beta-carotene produces sustained remissions in patients with oral leukoplakia - Results of a multicenter prospective trial

Background: beta-carotene has been reported to produce regressions in patie nts with oral leukoplakia, a pre- malignant lesion. However, previous studi es have all been of short duration, with clinical response as the end point . Objective: To evaluate the duration of response and the need for maintenanc e therapy in subjects who respond to beta-carotene. Methods: In this multicenter, double-blind, placebo-controlled trial, subje cts were given beta-carotene, 60 mg/d, for 6 months. At 6 months, responder s were randomized to continue beta-carotene or placebo therapy for 12 addit ional months. Results: Fifty-four subjects were enrolled in the trial, with 50 being eval uable. At 6 months, 26 subjects (52%) had a clinical response. Twenty-three of the 26 responders completed the second, randomized phase. Only 2 (18%) of 11 in the beta-carotene arm and 2 (17%) of 12 in the placebo arm relapse d. Baseline biopsies were performed in all patients, with dysplasia being p resent in 19 (38%) of the 50 evaluable patients. A second biopsy was obtain ed at 6 months in 23 subjects who consented to this procedure. There was im provement of at least 1 grade of dysplasia in 9 (39%), with no change in 14 (61%). Nutritional intake was assessed using food frequency questionnaires . There was no change in carotenoid intake during the trial. Responders had a lower intake of dietary fiber, fruits, folate, and vitamin E supplements than did nonresponders. beta-Carotene levels were measured in plasma and o ral cavity cells. Marked increases occurred during the 6-month induction. H owever, baseline levels were not restored in subjects taking placebo for 6 to 9 months after discontinuation of beta-carotene therapy. Conclusions: The activity of beta-carotene in patients with oral leukoplaki a was confirmed. The responses produced were durable for 1 year.