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Microsatellite instability (MSI) and deficiency of mismatch repair (dMMR) are key markers for predicting the response of immune checkpoint inhibitors (ICIs) and screening for Lynch syndrome (LS). This study examined the incidences of and factors associated with the concordance of MSI and MMR in human cancers. A total of 518 formalin-fixed cancer tissues were analyzed for MSI and MMR immunohistochemistry (IHC). MSI was analyzed by a PCR-based method using Promega markers. Concordance with MMR expression and factors associated with concordance were analyzed. In 2 colorectal cancer samples, MMR IHC failed due to inadequate staining conditions. In the remaining 516 cancers, a high level of MSI (MSI-H) was identified in 113 cases, and dMMR was identified in 112. The concordance of MSI and MMR IHC was 98.3%. Only 9 cases (4 pancreatobiliary, 3 colorectal, and 2 endometrial cancers) were discordant. Of the 113 MSI-H cases, 4 (3.5%) were proficient MMR (pMMR); of the 403 microsatellite stability (MSS) cases, 5 (1.2%) were dMMR. The independent factors associated with MSI-H/dMMR included meeting Amsterdam II criteria, assay purpose, and sampling method. Multivariate analysis revealed that cancer type (gastrointestinal cancers or others) was associated with concordance of MSI and MMR IHC. Three LS cases with pancreatic or endometrial cancer demonstrated MSS and dMMR, and one biliary cancer showed MSI-H and pMMR. Discordance between MSI and MMR IHC occasionally occurs in pancreaticobiliary and endometrial cancers. When suspected, both MSI and MMR IHC should be done to judge the ICI indication and screen for LS.

In 2021, Japan's national health insurance made germline BRCA (g.BRCA) testing available to unresectable pancreatic cancer (PC) patients as a companion diagnostic (CD) of the PARP inhibitor. This study investigated the incidence of the g.BRCA variant (g.BRCAv.) and the status of the genetic medicine associated with its testing. A total of 110 PC patients underwent the testing, five of whom (4.5%) had a deleterious g.BRCA2v. (all truncations) but no g.BRCA1v. The turnaround time (TAT) to the doctors was 13 days, and to the patients, 17 days. A higher incidence of a BRCA-related family history and a shorter TAT were seen in the g.BRCAv. patients, but they were insignificant (p = 0.085 and p = 0.059, respectively). Genetic counseling was not performed for three g.BRCA2v. patients because two of them had no accessible relatives and one died of the cancer before the genetic report was completed. Two families underwent generic counseling and testing based on the patient's genetic data. g.BRCAv. is recognized in a small fraction of PC cases, and the following genetic counseling is done more for the relatives than for the patients. TAT was constant and did not affect much on the genetic counseling, but the earlier testing is expected for patients with a deadly cancer.

The assessment of laparoscopic cholecystectomy (LC) skills using operating times has not been well reported. We examined the total and partial operating times for LC procedures performed by surgical trainees to determine the required number of surgeries until the surgical time stabilizes.We reviewed the video records of 514 consecutive LCs using the three-port method, performed by 16 surgical trainees. The total and partial surgical times were calculated and correlated to the surgeons' experience.The median total surgical time for a trainee's first LC was 112 (range 71-226) minutes. It reduced rapidly after the first 20 LCs and plateaued to its minimum after approximately 60 cases. A statistically significant time decrease was observed between the first 10 (median, range 112, 46-252 min) and the next 50-59 cases (64, 34-198 min), but not between the 50-59 and the subsequent 100-109 cases (71, 33-127 min). The total times taken by trainees who had performed 50 operations were not significantly different from those taken by instructors during the study period. Surgery for 125 patients with acute cholecystitis took a significantly longer time (median 99 vs. 74 min with non-acute cholecystitis); however, the abovementioned time reduction findings showed similar results regardless of the patient's acute inflammation status. The partial operating times around the cervical/cystic duct and gallbladder bed reduced uniformly between the first 10 and the following 50-59 cases. Although time variations in total and cervical/cystic duct operating times were not correlated to the surgical experience, time fluctuation of gallbladder bed procedures reduced after 60 cases.The time required to perform an LC was inversely correlated with the experience of surgical trainees and halved after the first 60 cases. The surgical experience required for LC time stabilization is approximately 60 cases.

