Thrombosis, markers of thrombotic risk, indwelling central venous catheters and antithrombotic prophylaxis using low-dose warfarin in subjects with malignant disease

Abstract
Markers of thrombotic risk – fibrinogen, factor VIII and immunoglobulin G (IgG) anticardiolipin titres – were measured, and the presence of lupus anticoagulant and factor V Leiden were assessed in 84 patients with a solid or haematological malignancy. These patients were monitored, following the insertion of an indwelling venous catheter, for thrombosis. Fifty‐five were given prophylactic low‐dose warfarin. Over a mean of 15 weeks there were 10 (12%) thrombotic events in 10 patients. Seven were on warfarin. Haemorrhagic problems occurred in three (5%), all on warfarin. Of the 84 patients, 86% had raised fibrinogen levels, 37% elevated factor VIII and 44% raised anticardiolipin levels. Lupus anticoagulant was present in five and three were heterozygous for factor V Leiden. A high prevalence of a range of prothrombotic changes was confirmed and the frequent presence of low‐titre anticardiolipin antibody in subjects with malignancy demonstrated. However, none of these parameters predicted the development of thrombosis (P > 0.05).