[A case of advanced colon cancer treated with preoperative chemotherapy (IRIS) leading to clinical complete response]

The patient was a 68-year-old male who had advanced rectal cancer with aortic bifurcation lymph node metastasis, who was given neo-adjuvant chemotherapy by IRIS, a combination of S-1 80 mg/m(2)/day (2-week administration and 1-week rest) and CPT-11 100 mg/day (day 1, 15). After 2 courses of this neo-adjuvant chemotherapy, a complete response (CR) was noted by CT scan and endoscopy. We were able to conduct a super low anterior resection of the colon and rectum. Postoperative histopathological examination of the resected rectum and lymph nodes showed only the spot of residual cancer tissue and the degeneration of cancer cells and fibrosis, revealing that the operation had been conducted radically. The changes from neo-adjuvant chemotherapy were judged to be Grade 2. And we could thus conduct the radical operation. The treatment was completed without adverse events. IRIS therapy can be an effective method as neo-adjuvant chemotherapy.