Quantity and Quality of Skeletal Muscle as an Important Predictor of Clinical Outcomes in Patients with Esophageal Cancer Undergoing Esophagectomy after Neoadjuvant Chemotherapy

Background Sarcopenia was previously linked to clinical outcomes for several cancer types, including esophageal cancer (EC), but most studies only measured the quantity of skeletal muscle mass. We aim to assess the clinical significance of evaluating the quantity and quality of skeletal muscle in patients with EC who underwent neoadjuvant chemotherapy (NAC) followed by esophagectomy. Methods We included 333 consecutive patients with EC who underwent NAC followed by esophagectomy. The psoas muscle index (PMI) and intracellular muscle adipose tissue content (IMAC) were measured by computed tomography. We defined low PMI combined with high IMAC as severe sarcopenia, and assessed its impact on clinical outcomes. Results Thirty-seven patients (11.1%) had severe sarcopenia. Compared with patients without severe sarcopenia, those with severe sarcopenia showed a significantly worse NAC response rate (54.1% vs 74.7%; P = 0.008), worse pathological response rate (24.3% vs 40.2%, P = 0.061), higher morbidity rate (67.6% vs 38.5%; P = 0.001), particularly for pneumonia (32.4% vs 14.9% P = 0.007) and expectoration disorder (37.8% vs 13.5% P < 0.001), and unfavorable survival (3-year overall survival rate: 54.1% vs 66.6% P = 0.027). Multivariable analysis of overall survival showed that severe sarcopenia (HR 1.68, P = 0.025) and cT (HR 1.52, P = 0.032) were independent prognostic factors of poor outcome. Conclusions PMI combined with IMAC represents a new criterion for sarcopenia that might be useful for predicting NAC response, postoperative complications, and long-term survival in patients with EC undergoing multidisciplinary treatments.