Solitary fibrous tumor/hemangiopericytoma treated with temozolomide plus bevacizumab: a report of four cases and literature review

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare tumor derived from mesenchymal tissue. Although standard chemotherapy for SHT/HPC has not been established, temozolomide plus bevacizumab (TMZ+Bev) therapy for SFT/HPC has been reported. The effectiveness and safety of TMZ+Bev (temozolomide 150 mg/m(2) orally on days 1-7 and days 15-21 and bevacizumab 5 mg/kg intravenously on day 8 and day 22 on a 28-day cycle), which was administered from December 2013 until April 2019 to four patients with SFT/HPC, were retrospectively analyzed. Four patients with SFT/HPC received TMZ+Bev. The age of the patients ranged from 41 to 75 years. Two were male, and the primary tumor sites were the meninges in three patients and the pleura in one. One achieved partial response; the others, stable disease (SD). The progression-free survival time ranged from 9.4 to 29.6 months according to RECIST v1.1. One patient died 59 months after using TMZ+Bev, and the others survived for 17 to 64 months. All patients experienced Grade 3 or higher lymphopenia, and three had Grade 3 or higher leukopenia and neutropenia. One patient subsequently received doxorubicin; another, pazopanib. TMZ+Bev therapy for SFT/HPC is safe and effective for maintaining long-term SD.