509P - Desmoid-type fibromatosis with a remarkable response to pazopanib treatment

Date 18 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Cytotoxic agents
Sarcoma
Presenter Eisuke Kobayashi
Citation Annals of Oncology (2016) 27 (suppl_9): ix163-ix168. 10.1093/annonc/mdw597
Authors E. Kobayashi, A. Kawai, H. Chuman
  • Musculoskeletal Oncology, National Cancer Center Hospital, 1040045 - Tokyo/JP

Abstract

Background

A wait-and-see policy at the initial presentation is the current standard treatment of desmoid-type fibromatosis (DTF). Although some cases of DTF have a very aggressive course with a high tendency toward local recurrence, the significance of surgery is still controversial, and systemic treatment options are very limited.

Methods

Here we report two Japanese patients with unresectable DTF treated with pazopanib.

Results

Case 1. A 19-year-old male Japanese patient with unresectable recurrent DTF in his thigh was admitted to our institution 6 months after initial surgical resection by a referring surgeon. Magnetic resonance imaging (MRI) confirmed a huge recurrent tumor involving his sciatic nerve. Though he had started systemic treatment with NSAIDS or tamoxifen or methotrexate for two years, there was a gradual increase in the size of the mass and worsening of pain. Eventually he started treatment with pazopanib (800 mg). Pazopanib treatment brought about a significant improvement in clinical symptoms after three months of treatment. MRI demonstrated a remarkable radiological response with significantly decreased gadolinium enhancement and persistent regression. Second-look biopsy confirmed the histological degeneration of this tumor. His tumor has remained stable in size one year after starting pazopanib treatment. Case 2. A 60-year-old male Japanese patient with huge DTF in his chest wall was admitted to our institution. CT confirmed a tumor seemed to be unresectable due to its involvement in his 2nd to 6th libs. Though he had started systemic treatment with NSAIDS or tamoxifen or methotrexate for one year, the mass showed progression in size. He started treatment with pazopanib (800 mg). Then he achieved a remarkable shrinkage of the tumor only one month after the pazopanib administration. The dose was finally reduced to 400 mg due to severe hand-foot syndrome.

Conclusions

Pazopanib can be an effective and promising treatment option for progressive or refractory DTF.

Clinical trial indentification

Legal entity responsible for the study

N/A

Funding

N/A

Disclosure

All authors have declared no conflicts of interest.