A Prospective Randomized Trial Comparing the Sequence of Adjuvant Chemotherapy and Radiotherapy following Curative Resection of Stage II, III Rectal Cancer / 대한방사선종양학회지

ABSTRACT

PURPOSE: To evaluate the side effects, pattern of failure, and survival rate according to the sequence of postoperative adjuvant radiotherapy and chemotherapy, patients with stages II and lll rectal cancer who had undergone curative resection were randomized to early radiotherapy group (arm I) or 'late radiotherapy group (arm II)', then we intend to determine the most effective sequence of the radiotherapy and chemotherapy. MATERIALS AND METHODS: From January 1996 to March 1999, 3 13 patients with curatively resected stages II and III rectal cancer have been randomized to early' or late radiation therapy group and recei ved combined chemotherapy (5-FU 375 mg/m/day, leucovorin 20 mg/m, IV bolus daily D1-5, 8 cycles) and radiation therapy (whole pelvis with 45 Gy/25 fractions/5 weeks). Arm I received radiation therapy from day 1 with first cycle of chemotherapy and arm II received radiation therapy from day 57 with third cycle of chemotherapy after completion of first two cycles. Preliminary analysis was performed with 228 patients registered up to Jun 1998. Two out of the 228 patients were excluded because of double primary cancer. Median follow-up period was 23 months. RESULTS: Local recurrence occurred in 11 patients (9.7%) for arm I and 9 patients (8%) for arm II. There was no significant difference between both groups (p=0.64). However, distant metastasis was found in 22 patients (19.5%) for arm I and 35 patients (31.0%) for arm II and which showed statistically significant difference between the two groups (p=0.046). And neither 3-year disease-free survival (70.2% vs 59.2%, p=0.2) nor overall survival (89.4% vs 88.0%, p=0.47) showed significant differences. The incidence of leukopenia during radiation therapy and chemotherapy was 78.3% and 79.9% respectively but leukopenia more than RTOG grade 3 was only 2.1% and 6.0% respectively. The incidence of diarrhea more than 10 times per day was significantly higher in the patients for arm I than for arm II (71.2% vs 4 1.6%, p=0.02) but this complication was controlled with supportive cares. CONCLUSION: Regardless of the sequence of postoperative adjuvant radiation therapy and chemotherapy a fter curative resection for rectal cancer, local recurrence rate was low with combined chemoradiotherapy. But distant metastasis rate was lower in early radiation therapy group than in late radiation therapy group and the reason is unclear. Most patients completed these treatments without severe complication, so these were thought to be safe treatments but the treatment compliance should be improved.