DNA AND KERATIN ANALYSIS OF ORAL EXFOLIATIVE CYTOLOGY IN THE DETECTION OF ORAL-CANCER

Refinements in oral exfoliative cytology may make it a suitable screen ing technique for the early diagnosis of oral cancer. In this study DN A range profiles were combined with keratin expression in an attempt t o improve the diagnostic accuracy of oral exfoliative cytology. Smears were taken from 33 biopsy-proven oral cancers and the contralateral n ormal site. For DNA range profiles the smears underwent Feulgen hydrol ysis, with DNA distribution being assessed using the Vickers M85 micro densitometer. For keratin expression a panel of antikeratin antibodies were applied. The smears for keratin expression were then graded on a three-point scale. Abnormal DNA range profiles were observed in 23 of 33 smears taken from oral cancers and in two smears from normal oral mucosa (sensitivity 70%, specificity 90%, positive predictive value 90 %). The simple epithelial keratins 8 and 19 were identified in the maj ority of oral cancer smears. The sensitivity of keratin 19 was greater (90%). However, keratin 8 was the most useful keratin marker associat ed with malignancy (sensitivity 62%, specificity 100%, positive predic tive value 100%). The combination of simple keratin expression and DNA content improved the cancer detection rate beyond that obtainable wit h DNA range profile alone.