To Evaluate the Efficacy and Safety of Afatinib for Advanced ALTRK-negative ESCC

Inclusion Criteria: Agree to participate and sign the informed consent form in writing; Age: 18-75 years old; No gender limit; Esophageal squamous cell carcinoma diagnosed by pathology; The results of 3-gene RNA sequencing (ALTRK) in tumor tissue were negative; Imagingly confirmed unresectable advanced esophageal squamous cell carcinoma; Failure of previous platinum-containing regimens and immunotherapy regimens (PD-1/PD-L1 monoclonal antibody); At least one measurable lesion (according to RECIST1.1 criteria) or non-measurable lesion that can be evaluated, with imaging diagnosis ≤ 21 days from enrollment; Estimated survival≥ 3 months; General Physical Condition (ECOG) 0-1; Sufficient bone marrow hematopoietic function (within 7 days): hemoglobin ≥ 9 g/dL, white blood cell ≥ 3.0×10^9/L, neutrophil ≥1.5×10^9/L, platelet ≥ 100×10^9/L; Normal liver and kidney function (within 14 days): TBIL ≤ 1.5 times the upper limit of normal; ALT and AST ≤ 2.5 times the upper limit of normal, and if liver metastases are present, ≤ 5 times the upper limit of normal; Creatinine ≤ 1.5 times the upper limit of normal; Exclusion Criteria: Those who are currently receiving other effective programs; Patients who have participated in other clinical trials within 4 weeks before enrollment; There is no measurable tumor foci, such as fluid accumulation in the body cavity or diffuse infiltration of organs; Those who have received radiotherapy for measurable lesions; Previous anti-EGFR monoclonal antibody or EGFR-TKI treatment; Patients with other primary malignant tumors other than esophageal cancer at the same time, except for cured skin basal cell carcinoma and cervical carcinoma in situ; Clinically significant cardiovascular diseases, such as heart failure (NYHA GRADE III-IV), uncontrolled coronary heart disease, cardiomyopathy, arrhythmia, uncontrolled hypertension or history of myocardial infarction within the past 1 year; Neurological or psychiatric abnormalities affecting cognitive ability, including central nervous system metastases; Active severe clinical infection (grade >2 NCI-CTCAE version 5.0) within 14 days prior to enrollment, including active TB; Known or reported HIV infection or active hepatitis B or C; Uncontrolled systemic diseases, such as poorly controlled diabetes; History of interstitial lung disease, such as interstitial pneumonia, pulmonary fibrosis, or evidence of interstitial lung disease on baseline chest x-ray/CT; Keratitis, ulcerative keratitis or severe dry eye; Known hypersensitivity or anaphylaxis to any component of the investigational drug; Pregnancy (determined by serum β-chorionic gonadotropin test) or breastfeeding; The investigator determines that there are abnormal heart or lung or kidney or liver function that is not suitable for the treatment of this study;