Mutations in TGFBR2, a component of the transforming growth factor (TGF)-β signaling pathway, occur in high-frequency microsatellite instability (MSI-H) colorectal cancer (CRC). In mouse models, Tgfbr2 inactivation in the intestinal epithelium accelerates the development of malignant intestinal tumors in combination with disruption of the Wnt-β-catenin pathway. However, no studies have further identified the genes influenced by TGFBR2 inactivation following disruption of the Wnt-β-catenin pathway. We previously described CDX2P-G19Cre;Apcflox/flox mice, which is stochastically null for Apc in the colon epithelium. In this study, we generated CDX2P-G19Cre;Apcflox/flox;Tgfbr2flox/flox mice, with simultaneous loss of Apc and Tgfbr2. These mice developed tumors, including adenocarcinoma in the proximal colon. We compared gene expression profiles between tumors of the two types of mice using microarray analysis. Our results showed that the expression of the murine homolog of GSDMC was significantly upregulated by 9.25-fold in tumors of CDX2P-G19Cre;Apcflox/flox;Tgfbr2flox/flox mice compared with those of CDX2P-G19Cre;Apcflox/flox mice. We then investigated the role of GSDMC in regulating CRC tumorigenesis. The silencing of GSDMC led to a significant reduction in the proliferation and tumorigenesis of CRC cell lines, whereas the overexpression of GSDMC enhanced cell proliferation. These results suggested that GSDMC functioned as an oncogene, promoting cell proliferation in colorectal carcinogenesis. In conclusion, combined inactivation of both Apc and Tgfbr2 in the colon epithelium of a CRC mouse model promoted development of adenocarcinoma in the proximal colon. Moreover, GSDMC was upregulated by TGFBR2 mutation in CRC and promoted tumor cell proliferation in CRC carcinogenesis, suggesting that GSDMC may be a promising therapeutic target.

Hereditary colorectal cancer (HCRC) accounts for < 5% of all colorectal cancer cases. Some of the unique characteristics commonly encountered in HCRC cases include early age of onset, synchronous/metachronous cancer occurrence, and multiple cancers in other organs. These characteristics necessitate different management approaches, including diagnosis, treatment or surveillance, from sporadic colorectal cancer management. There are two representative HCRC, named familial adenomatous polyposis and Lynch syndrome. Other than these two HCRC syndromes, related disorders have also been reported. Several guidelines for hereditary disorders have already been published worldwide. In Japan, the first guideline for HCRC was prepared by the Japanese Society for Cancer of the Colon and Rectum (JSCCR), published in 2012 and revised in 2016. This revised version of the guideline was immediately translated into English and published in 2017. Since then, several new findings and novel disease concepts related to HCRC have been discovered. The currently diagnosed HCRC rate in daily clinical practice is relatively low; however, this is predicted to increase in the era of cancer genomic medicine, with the advancement of cancer multi-gene panel testing or whole genome testing, among others. Under these circumstances, the JSCCR guidelines 2020 for HCRC were prepared by consensus among members of the JSCCR HCRC Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR guidelines 2020 for HCRC.

AimAs a result of the difficulty in effective prevention of gastroesophageal reflux, no standard reconstruction procedure after proximal gastrectomy (PG) has yet been established. The double‐flap technique (DFT), or Kamikawa procedure, is an antireflux reconstruction procedure in esophagogastrostomy. The efficacy of DFT has recently been reported in several studies. However, these were all single‐center studies with a limited number of cases.MethodsWe conducted a multicenter retrospective study in which patients who underwent DFT, irrespective of disease type and reconstruction approach, at each participating institution between 1996 and 2015 were registered. Primary endpoint was incidence of reflux esophagitis at 1‐year after surgery, and secondary endpoint was incidence of anastomosis‐related complications.ResultsOf 546 patients who were eligible for this study, 464 patients who had endoscopic examination at 1‐year follow up were evaluated for reflux esophagitis. Incidence of reflux esophagitis of all grades was 10.6% and that of grade B or higher was 6.0%. Male gender and anastomosis located in the mediastinum/intra‐thorax were independent risk factors for grade B or higher reflux esophagitis (odds ratio [OR]: 4.21, 95% confidence interval [CI]: 1.44‐10.9, P = 0.0109). Total incidence of anastomosis‐related complications was 7.2%, including leakage in 1.5%, strictures in 5.5% and bleeding in 0.6% of cases. Laparoscopic reconstruction was the only independent risk factor for anastomosis‐related complications (OR: 3.93, 95% CI: 1.93‐7.80, P = 0.0003).ConclusionDouble‐flap technique might be a feasible option after PG for effective prevention of reflux, although anastomotic stricture is a complication that must be well‐prepared for.

