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

Markers of thrombotic risk - fibrinogen, factor VIII and immunoglobulin G ( IgG) anticardiolipin titres - were measured, and the presence of lupus anti coagulant and factor V Leiden were assessed in 84 patients with a solid or haematological malignancy. These patients were monitored, following the ins ertion of an indwelling venous catheter, for thrombosis. Fifty-five were gi ven 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 antic ardiolipin levels. Lupus anticoagulant was present in five and three were h eterozygous for factor V Leiden. A high prevalence of a range of prothrombo tic changes was confirmed and the frequent presence of low-titre anticardio lipin antibody in subjects with malignancy demonstrated. However, none of t hese parameters predicted the development of thrombosis (P > 0.05).