Prevalence of venous thromboembolism (VTE) among patients (pts) with acute leukemia (AL) prior to treatment.

Abstract

6595 Background: Cancer and cancer treatment increases the risk of VTE. However, the association of AL and VTE is unknown. Methods: We performed a retrospective chart review to determine the prevalence of VTE prior to treatment and recurrence of VTE. Medical records of 1295 pts [299 acute lymphoblastic leukemia (ALL) pts and 996 acute myelogenous leukemia (AML) pts] at MD Anderson Cancer Center between November 1999 and May 2005 were reviewed and analyzed. All computations were conducted using Stata version 11. Results: Of the 1295 pts with AL, the overall prevalence of VTE was 1.6% (22 VTE cases, median age: 63.5 yrs). The prevalence was 2.3 % (7/299) and 1.5% (15/996) among ALL and AML patients, respectively. Two of 14 AML pts were M3-AML. In the ALL group, 1 pt had VTE approximately 1 month prior to ALL diagnosis (dx), and 6 pts developed VTE at the time of ALL dx. In the AML group, 3 pts had VTE prior and 12 pts developed VTE at AML dx. Pulmonary embolism occurred in 4 pts [3 had associated lower extremity (LE) deep venous thrombosis (DVT)]. Nine pts (7 AML, 2 ALL) had upper extremity DVTs, and 9 pts (6 AML, 3 ALL) had LE DVTs. Recurrent VTE occurred in 5/22 (23%) pts. In a univariate model, pts with baseline platelet (plt) count ≤ 50 x 109/L or 50-99 x 109/L had a protective effect on VTE development, with 69% and 85% less likely to develop VTE than pts who had plt count 100-349x 109/L, respectively. Pts with prior history of VTE were 17.8 times (95%CI: 6.3-49.27) more likely to develop a VTE than pts without a prior VTE history. Pts with phlebitis were 4.8 times (95%CI: 1.07-21.9) more likely to develop VTE than pts without phlebitis. In a multivariate model, significant predictors of VTE were baseline plt count and prior history of VTE. Overall survival did not differ between pts who developed VTE prior to treatment versus others. Conclusions: Acute leukemia pts have a high prevalence of VTE. Occurrence of VTE prior to initiation of chemotherapy was not associated with poor prognosis. Further studies should be conducted to establish guidelines for the prevention and management of VTE in pts with leukemia.