is warranted for molecular targeted therapy of metastatic synchronous CRC.

BACKGROUND: Adjuvant chemotherapy (AC) is known to be beneficial for stage III colorectal cancer (CRC). In contrast, only a few studies have reported the survival benefits of AC for stage IV CRC after curative surgery. METHODS: We identified 155 CRC patients with various organ metastases who underwent curative surgery in our hospital between 2003 and 2017. Clinicopathological parameters and postoperative AC were reviewed. Multivariate analyses were performed to identify prognostic factors. Moreover, the effects of AC on recurrence-free survival (RFS) and overall survival (OS) were analyzed using inverse probability of treatment weighting. RESULTS: The cohort comprised 94 males and 61 females, with a mean age of 63 years. AC was administered to 57% of patients who underwent surgery between 2003 and 2010 and 76% between 2011 and 2017 (p = 0.015). AC was more likely administered to patients with a good performance status, high preoperative albumin level, regional node and peritoneal metastases, and no intraoperative blood transfusion. Multivariate analyses identified AC as a significant prognostic factors for RFS and OS [hazard ratio (HR): 1.86, p = 0.003, and 2.66, p = 0.002, respectively]. After adjusting for different backgrounds, 5-year RFS and OS rates were higher in patients receiving AC (27% and 67%) than in those without AC (14% and 46%, p < 0.0001 and p = 0.0005). Subgroup analyses showed that AC significantly improved RFS in node-negative patients (HR: 2.16, p = 0.029), and RFS and OS in node-positive patients (HR: 2.03, p < 0.0001, and 2.02, p = 0.001, respectively). CONCLUSION: AC can be discussed with resectable stage IV CRC patients because of its significant survival-improving effects.

AIM: This study aimed to clarify the difference in the clinicopathological and prognostic features between synchronous colorectal cancer (CRC) and solitary CRC. MATERIALS AND METHODS: A retrospective analysis was conducted in patients with synchronous and solitary CRC. RESULTS: A total of 92 (7.1%) out of 1,295 consecutive patients had synchronous CRC. Mucinous adenocarcinoma was more frequent in patients with synchronous CRC than in those with solitary CRC (13.0% vs. 3.7%; p<0.001). The 5-year relapse-free survival (RFS) rate was poorer in patients with synchronous CRC than in those with solitary CRC (65.3% vs. 75.1%; p=0.035), which was contrived by the multivariate analysis (hazard ratio=1.52(HR); p=0.039). CONCLUSION: Patients with synchronous CRC had a poorer RFS than those with solitary CRC; thus, patients with synchronous CRC might require more intensive care than those with solitary CRC in follow-up.

Despite extensive research on cancer stem cells in colorectal cancer, the impact of stem cell markers on patient survival remains unclear, particularly in those with distant metastasis. In this study, we focused on colon cancer with peritoneal metastasis and investigated the association between the expression of CD133, aldehyde dehydrogenase-1 (ALDH1) and leucine-rich repeating G-protein coupled receptor-5 (Lgr5), and disease prognosis. Putative stem cell marker expression was immunohistochemically evaluated in samples from 142 primary tumours and 75 peritoneal nodules. The associations between the expression of these markers and clinicopathological characteristics, overall survival and disease-free survival were analysed. The expression of CD133, ALDH1 and Lgr5 was found to be positive in 55.6, 47.2 and 78.9% of the primary tumour samples, respectively. While their expression was not associated with overall survival, disease-free survival was significantly worse in the CD133‑negative group (36.1 vs. 13.7%, P=0.041). Multivariable analysis confirmed that a negative CD133 expression was an independent risk factor for a reduced disease-free survival (P=0.005). Furthermore, the benefit of systemic chemotherapy was significantly greater in the CD133-negative group (P=0.039). On the whole, our data indicated that patients with colon cancer with CD133-negative expression had a reduced disease-free survival. Thus, we propose that CD133 expression may be a useful clinical biomarker in the treatment of colon cancer with peritoneal metastasis.

