The high incidence of vascular thromboembolic events (VTE) in advanced urothelial cancer (UC) patients (pts) treated with carboplatin (Cb): Analysis of treatment with gemcitabine (G)/cb (GCb), gcb/bevacizumab (GCbBev), or gemcitabine/cisplatin (GCis)

316 Background: VTE occur in ~13% of pts receiving Cis-based therapy for UC. Cb-based therapy is considered less thrombogenic but no definitive data exist to support this conclusion. While Bev added to chemotherapy (Ch) increases VTE in other tumors, VTE impact when added to UC Ch is unknown. This study evaluated the incidence of and etiologic factors for VTE in UC pts treated with GCb, GCbBev and GCis. Methods: UC pts treated from 6/2006 to 6/2010 on a GCbBev protocol were analyzed prospectively. Planned therapy was 6 cycles of GCbBev then Bev alone; pts who had ≥ 3 cycles were included. Similar UC pts treated with GCb or GCis during the same time were retrospectively evaluated. Type of VTE and potential contributing clinical factors were collected. VTE was defined as pulmonary embolism, vascular thrombosis, myocardial infarction or cerebral vascular accident. Associations with Ch regimen were tested using Fisher’s exact test or linear regression. Factors associated with VTE were analyzed using conditional logistic regression stratified by Ch regimen. Results: 198 pts were analyzed. VTE occurred in 13/51 (26%) GCbBev pts, 22/92 (24%) GCb pts, and 8/55 (15%) GCis pts. Age (≤65 vs >65; p