Stage-specific overall survival with complete five-year follow-up after D2 gastrectomy for gastric cancer at a referral hospital in Shanghai, China: a reference for comparing hospitals

Background. Comparing long-term outcomes of gastric cancer surgery between hospitals requires a common reference. Risk-adjusted benchmarks depend on the model and population used to build them and are difficult for another hospital to reproduce. TNM stage is a prognostic classification already recorded for every resected gastric cancer. We report unadjusted stage-specific overall survival from a consecutive cohort with complete follow-up as reference data and propose a minimal dataset for producing comparable figures elsewhere. Methods. The cohort comprised 690 consecutive eligible patients who underwent curative-intent D2 gastrectomy for stage I to III adenocarcinoma at Ruijin Hospital, Shanghai, in 2019. All operations were performed by eight experienced, high-volume consultant surgeons. Stage followed the AJCC 8th edition: pTNM after upfront surgery (n = 570) and ypTNM after neoadjuvant chemotherapy (n = 120). Overall survival was estimated by the Kaplan-Meier method without adjustment. Results. There were 199 deaths, 181 within five years. Every survivor was followed for at least 68.1 months. After upfront surgery, five-year overall survival was 95.0% (95% CI 91.4 to 97.1) for stage I, 83.8% (76.5 to 89.0) for stage II and 56.5% (49.2 to 63.1) for stage III, and was 95.0% in IA and 95.2% in IB, falling to 26.7% in IIIC. After neoadjuvant chemotherapy, five-year survival was 78.6%, 61.9% and 31.3% for ypStage I, II and III. Pooling pTNM and ypTNM lowered stage III five-year survival to 50.2%. The proposed minimal dataset has 16 items, 13 of them recorded during the admission for gastrectomy. Conclusions. These figures are intended as a reference for comparing hospitals rather than as a standard of care. We propose 16 items, most of them routinely recorded, from which another hospital can produce the same table and compare its results by stage.