Effect of Hydroxyurea as Treatment for Primary Desmoid Tumors

The treatment of desmoid tumors is complicated by benign histology and potentially
aggressive and recurrent behavior. Invasive or intensive treatments with surgery or
radiation therapy can lead to good tumor control, but at the expense of significant side
effects along with a high risk of local recurrence after surgical excision. Low dose
regimens of standard chemotherapy drugs have been favored as a conservative first-line
treatment; however, refractory and recurrent tumors are not uncommon. The purpose of this
study is to investigate the efficacy and safety of using hydroxyurea, an anti-neoplastic
agent with relatively few side-effects, as a novel treatment for primary, unresectable
desmoid tumors, desmoid tumors that have had an incomplete primary resection, or desmoid
tumors that have recurred after other therapy.

Patients presenting to our oncology center with a new diagnosis of desmoid tumor, or a
recurrent desmoid tumor, will be eligible for this study. After informed consent, physical
examination, and baseline imaging studies (CT/MRI), patients will receive oral hydroxyurea
at a starting dose of 20 mg/kg daily. Laboratory tests will be performed at set intervals
to maintain the appropriate dose and monitor for cytopenias. Clinical evaluations, physical
examinations, and/or imaging studies will be conducted every three months to assess for
changes in tumor size. Patients will remain on hydroxyurea as long as there is a response
or stability in tumor size and associated toxicities are manageable. Data will be collected
regarding the response to the drug, the duration of the response, and the occurrence of
adverse events. The goal of the analysis will be to determine the efficacy of hydroxyurea
as a treatment modality for desmoid tumors.