[A Case of Complete Pathological Response in a Patient with Locally Advanced Sigmoid Colon Cancer after FOLFOX IRI Chemotherapy].

A 61-year-old man with advanced sigmoid colon cancer was admitted to our hospital. Abdominal computed tomography (CT) revealed locally advanced sigmoid colon cancer, with suspected invasion of the bladder and small intestine. The clinical stage of the disease was T4b, N1, M0, and Stage III a, with wild-type KRAS expression. A transverse colostomy was performed because of the presence of a bowel obstruction. The patient received 4 courses of Leucovorin, 5-fluorouracil, oxaliplatin, and irinotecan (FOLFOXIRI). The size of the tumor and lymph nodes decreased noticeably after chemotherapy and laparoscopic high anterior resection with lymph node dissection. During this phase, the pathological stage of the disease was ypT0, N0, and Stage 0(no viable carcinoma cells, Grade 3). This result suggested that preoperative FOLFOXIRI chemotherapy is a useful regimen for the treatment of locally advanced colon cancer.