Primary soft tissue sarcoma and its local recurrence: Genetic changes studied by comparative genomic hybridization

The alms of this study were to compare genetic aberrations in primary soft- tissue sarcomas and their local recurrences and to evaluate the genetic cha nges occurring during tumor progression. A primary soft-tissue sarcoma and its subsequent local recurrence were analyzed in 20 tumor pairs by comparat ive genomic hybridization. The samples were obtained before application of radio- or chemotherapy. Copy number aberrations were detected in 50% of the primary tumors and in 70% of the local recurrences. In primary tumors, the mean number of changes was 2.45 (range, 0 to 11) whereas in local recurren ces, it was 5.05 (range, 0 to 17). The mean increase of changes from primar y tumor to local recurrence was 2.6 per tumor pair (P=.02). Gains predomina ted over losses In both primary tumors and their local recurrences. The num ber of high-level amplifications was twofold in local recurrences. The most frequent gain affected 5p14-p15.1 (10% of primary tumors, 25% of local rec urrences) and the most frequent loss, 9p (9p21-pter in 5% of primary tumors ; 9p22-pter in 30% of local recurrences). In conclusion, our results show a n increase in the number of genetic changes in local recurrences, due to tu mor progression. Loss at 9p and gains at 5p and 20q were more frequent in l ocal recurrences, and high-level amplification of 18p11.3 was not detected in any of the primary tumors. Although all these alterations were not speci fic to local recurrences, they may represent changes important during tumor progression.