Effects of preoperative radiotherapy for T2, T3 distal rectal cancer

Preoperative radiotherapy has been used to induce tumor regression and allow complete resection of rectal cancer with a sphincter preservation surgery. This study was performed to determine the effectiveness of preoperative radiotherapy for T2, T3 distal rectal carcinoma. From November 1995 to June 1997, fifteen patients with invasive distal rectal cancer were treated with preoperative radiotherapy followed by sphincter preservation surgery. Classification by preoperative T stage considered of 7 T2 and 8 T3 tumors. Radiation therapy was delivered with 6 MV and 15 MV linear accelerator, at 1.8 Gy fractions for 5 days per week. Total radiation doses were 45 Gy to 50.4 Gy (median: 50.4 Gy). Sphincter preservation surgery was performed 4∼ 6 weeks after the completion of radiotherapy. Median follow-up was 22 months (range:16 ∼ 37 months). One patient (6.7%) had a complete pathologic response. Comparing the stage at the diagnostic workup with the pathologic stage, tumor downstaging of T stages occurred in 11 of 15 patients (73.3%) and M1 stages occurred in 2 of 5 patients (40%). No patient developed progressive disease undergoing treatment. Two patients suffered local recurrence at 7 and 20 months, and one a distant metastasis at 30 months. No grade 3 or 4 toxicity was observed. Our experience suggests that preoperative radiotherapy followed by sphincter preservation surgery is well tolerated, and can significantly reduce the tumor burden for T2, T3 distal rectal cancer