Predicting Postoperative Chemotherapy Efficacy in Patients With Esophageal Squamous Cell Carcinoma by Biopsy Specimens.

Esophageal cancer remains a disease with a poor prognosis. In the treatment of esophageal squamous cell carcinoma (ESCC), multidisciplinary treatment including surgery, chemotherapy, and radiation therapy is important. Chemotherapy is an effective treatment for esophageal cancer, but some patients do not respond to it. Non-response to chemotherapy can result in disease progression, loss of patient fitness, and even the opportunity to receive other treatments that might have originally had a therapeutic effect. If there are biomarkers that could indicate the efficacy of chemotherapy before treatment, ineffective patients would be able to change their treatment plan. Patients on preoperative chemotherapy would be able to avoid unnecessary chemotherapy and undergo surgery without the effects of physical weakness and side effects. On the other hand, patients on definitive chemotherapy may choose to intensify their treatment with additional radiation therapy or immunotherapy. The investigators aim to develop a model to predict the response to chemotherapy by DNA methylation of preoperative biopsy specimens to identify the chemotherapy ineffective