Metastases to the colon are rare and a high-frequency primary region is the stomach. In cases of metastases to the colon, the morphological type of the metastatic region is mostly the infiltrating type of poorly differentiated or undifferentiated adenocarcinoma with lymph and blood vessel invasion. A case of cancer metastasis to the transverse colon that originated from advanced gastric cancer, which shows the difficulties in the precise diagnosis of metastases to the colon, is presented. In the present case, the gastric carcinoma was determined to be an advanced infiltrative ulcerative adenocarcinoma and the colon carcinoma was determined to be a superficial depressed adenocarcinoma. After surgery, the colon carcinoma was diagnosed as a metastatic adenocarcinoma from gastric adenocarcinoma with high invasion of vessels, by immunohistopathological analysis of CK7, CK20, p53 and HER-2. In this report, previously reported cases of metastases to the colon from gastric cancer were reviewed and their morphological characteristics were analyzed.

A 66-year-old Japanese man was referred to our hospital because of suspected duodenal cancer. Upper gastric endoscopy revealed a giant polypoid-type tumor that extended from the duodenum bulb to the pyloric ring. A computed tomography scan revealed a slightly enhanced lobular tumor protruding into the duodenum bulb. Positron emission tomography showed an accumulation of (18)F-fluorodeoxyglucose in the area extending from the antrum of the stomach to the duodenum bulb. Since an endoscopic ultrasound test suggested that the tumor might invade the muscular tunic, indications of endoscopic mucosal resection were not favored, and the tumor was curatively removed via distal gastrectomy. The histopathologic diagnosis was papillary adenocarcinoma, and the invasion depth was the mucosal layer without vascular invasion, which was different from the preoperative diagnosis. Our case suggests the difficulties in precise diagnosis of the invasion depth of the giant polypoid cancer.

A 76-year-old Japanese man was referred to our hospital with chief complaint of right hypochondoralgia. Abdominal ultrasound showed a retroperitoneal tumor in the suprarenal region of the right kidney. Computed tomography revealed an enhanced lobular tumor with irregular, circumscribed, and indistinct border. Ultrasound-guided biopsy was performed. The tumor consisted of spindle-shaped cells with a giant nucleus and multinuclear cells. The diagnosis was leiomyosarcoma by immunohistochemical staining. The patient underwent surgery accessed by a right eighth intercostal thoracoabdominal incision. The tumor was completely resected, accompanied by removal of the posterosuperior segment of the right hepatic lobe, right adrenal gland, and a portion of the inferior vena cava (IVC). The histopathologic diagnosis was leiomyosarcoma arising from the IVC. We present a rare case of a successfully managed leiomyosarcoma of the IVC. This case suggests the importance of curative surgical resection of the tumor due to low efficacy of adjuvant chemotherapy for leiomyosarcoma.

Although organelles such as the endoplasmic reticulum and Golgi apparatus are highly compartmentalized, these organelles are interconnected through a network of vesicular trafficking. The marine sponge metabolite ilimaquinone (IQ) is known to induce Golgi membrane fragmentation and is widely used to study the mechanism of vesicular trafficking. Although IQ treatment causes protein kinase D (PKD) activation, the detailed mechanism of IQ-induced Golgi membrane fragmentation remains unclear. In this work, we found that IQ treatment of cells caused a robust activation of phospholipase D (PLD). In the presence of 1-butanol but not 2-butanol, IQ-induced Golgi membrane fragmentation was completely blocked. In addition, IQ failed to induce Golgi membrane fragmentation in PLD knock-out DT40 cells. Furthermore, IQ-induced PKD activation was completely blocked by treatment with either 1-butanol or propranolol. Notably, IQ-induced Golgi membrane fragmentation was also blocked by propranolol treatment. These results indicate that PLD-catalyzed formation of phosphatidic acid is a prerequisite for IQ-induced Golgi membrane fragmentation and that enzymatic conversion of phosphatidic acid to diacylglycerol is necessary for subsequent activation of PKD and IQ-induced Golgi membrane fragmentation.

