Impact of Preoperative Skeletal Muscle Quality Measurement on Long-Term Survival After Curative Gastrectomy for Locally Advanced Gastric Cancer

Background Skeletal muscle quality is a prognostic factor in various cancers. However, similar studies on curatively resected gastric cancer are lacking. We evaluated skeletal muscle quality using intramuscular adipose tissue content (IMAC) to clarify its impact on survival in patients with locally advanced gastric cancer. Methods We reviewed 370 patients who underwent curative resection for stage II/III gastric cancer. IMAC was calculated using preoperative computed tomography images. IMAC cutoff values were determined for each sex and were set at the 75th percentile. The patients were classified into normal and high IMAC groups according to the cutoff values. Clinicopathological factors and survival outcomes were compared between the two groups. Multivariate Cox regression analysis was used to identify independent prognostic factors for overall survival (OS) and cancer-specific survival (CSS). Results In all, 277 patients were classified into the normal IMAC group and 93 were classified into the high IMAC group. The patients in the high IMAC group were older, more obese, and had more comorbidities and poor Eastern Cooperative Oncology Group performance status than those in the normal IMAC group. Although no significant differences were observed in the pathological findings between the two groups, a high IMAC was significantly associated with poor OS and CSS. Multivariate analysis identified high IMAC as an independent prognostic factor for both OS and CSS ( p = 0.046 and p = 0.035, respectively). Conclusions High IMAC was significantly associated with poor survival, suggesting that skeletal muscle quality has oncological implications in patients with locally advanced gastric cancer.