Cees Tijssen

PURPOSE: Anaplastic oligodendroglioma are chemotherapy-sensitive tumors. We now present the long-term follow-up findings of a randomized phase III study on the addition of six cycles of procarbazine, lomustine, and vincristine (PCV) chemotherapy to radiotherapy (RT). PATIENTS AND METHODS: Adult patients with newly diagnosed anaplastic oligodendroglial tumors were randomly assigned to either 59.4 Gy of RT or the same RT followed by six cycles of adjuvant PCV. An exploratory analysis of the correlation between 1p/19q status and survival was part of the study. Retrospectively, the methylation status of the methyl-guanine methyl transferase gene promoter and the mutational status of the isocitrate dehydrogenase (IDH) gene were determined. The primary end points were overall survival (OS) and progression-free survival based on intent-to-treat analysis. RESULTS: A total of 368 patients were enrolled. With a median follow-up of 140 months, OS in the RT/PCV arm was significantly longer (42.3 v 30.6 months in the RT arm, hazard ratio [HR], 0.75; 95% CI, 0.60 to 0.95). In the 80 patients with a 1p/19q codeletion, OS was increased, with a trend toward more benefit from adjuvant PCV (OS not reached in the RT/PCV group v 112 months in the RT group; HR, 0.56; 95% CI, 0.31 to 1.03). IDH mutational status was also of prognostic significance. CONCLUSION: The addition of six cycles of PCV after 59.4 Gy of RT increases both OS and PFS in anaplastic oligodendroglial tumors. 1p/19q-codeleted tumors derive more benefit from adjuvant PCV compared with non-1p/19q-deleted tumors.

PURPOSE: Anaplastic oligodendrogliomas are more responsive to chemotherapy than high-grade astrocytomas. We investigated, in a multicenter randomized controlled trial, whether adjuvant procarbazine, lomustine, and vincristine (PCV) chemotherapy improves overall survival (OS) in newly diagnosed patients with anaplastic oligodendrogliomas or anaplastic oligoastrocytomas. PATIENTS AND METHODS: The primary end point of the study was OS; secondary end points were progression-free survival (PFS) and toxicity. Patients were randomly assigned to either 59.4 Gy of radiotherapy (RT) in 33 fractions only or to the same RT followed by six cycles of standard PCV chemotherapy (RT/PCV). 1p and 19q deletions were assessed with fluorescent in situ hybridization. RESULTS: A total of 368 patients were included. The median follow-up time was 60 months, and 59% of patients have died. In the RT arm, 82% of patients with tumor progression received chemotherapy. In 38% of patients in the RT/PCV arm, adjuvant PCV was discontinued for toxicity. OS time after RT/PCV was 40.3 months compared with 30.6 months after RT only (P = .23). RT/PCV increased PFS time compared with RT only (23 v 13.2 months, respectively; P = .0018). Twenty-five percent of patients were diagnosed with combined 1p/19q loss; 74% of this subgroup was still alive after 60 months. RT/PCV did not improve survival in the subgroup of patients with 1p/19q loss. CONCLUSION: Adjuvant PCV chemotherapy does not prolong OS but does increase PFS in anaplastic oligodendroglioma. Combined loss of 1p/19q identifies a favorable subgroup of oligodendroglial tumors. No genetic subgroup could be identified that benefited with respect to OS from adjuvant PCV.

