Potential new treatment for desmoid fibromatosis

New hope is available for children who have a tumor called desmoid fibromatosis, according to results of a national clinical trial that was led by a St. Jude researcher.

The study found that the combination treatment of vinblastine and methotrexate can reduce tumor size or block tumor growth in most children, according to a report on the results published in the February 10 issue of Journal of Clinical Oncology. In addition, the treatment is well tolerated by children with this disease.

Desmoid fibromatosis is a cancer that arises from cells that help form muscles, tendons and nervous tissue. Although these tumors do not spread to other parts of the body, they are aggressive and can invade neighboring tissues and organs, causing damage that can be fatal.

“To our knowledge, this is the first prospective clinical trial of chemotherapy for desmoid fibromatosis in children,” said the paper's first author, Stephen Skapek, MD, Oncology. “This trial showed that long-term control of the disease requires at least a year of therapy. Therefore, parents and families should understand that since treatment should continue as long as it's well tolerated and there's no evidence that the disease has progressed.”

The national trial followed 26 patients whose age at the start of the study ranged from 7.2 months to about 20 years. Sixteen of these patients had desmoid fibromatosis that had returned after previous treatment, while the other 10 children received this new treatment because clinicians believed that surgery or radiation would not be beneficial.

The investigators found that one patient had a complete response to treatment (no evidence of disease for at least a month); four had partial responses (tumor size reduced by more than half) and three had minor responses (tumor size reduced more than 25 percent but less than 50 percent). The disease progressed in eight patients, three of whom had elected to halt treatment; and eight others patients had not experienced progression of the disease for 12 to 71 months after the end of therapy. 

The trial was conducted with support from the Children's Oncology Group. Other St. Jude investigators included Anne Speights, Cancer Center, and former employee Frederic Hoffer, MD.