Hereditary colorectal cancer accounts for less than 5% of all colorectal cancer cases. Some of the unique characteristics that are commonly encountered in cases of hereditary colorectal cancer include early age at onset, synchronous/metachronous occurrence of the cancer, and association with multiple cancers in other organs, necessitating different management from sporadic colorectal cancer. While the diagnosis of familial adenomatous polyposis might be easy because usually 100 or more adenomas that develop in the colonic mucosa are in this condition, Lynch syndrome, which is the most commonly associated disease with hereditary colorectal cancer, is often missed in daily medical practice because of its relatively poorly defined clinical characteristics. In addition, the disease concept and diagnostic criteria for Lynch syndrome, which was once called hereditary non‐polyposis colorectal cancer, have changed over time with continual research, thereby possibly creating confusion in clinical practice. Under these circumstances, the JSCCR Guideline Committee has developed the “JSCCR Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (HCRC)," to allow delivery of appropriate medical care in daily practice to patients with familial adenomatous polyposis, Lynch syndrome, or other related diseases. The JSCCR Guidelines 2016 for HCRC were prepared by consensus reached among members of the JSCCR Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR Guidelines 2016 for HCRC.

Objective: Acute mesenteric ischemia is potentially fatal, but prognostic factors have not yet been established. This study was undertaken to elucidate them. Methods: This is a retrospective cohort study, consisting of 110 patients who had been treated in the past 5 years, from 26 national hospitals in Japan. Results: The overall in-hospital mortality rate was 51%. Logistic regression analysis demonstrated two independent prognostic factors, electrocardiogram scale with an odds ratio of 1.7 (95% CI 1.2–2.4) and shock index of 11 (95% CI 1.5–80). A stepwise analysis gave a prediction equation for in-hospital mortality (R) using these variables and age score. We further modified this equation to a simpler scoring system (S) using the same variables. Both R and S showed a good discriminatory ability as determined by areas under the receiver-operating characteristic curve (0.83, 95% CI: 0.74–0.91 for R; 0.82, 95% CI 0.74–0.91 for S). The observed mortality rates increased as the R or S increased (19% at R <0.25, 41% at 0.25 ≤ R <0.6, 85% at R ≥0.6; 19% at S ≤2, 37% at S of 3 or 4, 91% at S ≥5). Conclusion: The new prediction rules can be used at any hospital and may be promising tools for medical decision-making, informed consent and reviewing quality of care.

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BackgroundLaparoscopic cholecystectomy (LC) is the accepted standard management for benign gallbladder disease. LC rarely results in a diagnosis of incidental gallbladder carcinoma (IGBC). The aim of our study was to report our experience with IGBC diagnosed during or following LC.MethodsBetween January 2008 and January 2015, 352 patients underwent LC at Iwakuni Clinical Center. Among these patients, 8 (2.3%) were diagnosed with IGBC. We evaluated their characteristics, surgical related variables, histopathological findings and surgical outcomes.ResultsPatient median age was 71 (range 49–88) years, and 3 out of 8 were female. All patients with IGBC were Japanese. The grade of cancer was as follows: pT1a (3 cases), pT2 (4 cases) and pT3 (1 case). Two patients with pT2 disease underwent radical surgery. The median follow-up time of these patients was 24 (range 11–80) months. All patients are still alive and two of three patients who refused radical surgery have developed recurrence (liver metastases and recurrence in the peritoneum).ConclusionsAlthough the number of cases was small, the results of this study further support the suggestion that gallbladder carcinoma may be curable if diagnosed as IGBC at an early stage. If the cancer has reached an advanced stage, radical surgery should be performed.

Laparoscopic approach is increasingly being adopted for prophylactic FAP surgery in Japan and may provide clinically acceptable practical outcomes.