1. ¹CCRI, St. Anna Children's Hospital, A-1090 Vienna, Austria
2. ²Department of Medical Genetics, Haartman Institute, University of Helsinki, FIN-00014 Helsinki, Finland
3. ³Laboratory of Medical Genetics, Helsinki University Central Hospital, FIN-00014 Helsinki, Finland
4. ⁴Ontario Cancer Institute and Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5G 2M9, Canada
5. ⁵Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5G 2M9, Canada
6. ⁶Division of Pathology, Department of Pediatric Laboratory Medicine, Hospital for Sick Children, Toronto, Ontario M5G 2M9, Canada
7. ⁷St. Anna Children's Hospital, A-1090 Vienna, Austria
8. ⁸Department of Oncology, University Children's Hospital, CH-8032 Zürich, Switzerland

Correspondence: C M Hattinger, CCRI, St. Anna Children's Hospital, Kinderspitalgasse 6, A – 1090 Vienna, Austria

⁹Current address: Laboratorio di Ricerca Oncologica, Istituti Ortopedici Rizzoli, Via di Barbiano 1/10, I – 40136 Bologna; E-mail: genetica.onc@ior.it

Received 20 December 2001; Revised 25 March 2002; Accepted 27 March 2002.

Abstract

Although greater than 50% of Ewing tumours contain non-random cytogenetic aberrations in addition to the pathognomonic 22q12 rearrangements, little is known about their prognostic significance. To address this question, tumour samples from 134 Ewing tumour patients were analysed using a combination of classical cytogenetics, comparative genomic and fluorescence in situ hybridisation. The evaluation of the compiled data revealed that gain of chromosome 8 occurred in 52% of Ewing tumours but was not a predictive factor for outcome. Gain of 1q was associated with adverse overall survival and event-free survival in all patients, irrespective of whether the tumour was localised or disseminated (overall survival: P=0.002 and P=0.029; event-free survival: P=0.018 and P=0.010). Loss of 16q was a significant predictive factor for adverse overall survival in all patients (P=0.008) and was associated with disseminated disease at diagnosis (P=0.039). Gain of chromosome 12 was associated with adverse event-free survival (P=0.009) in patients with localised disease. These results indicate that in addition to a 22q12 rearrangement confirmation in Ewing tumours it is important to assess the copy number of 1q and 16q to identify patients with a higher probability of adverse outcome.