Phase III trial of chemotherapy plus radiotherapy compared with radiotherapy alone for pure and mixed anaplastic oligodendroglioma: Intergroup Radiation Therapy Oncology Group Trial 9402. Adjuvant procarbazine, lomustine, and vincristine improves progression-free survival but not overall survival in newly diagnosed anaplastic oligodendrogliomas and oligoastrocytomas: a randomized European Organisation for Research and Treatment of Cancer phase III trial.
Anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA) are treated with surgery and radiotherapy (RT) at diagnosis, but they also respond to procarbazine, lomustine, and vincristine (PCV), raising the possibility that early chemotherapy will improve survival. Furthermore, better outcomes in AO have been associated with 1p and 19q allelic loss.
                Patients with AO and AOA were randomly assigned to PCV chemotherapy followed by RT versus postoperative RT alone. The primary end point was overall survival. The status of 1p and 19q alleles was assessed by fluorescence in situ hybridization.
                Two hundred eighty-nine eligible patients were randomly assigned to either PCV plus RT (n = 147) or RT alone (n = 142). At progression, 80% of patients randomly assigned to RT had chemotherapy. With 3-year follow-up on most patients, the median survival times were similar (4.9 years after PCV plus RT v 4.7 years after RT alone; hazard ratio [HR] = 0.90; 95% CI, 0.66 to 1.24; P = .26). Progression-free survival time favored PCV plus RT (2.6 years v 1.7 years for RT alone; HR = 0.69; 95% CI, 0.52 to 0.91; P = .004), but 65% of patients experienced grade 3 or 4 toxicity, and one patient died. Patients with tumors lacking 1p and 19q (46%) compared with tumors not lacking 1p and 19q had longer median survival times (> 7 v 2.8 years, respectively; P < or = .001); longer progression-free survival was most apparent in this subset.
                For patients with AO and AOA, PCV plus RT does not prolong survival. Longer progression-free survival after PCV plus RT is associated with significant toxicity. Tumors lacking 1p and 19q alleles are less aggressive or more responsive or both. 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.
                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.
                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.
                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.
Early PCV chemotherapy in addition to standard treatment of surgery and RT does not improve OS in patients with AO or AOA. However, it does improve PFS. It also is associated with significant toxicities. Tumors with 1p and 19q co-deletions are associated with better OS and may indicate a more chemo-responsive tumor.