Betel chewing and dietary habits of chewers without and with submucous fibrosis and with concomitant oral cancer.

The betel-nut chewing habit and the intake of chillies in the diet were analysed in 178 chewers identified during a stratified random survey and in 124 hospital patients suffering from submucous fibrosis (SF). There were no signs or symptoms of SF in 115 chewers from the survey; the remaining 63 exhibited features of impending and established SF. Of the 124 hospital patients, 10 also had oral cancer. Subjects suffering from SF had practised the habit in whatever form for a significantly shorter period than chewers without SF and belonged to a significantly younger age group. A significantly larger proportion of this group preferred the boiled nut by itself and not as part of the betel package (paan or pan). No relationship could be established between SF and the use of tobacco, lime or chillies. There was no difference in frequency of the habit between chewers without SF and chewers with SF. The 10 oral cancer patients all had moderately to well-differentiated squamous carcinomas arising in the buccal sulci (8), the soft palate (1) and upper oesophagus (1). Eight had cancer on presentation and 2 developed the tumour while under observation. Nine chewed the nut only and only 1 preferred paan which included tobacco, lime and catechu, which is contrary to the proposal that tobacco or lime are the carcinogens. It is concluded that a relationship between betel-nut chewing and SF exists but the mechanism by which the disease develops is still obscure. A genetic predisposition may be important.