Abstract
BACKGROUND: Surgical management strategies for patients with synchronous liver metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are controversial. This study sought to investigate survival outcomes associated with various resection strategies. METHODS: Patients with grade I or II primary NETs originating from the small-bowel (SBNETs) or pancreas (PNETs) with synchronous liver metastasis alone were identified from the Surveillance, Epidemiology, and End Results (SEER) database (2010-2019). Data were analyzed using chi-square testing, the Kaplan-Meier method with the log-rank test, and Cox proportional hazards regression models. RESULTS: Overall, 1448 patients were identified with grade I or II SBNETs (n = 859, 59%) or PNETs (n = 589, 41%) and synchronous liver metastases. The median follow-up period for the patients was 46 months (interquartile range [IQR], 29.0-72.0 months). Both primary resection and metastasectomy were more likely to be performed for SBNETs than for PNETs (41% vs 26%; p < 0.001). Survival analysis showed that the patients receiving primary tumor resection and metastasectomy had a longer mean disease-specific survival (SBNETs, 97.0 months; PNETs, 71.6 months) than the patients who were surgical candidates but refused surgery (SBNETs, 73.5 months; PNETs, 56.5 months; p < 0.01). In the multivariate analysis controlling for grade, primary resection with metastasectomy was associated with a survival advantage compared with no surgical intervention for both the patients with SBNETs (hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.20-0.49; p = 0.01) and those with PNETs (HR, 0.22-0.47; 95% CI, 0.22-0.47; p < 0.001). CONCLUSIONS: This large population-level study suggests that the surgical management of patients who have primary SBNETs or PNETs with liver metastasis may be associated with a survival advantage. Surgeons should consider primary resection and metastasectomy (if safe and feasible) for this patient population.