1502P - Vinorelbine is an Active Drug in Desmoid Tumors / Aggressive Fibromatosis: Institut Gustave Roussy Experience

Abstract

ABSTRACT Background Desmoid tumors /aggressive fibromatosis (AF) are locally aggressive neoplasms with frequent relapses despite optimal loco-regional treatments. In case of disease progression, non loco-regional therapeutic options include non steroidal agents, hormonal therapy and systemic chemotherapy including Anthracyclins or Vinca Alkaloids. Vinorelbine (VNR) has been poorly investigated in AF. Methods This is a retrospective review of patients with recurrent/progressive AF treated with single agent oral VNR between April 2006 and April 2012 at Institut Gustave Roussy. Results Seventeen patients (pts) received oral VNR (90 mg weekly). There were 3 males and 14 females with a median age of 35 years (14-58 yrs). Eleven pts (65%) showed PD according to RECIST before inclusion while 6 pts (29%) were stable but with progressive symptoms. VNR was given as monotherapy in 7 pts, in combination with hormonal therapy (Tamoxifen plus LHRH agonist) in 9 pts and with COX 2 non-steroidal anti-inflammatory drugs in 2 pts. The median tumor size was 11cm (3.7-29cm). AF were extra-abdominal in 12 pts (extremity: 3, superficial trunk: 5, girdle 4) and intra abdominal in 5 pts. Prior therapy included surgery (53%), radiation therapy (12%), hormonal therapy (53%), Imatinib (12%) and chemotherapy (6%). The median duration of VNR treatment was 6 months (2-23m). Tolerance was excellent with no grade III-IV toxicities. Twelve pts had a tumor shrinkage including 7 RECIST PR (41%), 5 during VNR and 2 others few weeks after drug discontinuation. Nine pts (53%) achieved a RECIST disease stabilisation and one pt (6%) progressed during chemotherapy. Symptomatic relief during treatment was observed in 75% of pts. After a median follow-up of 3 years, the 1 and 3-yr PFS rates were 94% (72-99%) and 87% (62-96%) respectively. VNR was rechallenged in 3 progessing pts and a PR was seen in 2 cases. Conclusion Weekly oral VNR is a well tolerated regimen and highly effective in achieving significant and durable clinical benefit in AF. Tumor shrinkage can be observed after drug discontinuation .VNR can be rechallenged in previously responding pts. This regimen deserves further developments. Disclosure All authors have declared no conflicts of interest.