Postoperative chemoradiotherapy is the recommended standard therapy for patients with locally advanced rectal cancer.
In recent years, encouraging results with preoperative radiotherapy have been reported.
Dr Rolf Sauer and colleagues in Germany undertook a study to compare preoperative chemoradiotherapy with postoperative chemoradiotherapy for locally advanced rectal cancer.
The research group randomly assigned a group of patients with clinical stage T3 or T4 or node-positive disease to receive either preoperative or postoperative chemoradiotherapy.
The preoperative treatment consisted of 5040 cGy delivered in fractions of 180 cGy per day, five days per week.
The investigators also administered fluorouracil in a 120-hour continuous intravenous infusion at a dose of 1000 mg per square meter of body-surface area per day during the first and fifth weeks of radiotherapy.
|5-year cumulative incidence of local relapse:|
6 % for patients assigned to preoperative chemoradiotherapy
13 % for postoperative-treatment
|The New England Journal of Medicine|
The investigators arranged surgery to be performed six weeks after the completion of chemoradiotherapy.
The investigators oversaw four five-day cycles of fluorouracil (500 mg per square meter per day) one month after surgery.
Chemoradiotherapy was identical in the postoperative-treatment group, except for the delivery of a boost of 540 cGy.
The primary end point was overall survival.
In total, the investigators randomly assigned preoperative chemoradiotherapy to 421 patients and 402 patients were to receive postoperative chemoradiotherapy.
The researchers found that the overall 5-year survival rates were 76 % and 74 %, respectively.
In addition, the research group noted that the 5-year cumulative incidence of local relapse was 6 % for patients assigned to preoperative chemoradiotherapy and 13 % in the postoperative-treatment group.
Grade 3 or 4 acute toxic effects occurred in 27 % of the patients in the preoperative-treatment group
However 40 %of the patients in the postoperative-treatment group had grade 3 or 4 acute toxic effects.
The research group found that the corresponding rates of long-term toxic effects were 14 % and 24 % respectively.
Dr Sauer concluded, "Preoperative chemoradiotherapy, as compared with postoperative chemoradiotherapy, improved local control and was associated with reduced toxicity but did not improve overall survival."