[A Case of Locally Advanced Sigmoid Colon Cancer Invading the Urinary Bladder Treated with Neoadjuvant Chemotherapy and Robot Assisted Urinary Bladder-Conserving Surgery].

We report a case of 72s male with locally advanced sigmoid colon cancer. Colonoscopy revealed an advanced sigmoid colon cancer(AV 15 cm, type 2, semi-peripheral, deeper than T3). He was diagnosed as cT4bN2M0, cStage Ⅲc(Japanese Classification of Colorectal, appendiceal, and, Carcinoma, 9th edition), and was given chemotherapy as preoperative treatment. He was treated with CAPOX plus BEV as neoadjuvant chemotherapy. Preoperative diagnosis was ycT4bN0M0, ycStage Ⅱc. The robot assisted high anterior resection and partial bladder resection were performed. The bladder was sutured under robotic assistance. The residual bladder capacity was 100 mL. Postoperative diagnosis was ypT0N0M0, ypStage 0, TRG 0 (AJCC). We experienced a case of neoadjuvant chemotherapy for rectosigmoid colon cancer with bladder invasion, which resulted in pCR.