A Novel Prognostic Scoring System Based On Preoperative Sarcopenia Predicts The Long-term Outcome Of Patients After R0 Resection For Gastric Cancer

Background or Purpose:The relationship between sarcopenia and prognosis of gastric cancer(GC)is unclear.We sought to develop a prognostic scoring system combining sarcopenia with preoperative clinical parameters for patients with GC to predict 3-year overall survival(OS)and 3-year recurrence-free survival(RFS).Methods:924 patients with GC underwent radical gastrectomy were retrospectively analyzed.The data were divided into training set and validation set.Sarcopenia was diagnosed by the cut-off value of skeletal muscle index(SMI)obtained by X-tile software.COX regression was used to identify preoperative risk factors associated with3-year OS and RFS.Results:In the training set,103(14.8%)patients were sarcopenic based on the cut-off value of the SMI(32.5 cm~2/m~2 for men and 28.6 cm~2/m~2 for women).The 3-year OS and RFS rates after surgery were significantly worse in patients with sarcopenia than in patients without sarcopenia(55.33%vs 74.91%,P<0.001 and 52.39%vs 72.37%,P<0.001,respectively).Multivariate analysis showed the following preoperative risk factors for the training set:sarcopenia,and the preoperative T(cT)and N stage(cN),and we developed a prognostic scoring system based on regression coefficients:no sarcopenia,0 points;sarcopenia:1 point;cT1-3:0 points;cT4:2 points;cN+:1 point.3-year OS rates for low-,intermediate-and high-risk patients were 89%,77.9%and54.8%,respectively(p<0.001);and 3-year RFS rates were 86.9%,75.3%and 49.3%,respectively(p<0.001).The area under the receiver operating characteristic curves were0.708(0.664-0.752)for 3-year OS rates and 0.713(0.670-0.755)for 3-year RFS rates.There were no significant differences between the observed and predicted incidence rates for 3-year OS and RFS in the validation set.Conclusions:Preoperative sarcopenia is an independent prognostic factor in patients with gastric cancer after radical resection.The prognostic scoring system combining sarcopenia with the cT and cN system can accurately predict 3-year OS and RFS rates after radical gastrectomy for GC.