Preoperative skeletal muscle index and visceral-to-subcutaneous fat area ratio are associated with long-term outcomes of elderly gastric cancer patients after gastrectomy

Purpose Sarcopenia is a risk factor of severe surgical complications, short-term outcomes, and long-term outcomes for patients with gastric cancer. Several computed tomography (CT) measurements have been performed to diagnose sarcopenia. However, the optimal CT measurements for determining long-term outcomes have not been revealed. Methods A retrospective review of gastric cancer patients with clinical stage I, II, or III who underwent gastrectomy at age 75 years or more at Shizuoka General Hospital from 2007 to 2015 was performed. Using preoperative CT, skeletal muscle index (SMI), total psoas area, intramuscular adipose tissue content in multifidus muscle, morphologic change of psoas muscle, and visceral-to-subcutaneous adipose tissue area ratio (VSR) were measured in the third lumbar section. A Cox regression analysis was used to explore prognostic factors for overall survival. Results A total of 257 patients were reviewed. There were 171, 53, and 33 patients with clinical stages I, II, and III, respectively. A multivariate analysis indicated that, in addition to age, performance status, clinical stage, and types of resection, which are known prognostic factors, SMI and VSR are prognostic factors (p = 0.016, 0.046, respectively). The prognostic score, which was the frequency of positive SMI and VSR values within the cutoff, also indicates overall survival. The five-year OS rates of patients with prognostic scores of 0, 1, and 2 were 90.9%, 62.3%, and 52%, respectively (p < 0.001). Conclusion Preoperative SMI and VSR were prognostic factors for the overall survival of elderly patients with gastric cancer after gastrectomy.