This clinical trial is focused on studying the effects of a medication called nivolumab on patients with esophageal cancer. Esophageal cancer is a disease where cancer cells form in the tissues of the esophagus, the tube that carries food from the mouth to the stomach. The study is specifically looking at patients who have already received a treatment called neoadjuvant chemoradiation, which is a combination of chemotherapy and radiation therapy given before surgery to shrink the tumor.

The purpose of this study is to evaluate how effective nivolumab is when used during a period of active surveillance. Active surveillance is a way of monitoring a patient’s condition without giving any treatment unless there are changes in test results that show the disease is getting worse. In this study, patients who have shown a complete response to the initial treatment will receive nivolumab to see if it helps keep the cancer from coming back.

Participants in the study will receive nivolumab through an intravenous infusion, which means the medication is given directly into a vein. The study will monitor patients over a period of time to see how long they remain free of cancer and to observe any side effects that may occur. The goal is to understand if nivolumab can help improve outcomes for patients with esophageal cancer who are in active surveillance after their initial treatment.