Tumor size>5cm is a line of demarcation of mortality and progression of gastric cancer after D2+gastrectomy for Chinese population

Methods： Gastric cancer between May 2002 and December 2020 and who had undergone resection of the primary cancer. We analyzed these patients to study the association between survival and tumor size by Cox proportional hazards model and restricted cubic splines. Results: A total of 1708 patients met the inclusion criteria, with a median age of 58 years. The distribution of tumor size was correlated with patients underwent different D2+ gastrectomy(P<0.001) and located different tumor site(P=0.002). The size of the patient's tumor is closely related to the patient's prognosis, as well as the overall survival of patients experienced proximal gastrectomy(P for trend= 0.002) and progression free survival of distal(P for trend= 0.03) and total gastrectomy(P for trend= 0.016) in fully adjusted model. Likewise, tumor size displayed its prognostic predictability in subgroup of upper 1/3, but only for overall survival in final model(P for trend= 0.045). Nonlinear relationship of different tumor size and D2+ gastrectomy or tumor site showed in restricted cubic splines, >5cm showed a significant impact in each group, but not for proximal gastrectomy(P for nonlinear=0.305). Overall survival and progression decreased progressively along with upgrading of tumor size accordingly. Conclusions Tumor size>5cm can be seen as a line of demarcation of mortality and progression of gastric cancer after D2+gastrectomy, the hazard ratio began to rise when tumor size large than 5cm.