Clinical practice guidelines for the care and treatment of breast cancer: 14. The role of hormone replacement therapy in women with a previous diagnosis of breast cancer.

OBJECTIVE: To provide information and recommendations to women with a previous diagnosis of breast cancer and their physicians regarding hormone replacement therapy (HRT). OUTCOMES: Control of menopausal symptoms, quality of life, prevention of osteoporosis, prevention of cardiovascular disease, risk of recurrence of breast cancer, risk of death from breast cancer. EVIDENCE: Systematic review of English-language literature published from January 1990 to July 2001 retrieved from MEDLINE and CANCERLIT. RECOMMENDATIONS: * Routine use of HRT (either estrogen alone or estrogen plus progesterone) is not recommended for women who have had breast cancer. Randomized controlled trials are required to guide recommendations for this group of women. Women who have had breast cancer are at risk of recurrence and contralateral breast cancer. The potential effect of HRT on these outcomes in women with breast cancer has not been determined in methodologically sound studies. However, in animal and in vitro studies, the development and growth of breast cancer is known to be estrogen dependent. Given the demonstrated increased risk of breast cancer associated with HRT in women without a diagnosis of breast cancer, it is possible that the risk of recurrence and contralateral breast cancer associated with HRT in women with breast cancer could be of a similar magnitude. * Postmenopausal women with a previous diagnosis of breast cancer who request HRT should be encouraged to consider alternatives to HRT. If menopausal symptoms are particularly troublesome and do not respond to alternative approaches, a well-informed woman may choose to use HRT to control these symptoms after discussing the risks with her physician. In these circumstances, both the dose and the duration of treatment should be minimized. VALIDATION: Internal validation within the Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer; no external validation. SPONSOR: The steering committee was convened by Health Canada. COMPLETION DATE: October 2001.