Second-line treatment with carboplatin for recurrent or progressive oligodendroglial tumors after PCV (procarbazine, lomustine, and vincristine) chemotherapy: a phase II study

BACKGROUND: The efficacy of second-line chemotherapy for patients with recurrent or progressive oligodendroglial tumors is limited. In the current study, the authors investigated the use of carboplatin as a second-line chemotherapeutic agent against these types of tumors. METHODS: Twenty-three patients with recurrent or progressive oligodendrogliomas or oligoastrocytomas after first-line PCV (procarbazine, lomustine, and vincristine) chemotherapy were enrolled in a single-institution Phase II study of second-line carboplatin chemotherapy. All patients had undergone surgery, and most also had undergone conventional radiotherapy. Carboplatin was administered at a dose of 560 mg/m2 intravenously every 4 weeks. Responses were evaluated according to conventional criteria, based on magnetic resonance imaging (MRI) findings. RESULTS: Three of 23 patients (13%) had partial responses, with neurologic improvement. Twelve patients (52%) had stable disease; in 2 of these 12 patients, a minor response was seen on MRI. Eight patients (35%) had progressive disease. The median time to tumor progression was 3 months for all patients and 9 months for patients who experienced responses to treatment. Progression-free survival rates at 6 and 12 months were 34.8% and 8.7%, respectively. Among the salvage treatment plans followed after carboplatin chemotherapy were supportive care alone, radiotherapy, third-line chemotherapy, and reoperation. The median survival duration from the start of carboplatin administration was 16 months. Myelotoxicity was severe, with Grade 3 or 4 thrombocytopenia in 60% of patients and Grade 3 or 4 neutropenia in 48% of patients. CONCLUSIONS: When administered according to a monthly schedule, carboplatin exhibited modest activity in adult patients with recurrent or progressive oligodendroglioma or oligoastrocytoma who experienced treatment failure after PCV chemotherapy; the current treatment regimen also was associated with severe toxicity. Further improvement of second-line chemotherapy for the patient group examined in the current study is necessary.