THE PROGNOSIS OF THE DIFFERENT ESOPHAGEAL NEUROENDOCRINE CARCINOMA SUBTYPES: A POPULATION-BASED STUDY

Neuroendocrine neoplasms are extremely rare and account for 0.4% to 2% of all malignant esophageal neoplasms. The burden of the neuroendocrine histological type on the patients' prognosis and survival is poorly debated. This study aimed to compare the survival rates of primary neuroendocrine neoplasms compared with adenocarcinoma and squamous cell carcinoma of the esophagus.

This is a retrospective cohort from the Surveillance, Epidemiology, and End Results Program database. Overall survival and cancer-specific survival were evaluated with Kaplan-Meier curves and logrank tests. Proportional Cox regression models were used to evaluate variables related to overall survival.

After eligibility criteria, 66,528 patients were selected. The mean follow-up was 22.6 months (SD 35.6). Adenocarcinoma was predominant (62%), followed by squamous cell carcinoma (36%). Large cell carcinoma, small cell carcinoma, and mixed adenoneuroendocrine carcinoma each account for less than 1% each. On the long-term overall survival analysis, esophageal adenocarcinoma showed a better prognosis than all the other histologic types (P-value for logrank test <0.001). With adenocarcinoma as a reference, HR was 1.32 for large cell carcinoma (95%CI 1.2 to 1.45) and 1.37 for small cell carcinoma (95%CI 1.23 to 1.53). The HR was 1.22 for squamous cell carcinoma (95%CI: 1.2 to 1.24); and 1.3 for adenoneuroendocrine carcinoma (95%CI 1.01 to 1.66). For multivariate Cox regression analysis, besides age and stage, the neuroendocrine subtypes large cell carcinoma and small cell carcinoma were considered independent prognostic variables.

In the esophagus, large cell carcinoma and small cell carcinoma show poorer long-term survival rates than squamous cell carcinoma and adenocarcinoma.