The use of hormone replacement therapy (HRT) in postmenopausal women with a history of breast cancer—particularly estrogen, testosterone, or DHEA—remains controversial and must be approached with caution.

Current evidence suggests that systemic estrogen therapy is generally contraindicated in breast cancer survivors, especially those with estrogen receptor-positive (ER+) disease, due to increased risk of recurrence. Even in women who have undergone bilateral mastectomy and oophorectomy, the systemic hormonal milieu still matters, and residual breast tissue may remain.

However, local (vaginal) estrogen therapy for genitourinary syndrome of menopause (GSM) is considered relatively safe in selected patients with severe symptoms—especially those on aromatase inhibitors or tamoxifen—but only after consultation with the oncology team. Vaginal DHEA may offer similar symptom relief with minimal systemic absorption, though long-term safety data in breast cancer survivors is limited.

The role of testosterone therapy is less well defined; data are sparse, and it should only be considered in specialized settings with close monitoring