Reverse smoking as a risk factor for palatal cancer: a cross-sectional study in rural Andhra Pradesh, India.

A cross-sectional study of reverse smoking and its association with pre-malignant and malignant lesions of the palate was conducted in the north coastal areas of Andhra Pradesh, India. A total of 480 randomly selected persons were interviewed. Information about smoking status, diet and access to mass media was obtained in each case and an examination of the oral cavity was performed. Reverse smoking of chutta was practised by 33% of the total rural population. The prevalence rate of all palatal lesions was 55%. The prevalence rates of the separate lesions: leukoplakia palatii, palatal keratosis and palatal cancer, were 9.8%, 18.1% and 1.9%, respectively. The presence of these (pre-)malignant lesions was strongly associated with reverse smoking and also associated with conventional chutta smoking. Reverse smoking induced significantly more lesions than conventional chutta smoking, and was a major determinant of subsequent palatal cancer: all 9 newly diagnosed palatal cancers were observed within the group of reverse smokers. There was an inverse relationship between the incidence of palatal lesions and vitamin A intake. The study of access to mass media indicated that the most favourable medium for promoting a prevention campaign would be the cinema.