ROLE OF ARECA NUT IN THE CAUSATION OF ORAL SUBMUCOUS FIBROSIS - A CASE-CONTROL STUDY IN PAKISTAN

A case-control study on chewing and smoking habits and oral submucous fibrosis (OSF) was undertaken in Karachi in 1989/90. Cases were patien ts detected with fibrous bands and leathery mucosa and hospital-based controls were matched by age and sex. Information on habits was collec ted by personal interview of 157 cases and 157 controls. Despite overa ll female preponderance, a substantial number of young men were enlist ed. The male/female risks were found to be similar. Immigrants from In dia to Pakistan (Mohajir) had a similar risk status to local Punjabis. No differences between risks were found when comparing the three age categories, 21, 21-40, 41-60 yr. Among the cases, an increased risk wa s observed for areca nut chewing. This habit when practised alone appe ared to have the highest risk (RR 154), followed by pan with or withou t tobacco (RR 64, 32 respectively). Logistic regression and discrimina nt analysis showed that daily consumption rates appeared to be more im portant with respect to risk than lifetime duration of habit. Tobacco habits were more prevalent amongst those 15 cases who presented with c oncurrent carcinoma and OSF: We conclude that areca nut chewing has a causal relationship with OSF: additional tobacco insult may be necessa ry for subsequent carcinoma development.