Objective To investigate the clinicopathological characteristics and prognostic factors of biliary neuroendocrine neoplasms (NENs).

Methods The retrospective cohort study was conducted. The clinicopathological data of 36 patients who underwent surgical treatment for biliary NENs at The First Hospital of Jilin University from January 2013 to December 2023 were collected. There were 22 males and 14 females, aged (59±9)years. Observation indicators: (1) clinicopatholo-gical characteristics of patients; (2) follow‑up; (3) prognostic factors analysis of patients. Compari-son of measurement data with normal distribution among multiple groups was conducted using the ANOVA. Comparison of measurement data with skewed distribution among multiple groups was conducted using the Kruskal‑Wallis H test. Comparison of count data between groups was conducted using the chi-square test or Fisher exact probability. The Kaplan‑Meier method was used to calculate survival rate and plot survival curve, and Log‑rank test was used for survival analysis. The Cox risk regression model was used for univariate and multivariate analyses.

Results (1) Clinicopatholo-gical characteristics of patients. None of the 36 patients with biliary NENs had carcinoid syndrome. There were 11 cases with tumor located at gallbladder, 14 cases with tumor located at bile duct, and 11 cases with tumor located at ampulla of Vater. There were significant differences in weight loss and TNM stage among biliary NENs patients with different tumor location (χ²=9.14, 6.54, P<0.05). Of the 36 patients, there were 12 cases with neuroendocrine tumors, 16 cases with neuroendocrine carcinomas, and 8 cases with mixed neuroendocrine-non-neuroendocrine neoplasms. (2) Follow‑up. All 36 patients were followed up for 39(range, 10-93)months. Of the 36 patients, 19 patients experienced tumor recurrence and 16 patients experienced tumor metastasis. There were 18 patients died. The median overall survival time of 36 patients was 30 months, with the 1‑, 2‑, 3‑year overall survival rates of 63.9%, 51.0%, and 35.7%, respectively. The 1-, 2-, 3-year recurrence-free survival rates were 47.5%, 34.1% and 21.3%, respectively. The 1‑, 2‑, 3‑year overall survival rates of 19 patients with tumor recurrence were 55.6%, 55.6% and 27.8%, respectively. The 1‑, 2‑, 3‑year overall survival rates of 17 patients without tumor recurrence were 71.3%, 50.4% and 42.0%, respectively. There was no significant difference in overall survival between patients with and without tumor recurrence (χ²=0.24, P>0.05). (3) Prognostic factors analysis of patients. Results of multivariate analysis showed that pathological type as neuroendocrine carcinomas and mixed neuroendocrine-non-neuroendocrine neoplasms, non‑R₀ margin were independent risk factors influencing overall survival time of patients (hazard ratio=5.50, 5.33, 14.04, 95% confidence interval as 1.32-23.01, 1.17-24.35, 2.67-73.79, P<0.05).

Conclusions Biliary NENs lack specific clinical manifestations. Poorly differentiated neuroendocrine carcinomas are the most common pathological type. Pathological type as neuroendocrine carcinomas and mixed neuroendocrine-non-neuroendocrine neoplasms, non‑R₀ margin are independent risk factors influencing prognosis of patients.