Activity of temozolomide and bevacizumab in the treatment of locally advanced, recurrent, and metastatic hemangiopericytoma and malignant solitary fibrous tumor

BACKGROUND:

Hemangiopericytomas and malignant solitary fibrous tumors (HPC/SFT) are rare, closely related sarcomas with unpredictable behavior that respond infrequently to chemotherapy. An optimal systemic treatment strategy for advanced HPC/SFT has not yet been identified.

METHODS:

We retrospectively analyzed the records of 14 patients with histopathologically confirmed HPC/SFT who were treated at The University of Texas MD Anderson Cancer Center between May 2005 and June 2007. All patients were treated with temozolomide 150 mg/m² orally on days 1‐7 and days 15‐21 and bevacizumab 5 mg/kg intravenously on days 8 and 22, repeated at 28‐day intervals. Computed tomography assessment of tumor size and density (Choi criteria) was used to determine the best response to therapy. The Kaplan–Meier method was used to estimate progression‐free survival.

RESULTS:

The median follow‐up period was 34 months. Eleven patients (79%) achieved a Choi partial response, with a median time to response of 2.5 months. Two patients (14%) had stable disease as the best response, and 1 patient (7%) had Choi progressive disease as the best response. The estimated median progression‐free survival was 9.7 months, with a 6‐month progression‐free rate of 78.6%. The most frequently observed toxic effect was myelosuppression.

CONCLUSION:

Combination therapy with temozolomide and bevacizumab is a generally well‐tolerated and clinically beneficial regimen for HPC/SFT patients. Additional investigation in a controlled, prospective trial is warranted. Cancer 2011;. © 2011 American Cancer Society.