PATIENTS WITH ADVANCED COLORECTAL CANCER AND no prior chemotherapy were randomized to six treatment regimens: A) fluorouracil (FU) alone; B) FU + hydroxyurea (HU); C) semustine (SE) + dacarbazine (DA); D) FU + HU alternating with SE + DA; E) SE + razoxane (RA); F) mitomycin (MI) + DA. There were no significant treatment differences with respect to response, which ranged from 9–23% (overall 32/207 or 15%) or median survival duration, which ranged from 17 weeks to 32 weeks. Patients treated with FU or FU + HU experienced substantially less toxicity than those on the other treatment arms.