Adding testosterone to combination hormone therapy with estrogen and progesterone may counteract breast cell proliferation in postmenopausal women, according to the results of a 6-month, prospective, randomized, double-blind, placebo-controlled trial.
In the study, 99 post-menopausal women received continuous combined estradiol 2 mg/norethisterone acetate 1 mg and either a testosterone patch releasing 300 µg/24 hours or a placebo patch.
The women in the placebo group had more than a fivefold increase in total breast cell proliferation from a median value of 1.1% at baseline to a median of 6.2% after 6 months (P<0.001). No such increase occurred in the testosterone group (1.6% vs. 2.0%). Proliferative changes were noted in both epithelial and stromal cells.
Until such time as more data are available, caution should be exercised in adding testosterone to traditional hormone therapy regimens.
Hofling M, Hirschberg AL, Skoog L, et al. Testosterone inhibits estrogen/progestogen-induced breast cell proliferation in postmenopausal women. Menopause. 2007;14:183-190.
Burger HG. Should testosterone be added to estrogen-progestin therapy for breast protection? Menopause. 2007;14:159-162.