Successful immune checkpoint inhibitor-based rechallenge in a patient with advanced esophageal squamous cell cancer: A case report.

Immune checkpoint inhibitors (ICIs) have been shown to improve survival in patients with advanced or metastatic esophageal cancer. However, ICI-based rechallenges after recovery from fatal adverse events (AEs) are equivocal, especially in patients who have already undergone treatment-related AEs. In this study, we report the case of a patient with advanced esophageal squamous cell cancer (ESCC) who developed a treatment-related tracheoesophageal fistula (TEF) after two cycles of ICI administration, provided in combination with traditional chemotherapeutics. After spontaneous healing of the TEF, the patient was again treated with ICIs and achieved a durable clinical response without any signs of fistula recurrence. Successful ICI-based rechallenges after fistula healing have rarely been reported. Therefore, ICI-based rechallenge in patients with esophageal cancer having an Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1 after serious AEs may serve as a clinically viable treatment strategy that should be administered under close monitoring.