Clinical significance of genetic imbalances revealed by comparative genomic hybridization in chondrosarcomas

DNA copy number changes were studied by comparative genomic hybridization ( CGH) in 50 chondrosarcoma samples from 45 patients. Mean number of genetic aberrations in primary tumors was 4.8 +/- 1.8. The most frequently gained r egions were 20q12-qter (37%), 20q (32%), 8q24.1-qter (27%), 20p (24%), and 14q24-qter (24%). Losses were 5.5 times less frequent than gains and observ ed mainly at Xcen-q21, 6cen-q22, and 18cen-q11.2 (11% each). Recurrent and metastatic tumors showed a mean of 4.0 +/- 2.2 aberrations per sample. The most frequently gained regions were chromosome 7 (4 cases), 5q14-q32 (4 cas es), 6p (3 cases), and 12q (3 cases). Losses of DNA sequences were 3.4 time s less frequent than gains. Histological tumor grade was significantly asso ciated with metastasis-free survival (P = .002) and overall survival (P = . 003), being the strongest prognostic factor tested. A statistically signifi cant correlation was found between gain at 8q24.1-qter and shorter overall survival (P = .01) but not with local recurrence or metastasis-free surviva l. Gain at 14q24-qter was associated with a trend to shorter overall surviv al (P = .05) but neither with an increased risk for local recurrence nor wi th metastasis-free survival. In a multivariate analysis, only the tumor gra de associated with overall survival (P = .02). In a multivariate analysis t ogether with the tumor grade, gain at 8q24.1-qter did not retain its signif icance (P = .44), indicating that this imbalance is not an independent prog nostic factor. Copyright (C) 1999 by W.B. Saunders Company.