Descriptive epidemiology of oral neoplasms in Sudan 1970-1985 and the role of toombak.

Data from 1,916 cases of oral neoplasms occurring in the Sudan in a 16-year period, from January 1970 to December 1985, were retrieved and analysed. The study revealed a relatively high frequency of oral neoplasms in comparison with neighbouring countries. In this study, squamous-cell carcinoma was the most common oral malignancy (66.5%), followed by tumours of the salivary gland (14.7%), neoplasms of nonodontogenic and non-epithelial origin (9.6%) and odontogenic neoplasms (8.6%). Men had a higher frequency than women. The older age group of both genders showed a relatively high frequency of squamous-cell carcinoma. Among northern Sudanese there was a high rate of squamous-cell carcinoma, while southern Sudanese showed a high rate of odontogenic and salivary-gland neoplasms. The use of toombak has been stated to play a major role in the aetiology of oral squamous-cell carcinoma in the Sudan, and is suspected to be associated with neoplasms of the salivary glands.