Long-term complete response to Pembrolizumab in a young patient with MSI-H metastatic colorectal cancer: Would you stop?

Case presentation of a young patient with metastatic MSI-H colorectal cancer who achieved a sustained complete response to immune checkpoint inhibitors after multiple chemotherapy failures. The case raises the clinical question of when to discontinue immunotherapy in long-term responders, given the absence of toxicity and the patient’s preference to continue beyond two years. The discussion focuses on the evidence, uncertainties, and shared decision-making process involved.