Prognostic impact of low skeletal muscle mass in stage I-III colon cancer: A retrospective study

Colon cancer (CC) is a common malignancy. Although the TNM staging system is widely employed for prognosis, its ability to predict individual patient outcomes is limited. In recent years, however, low skeletal muscle mass (SM) has emerged as a marked prognostic factor in patients with cancer. The present study aimed to investigate the prognostic value of low SM in patients with stage I-III CC. The present retrospective analysis included 230 patients with CC who underwent tumor resection at Lanzhou University Second Hospital (Lanzhou, China). The skeletal muscle index (SMI) was assessed using preoperative abdominal CT scans. Patients were stratified into low SM and non-sarcopenia groups based on their SMI. The primary outcome was overall survival (OS). The prognostic significance of low SM was evaluated using Kaplan-Meier survival curves, Cox regression modeling and time-dependent receiver operating Characteristic analysis. Furthermore, a combined TNM and low SM model was developed. Among the 230 patients, results showed that 24.34% exhibited low SM. Kaplan-Meier curves indicated that patients in the low SM group exhibited significantly lower OS rates compared with the normal SM group (P<0.001). Cox regression identified low SM as an independent adverse prognostic factor (hazard ratio: 1.70; 95% CI: 1.05-2.75). Incorporating low SM into the TNM model increased the Harrell's C-index from 0.570 to 0.604 (likelihood ratio P=0.027), with improved predictive performance at 1, 3 and 5-year time points. Overall, the present study concluded that low SM was an independent prognostic factor for OS in patients with stage I-III CC and a valuable supplement to existing prognostic tools, further contributing to personalized treatment strategies.