HRT and cancer risk: separating fact from fiction

The benefits of hormone replacement therapy (HRT) in postmenopausal women are well known including control of vasomotor symptoms and long-term benefits on the cardiovascular, skeletal and central nervous systems. However, some studies have reported a link between long-term HRT use and cancer. This paper reviews some of the data related to HRT and major gynaecological cancers.

Appropriate HRT regimens can reduce the risk of endometrial hyperplasia in non-hysterectomised women and can reduce the incidence of colorectal cancer. There is no consensus on a link between HRT and ovarian cancer, and the data relating to HRT and breast cancer presents differing risk analyses. However, it is generally accepted that HRT taken for 5 years or less does not increase the risk of breast cancer. When HRT is taken for 10 years or more, the relative risk of being diagnosed with breast cancer is 1.46. Individual risk must be weighed against the benefits offered by HRT, especially in terms of the long-term beneficial effects on the cardiovascular, skeletal and central nervous systems. Whilst one in 8-12 women may contract breast cancer in the western world, one in 3 women over 65 will have cardiovascular disease and 30-50% of postmenopausal women will have osteoporosis.

Fear of cancer is one of the main reasons why women object to HRT. Physicians must be able to counteract this fear with fact, and counsel patients on their individual risk, as well as putting any cancer risk into perspective with other long-term benefits.