Trabectedin in synovial sarcoma: a retrospective case series analysis from two reference centers

Abstract

Background Synovial sarcomas (SS) are high grade tumors of mesenchymal origin. Although rare, they represent one of the most common soft tissue sarcoma (STS) in children and young adults. Responses were consistently seen amongst patients with metastatic SS with trabectedin (T). Here we report on the activity of T in patients with SS treated in 2 Italian referall centers. Patients and methods We retrospectively reviewed the medical records of patients with metastatic SS treated with T at Humanitas Clinical and Research Center, Rozzano, Milan and Santo Stefano Hospital, Prato, between January 2010 and June 2014. Results Between January 2010 and June 2014, 10 patients with metastatic SS received T, administered as 24- hour continuous infusion at a dose of 1.5 mg/m2 every 3 weeks (9 patients at Humanitas Clinical and Research Center, Rozzano, and 1 at Santo Stefano Hospital, Prato. Six were female, four male. Median age at diagnosis was 44 years (range 26-65). Primary sites of disease were upper limb (n=1), lower limb (n=6), right atrium (n=1), pleura (n=2). Nine patients had local disease at diagnosis. Among these patients, 8 received surgery, 6 radiotherapy, and 4 anthracycline-based chemotherapy, of whom 1 in the adjuvant and 3 in the neoadjuvant setting. Median time to metastasis was 12 months (range 6-146). Upon the development of metastatic disease, all patients received chemotherapy. Median number of chemotherapy regimens in the metastatic setting before trabectedin was 1 (range 0-2). Amongst the evaluable patients 3 PR, 2 SD and 4 PD were seen for a RR of 33% and CBR of 55%. Median PFS was 3 months (range 1-10). As of June 2014, one patient is still receiving T. The most common G3-4 adverse events related to trabectedin were transaminitis (G3 in 2:10, 20%), neutropenia (G3 in 2:10, 20% and G4 in 1:10, 10%). Conclusions Trabectedin showed significant activity in patients with metastatic SS although in our series responses were short lasting without any relevant toxicity.