Background:
• Desmoid tumor represents an intermediate grade neoplasm with a striking predilection for locally invasive growth and recurrence following resection
• More effective, well-tolerated non-surgical treatment options are needed
• Current approaches
• If feasible, watchful waiting is the preferred approach
• 20-30% spontaneous regression
• In situations where treatment is indicated, the following approaches are utilized
• Surgery is the primary approach if minimal morbidity is anticipated
• Medical therapies
• Cytotoxic drugs
• Tyrosine kinase inhibitors
• Hydroxyurea
• Gamma secretase inhibitors
• mTOR Inhibitor Rationale
• Desmoid tumor is well-known to be associated with deregulation of the APC/β-catenin pathway
• Deregulation of the mTOR cell proliferation/survival pathway may play an important role in tumor biology when the APC/βcatenin pathway is disrupted
• The mTOR inhibitor sirolimus is attractive as a potential targeted therapy for desmoid tumor
• Well-tolerated in children and young adults • Can be given orally in tablet or liquid formulatio
