O Kujan1, A M Glenny, A J Duxbury, N Thakker, P Sloan. 1. Oral Medicine, Oral Pathology, University Dental Hospital of Manchester, Higher Cambridge Street, Manchester, UK, M15 6FH.
Abstract
BACKGROUND: Although the second half of the last century has generated a rich and complex body of knowledge, the burden of oral cancer is still largely present. As with other cancers, there has been a strong debate whether screening strategies for oral cancer such as visual examination, the use of toluidine blue or newer methods such as brush biopsy or fluorescence imaging are effective in reducing the mortality rate associated with oral cancer. OBJECTIVES: To assess the effectiveness of current screening methods in decreasing oral cancer mortality. SEARCH STRATEGY: Electronic databases (MEDLINE, CANCERLIT, EMBASE, the Cochrane Central Register of Controlled Trials; 1966 to September 2002, The Cochrane Library - Issue 2, 2002), bibliographies, handsearching of specific journals and contact authors were used to identify published and unpublished data. SELECTION CRITERIA: Randomised controlled trials of screening for oral cancer or potentially premalignant oral lesions using visual examination, toluidine blue, fluorescence imaging or brush biopsy. DATA COLLECTION AND ANALYSIS: The search found 100 citations and these have been reviewed. One randomised controlled trial of screening strategies for oral cancer was identified as meeting the review's inclusion criteria. Validity assessment, data extraction and statistics evaluation have been undertaken by two independent reviewers. MAIN RESULTS: One ongoing randomised controlled trial has been included (n = 13 clusters: 153,708 eligible subjects, 130,799 included subjects). There was no difference in the age-standardised oral cancer mortality rates for the screened group (21.2/1000,000 person years) and the control group (21.3/100,000 person years). However this study has some methodological weaknesses. REVIEWER'S CONCLUSIONS: Given the limitation of evidence (only one included randomised controlled trial) and the potential methodological weakness in the included study, it is valid to say that there is no evidence to support or refute the use of a visual examination as a method of screening for oral cancer using a visual examination in the general population. Furthermore, no robust evidence exists to suggest other methods of screening, toluidine blue, fluorescence imaging or brush biopsy, are either beneficial or harmful. Further cost-effective, high quality studies to assess the efficacy and effectiveness of screening are required. In addition, studies to elucidate the natural history of oral cancer, prevention methods and the effectiveness of opportunistic screening in high risk groups are needed.
BACKGROUND: Although the second half of the last century has generated a rich and complex body of knowledge, the burden of oral cancer is still largely present. As with other cancers, there has been a strong debate whether screening strategies for oral cancer such as visual examination, the use of toluidine blue or newer methods such as brush biopsy or fluorescence imaging are effective in reducing the mortality rate associated with oral cancer. OBJECTIVES: To assess the effectiveness of current screening methods in decreasing oral cancer mortality. SEARCH STRATEGY: Electronic databases (MEDLINE, CANCERLIT, EMBASE, the Cochrane Central Register of Controlled Trials; 1966 to September 2002, The Cochrane Library - Issue 2, 2002), bibliographies, handsearching of specific journals and contact authors were used to identify published and unpublished data. SELECTION CRITERIA: Randomised controlled trials of screening for oral cancer or potentially premalignant oral lesions using visual examination, toluidine blue, fluorescence imaging or brush biopsy. DATA COLLECTION AND ANALYSIS: The search found 100 citations and these have been reviewed. One randomised controlled trial of screening strategies for oral cancer was identified as meeting the review's inclusion criteria. Validity assessment, data extraction and statistics evaluation have been undertaken by two independent reviewers. MAIN RESULTS: One ongoing randomised controlled trial has been included (n = 13 clusters: 153,708 eligible subjects, 130,799 included subjects). There was no difference in the age-standardised oral cancer mortality rates for the screened group (21.2/1000,000 person years) and the control group (21.3/100,000 person years). However this study has some methodological weaknesses. REVIEWER'S CONCLUSIONS: Given the limitation of evidence (only one included randomised controlled trial) and the potential methodological weakness in the included study, it is valid to say that there is no evidence to support or refute the use of a visual examination as a method of screening for oral cancer using a visual examination in the general population. Furthermore, no robust evidence exists to suggest other methods of screening, toluidine blue, fluorescence imaging or brush biopsy, are either beneficial or harmful. Further cost-effective, high quality studies to assess the efficacy and effectiveness of screening are required. In addition, studies to elucidate the natural history of oral cancer, prevention methods and the effectiveness of opportunistic screening in high risk groups are needed.
Authors: Ian Shemilt; Miranda Mugford; Michael Drummond; Eric Eisenstein; Jacqueline Mallender; David McDaid; Luke Vale; Damian Walker Journal: BMC Med Res Methodol Date: 2006-11-15 Impact factor: 4.615