Reevaluation of the requirement of adjuvant therapy for T2N0M0 gastric cancer following gastrectomy: a SEER database analysis

Abstract

Abstract Background Determining the requirement for adjuvant therapy in gastric cancer (GC) patients with stage T2N0M0 remains controversial. Methods An eligible population cohort was identified from the Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan-Meier method was used to assess the impact of adjuvant treatment modalities on overall survival (OS) and cause-specific survival (CSS). Multivariate Cox regression and competing risk model were used to investigate the prognostic factors for CSS. Propensity score matching (PSM) analysis was carried out to reduce the selection bias. Results A total of 776 patients were finally included. The 5-year OS for patients receiving surgery alone, adjuvant CRT, and adjuvant CT were 64.0%, 74.3%, and 69.0%, respectively (p = 0.004). The 5-year CSS for patients receiving surgery alone, adjuvant CRT, and CT were 73.0%, 84.3%, and 76.9%, respectively (p = 0.081). After PSM, no significant intergroup difference was observed on OS or CSS. When stratified by the number of lymph node (LN) examined, adjuvant CRT was shown to significantly increase the CSS than surgery alone in patients with LN examined ≤ 15 (p = 0.044), rather than in those with sufficient LN dissected (p = 0.590). Multivariate Cox analysis demonstrated that ethnicity, marital status, and number of LN examined > 15 were independent prognostic factors for CSS, of which number of LN examined > 15 was further validated by the competing risk model (SHR 0.701, p = 0.035). Conclusions Adjuvant therapy is not necessary for T2N0M0 GC patients undergoing standard radical gastrectomy, but adjuvant CRT should be reserved for those who have insufficient LN dissected patients.