Multimodal treatment of children with unresectable or recurrent desmoid tumors: an 11-year longitudinal observational study.

The primary goal of treatment for desmoid tumors is complete surgical resection to achieve negative margins. In adults with unresectable or recurrent lesions, treatment options include noncytotoxic and cytotoxic drugs, but little is known about nonsurgical treatment in children. Between 1992 and 2003 six children (four girls, two boys) with a median age of 2.5 years (range 11 months to 9 years) received multimodal adjuvant therapy for unresectable or recurrent desmoid tumors. Primary treatment consisted of noncytotoxic treatment with tamoxifen (1 mg/kg orally, twice daily) and diclofenac (2 mg/kg rectally, twice daily), whereas two children with life-threatening tumor progression in addition received treatment intensification with weekly vinblastine (6 mg/m intravenously) and methotrexate (30 mg/m intravenously). Of the four children with unresectable tumors, two achieved remarkable tumor shrinkage and two had stable disease, whereas two patients were disease-free for 3.7 and 2.6 years after nonradical resection. Median observation time was 3.1 years (range 1-11 years). Treatment was generally well tolerated; only one patient developed pubertal acceleration after a duration of tamoxifen treatment of 9.3 years. Because of the potential life-threatening situation, the management of children with unresectable or recurrent desmoid tumors requires a multidisciplinary approach. Nonaggressive therapy with tamoxifen and diclofenac may be the first treatment choice in these patients, but in patients with progressive disease, cytotoxic chemotherapy is indicated. Weekly administration of vinblastine and methotrexate seems to be safe and effective in these children.