The oncology treatment of patients who use oral anticoagulants is connected with high risk of bleeding complications

Vitamin K Antagonists Compared to Low-Molecular-Weight Heparins for Treatment of Cancer-Associated Venous Thromboembolism: An Observational Study in Routine Clinical Practice

Since several trials have demonstrated that low-molecular-weight-heparin (LMWH) is superior to vitamin K antagonist (VKA) in preventing recurrent venous thromboembolism (VTE) in patients with cancer-associated VTE, guidelines now recommend LMWH monotherapy in this setting. We evaluated whether this shift resulted in improved outcomes in routine clinical practice. We performed a cohort study of consecutive patients with cancer-associated VTE during 2001 and 2010. We compared the risks for recurrent VTE, major bleeding and mortality between patients diagnosed before and after 2008 during a 6-month routine follow-up. A total of 381 patients were included, of which 234 (61.4%) were diagnosed before 2008. Before 2008, 23% of the patients were treated with LMWH; thereafter, this percentage was higher: 67%. The 6-month incidence for recurrent VTE was 8.6% in patients diagnosed before 2008 versus 7.5% for patients diagnosed after 2008 (risk difference [RD]: −1.1%; 95% confidence interval [CI]: −6.3, 5.3). The respective risks for major bleeding were 6.4 versus 4.8% (RD: −1.6%; 95% CI: −3.8 to 5.8), and 39.7 versus 41.5% (RD: 1.8%; 95% CI: −8.8, 12) for overall mortality. The mean time in therapeutic range (TTR) of patients treated with VKA was 61%. Despite a clear shift toward LMWH as agent of choice for cancer-associated VTE, we did not observe a clear improvement in terms of recurrent VTE and bleeding complications.

The antiangiogenic properties of sulfated β-cyclodextrins in anticancer formulations incorporating 5-fluorouracil

Sulfated β-cyclodextrins (S-β-CDs) are useful excipients for improving the solubility of drugs. One such formulation incorporating 5-fluorouracil (5-FU), termed FD(S), showed improved efficacy over 5-FU alone in orthotopic carcinoma xenograft models. S-β-CDs have heparin-like anticoagulant properties, which may have contributed toward the improved antitumor effect of FD(S). S-β-CDs have also been reported to modify a number of processes involved in angiogenesis. Although the anticoagulant nature of S-β-CDs was established, the antiangiogenic properties of S-β-CDs within FD(S) were unknown. The effect of S-β-CD and FD(S) on the proliferation and migration of endothelial cells in live-cell kinetic assays, and the reorganization of human umbilical vein endothelial cells into tubule structures in vitro was assessed. The effects of S-β-CD on angiogenesis in vitro were validated ex vivo using the rat aorta ring assay and the chick embryo chorioallantoic membrane assay. S-β-CD does not alter proliferative endothelial cell sensitivity to 5-FU cytotoxicity. S-β-CD alone and within FD(S) significantly inhibited angiogenesis by impeding endothelial cell migration, resulting in the inhibition of tubule formation and hence new vasculature. In addition to the cytotoxic action of the drug 5-FU, therapeutic inhibition of angiogenesis by S-β-CDs within FD(S) could potentially limit local invasion and metastases. This has important implications for the exploitation of S-β-CDs for drug formulation improvements or for drug delivery of anticancer biologics.

Predictors of major bleeding in peri-procedural anticoagulation management

BACKGROUND

Appropriate periprocedural management for chronically anticoagulated patients requires assessment of patient-specific thrombosis and bleeding risks. However, predictors of post-procedure bleeding are unknown.

OBJECTIVES

To determine the 3-month cumulative incidence and independent predictors of peri-procedural bleeding in chronically anticoagulated patients requiring temporary warfarin interruption for an invasive procedure.

METHODS

In a protocol driven, cohort study design, all patients referred to the Mayo Clinic Thrombophilia Center for peri-procedural anticoagulation management (1997-2007; n = 2182), were followed forward in time to determine the 3-month cumulative incidence of peri-procedural bleeding (Kaplan-Meier product limit) and potential predictors of bleeding (Cox proportional hazards). Decisions to 'bridge' with low-molecular-weight heparin were based on estimated thromboembolism and bleeding risk.

RESULTS

Indications for chronic anticoagulation included venous thromboembolism (38%), atrial fibrillation (30%) and mechanical heart valves (27%). Of these, 1496 (69%) patients received bridging therapy. The 3-month cumulative incidence rates of major and overall bleeding were 2.1% and 5.1%, respectively. Major bleeding occurred more frequently in patients receiving bridging therapy (3% vs. 1%; P = 0.017). Independent predictors (hazard ratio; 95% confidence interval) of major bleeding included mitral mechanical heart valve (2.2; 1.1-4.3), active cancer (1.8; 1.0-3.1), prior bleeding history (2.6; 1.5-4.5) and re-initiation of heparin therapy within 24 h after the procedure (1.9; 1.1-3.4).

CONCLUSION

Factors predisposing to peri-procedural bleeding are primarily patient-specific. Premature heparin re-initiation is an avoidable provider-specific variable to consider.