ISTH Congress Abstracts

Official abstracts site for the ISTH Congress

MENU 
  • Home
  • Congress Archive
    • ISTH 2022 Congress
    • ISTH 2021 Congress
    • ISTH 2020 Congress
  • Resources
  • Search

Improved Overall Survival with Warfarin Compared with Direct Oral Anticoagulants in Cancer-associated Venous Thromboembolism: A SEER-medicare Analysis

T. Chiasakul1,2, A.M Khan1, R. Redd3, R. Patell1, E.P McCarthy1,4, D. Neuberg3, J.I Zwicker1

1Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States, 2King Chulalongkorn Memorial Hospital, Bangkok, Thailand, 3Dana-Farber Cancer Institute, Boston, United States, 4Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, United States

Abstract Number: OC 06.1

Meeting: ISTH 2021 Congress

Theme: Venous Thromboembolism » Cancer Associated Thrombosis

Background: Direct oral anticoagulants (DOACs) have comparable efficacy with low-molecular-weight heparin for the treatment of cancer-associated venous thromboembolism (VTE). Whether there is a mortality benefit of DOACs compared with warfarin in the management of VTE in cancer is not established.

Aims: Evaluate overall survival outcomes of DOACs versus warfarin in the treatment of cancer-associated VTE.

Methods: We performed a retrospective cohort analysis using the Surveillance, Epidemiology and End Results (SEER)-Medicare linked database from 2012 through 2016. Eligible patients were individuals with primary gastric, colorectal, pancreatic, lung, ovarian, or brain cancer who were diagnosed with venous thromboembolism and prescribed DOACs or warfarin within 30 days of VTE diagnosis. Patients were matched 1:2 DOAC:warfarin using exact matching for cancer stage and propensity score matching for age, cancer site, cancer stage, and time interval from cancer to VTE diagnosis. The primary outcome was overall survival. Cox proportional-hazards regression was performed to estimate hazard ratios and 95% confidence intervals (95% CI).

Results: A total of 4,044 patients were included (1,348 in DOACs group and 2,696 in warfarin group). Demographic characteristics are presented in Table 1. Within the DOACs group, 1,188 (88%) received rivaroxaban and 160 (12%) received apixaban. With a median follow-up of 40 months, DOACs were associated with a statistically significantly shorter overall survival compared to warfarin (median overall survival, 9.9 months [95%CI: 8.4 to 11.2] versus 12.0 months [95%CI: 10.9 to 13.5]; hazard ratio, 1.18; 95% CI: 1.10 to 1.27; p<0.001) (Figure 1). The observed trend in survival differences were consistent across subgroups of cancer sites, cancer stages, and type of VTE.

Total

N = 4,044

DOACs

N = 1,348

Warfarin

N = 2,696

Age at VTE diagnosis, median (IQR) 75 (70 – 81) 75 (70 – 81) 75 (70 – 81)
Female sex, n (%) 2,284 (56) 761 (56) 1,523 (56)
Median Elixhauser Comorbidity Index Score, median (IQR)  5 (4 – 7) 5 (4 – 7) 5 (4 – 7)

Primary cancer site, n (%)

  Gastric

  Colorectal

  Pancreatic

  Lung

  Ovarian

  Brain

172 (4)

1,376 (34)

532 (13)

1,624 (40)

199 (5)

141 (3)

59 (4)

446 (33)

207 (15)

558 (41)

31 (2)

47 (3)

113 (4)

930 (34)

325 (12)

1,066 (40)

168 (6)

94 (3)

Cancer stage at diagnosis, n (%)

  1-2

  3

  4

  N/A

  Unknown

1,170 (29)

1,116 (28)

1,371 (34)

189 (5)

198 (5)

390 (29)
372 (28)
457 (34)
63 (5)
66 (5)
780 (29)
744 (28)
914 (34)
126 (5)
132 (5)
Received systemic anti-cancer therapy within 3 months of VTE diagnosis, n (%) 1,522 (38) 559 (41) 963 (36)

Type of index VTE, n (%)

Deep-vein thrombosis

Pulmonary embolism

2,349 (58)

1,695 (42)

788 (58)

560 (42)

1,561 (58)

1,135 (42)

Months from cancer diagnosis to index VTE, median (IQR)  4.8 (1.1 – 20.6) 4.6 (1.1 – 19.5) 4.9 (1.1-21.0)

Demographic and clinical characteristics of study cohort after propensity-score Matching.
Kaplan-Meier curves of overall survival in DOACs-treated patients (solid line) versus warfarin-treated patients (dashed line) with cancer-associated venous thromboembolism.

Conclusions: In this retrospective analysis of a large registry database, warfarin was associated with improved overall survival compared to DOACs for treatment of cancer-associated VTE.

To cite this abstract in AMA style:

Chiasakul T, M Khan A, Redd R, Patell R, P McCarthy E, Neuberg D, I Zwicker J. Improved Overall Survival with Warfarin Compared with Direct Oral Anticoagulants in Cancer-associated Venous Thromboembolism: A SEER-medicare Analysis [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/improved-overall-survival-with-warfarin-compared-with-direct-oral-anticoagulants-in-cancer-associated-venous-thromboembolism-a-seer-medicare-analysis/. Accessed October 1, 2023.

« Back to ISTH 2021 Congress

ISTH Congress Abstracts - https://abstracts.isth.org/abstract/improved-overall-survival-with-warfarin-compared-with-direct-oral-anticoagulants-in-cancer-associated-venous-thromboembolism-a-seer-medicare-analysis/

Simple Search

Supported By:

Takeda logo

ISTH 2022 Congress site

Visit the official web site for the ISTH 2022 Virtual Congress »

  • Help & Support
  • About Us
  • Cookies & Privacy
  • Wiley Job Network
  • Terms & Conditions
  • Advertisers & Agents
Copyright © 2023 John Wiley & Sons, Inc. All Rights Reserved.
Wiley