Background: The aim of this study was to assess the objective response rate (ORR) of children and young adults with recurrent medulloblastoma/primitive neuroectodermal tumor (MB/PNET) treated with temozolomide (TMZ). The secondary purpose was to analyze the toxicity profile of TMZ when administered orally for 5 days in 3 divided daily doses every 28 days.
Methods: Forty-two patients with recurrent MB/PNET, aged 21 years and younger, were recruited. Patients were treated with oral TMZ. Starting doses ranged from 120 to 200 mg/m(2)/day based on previous treatments. A craniospinal MRI was performed prior to the first cycle of TMZ and following every 2 cycles of treatment.
Results: Median age was 10 years (range, 2-21 years). Forty of 42 patients were assessed for response and toxicity. The objective response rate was 42.5%: 6 patients achieved a complete response, 11 had a partial response, and 10 had stable disease. Progression-free survival rates for all patients at 6 and 12 months were 30% and 7.5%, respectively. Their median overall survival rates at 6 and 12 months were 42.5% and 17.5%, respectively. No major extrahematological effects or life-threatening events were reported. The most common grade 3/4 toxicity included thrombocytopenia (17.5%), neutropenia (7.5%), and anemia (2.5%).
Conclusions: TMZ proved to be an effective agent in children and young adults with MB/PNET, heavily pre-treated, with a tolerable toxicity profile.
Keywords: medulloblastoma; phase II trial; temozolomide.