NO EVIDENCE FOR MICROSATELLITE INSTABILITY FROM ALLELOTYPE ANALYSIS OF BENIGN AND LOW MALIGNANT POTENTIAL OVARIAN NEOPLASMS

The genetic events that lead to the development of benign and low mali gnant potential (LMP) tumors from normal ovarian surface epithelium ar e not well understood. In contrast to invasive ovarian neoplasms, loss of heterozygosity (LOH) is not common in these tumors except on the X chromosome, but one report has suggested that an alternative genetic mechanism, microsatellite instability (MSI), might be an important pat hogenic mechanism for LMP ovarian tumors. Objective. To determine the frequency of MSI in LMP tumors and to detect novel regions of LOH in b enign and LMP ovarian tumors. Methods. Sixty-nine microsatellite marke rs were analyzed in 23 benign and 31 LMP ovarian tumors. Results. No e vidence of MSI was found in any of the tumors studied, nor were any no vel regions of LOH identified. Conclusions. This suggests that new app roaches may be necessary to understand the genetic basis of benign and LMP ovarian neoplasms since neither LOH nor MSI appears to play a maj or role. (C) 1998 Academic Press.