Desmoid-type fibromatosis in children: a step forward in the cooperative group setting

Desmoid-type (aggressive) fibromatosis (desmoid tumor) is a soft tissue neoplasm that can occur in both children and adults. Although it is formally classified as an intermediate-grade neoplasm because of its propensity for locally invasive growth, it can lead to severe and life-threatening problems. Because metastases do not arise from desmoid tumor, therapeutic interventions have historically focused on surgery or radiation to achieve local tumor control. These approaches may be ineffective or impractical for some children. In those cases, systemic therapy with cytotoxic or noncytotoxic therapy has been used. Because of the relative rarity of this neoplasm in children, knowledge on the use of chemotherapy is based largely on anecdotal reports or retrospective series. Limited conclusions can be drawn, though, from these types of reports. In the last 10 years, two prospective phase II clinical trials of chemotherapy for children with desmoid tumor have been conducted in cooperative clinical trials centered in North America. We review the results of those clinical trials and suggest future directions for systematically approaching this disease to better define the role of chemotherapy for children with desmoid tumor.