Systemic treatment preferences for patients with advanced desmoid-type fibromatosis (DF) in Europe.

Abstract

e22523 Background: The treatment of DF as a rare, benign mesenchymal tumor is poorly standardized and based on physician’s choice. Only a few clinical trials have assessed the different treatment options in DF and randomized evidence is virtually non-existing. We evaluated systemic treatment preferences for patients (pts) with advanced DF among European sarcoma experts, aiming to provide a reference for a generally acceptable control treatment for potential prospective randomized trials. Methods: A 7-item structured questionnaire was sent to physicians in Europe and Israel involved in the multidisciplinary care and experimental treatment of mesenchymal tumors, to assess their systemic treatment choices for DF. Results: The questionnaire was sent to 266 experts (117 institutions, 21 countries), 54 experts (52 institutions, 14 countries) responded. Wait and see was the most common primary approach for pts with advanced DF. (Symptomatic) Disease progression and failure or non-availability of local treatment options were cited as common reasons for considering systemic therapy. Treatment preferences for pts with sporadic vs hereditary DF were similar, with a tendency of earlier use of chemotherapy in hereditary DF. At least 28 different agents or regimens are used in DF. Tamoxifen +/- nonsteroidal anti-inflammatory agents (NSAIDs) or NSAIDs alone are most commonly used in first line, followed by methotrexate- or anthracycline-containing regimen. Tyrosine kinase inhibitors are often used in further lines; other drugs are sporadically used. Clinical trial activity in DF was restricted to only one country/one multi-centric study. Conclusions: DF pts in Europe and Israel have broad off label access to systemic agents, but only to a few clinical trials. Treatment approaches are diverse, poorly standardized and based on weak evidence. There is an urgent need for practice-defining, prospective randomized trials. Such trials should ideally select a homogeneous population of pts with well documented, progressive, symptomatic disease and/or functional impairment after wait and see and/or local treatments. NSAIDs +/- tamoxifen could be considered a generally accepted standard control treatment for clinical trials.