CANCER
Venous thromboembolism in ambulatory day oncology patients
Patients with cancer are at higher risk for developing thromboembolic disease
February 18, 2014
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Venous thromboembolism (VTE) represents one of the most important causes of morbidity and mortality in cancer patients. VTE commonly includes deep vein thrombosis and pulmonary embolism, but also includes thrombosis in other vascular territories. Trousseau first described the association between thrombosis and malignancy in 1885. The pathophysiology of venous thromboembolism is related to multiple factors including hypercoagulability, vessel wall damage and venous stasis. Age, surgery, the presence of central venous indwelling catheters, performance status, immobilisation, prolonged hospitalisation, acquired or congenital thrombophilia and other comorbidities also influence the overall likelihood of thrombotic complications, as they do in patients without cancer.
The interrelationship between cancer and haemostasis is well known. Risk factors for thromboembolism in cancer patients include the cancer type, histology and the stage of the cancer. The risk of VTE is also increased in cancer patients by certain types of chemotherapy, hormonal therapy and anti-angiogenic regimens.
VTE development has serious clinical consequences and can have major impact on the clinical course of the disease, increasing both morbidity and mortality. The poor prognosis of VTE may reflect both a combination of fatal complications and higher disease agressiveness.1
Incidence
According to population-based case-control studies, the two-year cumulative incidence of VTE is between 0.8% and 8%.2 In a recent study of 17,284 patients undergoing chemotherapy in the ambulatory setting, VTE occurred in 12.6% of patients within 12 months of starting chemotherapy. The incidence of VTE in patients without cancer was 1.4% in the control cohort group.3
The increased risk of recurrent VTE in cancer patients is greatest in the first few months after malignancy is diagnosed and can persist for many years after an initial episode of symptomatic VTE.
The most reliable evidence of the incidence of VTE in individuals with a specific malignancy comes from controlled clinical trials of systemic therapy in women with early-stage breast cancer. The B14 and B20 trials in the National Surgical Adjuvant Breast Project4,5 involved women with oestrogen receptor-positive lymph node-negative breast cancer. It found the five-year incidences of VTE in women given placebo, tamoxifen, and tamoxifen plus chemotherapy were 0.2%, 0.9%, and 4.2%, respectively. In women with node-positive breast cancer on chemotherapy, the rate of thrombosis varies between 1% and 10%.6
A recent study found a 2.87% incidence of PE in a total of 13,783 outpatients with cancer in a single institution.7 The incidence of PE in the general population has been reported to be 0.11%.8