No microsatellite instability, but frequent LOH in liposarcomas

To evaluate the significance of microsatellite instability (MI) and loss of heterozygosity (LOH) in the development of different histological subgroups of liposarcomas, we examined 28 tissue-samples from 21 patients and the corresponding non-neoplastic reference tissues. We investigated nine microsatellite loci and detected no MI. LOH for at least one marker was observed in 11 of 28 tumours (39%). Widespread allelic losses were a common characteristic of pleomorphic liposarcomas. Well-differentiated variants did not show LOH (p<0.003). Our findings support the idea that liposarcoma subgroups are defined by different spectra of genetic alterations. Inefficient DNA mismatch repair does not seem to be involved in the oncogenesis of liposarcomas.