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

Inclusion Criteria: 1. Agree to participate and sign the informed consent form in writing; 2. Age: 18-75 years old; 3. No gender limit; 4. Esophageal squamous cell carcinoma diagnosed by pathology; 5. The results of 3-gene RNA sequencing (ALTRK) in tumor tissue were negative; 6. Imagingly confirmed unresectable advanced esophageal squamous cell carcinoma; 7. Failure of previous platinum-containing regimens and immunotherapy regimens (PD-1/PD-L1 monoclonal antibody); 8. 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; 9. Estimated survival≥ 3 months; 10. General Physical Condition (ECOG) 0-1; 11. 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: 1. Those who are currently receiving other effective programs; 2. Patients who have participated in other clinical trials within 4 weeks before enrollment; 3. There is no measurable tumor foci, such as fluid accumulation in the body cavity or diffuse infiltration of organs; 4. Those who have received radiotherapy for measurable lesions; 5. Previous anti-EGFR monoclonal antibody or EGFR-TKI treatment; 6. 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; 7. 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; 8. Neurological or psychiatric abnormalities affecting cognitive ability, including central nervous system metastases; 9. Active severe clinical infection (grade \>2 NCI-CTCAE version 5.0) within 14 days prior to enrollment, including active TB; 10. Known or reported HIV infection or active hepatitis B or C; 11. Uncontrolled systemic diseases, such as poorly controlled diabetes; 12. History of interstitial lung disease, such as interstitial pneumonia, pulmonary fibrosis, or evidence of interstitial lung disease on baseline chest x-ray/CT; 13. Keratitis, ulcerative keratitis or severe dry eye; 14. Known hypersensitivity or anaphylaxis to any component of the investigational drug; 15. Pregnancy (determined by serum β-chorionic gonadotropin test) or breastfeeding; 16. 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;