摘要Background:This study aimed to evaluate the prognostic value of the lymphocyte-to-monocyte ratio(LMR)and cancer antigen 724(CA724)in patients with proximal gastric cancer residing in cold climate regions.Methods:A retrospective analysis was conducted on 313 patients diagnosed with proximal gastric cancer in cold climate regions between 2014 and 2017.Preoperative hematological markers,including LMR and CA724,were assessed.Receiver operating characteristic(ROC)curves were used to determine optimal cutoff values,which were then combined to form the LMR+CA724 score.Statistical analyses included Kaplan-Meier survival curves,log-rank tests,and Cox proportional hazards regression.Results:A high preoperative LMR+CA724 score was significantly associated with older age,advanced pTNM stage,vascular invasion,and elevated levels of NMPVR,NMR,and AAR.The LMR+CA724 score demonstrated a higher area under the curve(AUC)compared to LMR or CA724 alone.Multivariate analysis identified pTNM stage,Borrmann type,histological type,and the LMR+CA724 score as independent prognostic factors for overall survival(OS).A nomogram incorporating these four variables achieved an AUC of 0.817,indicating strong predictive performance.Conclusion:The LMR+CA724 score is a reliable and independent prognostic indicator for patients with proximal gastric cancer in cold climate regions.Its integration into clinical practice may support treatment planning and long-term management by enhancing personalized care.Further prospective studies are warranted to validate these findings in broader and more diverse patient populations.