Sphingosine kinase (SPHK) is a key enzyme producing important messenger sphingosine 1-phosphate and is implicated in cell proliferation and suppression of apoptosis. Because the extent of agonist-induced activation of SPHK is modest, signaling via SPHK may be regulated through its localization at specific intracellular sites. Although the SPHK1 isoform has been extensively studied and characterized, the regulation of expression and function of the other isoform, SPHK2, remain largely unexplored. Here we describe an important post-translational modification, namely, phosphorylation of SPHK2 catalyzed by protein kinase D (PKD), which regulates its localization. Upon stimulation of HeLa cells by tumor promoter phorbol 12-myristate 13-acetate, a serine residue in a novel and putative nuclear export signal, identified for the first time, in SPHK2 was phosphorylated followed by SPHK2 export from the nucleus. Constitutively active PKD phosphorylated this serine residue in the nuclear export signal both in vivo and in vitro. Moreover, down-regulation of PKDs through RNA interference resulted in the attenuation of both basal and phorbol 12-myristate 13-acetate-induced phosphorylation, which was followed by the accumulation of SPHK2 in the nucleus in a manner rescued by PKD over-expression. These results indicate that PKD is a physiologically relevant enzyme for SPHK2 phosphorylation, which leads to its nuclear export for subsequent cellular signaling.

Sphingosine kinase (SPHK) 1 is implicated in the regulation of cell proliferation and anti-apoptotic processes by catalyzing the formation of an important bioactive messenger, sphingosine 1-phosphate. Unlike the proliferative action of SPHK1, another isozyme, SPHK2, has been shown to possess anti-proliferative or pro-apoptotic action. Molecular mechanisms of SPHK2 action, however, are largely unknown. The present studies were undertaken to characterize the N-terminal-extended form of SPHK2 (SPHK2-L) by comparing it with the originally reported form, SPHK2-S. Real-time quantitative PCR analysis revealed that SPHK2-L mRNA is the major form in several human cell lines and tissues. From sequence analyses it was concluded that SPHK2-L is a species-specific isoform that is expressed in human but not in mouse. At the protein level it has been demonstrated by immunoprecipitation studies that SPHK2-L is the major isoform in human hepatoma HepG2 cells. SPHK2-L, when expressed in human embryonic kidney (HEK) 293 cells, did not show any inhibition of DNA synthesis in the presence of serum, whereas it showed marked inhibition in the absence of serum. Moreover, serum deprivation resulted in the translocation of SPHK2-L into the nuclei. In addition, serum deprivation induced SPHK2-L expression in HEK293 cells. Furthermore, suppression of SPHK2 by small interfering RNA treatment prevented serum deprivation- or drug-induced apoptosis in HEK293 cells. Taken together, these results indicate that a major form of SPHK2 splice variant, SPHK2-L, in human cells does not inhibit DNA synthesis under normal conditions and that SPHK2-L accumulation in the nucleus induced by serum deprivation may be involved in the cessation of cell proliferation or apoptosis depending on the cell type.

Lysophosphatidic acid (LPA) is a simple bioactive phospholipid with diverse effects on various cells, that interacts with three G protein-coupled transmembrane receptors, LPA1, LPA2, and LPA3. The expression pattern and functions of these LPA receptors in various tumors have not been fully examined, except in ovarian cancer. To evaluate the LPA receptor expression profile in human colorectal cancer and in normal mucosa, we used real-time reverse transcription-polymerase chain reaction (RT-PCR) and measured the expression levels of LPA1, LPA2, and LPA3 messenger RNA (mRNA) in 26 colorectal cancers and 16 corresponding normal tissue samples. Normal epithelium expressed both LPA1 and LPA2 mRNA at similar levels. In comparison, colorectal cancers expressed LPA1 mRNA at a significantly lower level (0.3-fold; P<0.05), and LPA2 mRNA at a significantly higher level (three-fold; P<0.05), as compared with normal tissues. Thus, the ratio of LPA2/LPA1 increased markedly during malignant transformation (18-fold increase). LPA3 mRNA was expressed at only a low level in both normal and cancer tissues. We also assessed LPA2 expression immunohistochemically using a rat anti-LPA2 monoclonal antibody, and confirmed high expression of LPA2 in colorectal cancer at the protein level. As for LPA1, we examined Western blot analysis for 16 matched normal and cancer tissues. It revealed a significant decrease in the expression of LPA1 protein in cancer tissues compared to normal mucosa in nine of 16 cases, and in the remaining seven cases the expression levels was much the same. These results suggested that alteration of LPA receptor expression might be an important event in the development of colorectal cancer, and therefore, LPA and its receptors could be a chemopreventive target against colorectal cancer.

