Low-dose chemotherapy with methotrexate and vinblastine for patients with advanced aggressive fibromatosis

This Phase II study was undertaken to assess the activity of methotrexate plus vinblastine in the treatment of patients with inoperable aggressive fibromatosis (AF) and to observe the evolution of the disease after such low-dose chemotherapy.

Thirty patients with a median age of 27 years who were affected by primary (20%) or recurrent (80%), advanced, inoperable AF were treated with weekly methotrexate at a dose of 30 mg/m(2) plus vinblastine at a dose of 6 mg/m(2) for a median interval of 1 year. Patients with recurrent disease had received surgery, radiotherapy, tamoxifen, and antracycline-based chemotherapy. Tumor response was assessed in all patients as well as time to disease progression.

Eighteen patients (60%) showed stable disease or minor tumor shrinkage along with symptom relief. A partial response was detected in 12 patients (40%). No complete responses were observed, and no patients had tumor progression during treatment. Four patients received fewer than 15 cycles of chemotherapy, mainly because of severe myelotoxicity. One of these patients died of local disease progression 33 months later, and the other three patients were stable. After a median follow-up of 75 months, the 10-year actuarial progression free interval is 67%.

Methotrexate plus vinblastine given every 7-10 days for several months is associated with prolonged stable disease in a substantial subset of patients with advanced (inoperable) aggressive fibromatosis.