THE UTILITY OF CYTOKERATIN PROFILES FOR DETECTING ORAL-CANCER USING EXFOLIATIVE CYTOLOGY

It is generally agreed that there is a need for a routine, non-invasiv e screening procedure for oral cancer particularly of high risk groups . Refinements in oral exfoliative cytology now make this technique wor thy of consideration for such screening. This study assesses the utili ty of monitoring cytokeratin expression in smears of oral cancer in co mparison with assessing the keratin expression in corresponding biopsi es. Smears and biopsies were taken from 34 patients with oral cancer. A panel of antibodies, CAM5.2, LH1, AE8, LP2K and LH8 recognising kera tins 8, 10, 13, 19 and a basal cell marker respectively were employed. Keratins were identified using a standard immunocytochemical techniqu e (Vectastain) and assessed on a 3 point scale, for both smears and bi opsies. The vast majority of tumours were well differentiated. No part icular keratin profile seen within the smear was associated with any p articular state of differentiation. Although the sensitivity of K19 wa s greatest, its specificity was poor. The keratin antibodies with the best positive predictive value were CAM5.2 (K8) and the marker of the basal cell phenotype, LH8. The combination of down regulation of the s econdary differentiation markers (K13, K10) coupled with 'simple' kera tin expression (K8, K19) would seem to be the most consistent profile. We conclude that for exfoliative cytological screening to be of value as a diagnostic test it remains necessary to employ assays using more than one antikeratin antibody.