For Patients with Desmoid-Type Fibromatosis, Moderate Dose Radiotherapy Proves Effective

The data revealed that response after radiation therapy is gradual, and that continuing regression is seen even after three years.

The phase II EORTC (European Organization for Research and Treatment of Cancer; Brussels, Belgium) trial study’s findings were first published online July 17, 2013, in the journal Annals of Oncology. Dr. Ronald B. Keus, from the Arnhem Radiotherapy Institute (The Netherlands), and coordinator of the study, stated, “Although one should still be cautious to use radiotherapy in these young patients, it is important to have shown sound proof of efficacy of radiotherapy in this disease.”

A rare form of cancer, desmoid-type fibromatosis is a soft tissue neoplasm that can recur frequently but is not metastatic. The survival prognosis for patients with this disease is good, but due to the frequent recurrences, the consequences of treatment can lower functional outcomes and quality of life. Desmoid-type fibromatosis strikes most frequently in individuals between 30 and 40 years of age.

The first line of treatment for patients with desmoid-type fibromatosis is typically surgery, so the phase 2 EORTC 62991-22998 trial was done to determine if moderate doses of radiotherapy might improve outcome for patients with inoperable and progressive disease or in cases of expected extensive and mutilating surgery. The primary endpoint was local control rate at three years, and secondary endpoints were objective tumor response, acute toxicity, and late toxicity.

Dr. Winette van der Graaf, from the Radboud University Medical Center (Nijmegen, The Netherlands), and chair of the EORTC Soft Tissue and Bone Sarcoma Group, said, “Desmoid fibromatosis remains a challenge for surgeons, radiotherapists and medical oncologists. This study has generated valuable information about radiotherapy as an option for patients with desmoid-type fibromatosis which can be discussed at future multidisciplinary sarcoma tumor boards.”

The EORTC trial 62991-22998 enrolled 44 patients, 27 females and 17 males, between 2001 and 2008 in twelve sites located in five countries: Germany, Belgium, Poland, The Netherlands, and the United Kingdom. The median age was 39.5 years, and the key tumor areas included trunk 15 (34.1%) and extremities 27 (61.3%). At a median follow-up of 4.8 years, the three-year local control rate was 81.5%.

The best overall response during the first three years was complete response in six patients (13.6%), partial response in 16 patients (36.4%), stable disease in 18 patients (40.9%), and progressive disease in three patients (6.8%). One patient (2.3%) was non-evaluable. After three years two patients improved to total response and one patient improved to partial response. Five patients developed new lesions during the study, and 10 patients experienced mild edema as a late toxicity. Acute grade 3 side effects were limited to mucosal membranes, skin, and pain.

Related Links:
Arnhem Radiotherapy Institute