Microsatellite instability in squamous cell carcinoma and lichen sclerosus of the vulva

The usefulness of detecting genomic instability in the form of microsatellite instability (MSI) has been examined in a number of cancers. Squamous cell carcinoma (SCC) and adjacent normal and lichen sclerosis (LS) samples were taken from patients with radical vulvectomies. Vulvar SCC samples were compared with adjacent normal samples using four oligonucleotide markers (BAT-25, BAT-26, D10S208 and D10S587) found to be informative with other carcinomas. Using polymerase chain reaction techniques, 30 vulvar SCC DNA samples were examined for MSI. BAT-26 displayed the highest level of MSI and was considered to be the most sensitive marker in studying vulvar SCC. There was not a statistically significant difference between adjacent normal and LS samples analyzed. The level of MSI discovered in three loci (BAT-26, D10S208 and D10S587) was statistically significant when compared to adjacent normal samples and indicates a dysfunction in mismatch repair genes. Genomic instability pathways of carcinogenesis, characterized by mismatch repair defects and MSI, appear to have a role in the genesis of vulvar SCC, based on the high incidence of MSI in association with BAT-26