Skeletal Muscle Mass Depletion After Gastrectomy Negatively Affects the Prognosis of Patients With Gastric Cancer.

Abstract

Skeletal muscle mass (SMM) is often depleted in patients with gastric cancer undergoing gastrectomy. Using a novel method, we evaluated the effect of SMM depletion after gastrectomy on disease prognosis. The maximum cross-sectional area of the psoas-muscle (MCA-PM) was measured before surgery and at 1 year after in 233 patients with gastric cancer who underwent radical gastrectomy to determine the ratio (MCA-PMR) as an indicator of SMM depletion. The MCA-PMR cutoff value was set at 90%, and patients were divided into the groups with <90% and ≥90%. MCA-PMR <90% was an independent prognostic factor for all patients. In 88 patients who received adjuvant chemotherapy including S-1, the 5-year cancer-specific survival rate was significantly better for those with MCA-PMR ≥90% than for those with MCA-PMR <90% (84.1% vs. 59.1%; p=0.010; hazard ratio=2.974; 95% confidence interval=1.241-7.124). SMM depletion after gastrectomy can be measured using the MCA-PMR. This novel measurement can be easily implemented in the clinical setting.