Postoperative Adjuvant Chemotherapy and Chemoradiation for Rectal Cancer / 대한방사선종양학회지

ABSTRACT

PURPOSE: The aim of this study was to determine if postoperative adjuvant chemotherapy (CT) alone and concurrent chemoradiation (CCRT), following radical surgery, improved the disease free survival (DFS) and overall survival (OS) in rectal cancer AJCC stage II and III patients. MATERIALS AND METHODS: A total of 144 patients with AJCC stage II and III rectal cancer who had had radical surgery between 1989 and 1999 were included in the study. Of these patients, 72 had been treated with postoperative CT, and the other 72 with postoperative CCRT. The chemotherapy regimen consisted of oral UFT on a daily basis for 1~12 months (median 12 months) or 5-FU (500 mg/m2 for 5 days) intravenous (IV) chemotherapy with 4 week intervals for 1~18 cycles (median 6 cycles). Radiation of 4,500 cGy was delivered to the surgical bed and regional pelvic lymph nodes area, followed by 540~1,440 cGy (median 540 cGy) boost to the surgical bed. The follow-up period ranged from 20 to 150 months, with a median of 44 months. RESULTS: The 5-year OS was 60.9% and 68.9% (p=0.0915), and the 5-year DFS was 56.1% and 63.8% (p=0.3510) for postoperative CT and postoperative CCRT, respectively. In the stage II patients, the 5-year OS was 71.1% and 92.2%, and the 5-year DFS was 57.3% and 85.4% for postoperative CT and CCRT, respectively. The OS was significantly improved (p=0.0379) but the DFS was not with postoperative CCRT compared to the postoperative CT (p=0.1482). In the stage III patients, the 5-year OS was 52.0% and 55.0%, and the 5-year DFS was 47.8% and 49.8% for postoperative CT and postoperative CCRT. There were no statistically significant differences between postoperative CT and CCRT (p=0.4280 and p=0.7891) in OS and DFS. The locoregional relapses were 16.7% and 12.5% for postoperative CT and CCRT, respectively. The distant relapses were 25.0% and 26.4% for postoperative CT and CCRT, respectively. CONCLUSION: These results showed that postoperative CCRT compared with CT alone improved OS in stage II patients. Although there was no statistical significance, the addition of postoperative RT to CT reduced locoregional relapses compared to CT alone.