Association of Menopausal Hormone Therapy With Breast Cancer Incidence and Mortality During Long-term Follow-up of the Women’s Health Initiative Randomized Clinical Trials

This 2020 study analyzed long-term data from the Women's Health Initiative (WHI) to assess the impact of menopausal hormone therapy (MHT) on breast cancer incidence and mortality. Among 10,739 women with prior hysterectomy, those receiving conjugated equine estrogen (CEE) alone had a significantly lower breast cancer incidence (HR 0.78; 95%