Patients with cancer are at high risk of venous thrombosis
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《英国医生杂志》
Patients with cancer are seven times more likely to develop venous thrombosis than people without cancer, a Dutch study has found (JAMA 2005;293:715-22). The study found a particularly high risk of venous thromboembolism in the first few months after a diagnosis of cancer and in people with distant metastases.
The study included 3220 volunteers aged 18 to 70 with a first deep venous thrombosis of the leg or pulmonary embolism between March 1999 and May 2002. They were recruited from a larger group of more than 4000 consecutive patients attending six anticoagulation clinics in the Netherlands. The 2131 partners of the patients were the comparison group.
Both groups completed a detailed questionnaire on acquired risk factors for venous thrombosis. Three months after stopping anticoagulant treatment all the participants were interviewed again. Blood samples were also taken, from which DNA was isolated and analysed for two gene mutations that are associated with thrombosis梖actor V Leiden and prothrombin 20210A.
The overall risk of venous thrombosis increased by a factor of seven in patients with cancer compared with those without malignancy (odds ratio 6.7, 95% confidence interval 5.2 to 8.6). Patients with blood cancers had the highest risk of venous thrombosis, adjusted for age and sex (adjusted odds ratio 28.0, 4.0 to 199.7), followed by patients with lung cancer and gastrointestinal cancers. Patients with distant metastases had a higher risk than those without (19.8, 2.6 to 149.1).
The risk of venous thrombosis was highest in the first few months after diagnosis (53.5, 8.6 to 334.3). The relative risk fell considerably after two years but was still higher than in those without cancer. It took 15 years after diagnosis before the risk of thromboembolism returned to control levels.
Jeanet Blom, an author of the study from Leiden University Medical Center, said, "It may be cost effective to consider prophylactic anticoagulant treatment for patients with cancer who have an increased risk of developing venous thrombosis." She hypothesised that tumours may stimulate activation of the clotting system, which is likely to be highly active in recently diagnosed cancer. Cancer treatment is often associated with a hypercoagulable state, she added.
Carriers of the factor V Leiden mutation who also had cancer were at 12 times the risk of a venous thrombosis compared with those who had the mutation but were free of cancer (12.1, 1.6 to 88.1). Similar results were calculated for the prothrombin 20210A mutation. But the research team considered that there was little point in screening for these mutations in patients with cancer, because malignancy was itself associated with a greatly increased risk of venous thromboembolism.(London Susan Mayor)
The study included 3220 volunteers aged 18 to 70 with a first deep venous thrombosis of the leg or pulmonary embolism between March 1999 and May 2002. They were recruited from a larger group of more than 4000 consecutive patients attending six anticoagulation clinics in the Netherlands. The 2131 partners of the patients were the comparison group.
Both groups completed a detailed questionnaire on acquired risk factors for venous thrombosis. Three months after stopping anticoagulant treatment all the participants were interviewed again. Blood samples were also taken, from which DNA was isolated and analysed for two gene mutations that are associated with thrombosis梖actor V Leiden and prothrombin 20210A.
The overall risk of venous thrombosis increased by a factor of seven in patients with cancer compared with those without malignancy (odds ratio 6.7, 95% confidence interval 5.2 to 8.6). Patients with blood cancers had the highest risk of venous thrombosis, adjusted for age and sex (adjusted odds ratio 28.0, 4.0 to 199.7), followed by patients with lung cancer and gastrointestinal cancers. Patients with distant metastases had a higher risk than those without (19.8, 2.6 to 149.1).
The risk of venous thrombosis was highest in the first few months after diagnosis (53.5, 8.6 to 334.3). The relative risk fell considerably after two years but was still higher than in those without cancer. It took 15 years after diagnosis before the risk of thromboembolism returned to control levels.
Jeanet Blom, an author of the study from Leiden University Medical Center, said, "It may be cost effective to consider prophylactic anticoagulant treatment for patients with cancer who have an increased risk of developing venous thrombosis." She hypothesised that tumours may stimulate activation of the clotting system, which is likely to be highly active in recently diagnosed cancer. Cancer treatment is often associated with a hypercoagulable state, she added.
Carriers of the factor V Leiden mutation who also had cancer were at 12 times the risk of a venous thrombosis compared with those who had the mutation but were free of cancer (12.1, 1.6 to 88.1). Similar results were calculated for the prothrombin 20210A mutation. But the research team considered that there was little point in screening for these mutations in patients with cancer, because malignancy was itself associated with a greatly increased risk of venous thromboembolism.(London Susan Mayor)