title: Outpatient use of low molecular weight heparin monotherapy for first-line treatment of venous thromboembolism in advanced cancer.
abstract: BACKGROUND
  Evidence-based treatment guidelines recommend low molecular weight heparin (LMWH) monotherapy for cancer-associated venous thromboembolism (VTE). This analysis assessed the first-line treatment strategies for VTE in patients with advanced solid tumors.
  
  
  METHODS
  Using administrative data from advanced lung, prostate, colon, or breast cancer patients diagnosed between January 2000 and December 2007 at four HMOs with integrated delivery systems, patients with an inpatient or outpatient VTE diagnosed within 2 years after cancer diagnosis and an outpatient purchase of warfarin, LMWH, and/or fondaparinux anticoagulant within 7 days of the VTE diagnosis were identified. First-line outpatient VTE pharmacological treatment and factors independently associated with receipt/non-receipt of LMWH monotherapy were assessed.
  
  
  RESULTS
  Overall, 25% of the 1,089 eligible patients received LMWH monotherapy as primary VTE treatment. The percentage increased steadily over time from 18% among patients diagnosed in 2000 to 31% among those diagnosed in 2007. Factors associated with LMWH monotherapy included VTE diagnosis year, chemotherapy within 60 days prior to VTE diagnosis, history of VTE prior to cancer diagnosis, and invasive surgery in the 90 days following VTE diagnosis. Colorectal and prostate cancer patients versus lung cancer patients and stage III versus stage IV patients were less likely to be treated with LMWH monotherapy.
  
  
  CONCLUSIONS
  Adoption of LMWH monotherapy as initial treatment for cancer-associated VTE was low but increased steadily over the study period. Future studies should explore reasons underlying the underutilization of this preferred evidence-based treatment as well as the comparative effectiveness of LMWH versus warfarin-based anticoagulation in real-world cancer patients with VTE.
authors.affiliation: Clinical Pharmacy Research Scientist, Pharmacy Department, Kaiser Permanente Colorado, 16601 E. Centretech Parkway, Aurora, Colorado 80011, USA. tom.delate@kp.org
authors.forename: Thomas
authors.initials: T
authors.lastname: Delate
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Witt
authors.forename: Debra
authors.initials: D
authors.lastname: Ritzwoller
authors.forename: Jane C
authors.initials: JC
authors.lastname: Weeks
authors.forename: Lawrence
authors.initials: L
authors.lastname: Kushi
authors.forename: Mark C
authors.initials: MC
authors.lastname: Hornbrook
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Aiello Bowles
authors.forename: Deborah
authors.initials: D
authors.lastname: Schrag
mesh_terms: D000368:Aged; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009369:Neoplasms / Q000150:complications / Q000473:pathology; D010045:Outpatients; D012307:Risk Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000150:complications / Q000188:drug therapy*; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D006495:Heparin, Low-Molecular-Weight; D014859:Warfarin