Lessons learned from the Women's Health Initiative trials of menopausal hormone therapy

Area of Science:

• Reproductive Endocrinology
• Cardiovascular Health
• Oncology

Background:

• The Women's Health Initiative (WHI) provided critical data on menopausal hormone therapy (HT).
• Re-evaluation of WHI findings is essential for current clinical practice guidelines.
• Understanding the nuanced risks and benefits of HT based on timing and formulation is crucial.

Purpose of the Study:

• To re-evaluate the Women's Health Initiative findings on menopausal hormone therapy (HT).
• To clarify the implications of HT use for clinical practice, considering symptom relief and various health risks.
• To differentiate risks and benefits between estrogen-only and estrogen plus progestin therapy.

Main Methods:

• Analysis of Women's Health Initiative (WHI) trial data.
• Re-evaluation of findings concerning vasomotor symptom relief.
• Assessment of risks including coronary heart disease (CHD), stroke, venous thromboembolism, and breast cancer.

Main Results:

• Menopausal HT is effective for vasomotor symptoms; benefits for CHD risk appear greater in women closer to menopause.
• Estrogen plus progestin therapy, not estrogen alone, increased breast cancer risk, especially when initiated near menopause.
• Increased CHD risk observed in women over 20 years post-menopause; short-term risks of stroke and VTE are small in recently menopausal women.

Conclusions:

• Short-term menopausal HT (<5 years) is a reasonable option for moderate to severe vasomotor symptoms.
• Estrogen plus progestin therapy requires careful, periodic reassessment due to associated risks.
• Long-term HT is not recommended for CHD prevention; individualized risk assessment is paramount for all HT use.