Prognostic impact of sarcopenia and surgical timing in locally advanced esophageal squamous cell carcinoma receiving neoadjuvant chemoradiotherapy: TIMES study.

e16137 Background: Optimal timing for surgery after neoadjuvant chemoradiotherapy (NCRT) remains controversial, necessitating reliable preoperative indicators. This study examines how sarcopenia and surgical timing affect prognosis in locally advanced esophageal squamous cell carcinoma (LA-ESCC) patients. Methods: This retrospective study analyzed patients with LA-ESCC who underwent NCRT and surgery at three institutions in China from 2014 to 2023. The skeletal muscle area at the third lumbar vertebra was measured to calculate the skeletal muscle index (SMI). Prognostic analysis was performed using Cox proportional hazards models and propensity score matching (PSM), with survival curves generated using the Kaplan-Meier method, and statistical significance set at p < 0.05. Results: A total of415 patients were analyzed, with a median follow-up of39.1 months. The5-year overall survival (OS) and progression-free survival (PFS) rates were59.3% and53.1%, respectively. Malnutrition and time to surgery (TTS) were independent prognostic factors for both OS and PFS (P < 0.05). Patients with long TTS showed better OS (hazard ratio [HR] = 0.62, p = 0.01) and PFS (HR = 0.68, p = 0.02) compared to those with short TTS. Among sarcopenic patients, long TTS significantly improved OS (HR = 0.56; P = 0.01) and PFS (HR = 0.62; P = 0.02), while no survival benefit was observed for TTS in non-sarcopenic patients (P > 0.05). Conclusions: Sarcopenia does not independently impact OS or PFS. Patients with sarcopenia benefit from a longer surgical time interval after NCRT and preoperative evaluation of muscle quality may aid in optimizing surgical timing to improve outcomes.