Response of oral leukoplakias to the administration of vitamin A.
Tobacco/betel nut chewers (Kerala, India) with well-developed oral leukoplakias were chosen for a short-term intervention trial of vitamin A therapy. Participants were randomly distributed into two groups, one receiving 200,000 IU vitamin A per week (0.14 mg/kg body wt/per day) for 6 months, and the other receiving placebo capsules. Their cancer-causing habit, which can be quantitated (an average of 13.1 betel quids/day, 26.1 min/quid), did not change during the trial period. The 6-month oral administration of vitamin A caused complete remission in 57.1% of participants, and a total suppression of the development of new leukoplakias in all chewers receiving vitamin A (n = 21), as compared to 3% and 21%, respectively, in the placebo group (n = 33). The results were substantiated by examining the histological and cytological changes on small biopsies which were taken at the onset and at the completion of the trial period. Over the 6-month period of vitamin A administration, the number of layers of spinous cells decreased in 85% of the participants, the loss of polarity of basal cells was reduced from 72.2% to 22.2% of chewers, subepidermal lymphocytic infiltration was greatly diminished from 66.7% to 5.5% of chewers, and nuclei with condensed chromatin disappeared from the epidermal layer (72.2% before to 0% at the end of the trial).
Stich
H F
HF
Environmental Carcinogenesis Unit, British Columbia Cancer Research Centre, Vancouver, Canada.
Hornby
A P
AP
Mathew
B
B
Sankaranarayanan
R
R
Nair
M K
MK
D000328:Adult; D001114:Areca; D004341:Drug Evaluation; D006801:Humans; D007972:Leukoplakia, Oral / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D008297:Male; D010946:Plants, Medicinal; D010947:Plants, Toxic; D014030:Tobacco, Smokeless; D014801:Vitamin A / Q000627:therapeutic use*
D014801:Vitamin A