[Outcomes of preoperative chemoradiotherapy for rectal cancer with invasion to the adjacent organs].

We reviewed the clinical records of 13 patients who received preoperative chemoradiotherapy(CRT)to evaluate the clinical effectiveness of CRT for T4b rectal cancer. Preoperative radiotherapy consisted of 40-50 Gy delivered in fractions of 1.8-2.0 Gy per day, 5 days per week. Treatment with intravenous 5-fluorouracil, oral tegafur-uracil(UFT-E)with l-leucovorin, oral S-1, or intravenous irinotecan(CPT-11)with oral S-1 was administered during radiotherapy. At 63 days after CRT, 1 patient died because of pelvic abscess. Complete response(CR)or partial response(PR)was observed in 7 patients, 1 month after CRT. Curative surgery was performed in 9 patients. Among 10 patients who underwent surgery 70 days after CRT, 5 who showed PR 1 month after CRT underwent curative surgery; both urinary and anal function were preserved in 4 of these patients. Histological invasion to the adjacent organs was not observed in 6 patients, and 1 patient achieved histological CR. Of the 9 patients who underwent curative surgery, recurrence was observed in 2; however, the other patients survived without recurrence. Preoperative CRT was considered to be effective in improving the resection rate and prognosis in patients with T4b rectal cancer. However, careful attention should be paid to the severe toxicities associated with CRT, such as pelvic abscess.