Impact of Skeletal Muscle Mass Reduction on Long-term Survival After Radical Resection of Gastric Cancer

This study aimed to investigate the effect of preoperative skeletal muscle mass and muscle mass loss after surgery on overall survival in patients with gastric cancer who underwent radical resection. We also examined factors involved in postoperative skeletal muscle loss.

One hundred fifty gastric cancer patients who underwent radical resection were retrospectively examined. Skeletal muscle index (SMI) was measured using computed tomography before surgery and 1 year after. Degree of muscle reduction (MR) was calculated. Patients were stratified according to preoperative SMI (high/low) and MR (high/low) for analysis. In addition, patients were grouped according to SMI and MR stratification as follows: group A, low SMI/high MR; group B, low SMI/low MR; group C, high SMI/high MR; and group D, high SMI/low MR.

In multivariate analysis, preoperative SMI and MR were independent predictors of overall survival. Overall survival significantly differed among groups A, B, C, and D (p<0.0001). The list of groups in order of worsening overall survival was as follows: group D, group C, group B, and group A. In multivariate analysis, patient group according to SMI and MR stratification was an independent predictor of overall survival. MR was affected by operation time (>430 min) and surgical procedure (total gastrectomy).

Preoperative SMI and reduction in skeletal muscle mass after gastric cancer surgery were significantly associated with overall survival. Long-term management of these patients should focus on maintenance of postoperative skeletal muscle mass.