Appropriate number of retrieved lymph nodes is sufficient for node-negative patients with gastric cancer.

[BACKGROUND] Adequate lymphadenectomy with at least 16 lymph nodes is recommended for radical gastrectomy, but whether further increasing number of retrieved lymph nodes (NRLNs) confers additional survival benefit in patients with node-negative gastric cancer (GC) is unclear. This study aims to elucidate the optimal NRLNs for these patients.

[METHODS] The clinicopathological data of 1264 GC patients, including 1107 pN0 and 810 cN0 cases, treated at Peking University Cancer Hospital between 2007 and 2022 were retrospectively analyzed. Restricted cubic spline (RCS) analysis was used to explore potential cut-off values for NRLNs. Overall survival (OS) and disease-free survival (DFS) were assessed using Kaplan-Meier method and cox proportional hazards models.

[RESULTS] Most patients underwent adequate lymphadenectomy with at least 16 lymph nodes. Different NRLNs cut-off values (<20, 20-29, 30-47, >47; <16, 16-30, >30) were evaluated. In patients with pN0 disease, the NRLNs was not associated with OS or DFS in either Kaplan-Meier or cox analyses. In patients with cN0 disease, NRLNs >30 was associated with worse OS in univariate analysis (>30 vs 16-30, HR = 0.636, p = 0.048), but was not an independent predictor in multivariate analysis (>30 vs 16-30, HR = 1.060, p = 0.812). Furthermore, subgroup analyses stratified by pN stage showed no significant differences in OS and DFS across different NRLNs categories among cN0 patients.

[CONCLUSIONS] Adequate lymphadenectomy with at least 16 retrieved lymph nodes appears sufficient for patients with node-negative GC, as further increases in NRLNs do not confer additional survival benefit.