Efficacy of trabectedin in malignant solitary fibrous tumors: a retrospective analysis from the French Sarcoma Group.

J Khalifa,A Le Cesne,S Le Guellec,M Ouali,L Chaigneau,J-P Delord,E Bompas,J-Y Blay,P Cousin,B Bui-Nguyen,S Piperno-Neumann,C Chevreau,M Rios,N Penel,L Chaltiel

doi:10.1186/s12885-015-1697-8

Abstract

BackgroundAdvanced malignant solitary fibrous tumors (SFTs) are rare soft-tissue sarcomas with a poor prognosis. Several treatment options have been reported, but with uncertain rates of efficacy. Our aim is to describe the activity of trabectedin in a retrospective, multi-center French series of patients with SFTs.MethodsPatients were mainly identified through the French RetrospectYon database and were treated between January 2008 and May 2013. Trabectedin was administered at an initial dose of 1.5 mg/m2, q3 weeks. The best tumor response was assessed according to the Response Evaluation Criteria In Solid Tumors 1.1. The Kaplan–Meier method was used to estimate median progression-free survival (PFS) and overall survival (OS). The growth-modulation index (GMI) was defined as the ratio between the time to progression with trabectedin (TTPn) and the TTP with the immediately prior line of treatment (TTPn-1).ResultsEleven patients treated with trabectedin for advanced SFT were identified. Trabectedin had been used as second-line treatment in 8 patients (72.7 %) and as at least third-line therapy in a further 3 (27.3 %). The best RECIST response was a partial response (PR) in one patient (9.1 %) and stable disease (SD) in eight patients (72.7 %). Disease-control rate (DCR = PR + SD) was 81.8 %. After a median follow-up of 29.2 months, the median PFS was 11.6 months (95 % CI = 2.0; 15.2 months) and the median OS was 22.3 months (95 % CI = 9.1 months; not reached). The median GMI was 1.49 (range: 0.11–4.12).ConclusionTrabectedin is a very promising treatment for advanced SFTs. Further investigations are needed.

Highlights

Advanced malignant solitary fibrous tumors (SFTs) are rare soft-tissue sarcomas with a poor prognosis
Patients We identified eleven patients with progressive malignant SFT who were treated with trabectedin between January 2008 and May 2013
Trabectedin was used as a second-line treatment in eight patients (72.7 %): six had previously received anthracycline-based chemotherapy and two a targeted therapy; it was at least third-line treatment in three patients (27.3 %)

Summary

Introduction

Advanced malignant solitary fibrous tumors (SFTs) are rare soft-tissue sarcomas with a poor prognosis. Our aim is to describe the activity of trabectedin in a retrospective, multi-center French series of patients with SFTs. Solitary fibrous tumors (SFTs) are rare soft-tissue sarcomas with an estimated incidence of < 0.1/100,000/year [1]. It is established that SFTs can occur in almost any extra-pleural site. They develop mainly in people aged 50–70 years, with a gender ratio of 1:1. Solitary fibrous tumors constitute a heterogeneous group of rare spindle-cell tumors, with an unpredictable course. A small proportion of cases follow an aggressive course (recurrence after local treatment or metastatic progression). Increased mitotic activity (≥4 mitoses per 10 high-power fields), greater cellularity, cellular polymorphism, and the presence of necrosis are associated with malignant behavior [4]

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