Solitary Fibrous Tumor (Sft): a Registry Program to Assess Frequency and Managemente in Our Country. a Spanish Group for Research on Sarcoma (Geis) Study

Abstract

ABSTRACT Aim: SFT are soft tissue sarcomas with low incidence and intermediate biological potential behavior. The main aim of this observational study is to get new insights in clinical presentation, biological behavior and therapeutic approaches of SFT in our country. Methods: A web-based registry was built to collect diagnostic and therapeutic processes in patients (p) with SFT diagnosed in 22 centers (centers of reference and secondary centers) involved in this program. Median progression-free survival (PFS) and overall survival (OS), were estimated by Kaplan-Meier method. Ethics committee approval was obtained. Results: Between September 1999 and November 2013, 163 p (median age 52 years, 52.8% females, 88% had Karnofsky≥80%) were diagnosed. 12 p lacked some relevant data after diagnosis. 7 hospitals included 70% of cases. Primary tumor location was: 24% extremities and trunk-wall, 15% lungs, 13% pleural, 13% head and neck, 14% retroperitoneum and 2.5% meningeal sites. Excisional biopsy and core-biopsy were the method of diagnosis in 65% and 22% of p respectively. Median size was 8.6 cm (range 1-29). 11 p were metastatic at diagnosis. Initial treatment was surgery in 89% of 151 p, followed by adjuvant treatment in 23: 2 chemotherapy (CT), 15 radiotherapy (RT), 5 CT and RT, and 1 radiosurgery. The remaining p received: 1 CT, 2 RT, 1 sunitinib and 2 palliative care. 36 p progressed: 19 p could be resected. Antiangiogenic therapy was used in advanced disease:13 p received sunitinib (5 first line, 3 second line and 5 further lines), 5 p temozolamide-bevacizumab (3 first line and 2 further lines) and 2 p pazopanib (1 first line) . Sunitinib showed clinical benefit (CB) in 8 cases (35, 36, 30, 22, 8, 5, 4 and 2 months of duration), 4 progressions (PR) and 1 unknown. 2 p stopped for toxicity grade III-IV. Temozolamide-bevacizumab experienced CB in 3 cases (30,12, and 6 months of duration), 1 PR and 1 p stopped for toxicity grade III. 1p progressed with pazopanib and 1 was not evaluated for response. Median PFS was 5 years and median OS was not reached. OS and PFS at 10 years were 70% and 50% respectively. Conclusions: SFT are tumors that appear in different localizations, where radical surgery is the treatment of choice. In advanced disease, antiangiogenic therapy could provide longer CB in 60% of progressing cases. Studies with these drugs in advanced SFT are guaranteed. Disclosure: All authors have declared no conflicts of interest.