堀口 明彦

PURPOSE: This study aimed to clarify the current treatment status for biliary tract cancers based on data from the National Clinical Database (NCD) in Japan. METHODS: Total 3895 cases of biliary tract cancers registered in the NCD during 2021 were included. We identified the rates of resection, R0 resection, postoperative complications, and incidences of lymph node metastasis for gallbladder carcinoma, perihilar cholangiocarcinoma, distal bile duct carcinoma, and ampullary carcinoma. RESULTS: The number of biliary tract cancers registered in the NCD during 2021 was 3895 (1775 in extrahepatic bile duct carcinoma, 1422 in gallbladder carcinoma, and 698 in ampullary carcinoma). In gallbladder carcinoma, the resection (89.59%) and R0 resection rates (87.99%) were favorable, and the complication rate (6.05%) was lower than that of others. However, the postoperative complication rate could be higher in T3-T4 cases and when extrahepatic bile duct resection was performed concomitantly. Lymph node metastasis was frequently seen in 12.60% at the No. 13a lymph node. In perihilar cholangiocarcinoma, the R0 resection (69.82%) and complication rates (16.75%) were significantly lower and higher, respectively. In distal cholangiocarcinoma and ampullary carcinoma, metastasis was observed in approximately 2% and 10% of the dissected No. 16b1 para-aortic lymph nodes, respectively. In conclusion, although short-term surgical outcomes for biliary tract cancers in Japan might be acceptable, the significantly lower R0 resection and higher complication rates of perihilar cholangiocarcinomas indicate additional challenges for surgeons in the future and should continue to be monitored by the Japanese Society of Hepatobiliary and Pancreatic Surgery.

This study aimed to validate the DFS (direct fast scarlet) staining in the diagnosis of EC (eosinophilic colitis). The study included 50 patients with EC and 60 with control colons. Among the 60 control samples, 39 and 21 were collected from the ascending and descending colons, respectively. We compared the median number of eosinophils and frequency of eosinophil degranulation by HE (hematoxylin and eosin) and DFS staining between the EC and control groups. In the right hemi-colon, eosinophil count by HE was useful in distinguishing between EC and control (41.5 vs. 26.0 cells/HPF, p < 0.001), but the ideal cutoff value is 27.5 cells/HPF (high-power field). However, this method is not useful in the left hemi-colon (12.5 vs. 13.0 cells/HPF, p = 0.990). The presence of degranulation by DFS allows us to distinguish between the groups even in the left hemi-colon (58% vs. 5%, p < 0.001). DFS staining also enabled a more accurate determination of degranulation than HE. According to the current standard to diagnose EC (count by HE staining ≥20 cells/HPF), mucosal sampling from left hemi-colon is problematic since the number of eosinophils could not be increased even in EC. Determination of degranulated eosinophils by DFS may potentiate the diagnostic performance even in such conditions.

BACKGROUND: Surgical resection is standard treatment for invasive intraductal papillary mucinous carcinoma (IPMC); however, impact of multidisciplinary treatment on survival including postoperative adjuvant therapy (AT), neoadjuvant therapy (NAT), and treatment for recurrent lesions is unclear. We investigated the effectiveness of multidisciplinary treatment in prolonging survival of patients with invasive IPMC. METHODS: This retrospective multi-institutional study included 1183 patients with invasive IPMC undergoing surgery at 40 academic institutions. We analyzed the effects of AT, NAT, and treatment for recurrence on survival of patients with invasive IPMC. RESULTS: Completion of the planned postoperative AT for 6 months improved the overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) of patients with stage IIB and stage III resected invasive IPMC, elevated preoperative carbohydrate antigen 19-9 level, lymphovascular invasion, perineural invasion, serosal invasion, and lymph node metastasis on un-matched and matched analyses. Of the patients with borderline resectable (BR) invasive IPMC, the OS (p = 0.001), DSS (p = 0.001), and RFS (p = 0.001) of patients undergoing NAT was longer than that of those without on the matched analysis. Of the 484 invasive IPMC patients (40.9%) who developed recurrence after surgery, the OS of 365 patients who received any treatment for recurrence was longer than that of those without treatment (40.6 vs. 22.4 months, p < 0.001). CONCLUSION: Postoperative AT might benefit selected patients with invasive IPMC, especially those at high risk of poor survival. NAT might improve the survivability of BR invasive IPMC. Any treatment for recurrence after surgery for invasive IPMC might improve survival.

OBJECTIVE: This study was performed to demonstrate the clinical application of duodenum-preserving pancreatic head resection (DPPHR) as a surgical treatment for pancreatic neuroendocrine tumors (PNETs) in terms of both curability and maintenance of postoperative quality of life. METHODS: Seven patients diagnosed with PNETs underwent DPPHR from January 2011 to December 2021 at our institution. We investigated the clinical relevance of DPPHR based on the patients' clinicopathological findings. RESULTS: The median operative time was 492 min, and the median blood loss was 302 g. Postoperative complications were evaluated according to the Clavien-Dindo classification, and postoperative intra-abdominal bleeding was observed in one patient. Pathological examination revealed a World Health Organization classification of G1 in six patients and G2 in one patient. Microvascular invasion was observed in two patients (29%); however, no patients developed lymph node metastasis or recurrence during the follow-up period. A daughter lesion was observed near the primary tumor in one patient. All patients achieved curative resection, and no tumor specimens showed positive margins. CONCLUSIONS: DPPHR facilitates anatomical resection of the pancreatic head in patients with PNETs as well as detailed pathological evaluation of the resected specimen. Therefore, this surgical procedure is an acceptable alternative to pancreaticoduodenectomy or enucleation for patients with PNETs.

BACKGROUND & AIMS: Despite previously reported treatment strategies for nonfunctioning small (≤20 mm) pancreatic neuroendocrine neoplasms (pNENs), uncertainties persist. We aimed to evaluate the surgically resected cases of nonfunctioning small pNENs (NF-spNENs) in a large Japanese cohort to elucidate an optimal treatment strategy for NF-spNENs. METHODS: In this Japanese multicenter study, data were retrospectively collected from patients who underwent pancreatectomy between January 1996 and December 2019, were pathologically diagnosed with pNEN, and were treated according to the World Health Organization 2019 classification. Overall, 1490 patients met the eligibility criteria, and 1014 were included in the analysis cohort. RESULTS: In the analysis cohort, 606 patients (59.8%) had NF-spNENs, with 82% classified as grade 1 (NET-G1) and 18% as grade 2 (NET-G2) or higher. The incidence of lymph node metastasis (N1) by grade was significantly higher in NET-G2 (G1: 3.1% vs G2: 15.0%). Independent factors contributing to N1 were NET-G2 or higher and tumor diameter ≥15 mm. The predictive ability of tumor size for N1 was high. Independent factors contributing to recurrence included multiple lesions, NET-G2 or higher, tumor diameter ≥15 mm, and N1. However, the independent factor contributing to survival was tumor grade (NET-G2 or higher). The appropriate timing for surgical resection of NET-G1 and NET-G2 or higher was when tumors were >20 and >10 mm, respectively. For neoplasms with unknown preoperative grades, tumor size >15 mm was considered appropriate. CONCLUSIONS: NF-spNENs are heterogeneous with varying levels of malignancy. Therefore, treatment strategies based on tumor size alone can be unreliable; personalized treatment strategies that consider tumor grading are preferable.