[A Case of Locally Advanced Colorectal Cancer with Severe Bladder Invasion Successfully Treated with Preoperative Chemotherapy with Anti-EGFR Antibody and Avoiding Total Bladder Resection].

In recent years, the efficacy of preoperative treatment for locally advanced colorectal cancer has been reported to improve surgical cure rates and decrease postoperative recurrence rates. In this study, we report a case of locally advanced colorectal cancer with severe bladder invasion that responded to preoperative chemotherapy with an anti-EGFR antibody, resulting in the avoidance of total bladder resection. After diverting colostomy to change the bowel route, the patient underwent 5 courses of mFOLFOX6 therapy and 3 courses of mFOLFOX6 + cetuximab therapy to preserve bladder integrity. After confirming tumor shrinkage through imaging, laparoscopic high-level anterior resection and partial bladder resection were performed, allowing for R0 resection and bladder preservation. Approximately 4 years have passed since the resection of the primary tumor, and there has been no recurrence of the primary disease. Therefore, the indications and efficacy of preoperative treatment with molecularly targeted drugs, including anti-EGFR antibody drugs, for locally advanced colorectal cancer should be investigated in a prospective clinical trial.