Venous thromboembolic disease and cancer.

Venous thromboembolic disease is a common cause of mortality and morbidity in patients with cancer. Patients have a 5-6-fold increase in the risk for a venous thromboembolism (VTE) compared with the general population, increasing to 6-7-fold for some cancers. Prophylaxis for VTE should be considered whenever additional risk factors intervene. About 10% of patients with an idiopathic VTE will harbour an occult cancer. Half of these can probably be detected after a focused history, examination, routine blood tests and a chest x ray. The remaining cases may be diagnosed with an intensive screening protocol. About 60% of patients diagnosed on screening will have early disease, but we do not know whether screening improves the outcome. Evidence suggests that patients with cancer and a VTE should be treated with low-molecular-weight heparin, and treatment continued until the cancer is cured.