Clinicopathologic Features and Surgical Outcomes of Neuroendocrine Carcinoma of the Gallbladder.

Neuroendocrine carcinoma (NEC) of the gallbladder is highly aggressive and has a poor prognosis even after curative resection. The purpose of this study was to collate and analyze published data to clarify the surgical outcome of NEC of the gallbladder and the relationships between potential prognostic factors and survival after surgery. We surveyed worldwide literature from 1981 to 2018 and obtained clinicopathological data for 65 patients who had undergone surgical resection for NEC of the gallbladder. The relationships between potential prognostic factors and survival rates were examined by the Kaplan-Meier method and the log-rank test. The 1-, 3-, and 5-year disease-specific survival rates after surgery were 70.2%, 39.3%, and 29.5%, respectively. A multivariate analysis revealed that the factors that were independently associated with poor outcomes after surgery in patients with NEC of the gallbladder were older age, higher pathologic T stage, and positive lymph node metastasis. The major sites of recurrence were the liver, lung, lymph node, and local recurrence. The median time to the event for recurrence was 4.0 months. Even when curative resection was achieved, 36.9% of patients exhibited recurrence within 12 months after curative resection of gallbladder NEC. Although NEC of the gallbladder remains a rare disease worldwide, its poor prognosis, even after curative resection, demands further epidemiological and pathological studies that could lead to the development of new management strategies.