Testosterone for Women and Breast Cancer Awareness
October is breast cancer awareness month and here at Lawley Pharmaceuticals we have been asked the question by women – Is there an increased risk of developing breast cancer if I use testosterone cream? On the balance of evidence the answer to this question is no.
Underlying this concern is the ability of the breast tissue to aromatize testosterone to estradiol (estrogen). 70% of breast cancers are sensitive to the female sex hormone estrogen. These cancers are called hormone receptor positive cancers and are treated by medications that block estrogen production and/or its action on the breast tissue. In in vitro studies testosterone has shown to have inhibitory effects on breast cancer cells and also to have the ability to cause breast cancer cells to self destruct, however it is the conversion to estrogen which requires clarification with regard to breast cancer risk.
Professor Susan Davis, a world leader in the use of testosterone cream for women, has conducted further research into this issue and discusses her findings in the medical paper, Cardiovascular and Cancer Safety of Testosterone in Women (Current Opinion in Endocrinology, Diabetes and Obesity, 2011, 18:198-203). Prof Davis comments that to date there has not been a sufficiently large randomized controlled study on the effects of testosterone and breast cancer risk specifically, however the majority of observational studies do not show an increase in risk.
In one study of 631 Australian women who had been treated with testosterone between 1987 and 2008 there were 12 breast cancers diagnosed. This equates to an incidence rate of 298 per 100,000 women years which is lower than rates reported in the Women’s Health Initiative study (380 per 100,000 women-years) or in the Million Women Study (521 per 100,000 women-years). Another study undertook research into the effects of testosterone on mammographic density. A testosterone patch delivering 300 micrograms of testosterone per day was used in the randomized control study over a 12 month period. The results showed that testosterone was not associated with any change in percentage mammographic density compared to placebo.
Global awareness of breast cancer through campaigns such as Pink Ribbon Day has saved many women lives through early detection and reduction in risk factors. Women have a right to be aware if there are any concerns associated with using hormone products whether it is testosterone cream or other hormone replacement therapy. The Australasian Menopause Society has excellent information with regards to cancer risk and HRT containing estrogen (click here) and based on available research testosterone cream for women has not been associated with an increased risk with regard to breast cancer, although further long term studies are required. As always it is important that in consultation with your physician the benefits and risks of testosterone therapy should be discussed before starting treatment.
If you would like read more about Testosterone for Women, click on the booklet below.