Surgical adjuvant therapy of rectal carcinoma: a controlled evaluation of leucovorin, 5-fluorouracil and radiation therapy with or without interferon-α2b

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-α2b (IFN-α) in patients who have had a 'curative' resection, for rectal adenocarcinoma (Dukes' B 2 /C; T3 N0, T4 N0, N1-3). Patients and methods: A total of 207 eligible patients with a performance status of 0 or I were randomized postoperatively between days 21 and 70 to one of the two treatment groups: group A, LV 20 mg/m 2 i.v. bolus and 5-FU 425 mg/m 2 i.v. days 1-5 and 29-33. LV 20 mg/m 2 and 5-FU 400 mg/m 2 days 57-60 and 85-88, LV 20 mg/m 2 and 5-FU 380 mg/m 2 days 1-5 and 29-33 with the second day I occurring 28 days after the completion of RT (45 Gy ); group B, LV, 5-FU and RT as in group A, and IFN-α 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-α administration. Conclusions: There was no difference in efficacy between the two combinations. Toxicity was greater with the LV + 5-FU + IFN-α regimen because of the flu-like syndrome.