Systemic Therapy in Perivascular Epithelioid Cell Tumors (Pecoma)

Abstract

ABSTRACT Aim: Perivascular epithelioid cell tumors (PEComa) are a family of rare mesenchymal neoplasms with a variable biological behaviour. Surgical resection is the mainstay of therapy. However, approximately one third of patients have an advanced disease d'emblee or develop metastases later on. The role of chemotherapy is controversial, with anecdotal responses reported including some with mTOR inhibitors. Methods: Cases diagnosed with PEComa family tumors from January 2002 at Istituto Nazionale Tumori, Milan, or within the Italian Rare Cancer Network (RTR) were reviewed. Results: We identified 49 pts with PEComa. Nineteen pts (median age: 54.8 years; F/M= 8/11) received systemic therapy for advance disease (1-7 lines). Site of primary tumor was soft-tissues in 6/19pts (32%), retroperitoneum in 5/19pts (26%), kidney in 4/19pts (21%). Site of metastatic disease was lung (6/19pts), liver (6/19pts), peritoneum (3/19pts), bone (2/19pts) and lymph nodes (2/19pts). Eight pts received gemcitabine-based chemotherapy and were evaluable for response: 2 had a PR (25%) and 6 a PD (75%); median PFS was 2.8 mos (0.9-5). Nine pts received an antracyclin-based combination and were evaluable for response: 3 had SD (33%) and 6 a PD (66%); median PFS was 1.5 mos (0.7-3.3). Twelve pts received a mTOR inhibitor and were evaluable for response: 4 had a PR (33%), 5 a SD (41%) and 3 a PD (25%); median PFS was 4.5 mos (1.5-14). Four patients received an antiangiogenic therapy (pazopanib or sunitinib), obtaining 1 PR and 2 SD, with a median PFS 7.3 mos (0.9-9.6). Conclusions: In this series of advanced PEComa patients treated with medical therapy, chemotherapy seems to have played a limited role. However, chemotherapy with gemcitabine-based combinations allowed some objective responses, although their duration was short. We confirm the activity of mTOR inhibitors, again with a short duration. Disclosure: N. Hindi: Clinical Research grant from the Spanish Society of Medical Oncology; S. Stacchiotti: Silvia Stacchiotti has received research funds from Glaxo and Pfizer; P.G. Casali: Consultant / Advisory:Amgen, ARIAD,Bayer GSK,Merck SD,Novartis,Pfizer,PharmaMar, Sanofi-Aventis. Research funds:Amgen,Bayer,GSK ImClone,Infinity,Janssen Cilag,Lilly,Merck Molmed,Novartis,Pfizer,PharmaMar,Sanofi-Aventis Schering Plough. All other authors have declared no conflicts of interest.