Cardiovascular and cancer safety of testosterone in women

To examine the recent data pertaining to the relationships between testosterone and cardiovascular disease (CVD) and cancer in women.

Despite the entrenched belief that higher blood levels of testosterone increase the risk of CVD in women, data from recent observational studies mostly show an inverse relationship between testosterone and CVD risk. One pilot study suggests favorable effects of nonoral testosterone treatment of women with established congestive cardiac failure which merits further evaluation. The relationship between endogenous testosterone production and breast cancer risk remains contentious, with recent studies indicating either no relationship, or a possible increase in risk when estrone and estradiol are not taken into account. No randomized controlled trial of testosterone therapy has been sufficiently large or of sufficient duration to establish whether such treatment may influence breast cancer occurrence. There does not appear to be an association between testosterone and endometrial cancer, or other malignancies on review of published studies.

Testosterone is inversely associated with increased CVD risk in women, whereas low sex hormone binding globulin increases CVD risk. The relationship between testosterone and breast cancer remains unclear, although a clear signal of risk has not emerged from studies of women treated with testosterone therapy over the past decade.