Impact of Preoperative Comprehensive Body Composition on Postoperative Outcomes in Patients with Esophageal Cancer

<b>Background/Objectives:</b> Myopenia, myosteatosis, and loss of body fat have been reported as adverse prognostic factors in various malignancies. However, the prognostic value of a composite evaluation of these body composition (BC) parameters remains unclear. The purpose of this study was to investigate the impact of preoperative BC status on postoperative outcomes in patients with esophageal cancer (EC). <b>Methods</b>: Seventy patients who underwent curative resection for thoracic EC were retrospectively analyzed. Psoas muscle area, psoas muscle density, and body fat area were measured on preoperative computed tomography. Using sex-adjusted cutoff values, each parameter was assigned a score of 1 if above the cutoff or 0 if below, yielding a composite BC score ranging from 0 to 3. Associations with 5-year overall survival (5y-OS) and postoperative complications were assessed. <b>Results:</b> Low muscle mass, reduced muscle density, and low body fat were each associated with poorer survival, with hazard ratios (HRs) of 2.900, 2.909, and 2.990, respectively (<i>p</i> = 0.005, 0.028, and 0.002). Patients with unfavorable BC (score ≤1) showed significantly worse 5y-OS (25% vs. 72%, <i>p</i> < 0.001) and a higher incidence of postoperative severe complications (42% vs. 18%, <i>p</i> = 0.028). On multivariate analysis, BC status was identified as an independent prognostic factor (HR = 3.940, <i>p</i> = 0.002), comparable to pathological stage (HR = 6.028, <i>p</i> = 0.005). <b>Conclusions:</b> A composite BC status incorporating skeletal muscle mass, muscle density, and body fat serves as a valuable predictor of short- and long-term outcomes in postoperative EC patients, providing an integrated measure of patient vulnerability.