Characterization of chromosome aberrations associated with soft-tissue leiomyosarcomas by twenty-four-color karyotyping and comparative genomic hybridization analysis.

Data on the chromosome aberrations associated with leiomyosarcomas of soft tissues are limited, complex, and incomplete. The aim of this study was to characterize genetic aberrations associated with this tumor group, to identify consistent regions of involvement and to determine correlations with clinical outcome. Chromosomes were prepared from 10 primary soft-tissue leiomyosarcoma samples, and preparations from four of them, plus the cell line SK-LMS-1, were suitable for analysis using 24-color karyotyping by multifluor fluorescence in situ hybridization. This method allowed rearranged chromosomes to be characterized, which would not have been possible by banding analysis alone. The remaining six chromosome preparations were analyzed using standard Giemsa banding. The chromosome imbalances associated with all the samples were determined by comparative genomic hybridization analysis. Taken together, the results show both intra- and intertumor heterogeneity and considerable complexity. Although no highly consistent rearrangements were found, some regions of the genome frequently were involved, including 1q21, 5p14-pter, and 20q13, which likely harbor genes that play a role in the pathogenesis of soft-tissue leiomyosarcomas. There were no obvious correlations between the chromosomal changes identified and available clinical details.