Comparative genomic hybridization reveals novel chromosome deletions in 90primary soft tissue tumors

Comparative genomic hybridization (CGH) was used to detect chromosomal gain s and losses in a series of 90 frozen soft tissue primary tumors (STTs), al l untreated. The material consisted of 69 malignant sarcomas, including 20 malignant fibrous histiocytomas (MFH), 23 liposarcomas (LPS), 6 leiomyosarc omas (LMS), 4 synovial sarcomas, 4 primitive neuroectodermal tumors (PNETs) , and various others subtypes, in addition to 21 benign tumors. Within the benign tumors, only 2 of the 3 schwannomas showed genetic changes. In malig nant sarcomas, genetic changes were detected in 64 of the 69 samples analyz ed (92 %), with a mean of 4.5 per sample (range 0-10). Gains and losses on chromosome 13 were observed in 32% of the sarcomas with genomic imbalance. Recurring low-level copy number increases were found at new sites on chromo somes 7 (6 MFH samples, 30%) and 8 (10 LPS samples, 43%), the minimal commo n regions being 7p15-pter and 8q24. No new recurring high-level amplificati ons were found. Surprisingly, losses of DNA sequences Mere more frequent th an gains; particularly losses were the main feature in LMS, with highly rec urrent common minimal losses at 11q14-qter and 13q21-q22 (4 samples, 66%, a nd 5 samples, 83%, respectively). Losses of chromosome 2 sequences (minimal common regions at 2p24-pter and 2q32-qter) were observed in 50% of the MFH analyzed. New recurrent losses of whole or part of chromosome 14 Mere foun d in 57% of the pleomorphic LPS (PLPS) analyzed. This study uncovers new cl ues for the diagnosis of malignant STTs and shows the importance of deletio ns as events in the early steps involved in the tumorigenesis of STTs. (C) Elsevier Science Inc., 1999. AII rights reserved.