When colonic graft is used as an esophageal substitute after esophagectomy, one or two feeding vessels of the colon are cut to obtain sufficient length, the graft is passed via the subcutaneous route, and microvascular anastomosis is often used to avoid fatal complications. Sixteen consecutive ileo-right colonic reconstructions via the posterior mediastinal or retrosternal route with preservation of all four colonic vessels were performed in the past eight years. We presented the surgical technique and evaluation of this surgical method. In 15 out of 16 consecutive cases, the graft could be pulled up to the neck through the posterior mediastinal or retrosternal route while preserving all four colonic vessels. Reconstruction was not possible in one patient because of ileocolic vessel injury during colonic mobilization. Anastomotic leakage occurred in three patients, but all were minor and were treated conservatively. There were no patients with graft necrosis resulting from insufficient blood supply. Ileo-right colonic reconstruction with preservation of all four colonic vessels through the posterior mediastinal or retrosternal route is a safe and feasible procedure and is considered the first choice for colonic reconstruction as an esophageal substitute.

Previous studies have reported that sarcopenia increases the risk of postoperative complications following colorectal resection. This retrospective study assessed the postoperative complications of rectal resection associated with sarcopenia. We retrospectively analyzed 262 patients who underwent curative low anterior resection for primary rectal cancer from January 2008 to May 2020 at our institution. The patients were divided into a sarcopenia group (normalized total psoas muscle area

Background: The Japanese Society for Cancer of the Colon and Rectum guidelines in 2019, stated that stenting as a bridge to surgery (BTS) for obstructive cancer may cause perforation and other adverse effects, which may worsen the long‑term prognosis. This study aimed to evaluate retrospectively the surgical and oncological outcomes of BTS using a stent compared with surgery alone for obstructive colorectal cancer.Methods: Consecutive patients who underwent curative resection for stages II-III obstructive colorectal cancer at our institution from January 2009 to March 2020, were registered retrospectively and divided into 43 patients in the BTS group and 65 patients in the surgery alone group. We compared the surgical and oncological outcomes between the two groups.Results: Stent-related perforation did not occur in any patient. The patient in whom the stent placement was unsuccessful underwent emergency surgery with poor decompression even after SEMS placement (clinical success rate, 97.4%). The pathological characteristics were not significantly different between the groups. The following surgical outcomes in the BTS group were superior to those in the surgery alone group: non-emergency surgery (P < 0.001), surgical approach (P = 0.006), and length of hospital stay (P = 0.020). The median follow-up time was 44.9 months (range, 1.1 - 126.5 months). The 3-year relapse-free survival rates were 68.4% and 58.2% (P = 0.411), and the overall survival rates were 78.3% and 88.2% (P = 0.255) in the surgery alone and BTS groups, respectively. The 3-year locoregional recurrence rates were 10.2% and 8.0% (P = 0.948), and distant metastatic recurrence rates were 13.3% and 30.4% (P = 0.035) in the surgery alone and BTS groups, respectively. Conclusion: This study revealed that BTS with stent may be associated with a higher frequency of distant metastatic recurrence. Stent for stages II-III obstructive colorectal cancer potentially worsens oncological outcomes.Trial registration: This study was registered retrospectively in University hospital Medical Information Network (UMIN)- Clinical Trials Registry. (Trial registration: UMIN, UMIN000040771. Registered 15 June 2020 - Retrospectively registered, https://upload.umin.ac.jp/cgi-open-bin/icdr/ctr_view.cgi?recptno=R000046558).

Inflammatory myofibroblastic tumor (IMT) is a rare but benign entity masquerading as a malignant tumor. We herein report an 18-month-old boy with small bowel wall IMT who presented with intussusception. He was transferred to our hospital with a complaint of abdominal pain and diagnosed with intussusception. On laparotomy, the small bowel wall mass consisted of solid tissue measuring 2.5 × 3.0 cm. The postoperative pathology examination revealed numerous spindle cells arranged in dense bundles with diffuse infiltration of inflammatory cells and tumor involvement of the mucosa and serosa. As the postoperative pathology examination resulted in a diagnosis of IMT and suspected partial resection, small bowel resection and mesenteric lymph node resection were performed two months after the first operation. A pathology examination after the second surgery revealed no evidence of residual IMT and negative findings for metastasis in the regional lymph nodes. IMT is a locally aggressive lesion. The immunophenotypic feature of ALK-1 in particular is associated with a high recurrence rate. Long-term follow-up is absolutely needed. Keywords: Inflammatory myofibroblastic tumour, Small intestine, Child, Intussusception, Anaplastic lymphoma kinase