Survival outcomes of local versus radical resection for appendiceal neuroendocrine tumors: a population-based study.

Background: The optimal surgical modality for appendiceal neuroendocrine tumors (ANETs) remains undefined. This study aimed to explore the optimal surgical approach for ANETs by comparing the outcomes between local resection (LR) and radical resection (RR).

Methods: Individuals diagnosed with ANETs during the period from 2000 to 2020 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was used to minimize selection bias. The Kaplan-Meier method and Cox proportional hazards models were used to assess overall survival (OS) and cancer-specific survival (CSS). Additionally, multivariate Cox analysis assessed risk factors linked to OS and CSS.

Results: The study enrolled 4,944 patients, comprising 3,804 in the LR group and 1,140 in the RR group. Patients receiving RR had higher tumor-node-metastasis (TNM) stages (P<0.001), higher age (P<0.001), and larger tumor sizes (P<0.001). Both the 5-year OS and CSS in the LR group were significantly better than those in the RR group (87.3% vs. 73.7%, P<0.001; 95.6% vs. 85.0%, P<0.001). After PSM, 896 patient pairs were matched and compared, showing no demographic and clinical characteristic differences. There was also no difference in long-term OS [hazard ratio (HR) =1.16; 95% confidence interval (CI): 0.86-1.54; P=0.33] and CSS (HR =1.61; 95% CI: 1.00-2.61; P=0.052) between the two groups. Furthermore, multivariate Cox analysis delineated age, diagnosis year, and chemotherapy as independent prognostic risk factors for both OS and CSS, while surgical modality was excluded.

Conclusions: This study indicated that, for patients with ANETs, there was no survival advantage observed for RR when compared to LR, implying that LR might suffice as a treatment for these patients.