Neuroendocrine Component in Extrahepatic Cholangiocarcinoma is Associated with Better Survival: Data from the SEER Study.

ABSTRACT

INTRODUCTION: This study was performed to evaluate the prognostic value of the neuroendocrine component in patients with extrahepatic cholangiocarcinoma (EHCC). METHODS: Cases with EHCC derived from the SEER database were retrospectively reviewed and analyzed. The clinicopathological features and long-term survival were compared between patients with neuroendocrine carcinoma (NECA) and those with pure adenocarcinoma (AC). RESULTS: A total of 3277 patients with EHCC were included (62 patients with NECA and 3215 patients with AC). T stage (P = 0.531) and M stage (P = 0.269) were comparable between the two groups. However, lymph node metastasis was more frequently detected in NECA (P = 0.022). NECA was correlated with more advanced tumor stage than pure AC (P < 0.0001). Inconsistent differentiation status was also observed between the two groups (P = 0.001). The proportion of patients who received surgery was significantly higher in the NECA group (80.6% vs 62.0%, P = 0.003) while chemotherapy was more frequently performed among patients with pure AC (45.7% vs 25.8%, P = 0.002). Comparable incidence of radiotherapy was acquired (P = 0.117). Patients with NECA shared a better overall survival than those with pure AC (P = 0.0141), even after matching (P = 0.0366). The results of univariate and multivariate analyses indicated that the neuroendocrine component was a protective factor as well as an independent prognostic factor for overall survival (HR < 1, P < 0.05). CONCLUSION: Patients with EHCC with a neuroendocrine component shared a better prognosis than those with pure AC, and NECA could serve as a favorable prognostic factor for overall survival. Considering various unprovided but potentially confounding factors, future more well-conducted research is required.