Oxygen-derived free-radical scavengers prolong survival in colonic cancer.

The influence of scavengers of oxygen-derived free radicals on survival in colonic cancer was studied. Following curative surgery for carcinoma of the sigmoid colon at Dukes' stage C, 198 patients making an uneventful recovery from surgery were randomized to the control group or to receive allopurinol (50 mg orally 4 times a day) or dimethyl sulphoxide (DMSO, 500 mg orally 4 times a day). In 144 fully evaluable patients who were studied for 5 years, allopurinol and DMSO incurred a significant (p less than 0.01) survival advantage over the whole period of study. The similarity in efficacy between allopurinol and DMSO and the fact that the only action they share is scavenging oxyradicals, suggest that these radicals are implicated in the detrimental effects of malignancy and that removing them provides a survival advantage in patients bearing colonic carcinoma.