Background: Somatostatin receptors, especially the sst2A subtype, are present on most meningiomas. The addition of somatostatin inhibits meningioma growth in vitro in some studies. There have been anecdotal reports of octreotide inhibiting growth in meningiomas.
Objectives: A prospective pilot trial of sustained-release somatostatin (Sandostatin LAR) in 16 patients with recurrent meningiomas was conducted with a primary study objective of progression-free survival at 6 months.
Methods: Sixteen patients (11 women, 5 men; median age 58) with recurrent meningioma were treated prospectively with long-acting somatostatin. Patients had progressed radiographically after prior therapy with surgery (14/16; complete resection in 5; subtotal in 7; biopsy only in 2), radiotherapy (13/16), and chemotherapy (12/16). All patients had confirmation of the presence of somatostatin receptors in their tumor using (111)In-octreotide, a long-acting somatostatin agonist, SPECT scanning.
Results: Patients received 2 to 15 cycles (median 4.5) of somatostatin with minimal toxicity. Five [corrected] partial responses, five stable disease, and six [corrected] progressive disease patterns were seen. Duration of response ranged from 2 to 20+ months (median 5.0 months). Median survival was 7.5 months (range 3 to 20+). The overall progression-free survival was 44% (seven patients) at 6 months.
Conclusions: In this small trial of patients with recurrent meningiomas shown to overexpress somatostatin receptors by octreotide scintigraphy, long-acting somatostatin (Sandostatin LAR) was administered on a monthly schedule. Thirty-one percent of patients demonstrated a partial radiographic response and 44% achieved progression-free survival at 6 months. Toxicity was minimal, suggesting somatostatin analogues may offer a novel, relatively nontoxic alternative treatment for recurrent meningiomas.