Clinical Impact and Course of Anticoagulant-Related Major Bleeding in Cancer Patients

Cancer patients with venous thromboembolism (VTE) have a two- to six-fold increased risk of anticoagulant-related major bleeding events compared with VTE patients without cancer. It is unknown whether major bleeding events are more severe in cancer patients than in those without cancer. Individual patient data from four randomized phase III trials that compared factor Xa inhibitors and vitamin K antagonists for the treatment of VTE were used to compare the severity of major bleeding events in patients with and without cancer. Using predefined criteria, the severity of the clinical presentation and course of major bleeding events were classified into four categories of increasing severity. A one-stage meta-analysis was used to evaluate the effect of cancer on the severity of the clinical presentation and course by estimating crude odds ratios (ORs) and ORs adjusted for age, sex and anticoagulant type with 95% confidence intervals (CIs). The study group comprised 290 patients with major bleeding, of whom 50 (17%) had cancer. The clinical presentation was judged to be severe (category 3 or 4) in 38% of patients with cancer and 44% of patients without cancer (adjusted OR, 0.90; 95% CI, 0.47-1.72). The clinical course was found to be severe in 20 and 25% of patients with and without cancer, respectively (adjusted OR, 0.75; 95% CI, 0.35-1.61). The present study suggests that the clinical presentation and course of anticoagulant-related major bleeding events are not more severe in cancer patients than in patients without cancer. This may be reassuring for physicians who treat cancer patients with anticoagulant-related bleeding