佐田 尚宏

Abstract Background Osteopenia reflects frailty and has been shown to be associated with outcomes in cancer patients. This study was undertaken to examine whether osteopenia is an independent prognostic factor in patients with esophageal cancer after resection. Methods A total of 214 patients who underwent surgery for esophageal cancer were analyzed retrospectively. Bone mineral density (BMD) of the 11th thoracic vertebra was measured by computed tomography scan, and patients classified into osteopenia and normal BMD groups with BMD <160 Hounsfield units as the cutoff. Clinicopathological data and prognosis were analyzed. Results The 5‐year survival rate was 55.4% for the osteopenia group and 74.7% for the normal BMD group with a significantly worse prognosis in the osteopenia group (p = 0.0080). In multivariable analysis, osteopenia was a significant independent risk factor associated with overall survival (hazard ratio [HR] 1.90, 95% confidence interval [CI] 1.27–3.34, and p = 0.0151) along with R1/2 resection (HR 3.02, 95% CI 1.71–5.18, and p = 0.0002). Conclusion In patients with esophageal cancer undergoing resection, osteopenia may be a surrogate marker for frailty and an independent predictor of prognosis.

Alanine aminotransferase (ALT) is an enzyme that catalyzes the transfer of amino groups from alanine to ketoglutaric acid. ALT is an established marker of liver diseases. Occasionally, ALT levels may be abnormally low due to various factors, making accurate assessment difficult. To date, no studies have documented ALT alterations following Living donor liver transplantation (LDLT) in patients with low ALT levels. Here, we present a case of abnormally low ALT levels that were ameliorated by LDLT. A 27-year-old woman underwent LDLT for refractory cholangitis with biliary atresia. The patient's preoperative ALT level was 1 IU/L. Following graft reperfusion, ALT levels increased (peak value, 456 IU/L), primarily attributed to the donor liver. After LDLT, ALT levels consistently surpassed the lower limit. The differential diagnosis of abnormally low ALT levels suggested a genetic mutation as the most probable underlying cause. Even after LDLT, ALT levels in organs other than the transplanted liver would remain abnormally low. Therefore, to prevent underestimating liver damage, the standard ALT range for such cases should be set lower than the typical range.

Abstract The advent of Artificial Intelligence (AI)-based object detection technology has made identification of position coordinates of surgical instruments from videos possible. This study aimed to find kinematic differences by surgical skill level. An AI algorithm was developed to identify X and Y coordinates of surgical instrument tips accurately from video. Kinematic analysis including fluctuation analysis was performed on 18 laparoscopic distal gastrectomy videos from three expert and three novice surgeons (3 videos/surgeon, 11.6 h, 1,254,010 frames). Analysis showed the expert surgeon cohort moved more efficiently and regularly, with significantly less operation time and total travel distance. Instrument tip movement did not differ in velocity, acceleration, or jerk between skill levels. The evaluation index of fluctuation β was significantly higher in experts. ROC curve cutoff value at 1.4 determined sensitivity and specificity of 77.8% for experts and novices. Despite the small sample, this study suggests AI-based object detection with fluctuation analysis is promising because skill evaluation can be calculated in real time with potential for peri-operational evaluation.

Background: Osteopenia is a well-known risk factor for survival in patients with hepatocellular carcinoma; however, it is unclear whether osteopenia can apply to both genders and how osteopenia is associated with cancer progression. The aim of this study was to elucidate whether osteopenia predicts reduced survival in regression models in both genders and whether osteopenia is associated with the pathological factors associated with reduced survival. Methods: This study included 188 consecutive patients who underwent hepatectomy. Bone mineral density was assessed using computed tomography (CT) scan images taken within 3 months before surgery. Non-contrast CT scan images at the level of the 11th thoracic vertebra were used. The cutoff value of osteopenia was calculated using a threshold value of 160 Hounsfield units. Overall survival (OS) curves and recurrence-free survival (RFS) were constructed using the Kaplan–Meier method, as was a log-rank test for survival. The hazard ratio and 95% confidence interval for overall survival were calculated using Cox’s proportional hazard model. Results: In the regression analysis, age predicted bone mineral density. The association in females was greater than that in males. The OS and RFS of osteopenia patients were shorter than those for non-osteopenia patients. According to univariate and multivariate analyses, osteopenia was an independent risk factor for OS and RFS. The sole pathological factor associated with osteopenia was microvascular portal vein invasion. Conclusion: Models suggest that osteopenia may predict decreased OS and RFS in patients undergoing resection of hepatocellular carcinoma due to the mechanisms mediated via microvascular portal vein invasion.

