Molecular profiling of gliomas--time for a regional service.

Editor, Gliomas form a heterogeneous group of intrinsic primary brain neoplasms in terms of pathological and clinical features.1 Low-grade (WHO grade II) gliomas (e.g. astrocytomas and oligodendrogliomas) inevitably recur and progress to higher grade (WHO III-IV) anaplastic tumours. Although they have traditionally been classified using histological criteria, there is increasing evidence that gliomas can be further subtyped based on molecular profile which can predict prognosis and response to treatment.2 Longterm follow-up data has demonstrated a significant survival advantage with anaplastic oligodendroglioma (AO)/oligoastrocytoma (AOA) tumours co-deleted for chromosomal arms 1p and 19q following combined chemo-radiotherapy compared with non-1p19q codeleted cases. These findings validated in both European (EORTC 26951)3 and North American trials (RTOG 9402)4 have meant that 1p19q status predicts post-surgical treatment. The current standard of care is that co-deleted cases receive chemoradiotherapy while non-deleted cases receive only radiotherapy due to the lack of efficacy of combined treatment in this group. Prior to this recent change in practice, all patients with anaplastic oligodendroglial tumours were treated with radiotherapy upfront and received chemotherapy (typically procarbazine, lomustine and vincristine) on relapse. The aim of this regional retrospective study was to establish as a baseline NI clinical outcomes using this pre-1p 19q stratification as a comparator for future outcomes studies.