Response to chemotherapy of solitary fibrous tumour: a retrospective study

Abstract

Background: To report on anthracycline-based chemotherapy in a retrospective case-series analysis of solitary fibrous tumour (SFT) patients treated within the Italian Rare Cancer Network.

Patients and methods: We reviewed a set of SFT treated with chemotherapy since 2002, focusing on anthracycline, administered alone or in combination with ifosfamide. Responses to ifosfamide as a single agent were also evaluated. Pathologic diagnosis was centrally reviewed, distinguishing typical, malignant (MSFT) and dedifferentiated (DSFT) subtypes.

Results: Among 42 SFT patients treated with chemotherapy, we selected 31 cases (mean age: 62 years; locally advanced/metastatic: 13/18; front-line/further line: 25/6; typical/MSFT/DSFT/not assessable: 1/17/12/1) who received anthracycline-based chemotherapy (anthracycline monotherapy: eight; anthracycline+ifosfamide: 23). 30 patients are evaluable for response. Best response by Response Evaluation Criteria in Solid Tumours (RECIST) was: partial response (PR): 6 (20%), stable disease (SD): eight (27%), progressive disease (PD): 16 (53%) cases. Responses were confirmed after 3 months. Median progression-free survival (PFS) was 4 (range 2-15) months, with 20% of patients being progression-free at 6 months. PR was found in 2/18 (11%) MSFT and 4/12 (30%) DSFT, with a median PFS of 3.5 and 5 months in MSFT and DSFT, respectively. 19 patients received high-dose prolonged-infusion ifosfamide (front-line/further line: 11/8; typical/MSFT/DSFT: 0/15/4) with two (10%) PR, five (26%) SD, 12 (63%) PD.

Conclusions: This retrospective series suggests that in SFT anthracyclines have a degree of antitumour activity in the range of soft tissue sarcoma chemotherapy. Ifosfamide monotherapy seemed to have lower activity. A higher response rate was observed in DSFT in comparison to MSFT. Studies on targeted therapies are ongoing.