Postmenopausal hormone therapy and breast cancer risk: current status and unanswered questions.

Many women take hormone therapy (HT) for menopausal symptom relief. Studies have tried to clarify whether various factors can modify the risk of HT, such as the age at initiation, dose, duration, or type of HT, or characteristics of the individual, such as family history or body mass index. The relative risks of breast cancer associated with HT across various subgroups of women should be considered similar, but absolute risks can vary significantly among women and this may inform individual decision making. For breast cancer survivors, systemic HT should be discouraged.