TAS-102 Plus Radiotherapy in Elderly ESCC

Inclusion Criteria: * Patients must have newly confirmed histologically or cytologically diagnosed esophageal squamous cell carcinoma. * Age between 65 and 85 years. * Esophageal cancer staged as IIB to IVB according to the 8th edition AJCC staging system (including IVB with supraclavicular or celiac lymph node metastasis, but excluding IVB with other distant metastases). * ECOG performance status of 0 or 1. * No history of esophageal perforation, active esophageal bleeding, or significant invasion of the trachea or major thoracic blood vessels. * No prior anticancer therapy such as radiotherapy or chemotherapy. Adequate bone marrow function: hemoglobin ≥9 g/dL, white blood cells ≥3.0×10⁹/L, neutrophils ≥1.5×10⁹/L, platelets ≥100×10⁹/L. * Adequate liver and kidney function: serum creatinine (Scr) ≤1.5×ULN, total bilirubin ≤1.5×ULN, ALT and AST ≤2.5×ULN. * No history of interstitial lung disease. * Forced expiratory volume (FEV1) ≥0.8 liters. * Signed informed consent form before study initiation. Exclusion Criteria: * Patients with hematogenous metastasis or distant lymph node metastasis (except supraclavicular or celiac lymph node metastasis), multiple esophageal cancer lesions, or malignant pleural/pericardial effusion. * History of radiotherapy, chemotherapy, or surgery targeting the primary tumor or lymph nodes. * Tracheoesophageal fistula, invasion of the trachea or main bronchi by the primary tumor, deep esophageal ulcer, or hematemesis. * Severe comorbidities such as active infection, cardiovascular disease, or pulmonary disease. * History of other malignancies except adequately treated non-melanoma skin cancer. * Participation in another clinical trial within the past 30 days. * Any other condition deemed by the investigator to preclude participation in the study.