Scientists Shed Light on Tamoxifen Risks
4th March 2005 - Results of the largest study into the long-term risks of endometrial cancer after tamoxifen showed that women with breast cancer who are treated with tamoxifen are nearly 2½ times more likely than women not treated with the drug to go on to develop endometrial cancer, and that the risk increases with the length of time for which the patients are treated.
The researchers from The Institute noted that Tamoxifen is an effective treatment of breast cancer which can also reduce the risk of cancer developing in the other breast. However, the research pointed to uncertainties in the balance of benefits and drawbacks if treatment is continued beyond 5 years.
The study examined 1880 patients, 813 of whom had been diagnosed with endometrial cancer after their breast cancer and 1067 of whom had had breast cancer but not endometrial cancer. The scientists found that the effect of tamoxifen on risk of endometrial cancer was comparable in pre- and post-menopausal women, and was not associated with the daily dosage of the drug, varying from 10 mg to 40 mg per day.
The risk of endometrial cancer increased with the duration of the tamoxifen treatment: the longer the woman had been taking the drug, the greater the risk.
Find out more about this project:
- Professor Anthony Swerdlow
- Section of Epidemiology
