MS-24 * SYSTEMIC TREATMENT OF MENINGIOMAS: IS THERE A ROLE FOR LONG-ACTING SOMATOSTATIN?

Abstract

BACKGROUND: Meningiomas are the most common primary brain tumors. Resection and/or radiation therapy are the treatments of choice. Medical therapies have been investigated for inoperable, recurrent and aggressive meningiomas, but the optimal medical treatment is still to be defined. Among biologic agents, somatostatin has been found to inhibit meningioma growth due to the presence of somatostatin receptors on the surface of the tumors. AIM: We retrospectively reviewed our experience with sandostatin to assess the efficacy and toxicity in the treatment of recurrent meningiomas failing standard treatments. PATIENTS AND METHODS: A total of 17 patients (7 women and 10 men, median age 65 years) with recurrent grade I or II or III meningiomas have been studied. All patients had already been treated with multiple surgeries or radiation treatments, and all had an overex-pression of somatostatin receptors by octreotide scintigraphy. Before treatment KPS ranged from 60 to 90. The patients received long-acting somatostatin on a monthly administration schedule. Radiographic response on MRI has been assessed by MacDonald Criteria. RESULTS: Patients received 3 to 18 cycles (median 9) of somatostatin. Progression-free survival (PFS) at 6 months was 56%, while PFS ranged from 3 to 25 months with a median of 6 months. Two radiological responses on MRI were achieved (1 PR and 1). Toxicity was uncommon and manageable (2 patients with diarrhea). CONCLUSION: Long acting somatostatin displays minor activity as salvage treatment for recurrent meningiomas after surgery and radiation therapy.