Clinical Study The impact of molecular and clinical factors on patient outcome in oligodendroglioma from 20 years’ experience at a single centre Jonathon F. Parkinson ⇑ , Vahid Afaghi, Cathy A. Payne, Michael E. Buckland, Janice M. Brewer, Michael T. Biggs, Nicholas S. Little, Helen R. Wheeler, Raymond J. Cook, Kerrie L. McDonald Cerebral Tumour Research Laboratory, Hormones and Cancer Group, Kolling Institute of Medical Research, Royal North Shore Hospital, Pacific Highway, St Leonards, New South Wales, Australia article info Article history: Received 7 June 2010 Accepted 4 July 2010 Keywords: Anaplastic oligodendroglioma Chemosensitivity Chemotherapy Glioma Oligodendroglioma Prognosis Survival abstract The increased chemosensitivity of oligodendroglial tumours has been associated with loss of heterozy- gosity (LOH) of the p arm of chromosome 1 and the q arm of chromosome 19 (LOH 1p/19q). Other clinical and molecular factors have also been identified as being prognostic and predictive of treatment outcome. We reviewed 105 patients with oligodendroglioma treated at a single centre over 20 years. Median sur- vival in oligodendroglioma patients with LOH 1p/19q was significantly longer (10.9 vs. 2.0 years). In the anaplastic oligodendroglioma group, univariate analysis demonstrated decreased patient age, presenta- tion with seizures, use of adjuvant chemotherapy and LOH 1p/19q as predictors of improved survival. Multivariate analysis confirmed LOH 1p/19q as a significant predictor of improved survival (hazard ratio, 3.4; p = 0.015). Median survival in patients with anaplastic oligodendroglioma with LOH 1p/19q was 15.4 years vs. 1.2 years for those without LOH 1p/19q. This study confirms the utility of LOH 1p/19q as a prognostic marker in oligodendroglioma. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Oligodendroglioma comprise 3% to 5% of primary brain tu- mours 1 and are classified into two grades according to the World Health Organization (WHO) Classification System: oligodendrogli- oma (Grade II; OII) and anaplastic oligodendroglioma (Grade III; AO). Oligodendrogliomas primarily affect adults aged 40 years to 60 years, with a higher incidence of Grade II tumours in younger patients. 2 Despite an extensive search, no causative factor has been unequivocally linked to the development of this tumour. 2 In gen- eral, oligodendrogliomas represent a group of highly chemosensi- tive gliomas, especially to the combination of procarbazine, lomustine (CCNU), and vincristine (PCV). More recently chemo- therapy with temozolomide alone has been utilized, particularly in patients with AO. 3,4 The increased sensitivity to chemotherapy is widely attributed to the co-deletion of the 1p and 19q chromo- some arms, more commonly referred to as loss of heterozygosity of 1p/19q (LOH 1p/19q). Establishing the exact role of LOH 1p/19q in clinical decision- making has been the focus of numerous studies. It is still unclear as to whether LOH 1p/19q is marker of better prognosis alone and/or also a predictor of chemosensitivity. The routine testing of LOH 1p/19q for patients diagnosed with oligodendrogliomas has been ongoing at our Institute for the past 5 years. This clinical audit was conducted to specifically confirm a survival advantage in pa- tients with the co-deletion. In addition, do all patients with oligo- dendrogliomas who do not harbour the co-deletion do poorly? Other factors have been shown to improve prognosis and include younger age at presentation, good Karnofsky Performance Score (KPS), tumour grade, lack of contrast enhancement on MRI scan, low mitotic index and gross macroscopic resection of the tu- mour. 5,6 Patients who initially present with seizure, as opposed to those who present with a neurological deficit, also survive longer. 7 The objective of this study was to conduct an audit of patients diagnosed at Royal North Shore and North Shore Private Hospitals to determine if LOH 1p/19q is associated with better survival. In addition, we wanted to determine if there are factors associated with improved prognosis in those patients with 1p/19q intact oligodendrogliomas. 2. Methods 2.1. Clinical cohort A total of 105 patients diagnosed with an oligodendroglioma were identified. All patients were operated and subsequently treated at Royal North Shore (RNS) and North Shore Private 0967-5868/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2010.07.101 ⇑ Corresponding author. Postal address: 2004 35 Avenue SW, Calgary, Alberta T2T 2E1, Canada. Tel.: + 1 403 4605277. E-mail address: jparkinson@med.usyd.edu.au (J.F. Parkinson). Journal of Clinical Neuroscience 18 (2011) 329–333 Contents lists available at ScienceDirect Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn