[A Case of Rectal Cancer in Which Total Pelvic Organ Excision Could Be Avoided by TNT Therapy and Robotic Surgery].

The patient is a 50s year old man. He visited his local doctor with complaints of anal pain and bloody stools, and a rectal examination revealed a tumor on the anterior wall of the rectal canal. CT imaging showed tumors invading the prostate, urethra, and anorectal muscles, and a 3 mm-sized nodule was found in the lungs. The patient was diagnosed as cT4bN1M1a, Stage Ⅳ, and total neoadjuvant chemotherapy was planned as preoperative treatment. The 5 Gy×5 times radiation therapy followed by 5 courses of CAPOX plus BEV as preoperative chemotherapy and CAPOX. CAPOX was administered. After completion of treatment, the colonoscopy showed PR, and MRI showed clear boundary between the prostate and tumor but invasion into the anorectal muscles; CT showed no lung metastasis, and preoperative diagnosis was ycT4bN0M0, ycStage Ⅱ. Robotic-assisted rectal amputation and left lateral lymph node dissection were performed under general anesthesia. Pathologically, the patient was diagnosed as ycT4bN0M0, Stage Ⅱ, and the efficacy was determined as TRG 1(AJCC). Vertical dissection was negative and radical resection was possible.