The significance of neuroendocrine component in cases with intrahepatic cholangiocarcinoma: A SEER-based retrospective cohort study

Abstract

ObjectiveTo evaluate the significance of neuroendocrine component in cases with intrahepatic cholangiocarcinoma (IHCC). MethodsCases with IHNECA and IHBDAC from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively reviewed and analyzed. Comparative analyses in terms of clinic-pathological features and long-term survival were performed between cases with intrahepatic neuroendocrine carcinoma (IHNECA) and intrahepatic bile duct adenocarcinoma (IHBDAC). ResultsA total of 5211 cases with IHCC were included (103 with IHNECA and 5108 with IHBDAC). Comparable age status (P=0.168), sex status (P=0.274), and cirrhosis status (P=0.480) were acquired between two groups while inconsistent distributions in races (P=0.027) and marital status (P=0.028) were also acquired. Cases with IHBDAC were generally in a more advanced stage and shared a worse prognosis. A significantly higher incidence of lymph node metastasis was detected among cases with IHBDAC (24.8% vs 15.5%, P=0.031). Although the overall surgery rate was comparable between two groups (P=0.519), chemotherapy (53.0% vs 37.9%, P=0.002) and radiotherapy (6.0% vs 1.0%, P=0.032) were more frequently performed with a much higher cancer-related death (CRD) (79.4% vs 58.3%, P<0.001) acquired in cases with IHBDAC. INHECA served as an independent protective factor for cases with IHCC. Even after matching, cases with IHBDCA still shared a higher incidence with CRD (P=0.010) and a worse prognosis, especially for cases who received surgery. ConclusionIHNECA was associated with less aggressive tumor biological features and worse prognosis. More in-depth research focusing on IHNECA with more detailed clinical and pathological data is required.