Risk factors for thrombosis in cancer patients

Venous thromboembolism (VTE), comprised of deep vein thrombosis (DVT) and its complication, pulmonary embolism (PE), is a multifactorial disease, involving complex interactions between environmental exposures and patients, including their hemostatic system and genetic predispositions. VTE is relatively common, with an overall average age- and sex-adjusted incidence of about 1.04-1.9 per 1000 person-years that rises dramatically with increasing age [1-4]. Active malignancy accounts for almost 20% of incident VTE events occurring in the community [5], and imparts a 4- to 6.5-fold higher VTE risk compared to non-cancer patients, depending on concurrent use of anti-cancer therapy [6]. The risk of VTE also varies by cancer type and stage [7-10]. The association between VTE and malignancy has been recognized since 1861 when Trousseau, in a lecture, described thrombophlebitis as the presenting sign of visceral malignancy [11].