Abstract The vagus nerve is the only pathway for transmitting parasympathetic signals between the brain and thoracoabdominal organs, thereby exhibiting anti-inflammatory functions through the cholinergic anti-inflammatory pathway. Despite often being resected during lymph node dissection in upper gastrointestinal cancer surgery, the impact of vagotomy on postoperative outcomes in gastric cancer patients remains unclear. Sub-diaphragmatic vagotomy was performed on C57BL/6 mice. Three weeks later, syngeneic murine gastric cancer cell line YTN16P was injected into the peritoneal cavity, and the number of peritoneal metastases (PM) on the mesentery and omentum compared with control mice. The phenotypes of immune cells in peritoneal lavage and omental milky spots one day after tumor inoculation were analyzed using flow cytometry and immunohistochemistry. Intraperitoneal transfer of 3 × 10⁵ YTN16P significantly increased the number of metastatic nodules on the mesentery in the vagotomy group compared to the control group. The omental metastasis grade was also significantly higher in the vagotomy group. Phenotypic analysis of immune cells in peritoneal lavage did not reveal significant differences after vagotomy. However, vagotomized mice exhibited a notable increase in milky spot area, with a higher presence of cytokeratin(+) tumor cells, F4/80(+) macrophages, and CD3(+) T cells. Vagus nerve signaling appears to regulate the immune response dynamics within milky spots against disseminated tumor cells and inhibits the development of PM. Preserving the vagus nerve may offer advantages in advanced gastric cancer surgery to reduce peritoneal recurrence.

The liver and pancreas work together to recover homeostasis after hepatectomy. This study aimed to investigate the effect of liver resection volume on the pancreas. We collected clinical data from 336 living liver donors. They were categorized into left lateral sectionectomy (LLS), left lobectomy, and right lobectomy (RL) groups. Serum pancreatic enzymes were compared among the groups. Serum amylase values peaked on postoperative day (POD) 1. Though they quickly returned to preoperative levels on POD 3, 46% of cases showed abnormal values on POD 7 in the RL group. Serum lipase levels were highest at POD 7. Lipase values increased 5.7-fold on POD 7 in the RL group and 82% of cases showed abnormal values. The RL group's lipase was twice that of the LLS group. A negative correlation existed between the remnant liver volume and amylase (r = - 0.326)/lipase (r = - 0.367) on POD 7. Furthermore, a significant correlation was observed between POD 7 serum bilirubin and amylase (r = 0.379)/lipase (r = 0.381) levels, indicating cooccurrence with liver and pancreatic strain. Pancreatic strain due to hepatectomy occurs in a resection/remnant liver volume-dependent manner. It would be beneficial to closely monitor pancreatic function in patients undergoing a major hepatectomy.

Recent evidence indicates ferroptosis is implicated in the pathophysiology of various liver diseases; however, the organ-specific regulation mechanism is poorly understood. Here, we demonstrate 7-dehydrocholesterol reductase (DHCR7), the terminal enzyme of cholesterol biosynthesis, as a regulator of ferroptosis in hepatocytes. Genetic and pharmacological inhibition (with AY9944) of DHCR7 suppress ferroptosis in human hepatocellular carcinoma Huh-7 cells. DHCR7 inhibition increases its substrate, 7-dehydrocholesterol (7-DHC). Furthermore, exogenous 7-DHC supplementation using hydroxypropyl β-cyclodextrin suppresses ferroptosis. A 7-DHC-derived oxysterol metabolite, 3β,5α-dihydroxycholest-7-en-6-one (DHCEO), is increased by the ferroptosis-inducer RSL-3 in DHCR7-deficient cells, suggesting that the ferroptosis-suppressive effect of DHCR7 inhibition is associated with the oxidation of 7-DHC. Electron spin resonance analysis reveals that 7-DHC functions as a radical trapping agent, thus protecting cells from ferroptosis. We further show that AY9944 inhibits hepatic ischemia-reperfusion injury, and genetic ablation of Dhcr7 prevents acetaminophen-induced acute liver failure in mice. These findings provide new insights into the regulatory mechanism of liver ferroptosis and suggest a potential therapeutic option for ferroptosis-related liver diseases.

