[Minimally invasive brush-biopsy: innovative method for early diagnosis of oral squamous cell carcinoma].

The aim of this prospective and blinded study was to investigate the diagnostic accuracy of conventional cytopathology of oral brush biopsies taken from suspicious oral lesions. In addition we checked slide based DNA image cytometry as an adjuvant diagnostic tool. Our hypothesis is that DNA aneuploidy is a sensitive and specific marker for earliest detection of oral cancer using brush biopsies. Therefore the nuclear DNA contents were measured after Feulgen re-staining using a TV image analysis system. DNA aneuploidy was assumed if abnormal DNA stemlines or cells with DNA content greater 9c were observed. Sensitivity of our cytological diagnosis in oral smears for the detection of cancer cells thus was 91.3%, specificity for the detection of non-neoplastic cells was 95.1%, positive predictive value 94.4% and negative predictive value 92.3%. The adjuvant DNA image cytometry reached a sensitivity of 97.8%, the specificity and the positive predictive value were 100% and negative predictive value was 98.1%, respectively. Smears from oral brush biopsies of all visible oral lesions are an easily practicable, cheap, minimal invasive, painless and safe screening method for detection of oral precancerous lesions and squamous cell carcinomas in all stages. We conclude that DNA image cytometry is a very sensitive and highly specific, objective and reproducible adjuvant tool for identification of neoplastic cells in oral smears.