The Use of Hormone Replacement Therapy in Women Previously Treated for Breast Cancer

Abstract

The postmenopausal woman who has had breast cancer presents the clinician with special difficulties. Most are unhappy to prescribe hormone replacement therapy (HRT) for these women for fear that HRT may stimulate their cancer. However, premenopausal women who have had early stage breast cancer are usually permitted to produce their own endogenous estrogen (1). Screening programs are detecting an increased number of early stage breast cancers and so many women may survive the tumor only to die of a cardiovascular disease or osteoporotic fracture. A number of lifestyle changes and non-sex hormone treatments are now available to reduce the risk of cardiovascular disease and osteoporotic fractures. Tamoxifen usage may also reduce the risk of heart disease and fractures but this drug is known to aggravate hot flashes and is associated with potentially serious problems including an increased risk of endometrial cancer (2). A small number of menopausal women (10–20%) will suffer severe debilitating menopausal symptoms, particularly hot flashes. For these women, life is unbearable. Quality of life is an important issue for women who have had cancer, so it is important for physicians involved in the care of such patients that treatment strategies are developed to deal with these symptoms. HRT includes a number of different sex hormone combinations of estrogen, progestins and sometimes androgens. Epidemiological studies have demonstrated small but significant differences in breast cancer risk associated with different types of estrogen (3, 4) and different combinations of progestin with estrogen (5). It is also likely that androgens will influence breast cancer risk (6, 7).