Autofluorescence for the Screening of Precancerous and Malignant Lesions

Overview

Diagnosis of oral squamous cell carcinoma is always too late. Due to this delay for diagnosis, prognosis is very bad. It has been demonstrate that systematic oral examination decrease mortality in tobacco and alcohol consumers population (Sankaranarayanan and al. Lancet 2005, 4, 1927-1933 ). An other study has demonstrate that autofluorescence is a useful technic for detection of dysplasia and squamous cell carcinoma that cannot be seen with conventional oral examination((Poh CF Wink Cancer Res on 2006 ( 22 ): 6616-22; Poh CF Head Neck 2007 ( 1 ) 7 71-6).However autofluorescence has never been evaluated has a screening tool for systematic oral examination and the reproductibility has never been studied.

The study of Sankaranarayanan and al. (Lancet on 2005, 4, 1927-1933) demonstrated the influence on the decline of mortality of a realized systematic screening, by a simple visual inspection of the oral cavity in alcohol-smoker patients. The sensibility of the visual inspection to diagnose the oral cancers is estimated at 85 % and the specificity in 97 %. However some lésions are not diagnosed with common oral examination(Downer MC Oral Oncol. 2004 ( 3 ) 264-73). The examination in autofluorescence coupled with the visual inspection could be a solution to improve early diagnosis of potentially malignant disorders . Indeed, dysplasia and cancerous lesions can be revealing by an autofluorescence examination (Lane PM J Biomed opt on 2006 ( 2 ): 024006). Other works demonstrated that infra-clinical lesions could be revealed by the autofluorescence (Poh CF Wink Cancer Res on 2006 ( 22 ): 6616-22; Poh CF Head Neck 2007 ( 1 ) 7 71-6). On the other hand the sensibility and the specificity of the autofluorescence in situation of screening were not estimated and studies carried out on sick subjects tend to overestimate the metrological performances of a technique. Besides the reliability of the technique (reproducibility) was not studied. For these reasons, it is recommended to realize in situation of screening in an alcohol-smoker population: * a study of reliability to estimate the reproducibility inter-observer of the examination of the oral cavity in tissular autofluorescence and, * a feasibility study to estimate the potential contribution of the autofluorescence with regard to a simple visual inspection in the screening of the potential malignant disorders.