Temozolomide in rare brain tumors of the adult: a prospective study

Abstract

1574 Background: Little is known about the role of salvage chemotherapy in adult patients with rare brain tumors relapsing after conventional treatments. Methods: Patients with histologically confirmed ependymomas (grade II and III WHO), medulloblastomas, germinomas, gliomatosis cerebri and brain stem gliomas, an age ≥18 yrs, and a Karnofsky performance status ≥ 60, who recurred after surgery and/or radiotherapy, were enrolled. Some patients had received a prior treatment with nitrosureas or platinum compounds. TMZ was administered at 200 mg/m2 for 5 days in cycles of 28 days up to tumor progression or unacceptable toxicity. Tumor response was evaluated according to Macdonald’s criteria basing on MRI. Results: Thirty-three patients were evaluable, with a median of 5 cycles of TMZ (range 1–18). Among ependymomas (11 pts) we observed 2 CR with TTP of 9–48+ months, 3 PR with TTP of 4–15 months, 5 SD (3 minor responses) with TTP of 7–44+ months and 1 PD. All responding (CR + PR) patients had grade III (anaplastic) ependymomas, and 2 of them displayed delayed responses (after 6 and 12 cycles respectively). All 3 patients with medulloblastoma had a SD (TTP 3–6 months) and 1 patient with a germinoma progressed under TMZ. Among patients with gliomatosis (12) we observed 1 CR (TTP 13 months), 1 PR (TTP 15 months), 5 SD (median TTP 8 months) and 5 PD. Four patients had a significant improvement in headache or seizures. The 6 patients with brain stem glioma (grade II) had 1 PR, 3 SD and 2 PD (median TTP 6 months). Myelotoxicity was mild, with 1 patient with grade IV thrombocytopenia. Conclusions: Temozolomide has activity in ependymomas (CR + PR 45%) and gliomatosis cerebri (CR + PR 16%). Further clinical and translational studies in these two tumor types are warranted. No significant financial relationships to disclose.