Skeletal muscle depletion and sarcopenia are the most typical features of cachexia, which occurs in 80% of patients with advanced esophageal cancer. Skeletal muscle consumption is an independent factor for poor prognosis, which negatively affects therapeutic toxicity, length of hospital stay, quality of life, complications, infection, and survival. The vast majority of patients had already experienced severe weight loss and skeletal muscle loss before the treatment began. During the concurrent chemoradiotherapy period, the intensity and long cycle of treatment, the toxic and side effects of treatment and the occurrence of radiation esophagitis would further lead to the increased demand for energy and decreased intake of patients, thus leading to continuous weight loss. Based on the previous literature, we suggest that baseline body composition has a significant impact on nutritional status, the incidence of adverse reactions, and survival during treatment. This research mainly for the thorough chemoradiation in patients with esophageal cancer, analysis treatment precursor composition, including skeletal muscle index, visceral fat area, body fat percentage and other parameters on the side reaction of chemoradiation, nutritional status and the influence of survival, and observe the baseline body composition and cure after 1 month of body composition changes of the impact on the survival time.

Inclusion Criteria:

• Voluntary participation and face to face signed informed consent;
• 18 -- 75 years old, gender unlimited;
• The histological diagnosis was esophageal squamous cell carcinoma, and the clinical staging was stage II-IVA (according to AJCC stage 8, pre-treatment clinical staging was: CT1N2-3M0, CT2-4BN0-3M0).
• Initial treatment patients receiving radical concurrent chemoradiotherapy; Immunotherapy with or without combination;
• The primary tumor can be evaluated;
• No distant metastasis;
• No serious abnormal function of blood system, heart, lung, liver and kidney or immune deficiency;
• Hemoglobin (Hb) ≥9 g/dL; White blood cell (WBC) ≥3×109/L; Neutrophils (ANC)≥1.5×109/L; Platelet (PT)≥100×109/L;
• Bilirubin < 1.5 times the upper limit of normal; Alanine aminotransferase (ALT) and alanine aminotransferase (AST) ≤2.5 times the upper limit of normal;
• Serum creatinine ≤1.5 times the upper limit of normal value;
• The willingness of men or women of reproductive age to use contraception in the trial;
• Physical condition score ECOG 0 ~ 2;
• The expected survival time was >3 months.

Exclusion Criteria:

• Patients who lacked an evaluation of CT body composition within 15 days prior to treatment initiation;
• Patients with severe intestinal function damage or inability to tolerate intestinal nutrition;
• The digestive tract is severely obstructed, unable to take food orally and unable/unwilling to undergo nasogastric tube or percutaneous gastrostomy;
• Previous surgery, chemoradiotherapy or bio-targeted therapy for esophageal cancer;
• Previous history of malignant tumor.

Patients with esophageal cancer receiving radical concurrent chemoradiotherapy with or without PD1 antibodies