Cytogenetic aberrations in Ewing sarcoma: Are secondary changes associatedwith clinical outcome?

Background. Ewing sarcoma is associated with a nonrandom pattern of primary and secondary chromosomal aberrations. Whereas the finding of rearrangemen ts of chromosome 22, usually in the form of a balanced translocation t(11;2 2)(q24;q12), is important diagnostically, nothing is known about the potent ial prognostic impact of the secondary chromosomal aberrations. Procedure. During a 13-year-period, short-term cultured tumor samples from 21 children and young adults with Ewing sarcoma were cytogenetically analyzed successf ully. Results. Clonal chromosome aberrations were detected in 18 patients, 17 of whom had the characteristic t(11;22)(q24;q12) or variants thereof. Th e most frequent secondary change was +8, followed by +12, +2, +5, +9, +15, and gain of material from the long and short arms of chromosome 1. The only recurrent secondary change that was restricted to tumors from the ten pati ents that were dead at latest follow-up was gain of 1q material. Furthermor e, all three patients with tumors with chromosome numbers over 50 had died, and the only patient with a tumor karyotype lacking chromosome 22 rearrang ement was alive without evidence of disease. Conclusions. These data and pr eviously published results indicate that the karyotypic pattern not only ma y be of diagnostic significance but also may be important prognostically. M ed. Pediatr. Oncol. 32:79-83, 1999. (C) 1999 Wiley-Liss, Inc.