Background: The aim of this study was to determine whether the efficacy of the combination of 5-fluorouracil (5-FU), leucovorin (LV) and radiation therapy (RT) could be improved by the addition of interferon-alpha2b (IFN-alpha) in patients who have had a 'curative' resection, for rectal adenocarcinoma (Dukes' B2/C; T3 N0, T4 N0, N1-3).
Patients and methods: A total of 207 eligible patients with a performance status of 0 or 1 were randomized postoperatively between days 21 and 70 to one of the two treatment groups: group A, LV 20 mg/m2 i.v. bolus and 5-FU 425 mg/m2 i.v. days 1-5 and 29-33, LV 20 mg/m2 and 5-FU 400 mg/m2 days 57-60 and 85-88, LV 20 mg/m2 and 5-FU 380 mg/m2 days 1-5 and 29-33 with the second day 1 occurring 28 days after the completion of RT (45 Gy); group B, LV, 5-FU and RT as in group A, and IFN-alpha 5 x 10(6) IU s.c. three times during each week chemotherapy is given.
Results: 104 patients were randomized into group A and 103 into group B. There was no statistically significant difference in either disease-free survival or overall survival between the two groups. Toxicity was also the same, except for the flu-like syndrome associated with the IFN-alpha administration.
Conclusions: There was no difference in efficacy between the two combinations. Toxicity was greater with the LV + 5-FU + IFN-alpha regimen because of the flu-like syndrome.