Survival of patients with appendiceal neuroendocrine tumors: whether they benefit from right hemicolectomy?

Abstract Background: Current guidelines recommend right hemicolectomy for appendiceal neuroendocrine tumors (A-NETs) patients with lymph node (LN) metastasis. However, prognosis of these patients is favorable, and the prognostic impact of metastatic LN is controversial.Objective: The study aims to evaluate the prognostic factors of A-NETs, and explore whether right hemicolectomy/ more extended procedure (RHCM) improves prognosis compared to less extended than right hemicolectomy (LRHC).Methods: Patients with A-NETs were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The Fine-Gray proportional hazards model was established to calculate subdistribution hazard ratios of prognostic factors. A propensity score matching was performed to balance intergroup differences between the LRHC and RHCM groups, and survival difference between the after-matched groups was tested using the Gray test. Subgroup analyses were also conducted.Results: In the multivariate analysis, histological type and distant metastatic status were associated with prognosis, while tumor size and nodal status were not. After propensity score matching, the patients’ characteristics were well balanced. RHCM did not confer survival benefits in the whole after-matched patients or any subgroup.Conclusions: Metastatic LN does not significantly impact prognosis, and RHCM fails to improve prognosis compared to LRHC. Therefore, the current “LN-decided” surgical procedure may not be suitable for patients with A-NETs.