Aberrations of erbB-1 and erbB-2 oncogenes in non-dysplastic leukoplakias of the oral cavity.

The purpose of this study was to analyse erbB-1 and erbB-2 oncogenes in non-dysplastic oral leukoplakia to see if we could pinpoint the first steps towards dysplasia and possible carcinogenesis. Fresh biopsy specimens of leukoplakia in 13 patients with no history of oral cancer were examined using the competitive-differential polymerase chain reaction. The mean gene copy numbers of erbB-1 and erbB-2 were calculated from the formula to compare the absolute quantities of reference gene and oncogene from 24 patients who did not have leukoplakia. Healthy mucosa was taken as controls. In eight patients with leukoplakias, the results indicated aberrations of the erbB-1 oncogene, and two patients had gene dosage changes of erbB-2. There were no signs of deletions or amplifications in the controls. These results suggest that aberrations of erbB-1 and erbB-2 are additional markers in premalignant oral lesions at the beginning of the carcinogenic process, and that genetic alterations in histologically non-dysplastic premalignant oral lesions are common.