Leukoplakia--an epidemiologic study of 1504 cases observed at the Tata Memorial Hospital, Bombay, India

An epidemiological study of 1504 cases of leukoplakia seen at the Tata Memorial Hospital, Bombay, indicates that the oral cavity was the site of the disease in 95% of the cases. The buccal mucosa was the commonest site affected in all religious communities of Western India except among Parsis. Parsis, a majority of whom are non-smokers and non-chewers of tobacco, had leukoplakia more often on the anterior 2/3rd tongue than on the buccal mucosa and this pattern persisted in the distribution of cancer also, whereas people from Gujarat more often smoke; in these the buccal mucosa was commonly affected with leukoplakia, but cancer was not so frequent in this site. Statistical computation of the risk of malignant transformation indicates that males have a 4·8 times higher risk of developing cancer when they have leukoplakia than the normal population, and the females have 7 times higher risk of developing cancer in the presence of leukoplakia. It was felt that leukoplakia not associated with smoking habits had a greater chance of malignant transformation.