Microparticles and cancer.

Cancer is a prothrombotic state, with an increased prevalence of arterial and venous thromboemboli. Microparticles (MPs) are sub-micron-sized vesicles derived from activated or apoptotic cancer cells and/or host cells that may causally contribute to these clinical events, although the strength of the evidence thus far is inconclusive. We review the state-of-the-art understanding of the origin of circulating MPs, their role as a potentially important procoagulant entity in cancer, and their clinically documented association with malignancies. It is anticipated that if the functional importance of circulating MPs in clinically meaningful endpoints in cancer can be proven by appropriately designed and powered prospective studies, future investigation will focus on whether MPs can be targeted for therapeutic purposes. Copyright 2009 S. Karger AG, Basel.