References & Sources

Hormone therapy and breast cancer recurrence

Bluming AZ, Tavris C. Estrogen Matters: Why Taking Hormones in Menopause Can Improve Women's Well-Being and Lengthen Their Lives, Without Raising the Risk of Breast Cancer. Revised edition, 2024. A review of 25 studies of hormone therapy use after a breast cancer diagnosis, published between 1980 and 2013, found that only one (the HABITS trial) showed an increased risk of recurrence, and that risk was limited to local or contralateral recurrence rather than distant spread.

Progesterone and breast cancer risk

Fournier A, Berrino F, Clavel-Chapelon F. "Breast cancer risk in relation to different types of hormone replacement therapy in the E3N-EPIC cohort." International Journal of Cancer. 2005;114(3):448-454. This study found that micronized (bioidentical) progesterone combined with estrogen carried meaningfully lower breast cancer risk than synthetic progestins combined with estrogen. View on PubMed

Testosterone and breast cancer incidence

Glaser RL, Dimitrakakis C. "Reduced breast cancer incidence in women treated with subcutaneous testosterone, or testosterone with anastrozole: a prospective, observational study." Maturitas. 2013;76(3):342-349. View on PubMed

Estriol and estrogen receptor-beta

Estriol binds preferentially to estrogen receptor-beta, the receptor subtype associated with anti-proliferative effects, rather than receptor-alpha, which is more strongly linked to cell growth. This is a biological and mechanistic rationale rather than a clinical outcomes study, and is presented here as context rather than as direct evidence of reduced breast cancer risk or recurrence.

This page is provided for informational purposes and does not replace individualized medical advice. Please discuss your personal health history and risk factors directly with Dr. Sapan.