[Venous thromboembolism and cancer].

Malignant disease predisposes to deep venous thrombosis (DVT) or pulmonary embolism (PE) in several ways. One classical situation is that of DVT or PE with no apparent cause which may be the first sign of an occult cancer. In this domain, although the epidemiological data is well known, it is important to recognise the limitations of "blind" investigations. Another situation is more common. The patients have a diagnosed malignancy and thromboembolic disease is the main extra-cancer complication. The approach to this problem is changing, both in primary prevention where many trials have already reported encouraging results, and in the treatment after the event where classical therapeutic protocols are not always well adapted. Ancestral fears of the prescription of anticoagulants in cancer patients must cede to a more objective benefit/risk analysis which seems to be very favourable in some situations. Moreover, some publications have demonstrated a chance finding of a possible anticancer effect of antithrombotic agents.