[A case of sigmoid colon cancer invading urinary bladder treated with preoperative mFOLFOX6 and urinary bladder conserving surgery].

A 69-year-old man visited our hospital because of melena and anemia. Colonoscopy revealed a type 3 tumor at sigmoid colon, and by abdominal CT, we detected a sigmoid colon cancer invading the urinary bladder with a single liver metastasis. The patient required sigmoidectomy with partial hepatectomy and total urinary bladder resection. Preoperative chemotherapy with mFOLFOX6 was initiated as a part of multidisciplinary therapy. After the 6th course was completed, CT revealed a reduction in the primary tumor's size and the disappearance of liver metastasis. After the 8th course was completed, we performed urinary bladder conserving sigmoidectomy. The pathological diagnosis of the surgical specimen was tub1, pSS, ly0, v0, pN0, and pStage II. Down-sizing chemotherapy might improve the quality of life(QOL)of colon cancer patients with extensive invasion of the urinary bladder.