Differential Metastasis Inhibition by Clinically Relevant Levels of Heparins—Correlation with Selectin Inhibition, Not Antithrombotic Activity

Abstract

Heparin can attenuate metastasis at clinically relevant doses, likely by inhibiting selectins. Equivalent anticoagulation alone with Fondaparinux is ineffective. Clinically approved heparins have differing abilities to inhibit selectins, likely explained by size distribution. It should be possible to size fractionate heparins and inhibit selectins at concentrations that do not have a large effect on coagulation. Caution is also raised about the current preference for smaller heparins. Despite equivalent anticoagulation, hitherto unsuspected benefits of selectin inhibition in various clinical circumstances may be unwittingly discarded.