Cytological study of exfoliative buccal mucosal cells of Qat chewers in Yemen.

Prevalence of oral cancer is relatively increasing in Yemen in recent years, which is ascribed to Qat with other carcinogens. Since the establishment of a simple and reliable method for the detection of oral cancerous and precancerous lesions is essential, exfoliative cytology (EC) was applied to a case-control study to appraise the presence and severity of oral epithelial atypia in 300 subjects (150 were Qat chewers and 150 were non-Qat users) without prior knowledge of the subjects' Qat exposure. Ten patients with oral squamous-cell carcinoma (OSCC) were included as internal controls.