RISK-FACTORS ASSOCIATED WITH ORAL-CARCINOMA IN PAKISTAN

Background - Risk factors for oral carcinoma (cigarette smoking, alcoh ol consumption, areca-nut chewing and human papillomavirus and HPV inf ections) were investigated to determine which are most prevalent among st patients in the Karachi region of Pakistan. Methods - Twenty-four p atients with recently diagnosed tumours (19 were diagnosed within the preceding 3 months and were untreated) and 24 age- and sex-matched con trols were recruited from clinics in Karachi. Subjects were clinically examined and interviewed to determine their usage of tobacco, areca-n ut, quid composition, and buccal swabs (for detection of HPV DNA) were collected. Results - Cigarette smoking and areca-nut chewing were sig nificantly more common among patients than controls (p<0.05 & p<0.02: odds ratios 4.04 & 5.9, respectively). No significant associations bet ween the period of smoking or cigarettes smoked/day were found. Both d uration of chewing (p<0.01) and amount of areca nut consumed/day (p<0. 02) were greater for patients than controls. Amongst those who chewed areca nut there were no correlations between the use of individual add itives (betel leaf, tobacco, lime or catechu) to quids that suggested any particular associations with cancer. Few (n=3) subjects admitted a lcohol consumption and no HPV DNA was detected in tumour scrapes by po lymerase chain reaction tests. Conclusions - Areca-nut chewing in part icular and cigarette smoking, but not HPV infection, are most highly a ssociated with oral cancer in the Karachi region of Pakistan.