A Phase II Trial of Imatinib for Patients With Aggressive Desmoid Tumor (Aggressive Fibromatosis)

Aggressive fibromatosis (AF, also known as desmoid tumor) is a fibroproliferative neoplasm that typically arises in the abdomen but can develop at other anatomic sites, most commonly in the extremities. These tumors have a relatively high local failure rate after primary treatment using surgery and/or radiotherapy, and although rarely giving rise to distant metastases, can be multifocal and, therefore, not surgically resectable. Moreover, tumor may recur adjacent to the site of surgical resection, underscoring the limitations of surgery in the palliative setting. Therefore, effective medical therapies for AF are needed to maintain quality of life and prolong survival.The goal of the current study was to better define the activity of imatinib in the treatment of AF and to determine the molecular basis for response/nonresponse