1,720,969 research outputs found
Primary prophylaxis for venous thromboembolism in ambulatori cancer patients receiving chemotherapy.
No full textAbstract
BACKGROUND:
Venous thromboembolism (VTE) often complicates the clinical course of cancer. The risk is further increased by chemotherapy, but the safety and efficacy of primary thromboprophylaxis in cancer patients treated with chemotherapy is uncertain. This is an update of a review first published in February 2012.
OBJECTIVES:
To assess the efficacy and safety of primary thromboprophylaxis for VTE in ambulatory cancer patients receiving chemotherapy compared with placebo or no thromboprophylaxis.
SEARCH METHODS:
For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2013), CENTRAL (2013, Issue 5), and clinical trials registries (up to June 2013).
SELECTION CRITERIA:
Randomised controlled trials (RCTs) comparing any oral or parenteral anticoagulant or mechanical intervention to no intervention or placebo, or comparing two different anticoagulants.
DATA COLLECTION AND ANALYSIS:
Data were extracted on methodological quality, patients, interventions, and outcomes including symptomatic VTE and major bleeding as the primary effectiveness and safety outcomes, respectively.
MAIN RESULTS:
We identified 12 additional RCTs (6323 patients) in the updated search so that this update considered 21 trials with a total of 9861 patients, all evaluating pharmacological interventions and performed mainly in patients with advanced cancer. Overall, the risk of bias varied from low to high. One large trial of 3212 patients found a 64% (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.22 to 0.60) reduction of symptomatic VTE with the ultra-low molecular weight heparin (uLMWH) semuloparin relative to placebo, with no apparent difference in major bleeding (RR 1.05, 95% CI 0.55 to 2.00). LMWH, when compared with inactive control, significantly reduced the incidence of symptomatic VTE (RR 0.53, 95% CI 0.38 to 0.75; no heterogeneity, Tau(2) = 0%) with similar rates of major bleeding events (RR 1.30, 95% CI 0.75 to 2.23). In patients with multiple myeloma, LMWH was associated with a significant reduction in symptomatic VTE when compared with the vitamin K antagonist warfarin (RR 0.33, 95% CI 0.14 to 0.83), while the difference between LMWH and aspirin was not statistically significant (RR 0.51, 95% CI 0.22 to 1.17). No major bleeding was observed in the patients treated with LMWH or warfarin and in less than 1% of those treated with aspirin. Only one study evaluated unfractionated heparin against inactive control and found an incidence of major bleeding of 1% in both study groups while not reporting on VTE. When compared with placebo, warfarin was associated with a statistically insignificant reduction of symptomatic VTE (RR 0.15, 95% CI 0.02 to 1.20). Antithrombin, evaluated in one study involving paediatric patients, had no significant effect on VTE nor major bleeding when compared with inactive control. The new oral factor Xa inhibitor apixaban was evaluated in a phase-II dose finding study that suggested a promising low rate of major bleeding (2.1% versus 3.3%) and symptomatic VTE (1.1% versus 10%) in comparison with placebo.
AUTHORS' CONCLUSIONS:
In this update, we confirmed that primary thromboprophylaxis with LMWH significantly reduced the incidence of symptomatic VTE in ambulatory cancer patients treated with chemotherapy. In addition, the uLMWH semuloparin significantly reduced the incidence of symptomatic VTE. However, the broad confidence intervals around the estimates for major bleeding suggest caution in the use of anticoagulation and mandate additional studies to determine the risk to benefit ratio of anticoagulants in this setting. Despite the encouraging results of this review, routine prophylaxis in ambulatory cancer patients cannot be recommended before safety issues are adequately addressed
International registry on the treatment of unsuspected pulmonary embolism in cancer patients
No full text
Primary prophylaxis for venous thromboembolism in ambulatory cancer patients receiving chemotherapy
No full textBACKGROUND: Venous thromboembolism (VTE) often complicates the clinical course of
cancer disease. The risk is further increased by chemotherapy but the safety and
efficacy of primary thromboprophylaxis in cancer patients treated with
chemotherapy is uncertain.
OBJECTIVES: To assess the efficacy and safety of primary thromboprophylaxis in
ambulatory cancer patients receiving chemotherapy.
SEARCH METHODS: The Cochrane Peripheral Vascular Diseases Group searched their
Specialised Register (last searched 3 May 2011) and CENTRAL (2011, Issue 2). The
authors searched clinical trials registries and reference lists of relevant
studies.
SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing unfractionated
heparin (UFH), low molecular weight heparin (LMWH), vitamin K antagonists (VKA),
direct thrombin inhibitors, direct factor Xa inhibitors or mechanical
intervention to no intervention or placebo; or comparing two different
anticoagulants.
DATA COLLECTION AND ANALYSIS: Data were extracted on methodological quality,
patients, interventions and outcomes including symptomatic VTE and major bleeding
as the primary effectiveness and safety outcomes, respectively.
MAIN RESULTS: Nine RCTs with a total of 3538 patients were considered. None of
the RCTs tested UFH, fondaparinux, direct factor Xa inhibitors or mechanical
interventions. Overall, the risk of bias was low in most of the studies. LMWH,
when compared with inactive control, significantly reduced the incidence of
symptomatic VTE (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.41 to 0.93)
with no evidence of heterogeneity (I(2) = 0%). The number needed to treat to
prevent a symptomatic VTE was 60. LMWH was associated with a 60% increase in
major bleeding when compared with inactive control, although this was not
statistically significant (RR 1.57, 95% CI 0.69 to 3.60; I(2) = 10%). There was a
45% reduction in overall VTE (RR 0.55, 95% CI 0.34 to 0.88; I(2) = 0%) while for
symptomatic pulmonary embolism, asymptomatic VTE, minor bleeding and one-year
mortality the differences between the LMWH and control groups were not
statistically significant. The effect of the vitamin K antagonist warfarin on
preventing symptomatic VTE, measured in only one study, was not statistically
significant (RR 0.15, 95% CI 0.02 to 1.20). In one RCT of patients with myeloma,
LMWH was associated with a 67% reduction in symptomatic VTE (RR 0.33, 95% CI 0.14
to 0.83) compared with warfarin, with no differences in major bleeding.
Antithrombin, evaluated in one study on paediatric patients, had no significant
effect on VTE nor major bleeding when compared with inactive control.
AUTHORS' CONCLUSIONS: Primary thromboprophylaxis with LMWH significantly reduced
the incidence of symptomatic VTE in ambulatory cancer patients treated with
chemotherapy. However, the lack of power hampers definite conclusions on the
effects on major safety outcomes, which mandates additional studies to determine
the risk to benefit ratio of LMWH in this settin
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