Methods: Various methods to obtain exfoliated cells in the oral cavity were tested. Three different methods were applied to detect genetic alterations: 1) loss of heterozygosity (LOH), 2) multiplex ligation-dependent probe amplification (MLPA), a method to measure DNA copy number changes, and 3) DNA ploidy. These methods were tested on DNA derived from 15 oral carcinoma-adjacent lesions that, based on a similar p53 mutation, belonged to the precursor field within which the tumor has developed.
Results: A non-invasive sampling method using a small disposable brush was developed with sufficient DNA yields. Both the LOH and MLPA assay were able to detect 14 out of 15 preneoplastic lesions, whereas DNA ploidy measurements could detect only two. In addition, detection limits and feasibility on non-invasive samples were measured for each assay.
Conclusions: Our data show that both LOH and MLPA are promising methods for early detection of preneoplastic lesions in the oral cavity in small non-invasive samples.