Prognostic Significance Of Preoperative Skeletal Muscle Status In Patients With Gastric Cancer After Radical Gastrectomy

Objective:The association between skeletal muscle status and gastric cancer(GC)prognosis remains uncertain.This study aimed to assess the impact of skeletal muscle index(SMI)on overall survival(OS)of patients with GC after radical gastrectomy.Methods:A retrospective analysis of 178 patients with GC who underwent radical gastrectomy at Peking University Shenzhen Hospital from January 2013 to June 2018 was conducted.Abdominal CT images were used to quantifying SMI.Then the SMI was graded by the cutoff values of group-specific tertiles: low SMI,medium SMI and high SMI.Age,body mass index,SMI grade,American Society of Anesthesiologists score,Charlson comorbidity index,operative method(total vs distal gastrectomy),tumor stage,and histology type and differentiation were included in a Cox regression model to assess the primary outcome parameter of OS.A new prognostic score of3-year OS was established and combined with SMI grade and tumor stage.Receiver operating characteristic(ROC)curve analyses were used to observe the predictive reliability.Results:The 3-year OS rates in patients who underwent distal gastrectomy stratified by high,medium,and low SMI grades were 94.04,79.08 and 59.09%,respectively(P? 0.001);in patients who underwent total gastrectomy,the corresponding rates were86.09,70.11 and 49.11%,respectively(P? 0.001).Univariate analysis showed that in the whole cohort,low SMI,advanced tumor stage,high CCI,total gastrectomy(vs distal gastrectomy),and Roux-en-Y reconstruction(vs Billroth I and II reconstruction)were significantly related to poor OS rates(P? 0.05).Multivariate analysis showed that low SMI(HR 1.82,95% CI 1.14-2.90,P= 0.012),advanced stage(HR 2.89,95%CI 1.43-5.83,P= 0.003)and total gastrectomy(HR 1.69,95% CI 0.95-3.01,P= 0.076)were independent risk factors related to poor OS rates.The area under the ROCs of the prognostic score were 0.76(95%CI 0.65-0.86,P < 0.001)and 0.77(95%CI0.61-0.93,P < 0.001)in patients who underwent total and distal gastrectomy,respectively.Conclusion:The preoperative SMI was an independent prognostic factor for long-term survival in patients with GC after radical gastrectomy.The long-term survival of patients with GC after radical gastrectomy varies depending on differences in preoperative skeletal muscle status and operative method.