Abnormal Oral Mucosal Light Reflectance: A New Clinical Marker of High Risk for Colorectal Cancer.

Background: A familial predisposition to colorectal cancer (CRC) has been clearly established, consisting of familial clustering in 15-20% and clear hereditary aetiology in 5-10% of overall CRC cases. Early identification of families and individuals at high risk is essential as intensive surveillance has been demonstrated to reduce cancer incidence and overall mortality. In the present study, the value of oral mucosal light reflectance in identifying hereditary non-polyposis colorectal cancer (HNPCC) carriers was investigated. Methods: Twenty members of six different genetically unrelated HNPCC kindred and 30 genetically unrelated age and sex matched healthy controls were examined. Lower gingival and vestibular oral mucosal reflectance was measured using an imaging spectrophotometer. Results: HNPCC carriers showed significantly Tower values in the 590-700 nm wavelength range (p≤0.0004). A reflectance cut off value ≤47.9% at the 700 nm wavelength discriminated between HNPCC carriers and controls, with 100% sensitivity and 100% specificity. Conclusions: These findings may provide an additional phenotypic sign in HNPCC carriers, which could be used in first level CRC population screening programmes.