The Combination of Preoperative Skeletal Muscle Quantity and Quality is an Important Indicator of Survival in Elderly Patients Undergoing Curative Gastrectomy for Gastric Cancer

Background The diagnosis of sarcopenia emphasizes both, the quantity and quality of skeletal muscle. However, the impact of the combination of muscle quantity and quality on long-term survival remains unclear. This study aimed to assess the impact of the combination of skeletal muscle quantity and quality on long-term outcomes in patients with gastric cancer who underwent curative resection. Methods We retrospectively assessed 242 patients aged ≥ 65 ears who underwent curative gastrectomy between 2006 and 2015. The psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC) were measured on preoperative computed tomography as skeletal muscle quantity and quality, respectively. The sarcopenia stage was classified by the combination of preoperative skeletal muscle quantity and quality (non-sarcopenia, sarcopenia, and severe sarcopenia). Prognostic factors for the 5-year overall survival (OS), non-cancer-specific survival (non-CSS), and cancer-specific survival (CSS) were evaluated by multivariable Cox regression. Results The median follow-up period was 63.2 months. The non-sarcopenia, sarcopenia, and severe sarcopenia groups comprised 88, 121, and 33 patients (36.4%, 50.0%, and 13.6%), respectively. The severe sarcopenia group was older, and had a greater depth of invasion, than the non-sarcopenia group. Multivariable analysis revealed severe sarcopenia as an independent predictive indicator of OS (hazard ratio [HR] 4.01; 95% confidence interval [CI] 1.75 to 9.22) and non-CSS (HR 3.27; 95% CI 1.61 to 6.67), but not CSS. Conclusions The combination of preoperative skeletal muscle quantity and quality was useful for predicting survival, especially death from other diseases, in elderly patients who underwent gastrectomy for gastric cancer.