Hormonal manipulation with toremifene in sporadic desmoid-type fibromatosis

Abstract

Introduction: Many patients affected by desmoid-type fibromatosis (DF) are treated with a course of hormonal therapy as front line. So far, tamoxifene has been the preferred choice. Toremifene is an anti-oestrogen agent, but possible further mechanisms of action in desmoids are related to its role in regulation of transforming growth factor-beta and β-catenin pathways.

Material and methods: We retrospectively reviewed all patients treated with toremifene between 2005 and 2012 at a reference institution. Indication to toremifene was radiologically progressive disease and/or symptomatic deterioration. Progression-free survival (PFS), clinical benefit (CB) and safety profile were analysed.

Results: Forty-four patients were treated with toremifene 180 mg daily, 20 for radiological progression, 16 for pain and 8 for both. In 28 patients, toremifene was offered as front-line therapy, while in 11 after tamoxifen failure. PFS was 89.6% at 2 years. According to Response Evaluation Criteria in Solid Tumours, partial response, stable disease and disease progression were observed in 25%, 65% and 10% of the patients, respectively. Symptomatic relief was obtained in 75% of patients. Median time to response was 4 months. Overall CB was 86%. Adverse events G≥2 according to National Cancer Institute Common Toxicity Criteria were recorded in ten patients.

Discussion: Present series provides evidence to make toremifene an option in patients with DF, even after failure on different hormonal agents. A prospective trial is ongoing to confirm these results.

Trial registration: ClinicalTrials.gov NCT02353429.

Keywords: Aggressive fibromatosis; Desmoid-type fibromatosis; Hormonal therapy; Soft tissue sarcoma; Toremifene.