Excessive muscle loss during neoadjuvant therapy significantly predicts survival outcomes in locally advanced esophageal squamous cell carcinoma.

• Among 421 patients, 5-year overall survival was 60%, with 26.6% experiencing muscle loss during the initial treatment.
• Muscle loss at two points during therapy was linked to a higher risk of mortality (stage A HR 1.78; stage B HR 1.83).

Maintaining muscle mass post-therapy correlates with better survival rates, indicating the need for nutritional strategies during treatment.

• Patients without initial muscle loss who retained muscle in stage B had a 51% lower risk of death (HR 0.49).