Menopausal hormone therapy and breast cancer: Balancing risks and benefits

Menopausal hormone therapy remains the most effective treatment for vasomotor symptoms and plays an important role in the prevention of bone loss and fractures. When initiated earlier in menopause, hormone therapy may have some favorable cardiovascular effects, though it is not recommended for cardiovascular disease prevention. Although these benefits are established, perceptions of safety have long been shaped by concerns about breast cancer risk. Evidence accumulated over the past two decades has helped to refine our understanding of the risk of breast cancer associated with hormone therapy, showing that risk varies by hormone therapy formulation, duration of use, and patient-specific factors. For example, combined estrogen-progestogen therapy has been associated with a higher risk of developing breast cancer while estrogen-alone therapy has been linked to reductions in both breast cancer incidence and mortality. The choice of progestogen also matters, with observational evidence indicating that micronized progesterone may have a more favorable breast cancer risk profile than some synthetic progestins. Beyond regimen and duration of use, outcomes are further influenced by timing of initiation and route of administration, underscoring the importance of tailoring therapy to the individual. This narrative review synthesizes current evidence on the benefits and risks of hormone therapy with a focus on breast cancer and risk modifiers to guide evidence-based clinical decision-making in menopause management. It also highlights important research gaps.