A Complete Pathological Response to Pembrolizumab following ex vivo Liver Resection in a Patient with Colorectal Liver Metastases.

Advances in the systemic treatment of stage IV colorectal cancer with liver metastases has offered improved survival rates for patients who otherwise face a dismal prognosis. However, a pathologically complete response (PCR) to chemotherapy for colorectal liver metastases is still rare, and its significance is not fully understood. In this case report, we describe a patient who achieved PCR after neoadjuvant immunotherapy with pembrolizumab and a left hepatectomy using an ex vivo resection technique.