Background: Approximately 3,000 new cases of oral cancer are diagnosed each year in Canada. Most of these cases occur among older adults with a history of tobacco use or excessive alcohol consumption. Preventive interventions for oral cancer include counselling of patients to modify risk factors and screening to identify precancerous and early-stage lesions. This report presents evidence-based guidelines on the prevention of oral cancer and precancer among asymptomatic patients.
Methods: Literature searches of the 1966-1999 MEDLINE and CANCERLIT databases were completed using the major MeSH heading mouth neoplasms. References from articles and recommendations of organizations were also reviewed. The evidence-based methods of the Canadian Task Force on Preventive Health Care were used to assess evidence and to develop guidelines. Advice from experts and other recommendations were taken into consideration.
Results: In cohort and case-control studies, smoking cessation decreased the risk of oral cancer and precancer. Randomized controlled trials (RCTs) indicate counselling by trained health care professionals is effective in promoting smoking cessation. Although counselling has been effective for the reduction of excessive alcohol consumption in RCTs, no studies have examined whether alcohol reduction reduces the risk of oral cancer or precancer. The usefulness of general population screening is limited by the low prevalence and incidence of the disease, the potential for false-positive diagnoses and the poor compliance with screening and referral. There is no evidence that screening of the general population or high-risk groups leads to a reduction in mortality or morbidity from oral cancer.
Interpretation: There is good evidence to specifically consider smoking cessation counselling in a periodic health examination (grade A recommendation). For population screening, there is fair evidence to specifically exclude screening for oral cancer (grade D recommendation). For opportunistic screening during periodic examinations, there is insufficient evidence to recommend inclusion or exclusion of screening for oral cancer (grade C recommendation). For patients at high risk, annual examination by physician or dentist should be considered. Risk factors include tobacco use and excessive consumption of alcohol. These recommendations are similar to those made by the Canadian Task Force on the Periodic Health Examination in 1994 and by the U.S. Preventive Services Task Force in 1996.