136. IMPACT OF SKELETAL MUSCLE LOSS AND SARCOPENIA ON OUTCOMES OF LOCALLY ADVANCED ESOPHAGEAL CANCER

Abstract

Abstract Background The impact of change in skeletal muscle and the sarcopenia on outcomes during neoadjuvant chemoradiotherapy (NACR) for patients with esophageal cancer remains controversial. Methods We retrospectively analyzed the data of patients with locally advanced esophageal squamous cell cancer who received NACR followed by esophagectomy between June 2013 and December 2021. The images at third lumbar were analyzed to measure the cross-sectional area and calculate skeletal muscle index (SMI) before and after neoadjuvant chemoradiation. The SMI less than 52.4 cm2/m2 for men and less than 38.5 cm2/m2 for women were defined as sarcopenia. The nonlinearity of the effect of percent change in SMI (ΔSMI%) to survival outcomes was assessed by restricted cubic splines. Results Overall, data of 367 patients were analyzed. The survival outcomes between sarcopenia and non-sarcopenia groups had no significant differences before NACR. However, patients in post-NACR sarcopenia group showed poor overall survival (OS) benefit (P = 0.016) and poor disease-free survival (DFS) (P = 0.043). Severe postoperative complications rates were 11.9% in post-NACR sarcopenia group and 5.0% in post-NACR non-sarcopenia group (P = 0.019). The association of ΔSMI% with survival outcomes was nonlinear significantly. On the multivariate analysis of OS, ΔSMI % > 12% was the independent prognostic factor (HR = 1.76, 95%CI: 1.03–2.99, P = 0.039) and significant difference was also found on DFS analysis (P = 0.025). Conclusion Patients with post-neoadjuvant chemoradiotherapy sarcopenia have worse survival and adverse short-term outcomes. Moreover, additional skeletal muscle index loss increases risk of death and disease progression during neoadjuvant chemoradiotherapy, and max significant difference was reached when it loss over 12%.