PURPOSE: Recent studies have shown the prognostic significance of IDH1 mutations in glioma. It is yet unclear if IDH1 mutations are predictive for outcome to chemotherapy. We determined the effect of IDH1 mutations on progression-free survival and overall survival (OS), and its correlation with other clinical and molecular features in the prospective randomized European Organization for Research and Treatment of Cancer study 26951 on adjuvant procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea, and vincristine (PCV) in anaplastic oligodendroglioma. EXPERIMENTAL DESIGN: IDH1 and IDH2 alterations of the mutational hotspot codons R132 and R172 were assessed by the bidirectional cycle sequencing of PCR-amplified fragments. MGMT promoter methylation was assessed using methylation-specific multiplex ligation-dependant probe amplification based on methylation-sensitive restriction analysis. Loss of chromosomes 1p, 19q, 10, and 10q and the gain of 7 and the EGFR gene were assessed with fluorescence in situ hybridization. RESULTS: From 159 patients, sufficient material was available for IDH1 analysis. In 151 and 118 of these patients, respectively, the 1p/19q status and the MGMT promoter methylation status were known. In 73 cases (46%), an IDH1 mutation was found and only one IDH2 mutation was identified. The presence of IDH1 mutations correlated with 1p/19q codeletion and MGMT promoter methylation, and inversely correlated with loss of chromosome 10, EGFR amplification, polysomy of chromosome 7, and the presence of necrosis. IDH1 mutations were found to be prognostic in the radiotherapy- and the radiotherapy/PCV-treated patients, for both progression-free survival and OS. With Cox proportional hazard modeling for OS with stepwise selection, IDH1 mutations and 1p/19q codeletion but not MGMT promoter methylation were independent prognostic factors. CONCLUSION: In this homogeneously treated group of anaplastic oligodendroglioma patients, the presence of IDH1 mutations was found to carry a very strong prognostic significance for OS but without evidence of a predictive significance for outcome to PCV chemotherapy. IDH1 mutations were strongly associated with 1p/19q codeletion and MGMT promoter methylation.

Spinal dural arteriovenous fistula (SDAVF) is a rare and enigmatic disease entity. The clinical features and structural changes have been recognized since 1926, and the pathophysiology and the essentials of treatment since 1974, but up to the present day it is unknown why these fistulas develop. The fistula between a radicular artery and the corresponding radicular vein within the dural root sleeve leads to congestion of the venous outflow of the spinal cord and eventually ischaemia. Patients, who are mostly middle-aged men, develop a progressive myelopathy, which at the early stages of the disease often mimics a polyradiculopathy or anterior horn cell disorder. By the time involvement of upper motoneurons or sacral segments makes the diagnosis of SDAVF inescapable, patients suffer from considerable neurological deficits. The diagnosis relies on MRI, which shows swelling of the spinal cord, with a centrally located hyperintense signal on T2-weighted images, and with hypointense 'flow void' phenomena dorsal to the cord, representing enlarged and tortuous veins. Catheter angiography is required to determine the exact location of the fistula as well as the angio-architecture, on which the mode of treatment depends. If the arterial feeder of the fistula is a tributary of the anterior spinal artery, embolization is not possible. After embolization recanalization may occur, but this is rarely seen after filling of the draining vein with glue. Alternatively, operation is a safe and permanent mode of treatment. No prognostic factors have been reliably established. Muscle strength and gait disturbances respond better to treatment than pain and symptoms related to damage of sacral segments. In any middle aged male patient with ascending motor or sensory deficits in the legs, SDAVF should be considered in order to prevent irreversible handicap.

OBJECTIVES: To determine the response rate and factors correlated with response of oligodendroglial tumors to procarbazine, lomustine (CCNU), and vincristine (PCV) chemotherapy. DESIGN: Retrospective, observational multicenter study. METHODS: Patients treated with PCV or intensified PCV chemotherapy for a recurrent oligodendroglial tumor after surgery and radiation therapy with measurable disease were retrospectively evaluated for response. A 50% reduction in cross-sectional enhancing tumor area was considered a partial response. Stabilized or responding patients received six cycles of PCV unless unacceptable toxicity occurred. RESULTS: Fifty-two patients were included; median time to progression (MTP) for the entire group was 10 months. In 17% of patients a complete response (MTP, 25 months) was obtained, and in 46% a partial response (MTP, 12 months) was obtained. Median overall survival was 20 months. Although treatment was discontinued for toxicity in seven patients, it was generally well tolerated. The intensified PCV regimen was more toxic. Patients initially presenting with seizures and patients with tumor necrosis in histologic specimens had a better response rate in contrast to patients who had their first relapse within 1 year of first treatment (surgery and radiation therapy). CONCLUSIONS: Oligodendroglial tumors are chemosensitive, but most patients will have relapsed after 12 to 16 months. New studies must aim at improving initial treatment and second-line chemotherapy.