Currently, there is no strong evidence directly linking testosterone therapy to an increased risk of uterine (endometrial) cancer. However, the relationship between testosterone, estrogen, and endometrial health is complex, and more research is needed to fully understand the risks and benefits.
What We Know So Far:
- Testosterone Can Convert to Estrogen
- In women, testosterone aromatizes into estradiol (a potent form of estrogen).
- Since unopposed estrogen (estrogen without progesterone) increases the risk of endometrial hyperplasia and cancer, theoretically, excess testosterone that converts to estrogen could contribute to this risk.
- However, studies have not yet confirmed a clear clinical association.
- Testosterone Alone May Not Stimulate the Uterine Lining
- Unlike estrogen, testosterone itself does not directly stimulate the endometrial lining.
- Some studies suggest that testosterone may even have protective effects against endometrial proliferation.
- Testosterone + Estrogen Therapy in Menopause
- Women on estrogen plus testosterone therapy (often for menopause symptoms) may need to be monitored for endometrial changes, especially if they are not on progesterone, which helps protect the uterine lining.
- A progestin-containing intrauterine device (IUD) or cyclic progesterone therapy may be recommended for women on testosterone therapy who still have a uterus.
- Limited Research on Long-Term Effects
- Most studies on testosterone therapy focus on bone density, cardiovascular health, and libido rather than cancer risk.
- Ongoing research is needed to determine whether long-term testosterone use in women influences endometrial cancer risk.
Who Should Be Monitored?
- Women on high doses of testosterone or long-term therapy
- Women using testosterone therapy without progesterone
- Women with a history of PCOS (which is linked to higher androgen levels and endometrial hyperplasia risk)
Bottom Line
While testosterone therapy is not currently linked to a significant increase in uterine cancer risk, its conversion to estrogen means that monitoring endometrial health remains important. Women on testosterone therapy who have a uterus should consult their healthcare provider about the need for progesterone protection, endometrial screening, or ultrasounds if abnormal bleeding occurs.
Would you like more information on testosterone therapy safety and monitoring recommendations? Let me know!
