Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignant tumors. Although neoadjuvant chemoradiotherapy combined with surgery has significantly improved the survival rate of patients with locally advanced esophageal cancer, approximately half of the patients will experience local regional recurrence or distant metastasis. Lymphocytes are crucial immune cells in the human body, playing a key role in combating infections and tumor development. In recent years, an increasing body of research has indicated that lymphocyte depletion is a significant factor associated with poor prognosis in various solid tumors, including esophageal cancer. The lymphocyte depletion caused by radiotherapy has garnered considerable attention from oncologists. However, there is still a lack of prospective clinical research data on lymphocyte protection in thoracic tumors. Therefore, this study aims to provide high-level evidence from evidence-based medicine regarding the correlation between lymphocyte depletion and prognosis in esophageal cancer patients, offering more effective strategies and methods to improve the outcomes of neoadjuvant chemoradiotherapy for esophageal cancer.