(2002; 91 pages)
Tamoxifen and risks of thromboembolic events
Tamoxifen is already a widely used hormonal treatment in women following treatment for early and advanced breast cancer. Now, in addition to its use as a treatment in cancer, preliminary results from the International Breast Cancer Intervention Study (IBIS) provide evidence for the use of tamoxifen to prevent breast cancer in healthy women at high risk. The results so far show that the incidence of breast cancer has been reduced by one-third in women at high risk, compared to women taking placebo. However, the study also indicated that tamoxifen can increase the risk of thromboembolism, particularly during and immediately after major surgery or periods of immobility. The Department of Health in the United Kingdom has communicated the following information.
1. The benefits for women being treated for breast cancer with tamoxifen outweigh the risks. It is important that women taking the drug as a treatment continue to do so.
2. There is evidence of some increase in risk from thromboembolism with tamoxifen especially during and immediately after major surgery or periods of immobility. Patients should be made aware of the symptoms of venous thromboembolism and if they have any sudden onset of breathlessness they should consult their doctor immediately.
2. The IBIS study gives evidence of the preventative action of tamoxifen in breast cancer. However this is not a use of tamoxifen that has yet been approved except in the context of clinical trials.
Reference: Urgent Communication from Chief Medical Officer, 27 March 2002. http://www.mca.gov.uk