Seung-Do Ahn

Randomized Trial of Postoperative Adjuvant Therapy in Stage II and III Rectal Cancer to Define the Optimal Sequence of Chemotherapy and Radiotherapy: A Preliminary Report

PURPOSE We conducted a prospective randomized trial to define the optimal sequence of chemotherapy and radiotherapy of postoperative adjuvant treatment in stage II and III rectal cancer. PATIENTS AND METHODS Three hundred eight patients were enrolled onto the study. We randomly assigned 155 to arm I (early radiotherapy group) and 153 to arm II (late radiotherapy group). Treatment included eight cycles of chemotherapy at 4-week intervals and pelvic radiotherapy of 45 Gy in 25 fractions. Radiotherapy started on day 1 of the first chemotherapy cycle in arm I and on day 1 of the third chemotherapy cycle in arm II. The chemotherapy regimen consisted of fluorouracil 375 mg/m(2)/d and leucovorin 20 mg/m(2)/d. Chemotherapy was administered for 3 days per cycle in two cycles during the period of radiotherapy and for 5 days per cycle in the remaining six cycles. RESULTS Twenty patients in arm I and 14 in arm II were not eligible. We included 274 patients in the analysis. With a median follow-up of 37 months for surviving patients, disease-free survival was significantly prolonged in arm I compared with arm II (81% v. 70% at 4 years; P =.043). Twenty-three recurrences occurred in arm I and 38 in arm II (P =.047). Overall survival was not significantly different between arms I and II (84% v. 82% at 4 years; P =.387). CONCLUSION Early radiotherapy with concurrent chemotherapy after resection of stage II and III rectal cancer demonstrated a statistically significant advantage for disease-free survival compared with late radiotherapy with chemotherapy.

Randomized Trial of Postoperative Adjuvant Therapy in Stage II and III Rectal Cancer to Define the Optimal Sequence of Chemotherapy and Radiotherapy: 10-Year Follow-Up

PURPOSE To determine the optimal sequence of postoperative adjuvant chemotherapy and radiotherapy in patients with Stage II or III rectal cancer. METHODS AND MATERIALS A total of 308 patients were randomized to early (n = 155) or late (n = 153) radiotherapy (RT). Treatment included eight cycles of chemotherapy, consisting of fluorouracil 375 mg/m(2)/day and leucovorin 20 mg/m(2)/day, at 4-week intervals, and pelvic radiotherapy of 45 Gy in 25 fractions. Radiotherapy started on Day 1 of the first chemotherapy cycle in the early RT arm and on Day 1 of the third chemotherapy cycle in the late RT arm. RESULTS At a median follow-up of 121 months for surviving patients, disease-free survival (DFS) at 10 years was not statistically significantly different between the early and late RT arms (71% vs. 63%; p = 0.162). A total of 36 patients (26.7%) in the early RT arm and 49 (35.3%) in the late RT arm experienced recurrence (p = 0.151). Overall survival did not differ significantly between the two treatment groups. However, in patients who underwent abdominoperineal resection, the DFS rate at 10 years was significantly greater in the early RT arm than in the late RT arm (63% vs. 40%; p = 0.043). CONCLUSIONS After the long-term follow-up duration, this study failed to show a statistically significant DFS advantage for early radiotherapy with concurrent chemotherapy after resection of Stage II and III rectal cancer. Our results, however, suggest that if neoadjuvant chemoradiation is not given before surgery, then early postoperative chemoradiation should be considered for patients requiring an abdominoperineal resection.