Clinical importance of genomic imbalances in synovial sarcoma evaluated bycomparative genomic hybridization

The t(X;18)(p11.2;q11.2) (SYT/SSX1 or SSX2) is represented in more than 95% of synovial sarcoma. Even if recent data has implicated that the type of f usion gene (SYT/SSX1 or SYT/SSX2) can be of prognostic importance, the cell ular and molecular mechanisms underlying the clinical behavior of synovial sarcoma are still poorly understood. To approach this issue, we investigate d whether secondary genetic aberrations may influence the clinical outcome of synovial sarcoma. Clinical outcome with reference to comparative genomic hybridization (CGH) findings (losses or gains of genetic material) were an alyzed for a uniquely large modern material of 69 synovial sarcomas. Thirty -five of 69 specimens showed DNA sequence copy number changes. The frequenc y of aberrations/tumor were higher (mean 4.7) for monophasic tumors than fo r biphasic tumors (mean 2.1). Gains of the whole or parts, including the lo ng arm, of chromosome 8 were significantly overrepresented in large tumors (>5 cm), suggesting that tumors with this genetic abnormality have an incre ased growth rate. No difference regarding metastasis-free or overall surviv al was seen between patients with or without tumors containing secondary co py number changes. No specific copy number change was linked to a significa ntly improved or impaired metastasis-free survival. (C) 1999 Elsevier Scien ce Inc. All rights reserved.