A Novel Prognostic Scoring System Based on Preoperative Sarcopenia Predicts the Long-Term Outcome for Patients After R0 Resection for Gastric Cancer: Experiences of a High-Volume Center

The relationship between sarcopenia and prognosis of gastric cancer (GC) is unclear. This study aimed 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). In this study, 924 patients with GC who underwent radical gastrectomy were retrospectively analyzed. The data were divided into a training set and a validation set. Sarcopenia was diagnosed by the cutoff value of the skeletal muscle index (SMI) obtained by X-tile software. The study used COX regression to identify preoperative risk factors associated with 3-year OS and RFS. In the training set, 103 patients (14.8%) were sarcopenic based on the cutoff value of the SMI (32.5 cm(2)/m(2) for men and 28.6 cm(2)/m(2) for women). Multivariate analysis showed the following preoperative risk factors for the training set: sarcopenia and preoperative T (cT) and N (cN) stages. A prognostic scoring system was developed based on these findings. The 3-year OS rates were 89% for the low-risk patients, 77.9% for the intermediate-risk patients, and 54.8% for the high-risk patients (P < 0.001), and the 3-year RFS rates were respectively 86.9, 75.3 and 49.3% (P < 0.001). The area under the receiver operating characteristic curves were 0.708 for the 3-year OS rates and 0.713 for the 3-year RFS rates. The observed and predicted incidence rates for 3-year OS and RFS in the validation set did not differ significantly. 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.