.jpg)
Breast self-examination
According to a study published in October 2009 by researchers at the UCLA School of Medicine, breast tenderness during hormone replacement therapy may suggest an increased cancer risk. The study was based on data from more than 16,000 participants in the Women's Health Initiative estrogen-plus- progestin clinical trial. Women who experienced breast tenderness after beginning combination hormone replacement therapy (estrogen plus progesterone) were at significantly higher risk for developing breast cancer than women on the combination therapy who did not experience such tenderness.
The study compared the daily use of oral conjugated equine estrogens 0.625 mg (i.e., Premarin®) plus medroxyprogesterone acetate 2.5 mg (i.e., Provera®) to the daily use of a placebo pill. About 50% of the participants took the combination therapy and 50% took the placebo. At the beginning of the trial, all the women received a mammogram and a breast exam. They were questioned regarding breast tenderness at this time and one year later. The development of an invasive breast cancer over the next 5.6 years was documented by a medical record review. Compared to women who received the placebo, women on the combination therapy who did not have breast tenderness at the beginning of the trial were found to have a three times greater risk of developing tenderness after one year (36.1% vs. 11.8%). Of the women who reported breast tenderness at the onset of the study and received combination therapy, the risk at one-year mark was about 1.26 times that of the women who received placebos. Of the women who reported breast tenderness after beginning combination therapy, 76.3% received the combination therapy.
A limitation of this study is that it employed only one form and one dose of oral estrogen, conjugated equine estrogen, which is derived from the urine of pregnant mares. Other forms of estrogen are commercially available and come in different dosages. For example, conjugated equine estrogen is available in 0.3 mg tablets (half the strength of the study dosage). A problem with oral estrogen is that it must go through the digestive process before reaching the blood stream; thus, the amount reaching the blood stream may vary. Estrogen is available as a patch, injection, and even a vaginal cream. All these methods bypass the digestive process and directly enter the blood stream. For example, the estrogen patch reduces menopausal symptoms at much lower dosages than the tablets. Future research may show that lower dosage pills or patches may have a lower breast cancer risk.
Comments