Cancer patients and characteristics of pulmonary embolism

To check the hypothesis that cancer patients suffer from extended pulmonary embolism (PE) more frequently than patients without cancer we analysed PEs proved by computed tomography (CT)-imaging.

One hundred and fifty consecutive CT scans at the University Hospital of Essen from March 2002 until December 2004 which proved a definite case of pulmonary embolism were retrospectively reviewed (79 men, 71 women; mean age 57+/-15 years). Underlying disease and blood parameters were included (haemoglobin, haematocrit, fibrinogen and total protein, if determined within 48 h before the CT scans).

Patients with malignant disease were older (59+/-12 years vs. 54+/-19 years, p=0.05) and tend to have a higher rate of central PEs (52% vs. 34%, p=0.08) than patients without malignancies. The odds of a central PE in cancer patients was about twice as high as in patients without a malignant disease (Odds ratio: 2.08, 95%-confidence interval: 1.06-4.10; age-adjusted Odds ratio 1.88, 95%-confidence interval: 0.92-3.84). Additional adjustment for the clinical information dyspnoea, inhospital patient and clinically expected PE did not deteriorate the odds. Thrombus density determined in patients with central PE only shows a trend towards a lower density in patients with malignant disease (52+/-13 HE vs. 45+/-15 HE, p=0.13). There is no statistical evidence that thrombus density is related to one of the blood parameters or even blood density measured in the pulmonary artery.

Although this is a retrospective study including a small number of patients it shows that cancer patients are at a higher risk for central PE than patients without cancer. Characteristics of the intrapulmonal thrombus in cancer and non-cancer patients seem to be different.