The Epidemiology of Neuroendocrine Carcinomas in Taiwan: A Population-Based Cancer Registry Study

Lung and small cell neuroendocrine carcinomas (SCCs) are the most common sites and histological types of high-grade neuroendocrine carcinoma (NEC). Comprehensive epidemiological information on NECs is limited. We used the Taiwan Cancer Registry database to analyze the nationwide epidemiology and clinical outcomes of NECs in Taiwan.

We used morphology codes from the International Classification of Diseases for Oncology, third edition (ICD-O-3) and ICD codes to identify the histologic type and sites of NECs, respectively. The Kaplan-Meier method was used to estimate the overall survival (OS) of NECs. The risk of NEC death was evaluated using Cox proportional hazards regression analysis.

The incidence of NECs in Taiwan was 3.892 per 100,000 in 2006 and increased to 4.039 per 100,000 in 2021, with the predominant site being the lung and bronchus and the histologic type of SCC. The median OS of all NECs was 8.3 months. Female sex, earlier stage, and later diagnosis (2016-2021) were good prognostic factors for the OS of NECs, whereas the histologic type of SCC and large cell neuroendocrine carcinoma, primary sites of the lung and bronchus, esophagus, and unknown primary sites were poor prognostic factors for the OS of NECs. Surgery combined with chemotherapy and/or radiation therapy resulted in longer survival for stage III/IV NECs.

Differences in the incidence trends and clinical outcomes of NECs suggest different etiologies and heterogeneities of NECs. Further investigations on risk factor identification and novel treatment strategies for NECs are warranted.