Solid cancer, antiphospholipid antibodies, and venous thromboembolism.

The pathogenic role of antiphospholipid antibodies (aPL) in the development of venous thromboembolism (VTE) in patients with malignancies has not been established. From May 2006 to April 2008, 258 consecutive patients with solid-organ malignancies who developed VTE (VTE+) were recruited. A group of 142 patients matched for age, sex and tumor type cancer patients without VTE (VTE-) and an age-and-sex matched group of 258 healthy subjects were also included. A second blood sample was taken in positive aPL patients at least 12 weeks later. Twenty-one (8.1%) VTE+ patients, 2 (1.4%) VTE- patients (p=0.006) and 2 (0.8%) healthy subjects (p<0.001) were positive for aPL. Persistent aPL positivity was observed in only 4 out of 15 available VTE+ patients. No differences in demographic characteristics, clinical pattern and outcome were observed in VTE+ patients according to aPL status. The low prevalence and transience of aPL positivity in patients with solid-organ malignancies with VTE argues against a pathogenic role in the development of thrombosis in this setting. The published evidence of the relationship between cancer, aPL, and thrombosis is reviewed.