Muscle Quality Predicts Outcomes after Surgery for Early-Stage Non–Small-Cell Lung Cancer

Purpose: This study investigated the impact of skeletal muscle quality on the outcomes of patients undergoing surgery for early-stage non–small-cell lung cancer (NSCLC). Methods: A total of 98 patients with pathological stage I–II NSCLC who underwent lobectomy or segmentectomy were retrospectively analyzed. Along with skeletal muscle quantity, muscle quality was evaluated by intramuscular adipose tissue content (IMAC) at the first lumbar vertebral level; a higher IMAC indicates lower skeletal muscle quality. Patients were divided into two groups according to the gender-specific quartiles of IMAC, and the prognostic impact of IMAC was investigated. Results: No significant differences in the body and skeletal mass indices, which indicate skeletal muscle quantity, were observed between patients with high and those with normal IMAC. Patients with high IMAC (n = 23) showed a significantly poorer prognosis in overall and disease-specific survivals than those with normal IMAC (n = 75; P <0.001 and P = 0.048, respectively). In a bivariate analysis that included other clinicopathological factors, a high IMAC was independently associated with worse overall survival. Conclusion: The skeletal muscle quality evaluated by IMAC could be used to predict survival risk after surgery for early-stage NSCLC.