LMWH in cancer patients with renal impairment - better than warfarin?

Venous thromboembolism (VTE) is one of the leading causes of death in cancer patients, which are known to have a 5- to 7-fold increased risk for VTE. The anticoagulant treatment of VTE in cancer patients is less effective with a three-fold increased risk of VTE recurrence compared to non-cancer patients, and it is less safe with more than double rates of major bleeding. Compared to vitamin-K antagonists (VKA), long-term secondary prevention with low molecular weight heparin (LMWH) has been shown to reduce the risk of recurrent VTE in cancer-associated thrombosis (CAT), and therefore, current international guidelines recommend the use of LMWH over VKA. With increasing age, cancer prevalence and VTE incidence increase while renal function decreases. Anti-cancer treatment may impair renal function additionally. Therefore, renal insufficiency is a frequent challenge in CAT patients, which is associated with a higher risk of both bleeding and recurrent VTE. Both VKA and LMWH may be associated with less efficacy and higher bleeding risk in renal insufficiency. Unfortunately, there is a lack of prospective data on renal insufficiency and CAT. A recent sub-analysis from a large randomized controlled trial shows that the bleeding risk in patients with severe renal insufficiency in CAT is not elevated with the use of LMWH compared to VKA while efficacy is maintained. In addition, LMWH treatment has several practical advantages over VKA, particularly in patients with CAT while they are receiving anti-cancer treatment.