Skeletal muscle mass and quality before preoperative chemotherapy influence postoperative long-term outcomes in esophageal squamous cell carcinoma patients

BACKGROUND: Previous reports have focused on muscle mass as a prognostic factor in esophageal cancer. AIM: To investigate how preoperative body type influences the prognosis of patients with esophageal squamous cell carcinoma who underwent neoadjuvant chemotherapy (NAC) and surgery. METHODS: The subjects were 131 patients with clinical stage II/III esophageal squamous cell carcinoma who underwent subtotal esophagectomy after NAC. Skeletal muscle mass and quality were calculated based on computed tomography images prior to NAC, and their statistical association with long-term outcomes was examined retrospectively in this case-control study. RESULTS: The disease-free survival rates in the low psoas muscle mass index (PMI) group vs the high PMI group were 41.3% vs 58.8% (P = 0.036), respectively. In the high intramuscular adipose tissue content (IMAC) group vs the low IMAC group, the disease-free survival rates were 28.5% vs 57.6% (P = 0.021), respectively. The overall survival (OS) rates for the low PMI group vs the high PMI group were 41.3% vs 64.5% (P = 0.008), respectively, and for the high IMAC group vs the low IMAC group, they were 29.9% vs 61.9% (P = 0.024), respectively. Analysis of the OS rate revealed significant differences in patients aged 60 years or older (P = 0.018), those with pT3 or above disease (P = 0.021), or those with lymph node metastasis (P = 0.006), aside from PMI and IMAC. Multivariate analysis demonstrated that pT3 or above [hazard ratio (HR): 1.966, 95% confidence interval (CI): 1.089-3.550, P = 0.025), lymph node metastasis (HR: 2.154, 95%CI: 1.118-4.148, P = 0.022), low PMI (HR: 2.266, 95%CI: 1.282-4.006, P = 0.005), and high IMAC (HR: 2.089, 95%CI: 1.036-4.214, P = 0.022) were significant prognostic factors for esophageal squamous cell carcinoma. CONCLUSION: Skeletal muscle mass and quality before NAC in patients with esophageal squamous cell carcinoma are significant prognostic factors for postoperative OS.