Abstract Intestinal adaptation does not necessarily recover absorptive capacity in short bowel syndrome (SBS), sometimes resulting in intestinal failure-associated liver disease (IFALD). Additionally, its therapeutic options remain limited. Polyamines (spermidine and spermine) are known as one of the autophagy inducers and play important roles in promoting the weaning process; however, their impact on intestinal adaptation is unknown. The aim of this study was to investigate the impact of polyamines ingestion on adaptation and hepatic lipid metabolism in SBS. We performed resection of two-thirds of the small intestine in male Lewis rats as an SBS model. They were allocated into three groups and fed different polyamine content diets (0%, 0.01%, 0.1%) for 30 days. Polyamines were confirmed to distribute to remnant intestine, whole blood, and liver. Villous height and number of Ki-67-positive cells in the crypt area increased with the high polyamine diet. Polyamines increased secretory IgA and mucin content in feces, and enhanced tissue Claudin-3 expression. In contrast, polyamines augmented albumin synthesis, mitochondrial DNA copy number, and ATP storage in the liver. Moreover, polyamines promoted autophagy flux and activated AMP-activated protein kinase with suppression of lipogenic gene expression. Polyamines ingestion may provide a new therapeutic option for SBS with IFALD.

Abstract The spleen is a key source of circulating and tumor-infiltrating immune cells. However, the effect of splenectomy on tumor growth remains unclear. At 3 weeks after splenectomy, we subcutaneously injected LuM1 cells into BALB/c mice and evaluated the growth of primary tumors and lung metastases at 4 weeks after tumor inoculation. In addition, we examined the phenotypes of immune cells in peripheral blood by using flow cytometry and in tumor tissue by using multiplex immunohistochemistry. The growth of primary tumors was reduced in splenectomized mice compared with the sham-operated group. Conversely, splenectomized mice had more lung metastases. Splenectomized mice had fewer CD11b⁺cells, especially monocytic MDSCs (CD11b⁺Gr-1^neg-lowLy6c^high), and NK cells (CD49b⁺CD335⁺). The proportion of NK cells was inversely correlated with the number of lung metastases. In splenectomized mice, the density of CD3⁺ and granzyme B⁺ CD8⁺ T cells was increased, with fewer M2-type macrophages in primary tumors, but NK cells were decreased markedly in lung. Splenectomy concurrently enhances T cell-mediated acquired immunity by reducing the number of monocytic MDSCs and suppresses innate immunity by decreasing the number of NK cells. Splenectomy has opposite effects on primary and metastatic lesions through differential regulation on these two immune systems.

BACKGROUND: Adjuvant nivolumab therapy has become the standard therapy for patients with localized advanced esophageal cancer with non-pathological complete response after neoadjuvant chemoradiotherapy followed by curative surgery. However, the necessity of this therapy for patients after neoadjuvant chemotherapy (NAC) with docetaxel, cisplatin, and 5-fluorouracil (DCF) regimen followed by surgery is unclear, and the prognosis of grouping based on the presence or absence of pathological tumor and lymph node findings has not been analyzed. Therefore, our study aimed to address these questions. METHODS: This retrospective cohort study included patients with cT1N1-3M0 and cT2-3N0-3M0 esophageal cancer according to the Japanese Classification of Esophageal Cancer, 11th edition, who received NAC with DCF followed by curative surgery between 2008 and 2020 at Jichi Medical University Hospital. We divided patients with ypT0-3N0-3M0 into four histological groups, namely ypT0N0, ypT+N0, ypT0N+, and ypT+N+, and we evaluated overall survival as the primary outcome and the prognostic relationship of lymph node metastasis as the secondary outcome. RESULTS: A total of 101 patients were included in this study. Kaplan-Meier analysis showed that the curves of the ypT0N0 and ypT+N0 groups were almost identical, while they differed from the other two groups. The hazard ratio of ypN+ was 4.44 (95% confidence interval: 2.03-9.71; P<0.001). CONCLUSIONS: The prognosis of the ypT+N0 group after NAC with DCF followed by surgery was similar to that of pathological complete remission. Grouping patients according to pathological lymph node status is a reasonable predictor of prognosis.

