Background: Although surgery is the mainstay of curative-intent treatment for extrahepatic biliary tract cancer (EBTC), recurrence following surgery can be high and prognosis poor. The impact of neoadjuvant therapy (NAT) relative to upfront surgery (US) among patients with EBTC remains unclear. Methods: The Surveillance, Epidemiology, and End Results (SEER) databases was utilized to identify patients who underwent surgery from 2006 to 2017 for EBTC, including gallbladder cancer (GBC) and extrahepatic cholangiocarcinoma (ECC). Trends in NAT utilization were investigated, and the impact of NAT on prognosis was compared with US using a propensity score-matched (PSM) analysis. Results: Among 6582 EBTC patients (GBC, n = 4467, ECC, n = 2215), 1.6% received NAT; the utilization of NAT for EBTC increased over time (P_trend = 0.03). Among patients with lymph node metastasis, the lymph node ratio was lower among patients with NAT (0.18 vs. 0.40, p < 0.01). After PSM, there was no difference in overall survival (OS) and cancer-specific survival (CSS) among patients treated with NAT versus US (5-year OS: 24.0% vs. 24.6%, p = 0.14, 5-year CSS: 38.0% vs. 36.1%, p = 0.21). A subgroup analysis revealed that NAT was associated with improved OS and CSS among patients with stages III–IVA of the disease (OS: HR 0.65, 95%CI 0.46–0.92, p = 0.02, CSS: HR 0.62, 95%CI 0.41–0.92, p = 0.01). Conclusions: While NAT did not provide an overall benefit to patients undergoing surgery for EBTC, individuals with advanced-stage disease had improved OS and CSS with NAT. An individualized approach to NAT use among patients with EBTC may provide a survival benefit.

Aim: Lymph node metastasis is an adverse prognostic factor in pancreatic ductal adenocarcinoma. However, it remains a challenge to predict lymph node metastasis using preoperative imaging alone. We used machine learning (combining preoperative imaging findings, tumor markers, and clinical information) to create a novel prediction model for lymph node metastasis in resectable pancreatic ductal adenocarcinoma.Methods: The data of patients with resectable pancreatic ductal adenocarcinoma who underwent surgery between September 1991 and October 2022 were retrospectively examined. Machine‐learning software (Statistical Package for the Social Sciences Modeler) was used to create a prediction model, and parameter tuning was performed to improve the model's accuracy. We also analyzed the contribution of each feature to prediction using individual conditional expectation and partial dependence plots.Results: Of the 331 cases included in the study, 241 comprised the training cohort and 90 comprised the test cohort. After parameter tuning, the areas under the receiver operating characteristic curves for the training and test cohorts were 0.780 and 0.795, respectively. Individual conditional expectation and partial dependence plots showed that larger tumor size and carbohydrate antigen 19–9 and Duke pancreatic monoclonal antigen type 2 levels were associated with positive lymph node metastasis prediction in this model; neoadjuvant treatment was associated with negative lymph node metastasis prediction.Conclusion: Machine learning may contribute to the creation of an effective predictive model of lymph node metastasis in pancreatic ductal adenocarcinoma. Prediction models using machine learning may contribute to the development of new treatment strategies in resectable pancreatic ductal adenocarcinoma.

Background: Due to the limited efficacy of chemotherapy alone in the treatment of unresectable biliary tract cancer, we performed conversion surgery in patients with unresectable biliary tract cancer who responded to down-staging chemotherapy. Methods: Patients with unresectable biliary tract cancer who initiated chemotherapy between 2007 and 2018 were included in this study. We evaluated the short- and long-term outcomes of patients with initially unresectable biliary tract cancer who underwent conversion surgery. Results: A total of 101 patients with unresectable biliary tract cancers treated with chemotherapy were eligible for the present study. A total of 20 patients eventually underwent conversion surgery; these patients had locally advanced disease in 6 cases, liver metastasis in 6 cases, para-aortic lymph node metastasis in 5 cases, and peritoneal dissemination in 3 cases. The mean operative time was 823 min, and the mean intraoperative blood loss was 1902 mL. Histological R0 resections were performed in 17 patients. Postoperative complications of Clavien–Dindo grade IIIa or higher occurred in 10 patients, with no surgery-associated deaths. The 5-year survival rate was significantly higher in patients who underwent conversion surgery (65.0%) than in those who did not (4.3%, p < 0.001). Conclusions: Conversion surgery for initially unresectable biliary tract cancer resulted in favorable overall survival and was safely performed despite its high surgical invasiveness. Conversion surgery for an initially unresectable biliary tract cancer is worth considering.

Background/Objectives: Postoperative complications following pancreaticoduodenectomy (PD) remain high, particularly in patients with soft pancreatic texture. Abdominal aortic calcification volume (AACV), a surrogate marker of systemic arteriosclerosis, has been associated with increased surgical risk in lower gastrointestinal procedures; however, its relevance in hepatopancreatobiliary surgery has not been well established. This study aimed to evaluate the clinical significance of AACV in predicting postoperative complications after PD. Methods: We retrospectively analyzed 182 patients who underwent PD for nonpancreatic malignancies at our institution between January 2007 and December 2023. AACV was measured using the SYNAPSE VINCENT 3D imaging system, assessing calcification from the renal artery to the common iliac artery bifurcations on preoperative CT. Clinical characteristics and short‐term postoperative outcomes were evaluated. Results: The cohort included distal cholangiocarcinoma (57.1%), papillary carcinoma (35.7%), duodenal cancer (2.7%), IPMN (2.2%), and pancreatic neuroendocrine tumors (1.6%). Soft pancreatic texture was observed in 85.2% of patients. The median AACV was 894.5 mm ³ (range: 284.6–2951.9) and correlated weakly with age ( r = 0.377, p < 0.001). Patients with Clavien–Dindo grade≥IIIa complications had significantly higher AACV than those without (1745.9 vs. 751.9 mm ³ , p < 0.001). AACV was identified as an independent predictor of both severe complications (HR: 10.9; 95% CI: 4.44–26.3) and POPF≥Grade B (HR: 4.85; 95% CI: 2.2–10.8). Conclusion: AACV is significantly associated with severe postoperative complications and clinically relevant pancreatic fistula following PD, particularly in patients with nonpancreatic malignancies. It may serve as a valuable preoperative risk predictor in this population.