Retrospective analysis of outcomes among more than 1,000 patients with newly diagnosed anaplastic oligodendroglial tumors

Abstract

2014 Background: Treatment of anaplastic oligodendroglial tumors is controversial. Early results of randomized trials suggest chemotherapy (CT) with procarbazine-lomustine-vincristine (PCV) before or after radiotherapy (RT) improves progression-free but not overall survival (OS) versus RT alone. It is unknown if CT alone affects outcome versus CT&RT, or if temozolomide (TMZ) compares favorably with PCV. Methods: We retrospectively identified adults with newly diagnosed anaplastic oligodendroglioma (AO) or oligo-astrocytoma (AOA) seen at 17 medical centers from 1981–2007 exclusive of phase III or bone marrow transplant trials. Data were updated January 1, 2009. Survivals were estimated by Kaplan-Meier method and compared with log-rank. Results: There were 1054 patients: 594 men, 460 women; median age 42 (18–88); 661 with AO, 443 with AOA. Treatment was: observation (82, 8%), RT alone (n = 210, 20%), RT then chemotherapy (283, 27%), RT + CT concurrently (118, 11%), CT alone (205, 19%), CT then RT (137, 13%), or other (19, 2%). Median time to progression (TTP) and OS were 2.8 and 6.5 years, respectively, with median follow up of 4.1 years (0.03–20.8) on surviving patients (n = 560, 53%). 1p19q co-deletion was observed in 292 (48%) and no deletion in 232 (38%) of 606 tested tumors. Co-deletion predicted longer median TTP (4.2 vs. 1.8 years for no deletion, p = 0.0002) and OS (8.4 vs. 3.3 years, p < 0.0001). Median TTP was longer following CT&RT (sequential or concurrent) than CT alone (3.7 vs. 2.6 years, p = 0.0007), but median OS did not differ (6.6 vs. 7.1 years, p = 0.8); co-deletion was more common with CT alone than CT&RT (p < 0.0001, χ2), although restricting analysis of CT&RT versus CT to the co-deletion cohort yielded analogous results (median TTP 7.2 vs. 3.8 years, p = 0.011; OS 7.9 vs. 10.4 years, p = 0.26). Median TTP was longer following PCV alone (7.6 years, n = 17) than TMZ alone (3.3 years, n = 65) with co-deletion (p < 0.02); median OS was also longer (not reached, vs. 7.1 years), but did not reach statistical significance (p = 0.07 log-rank). Conclusions: 1p19q co-deletion predicted improved outcome. Treatment strategies varied widely. CT alone did not appear to shorten OS versus CT&RT. PCV may be superior in efficacy to TMZ. Multivariate analyses and additional 1p19q testing are in progress. [Table: see text]