Polysomy for Chromosomes 1 and 19 Predicts Earlier Recurrence in Anaplastic Oligodendrogliomas with Concurrent 1p/19q Loss

• Published in: Clinical cancer research 2009-10, Vol.15 (20), p.6430-6437
• Main Authors: SNUDERL, Matija, EICHLER, April F, LIGON, Keith L, VU, Quynh U, SILVER, Michael, BETENSKY, Rebecca A, LIGON, Azra H, WEN, Patrick Y, LOUIS, David N, IAFRATE, A. John
• Format: Article
• Language: English
• Subjects: 1p/19q; Adolescent; Adult; Aged; Aged, 80 and over; anaplastic oligodendroglioma; Aneuploidy; Antineoplastic agents; Biological and medical sciences; Brain Neoplasms - genetics; Chromosome Deletion; Chromosomes, Human, Pair 1; Chromosomes, Human, Pair 19; Female; Humans; Male; Medical sciences; Middle Aged; Neoplasm Recurrence, Local; Oligodendroglioma - genetics; Oligodendroglioma - pathology; Pharmacology. Drug treatments; polysomy; Prognosis
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.CCR-09-0867

Purpose: Loss of chromosome arms 1p and 19q is a molecular feature of oligodendroglial tumors characterized by responsiveness to chemotherapy and a favorable prognosis. The purpose of this study was to evaluate the prognostic significance of polysomy of chromosomes 1 and 19 in the setting of 1p/19q codeletion. Experimental Design: We analyzed 64 anaplastic oligodendrogliomas with 1p/19q loss or maintenance diagnosed at Massachusetts General Hospital and Brigham and Women's Hospital from 1996 to 2005; fluorescence in situ hybridization for 1p/19q and Ki-67 immunohistochemistry was done. Polysomy was defined as more than two 1q and 19p signals in >30% of the cells with concurrent 1p/19q deletion. Tumors were divided into groups based on their 1p/19q status and compared for progression-free survival, overall survival, and 5-year survival probabilities. Results: Forty-six tumors (72%) in our cohort had 1p/19q loss and 18 (28%) had 1p/19q maintenance. Of those with loss, 19 (41%) had concurrent polysomy and 27 (59%) lacked polysomy. In agreement with previous studies, the group of anaplastic oligodendrogliomas with 1p/19q loss had significantly better progression-free survival and overall survival than anaplastic oligodendrogliomas with 1p/19q maintenance ( P = 0.0009 and P < 0.0003, respectively). Among anaplastic oligodendrogliomas with 1p/19q loss, those with polysomy showed shorter progression-free survival than those with 1p/19q loss without polysomy ( P = 0.0048). Overall survival was similar in tumors with and without polysomy. The Ki-67 labeling index was not associated with polysomy and did not have prognostic significance. Conclusion: The presence of polysomy in anaplastic oligodendrogliomas with deletion of 1p/19q is a marker of earlier recurrence. (Clin Cancer Res 2009;15(20):6430–7)