We have identified a novel phospholipase A1, named mPA-PLA1beta, which is specifically expressed in human testis and characterized it biochemically together with previously identified mPA-PLA1alpha. The sequence of mPAPLA1beta encodes a 460-amino acid protein containing a lipase domain with significant homology to the previously identified phosphatidic acid (PA)-selective PLA1, mPA-PLA1alpha. mPA-PLA1beta contains a short lid and deleted beta9 loop, which are characteristics of PLA1 molecules in the lipase family, and is a member of a subfamily in the lipase family that includes mPA-PLA1alpha and phosphatidylserine-specific PLA1. Both mPA-PLA1beta and mPA-PLA1alpha recombinant proteins exhibited PA-specific PLA1 activity and were vanadate-sensitive. When mPAPLA1beta-expressing cells were treated with bacterial phospholipase D, the cells produced lysophosphatidic acid (LPA). In both mPA-PLA1alpha and beta-expressing cells, most of the PA generated by the phospholipase D (PLD) treatment was converted to LPA, whereas in control cells it was converted to diacylglycerol. When expressed in HeLa cells most mPA-PLA1alpha protein was recovered from the cell supernatant. By contrast, mPA-PLA1beta was recovered almost exclusively from cells. Consistent with this observation, we found that mPA-PLA1beta has higher affinity to heparin than mPA-PLA1alpha. We also found that the membrane-associated mPA-PLA1s were insoluble in solubilization by 1% Triton X-100 and were detected in Triton X-100-insoluble buoyant fractions of sucrose gradients. The present study raises the possibility that production of LPA by mPA-PLA1alpha and -beta occurs on detergent-resistant membrane domains of the cells where they compete with lipid phosphate phosphatase for PA.

Lysophosphatidic acid (LPA) is a lipid mediator with diverse biological properties, although its synthetic pathways have not been completely solved. We report the cloning and characterization of a novel phosphatidic acid (PA)-selective phospholipase A(1) (PLA(1)) that produces 2-acyl-LPA. The PLA(1) was identified in the GenBank(TM) data base as a close homologue of phosphatidylserine (PS)-specific PLA(1) (PS-PLA(1)). When expressed in insect Sf9 cells, this enzyme was recovered from the Triton X-100-insoluble fraction and did not show any catalytic activity toward exogenously added phospholipid substrates. However, culture medium obtained from Sf9 cells expressing the enzyme was found to activate EDG7/LPA(3), a cellular receptor for 2-acyl-LPA. The activation of EDG7 was further enhanced when the cells were treated with phorbol ester or a bacterial phospholipase D, suggesting involvement of phospholipase D in the process. In the latter condition, an increased level of LPA, but not other lysophospholipids, was confirmed by mass spectrometry analyses. Expression of the enzyme is observed in several human tissues such as prostate, testis, ovary, pancreas, and especially platelets. These data show that the enzyme is a membrane-associated PA-selective PLA(1) and suggest that it has a role in LPA production.

p125, a mammalian Sec23p-interacting protein, exhibits sequence homology with bovine testis phosphatidic acid-preferring phospholipase A(1). In this study, we identified and characterized a new homologue of p125, KIAA0725p. KIAA0725p exhibited remarkable sequence similarity with p125 throughout the entire sequence determined but lacked an N-terminal proline-rich, Sec23p-interacting region. In vitro binding analysis showed that KIAA0725p does not bind to Sec23p. KIAA0725p possessed phospholipase A(1) activity preferentially for phosphatidic acid. We examined the effects of overexpression of KIAA0725p on the morphology of organelles. Overexpression of KIAA0725p, like that of p125, caused dispersion of the endoplasmic reticulum-Golgi intermediate compartment and Golgi apparatus. Different from the case of p125, overexpression of KIAA0725p resulted in dispersion of tethering proteins located in the Golgi region and caused aggregation of the endoplasmic reticulum. Our results indicate that KIAA0725p is a new member of the phosphatidic acid-preferring phospholipase A(1) protein family and suggest that the cellular function of KIAA0725p is different from that of p125.