Breast cancer and hormone replacement therapy

Last reviewed: November 2003

For general information about CancerBACUP’s Controversial topics please see the introductory page.

This statement is a review of the current literature relating to the risks and benefits of using HRT following onset of the menopause. At the menopause, loss of oestradiol production leads to numerous changes that may have adverse effects on a woman’s quality of life. These changes include vasomotor symptoms (hot flushes), increased risk of osteoporosis leading to fractures, genito-urinary symptoms, and subtle cognitive changes that may lead to memory impairment and loss of self-esteem. While there is no doubt that use of HRT can ameliorate certain menopausal symptoms such as hot flushes and vaginal dryness, and can reduce the risk of osteoporotic fractures, there has been concern for many years about the possible adverse effects of HRT use on the health of menopausal women. One of the anxieties women have is the association between HRT use and breast cancer risk. The increase in breast cancer risk has been previously documented in studies and has now been confirmed in a large randomised clinical trial (1) and the Million Women Study (2). The issue is discussed in detail in this section.