INTRODUCTION: Treatment guidelines for colorectal cancer (CRC) suggest two classifications for histological differentiation-highest-grade and predominant. However, the optimal predictor of lymph node metastasis (LNM) in T1 CRC remains unknown. This systematic review aimed to evaluate the impact of the use of highest-grade or predominant differentiation on LNM determination in T1 CRC. METHODS: The study protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO, registration number: CRD42023416971) and was published in OSF (https://osf.io/TMAUN/) on April 13, 2023.We searched five electronic databases for studies assessing the diagnostic accuracy of highest-grade or predominant differentiation to determine LNM in T1 CRC. The outcomes were sensitivity and specificity. We simulated 100 T1 CRC cases, with an LNM incidence of 11.2%, to calculate the differences in false positives and negatives between the highest-grade and predominant differentiations using a bootstrap method. RESULTS: In 42 studies involving 41,290 patients, the differentiation classification had a pooled sensitivity of 0.18 (95% confidence interval [CI], 0.13-0.24) and 0.06 (95% CI, 0.04-0.09) (P<0.0001) and specificity of 0.95 (95% CI, 0.93-0.96) and 0.98 (95% CI, 0.97-0.99) (P<0.0001) for the highest-grade and predominant differentiations, respectively. In the simulation, the differences in false positives and negatives between the highest-grade and predominant differentiations were 3.0% (range, 1.6-4.4) and -1.3% (range, -2.0 to -0.7), respectively. CONCLUSIONS: Highest-grade differentiation may reduce the risk of misclassifying LNM cases as negative, whereas predominant differentiation may prevent unnecessary surgeries. Further studies should examine differentiation classification using other predictive factors.

Lateral lymph node (LLN) metastasis in T1 rectal cancer has an incidence of less than 1%. However, its clinical features are largely uncharted. We report a case of LLN metastasis in T1 rectal cancer and review the relevant literature. A 56-year-old female underwent rectal resection for lower rectal cancer 2 years previously (pT1bN0M0). During follow-up, an elevated tumor marker CA19-9 was documented. Enhanced CT and MRI showed a round shape nodule 2 cm in size on the left side of pelvic wall. PET-CT showed high accumulation of FDG in the same lesion, leading to a diagnosis of isolated LLN recurrence. Because no other site of recurrence was detected, surgical resection of the LLN was performed. Microscopic findings were consistent with metastatic lymph node originating from the recent rectal cancer. Adjuvant chemotherapy for six months was given, and patient remains free of recurrent disease seven months after LLN resection. Although LLN recurrence after surgery for T1 rectal cancer is rare, post-surgical follow-up should not be omitted. When LLN metastasis is suspected on CT, MRI and/or PET-CT will be recommended. Surgical resection of LLN metastasis in patients with T1 rectal cancer may lead to favorable outcomes, when recurrence in other areas is not observed.

AIM: Low anterior resection syndrome (LARS) causes devastating symptoms and impairs quality of life (QOL). Although its incidence and risk factors have been reported, these data are scarce in Japan. This study aimed to elucidate the incidence and risk factors of LARS as well as to evaluate its association with QOL in Japanese patients. METHOD: Patients with anal defecation at the time of the survey between November 2020 and April 2021 were included, among those who underwent anus-preserving surgery for rectal tumors between 2014 and 2019 in tertiary referral university hospital. The severity of LARS and QOL were evaluated with the LARS score and the Japanese version of the fecal incontinence quality of life scale (JFIQL), respectively. Primary endpoint was the incidence of major LARS. Secondary endpoints were risk factors and association with JFIQL. RESULTS: Of 332 eligible patients, 238 (71.7%) answered the LARS survey completely. The incidence of major LARS was 22% overall, and 48% when limited to lower tumors. Independent risk factors included lower tumors (OR: 7.0, 95% CI: 2.1-23.1, p = 0.001) and surgical procedures with lower anastomoses (OR: 4.6, 95% CI: 1.2-18.5, p = 0.03). The JFIQL generic score correlated moderately with the LARS score (correlation coefficient of -0.65). The JFIQL generic score was also significantly lower in lower tumors. CONCLUSIONS: The incidence of major LARS is 22% in Japanese patients, and independent risk factors include lower tumors and surgical procedures with lower anastomoses. More severe LARS is associated with worse QOL which is significantly more impaired in patients with lower tumors.