Essentials
Bleeding risk by
anticoagulant choice for
cancer-associated
venous thrombosis (CA-VTE) is unknown. 26 894 people with CA-VTE were followed for
bleeding in a claims database in the United States. Hospitalized
bleeding risk was similar with
direct acting oral anticoagulants vs.
warfarin. Relative hospitalized
bleeding risk varied by
cancer type and
anticoagulant choice. SUMMARY: Background
Direct acting oral anticoagulants (DOACs) are associated with less
bleeding than traditional
venous thromboembolism (VTE) treatments in the general population but are little studied in
cancer-associated VTE (CA-VTE). Objective To determine whether different anticoagulation strategies for CA-VTE have different hospitalized
bleeding rates. Patients/Methods We conducted a retrospective study of patients with CA-VTE, diagnosed between 2011 and 2015, in a large administrative database. Using validated algorithms, we identified 26 894 CA-VTE patients treated with
anticoagulants and followed them for hospitalized severe
bleeding. Cox models were used to assess
bleeding risk, adjusted for age, sex, high dimensional propensity score and
frailty. Results Over 27 281 person-years of follow-up (median 0.6 years), 1204
bleeding events occurred, for a
bleeding rate of 4.4% per patient-year.
Bleeding rates varied by
cancer type, with the highest rate for upper
gastrointestinal cancers (8.6%) and the lowest for
breast cancer (2.9%). In Cox models (hazard ratio [HR]; 95% confidence interval [CI]), compared with
warfarin, DOACS and
low-molecular-weight heparin (
LMWH) had similar hazards of
bleeding (HR, 0.88; 95% CI, 0.69-1.11 and 0.98; 0.85-1.13). Compared with
LMWH, there was no difference in hazard of
bleeding with DOACs (0.86; 0.66-1.12). There was heterogeneity in
bleeding risk with DOACs by
cancer type, with a higher risk of
bleeding in upper
gastrointestinal cancers and lower risk of
bleeding in
prostate cancer and hematologic
cancers. Conclusions In this practice-based sample of CA-VTE patients, DOACs were associated with similar
bleeding risks to
warfarin and
LMWH. These findings suggest a complex association of
bleeding risk with
anticoagulant choice in
cancer patients.