Management of oral mucosal dysplasia with beta-carotene retinoic acid: a pilot cross-over study.

Mucosal dysplasia in the head and neck region is recognized to be a precancerous lesion. Between January 1983 and December 1987, a pilot study was conducted at the Manitoba Cancer Treatment and Research Foundation to determine the effects of beta-carotene and cis-retinoic acid on mucosal dysplasias. Eighteen patients were treated with a "cross-over" regimen. The overall response to treatment was 61%, with 33.3% complete responses. Patients who smoked had a significantly better response than nonsmokers. The response rate for 9 of 11 smokers was 81.2%, and 2 of 7 nonsmokers or 28.6% responded to this protocol. The beneficial effect of these drugs should be established by prospective, randomized trial in high risk populations.