摘要Objective:Pathologic complete response(pCR)following neoadjuvant therapy(NAT)for gastric cancer(GC)is rare but associated with a favorable prognosis.This study aims to reassess the optimal response population(ORP)following NAT by evaluating the prognostic outcomes associated with various T and N stages,utilizing multicenter data from China.Methods:Patients who underwent NAT following radical gastrectomy at 10 tertiary hospitals in China between 2008 and 2021 were included.The ORP was introduced to explore the disease-free survival(DFS),overall survival(OS),recurrence patterns,and influencing factors following propensity score matching(PSM).Results:A total of 1,076 patients were enrolled in this study(median follow-up period:60 months).We defined ORP as a pCR or tumor infiltration of the mucosal or submucosal layer without lymph node metastasis(pCR or ypT1N0)after NAT.The ORP group comprised 136 patients(12.6％),while the non-ORP group comprised 940 patients(87.4％).After applying a 1∶4 PSM,we obtained an ORP group of 136 patients and non-ORP group of 544 patients.Survival analysis demonstrated that both the 3-year OS(before PSM:89.0％ vs.55.0％,P＜0.001;after PSM:89.0％ vs.55.4％,P＜0.001)and DFS(before PSM:85.8％ vs.49.7％,P＜0.001;after PSM:85.8％ vs.50.6％,P＜0.001)were significantly superior in the ORP group compared to that in the non-ORP group.Remarkably,adjuvant chemotherapy did not impact the prognosis of patients in the ORP group(3-year OS:89.0％ vs.89.7％,P=0.988;3-year DFS:84.9％ vs.89.7％,P=0.700).Conclusions:This study reevaluates patients with ORP following NAT,providing a more comprehensive and accurate depiction of the potential beneficiary group and survival outcomes in patients with locally advanced GC.