Toward assessing trends in oral mucosal lesions: lessons learned from oral cancer.

Trend data on oral mucosal lesions are limited. The literature is comprised of a large number of studies documenting the prevalence of various lesions in different populations. Trend data on cancers of the oral cavity and pharynx are the exception. An overview of the international epidemiologic studies of these cancers is provided. General conclusions across studies and countries for trend data of these cancers cannot easily be drawn, since variations exist in data collection methods, risk factors, and other characteristics of the study populations. This paper also reviewed the available prevalence data for oral mucosal lesions in general as well as data on leukoplakia, recurrent herpes labialis, and recurrent aphthous ulcers. A few studies of the incidence of leukoplakia are described. In order to explore the potential for future trend data on oral mucosal lesions, this paper discusses issues related to the feasibility and structure of monitoring these lesions. Criteria that could be used to identify which conditions should be monitored in the future were discussed, such as, those that present a public health problem, those that are sentinel events for serious conditions, and infectious lesions. Once lesions are identified, it is clear that international consensus for diagnostic criteria of these lesions is needed in order to permit comparisons to be made among studies. Finally, strategies for monitoring these conditions and factors that may affect future trends are reviewed.