Randomized controlled trial of postoperative radiotherapy and short-term time-scheduled 5-fluorouracil against surgery alone in the treatment of Dukes B and C rectal cancer. Norwegian Adjuvant Rectal Cancer Project Group.

Background: The purpose of the present study was to investigate whether a 1-month regimen of postoperative radiotherapy combined with 5-fluorouracil could reduce the local recurrence rate and improve survival in patients with Dukes B and C rectal cancer.

Methods: One hundred and forty-four patients were randomized to surgery alone or surgery combined with postoperative radiotherapy (46 Gy) and bolus 5-fluorouracil 30 min before six of the radiotherapy fractions. One hundred and thirty-six patients were eligible.

Results: The adjuvant treatment was well tolerated. After an observation time of 4-8 years, patients in the adjuvant treatment group had a cumulative local recurrence rate of 12 per cent compared with 30 per cent in the group that had surgery only (P = 0.01). The 5-year recurrence-free and overall survival rate was 64 per cent in the adjuvant group compared with 46 per cent (P = 0.01) and 50 per cent (P = 0.05) respectively in the surgery group. The adjusted relative risk of recurrence and death for the adjuvant group was 0.48 (95 per cent confidence interval 0.28-0.82) and 0.56 (0.33-0.94) respectively.

Conclusion: The 1-month postoperative combination regimen improved treatment results in patients with Dukes B and C rectal cancer, in terms of local recurrence rate, recurrence-free survival and overall survival, without serious side-effects.