Response rate and prognostic factors of recurrent oligodendroglioma treated with procarbazine, CCNU, and vincristine chemotherapy. Dutch Neuro-oncology Group.

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.