According to recent results published in The Lancet, the largest analysis to date has indicated that hormone replacement therapy (HRT) not only increases the risk of developing breast cancer, but increases the risk of death from breast cancer in postmenopausal women.
Hormone replacement therapy (HRT) is often prescribed for women during menopause. Menopause is a natural phase of maturing womanhood, during which the ovaries produce significantly less estrogen, ovulation ceases and menstruation ends. For many women, menopause has uncomfortable side effects. Hot flashes, sleep disturbances, depression, mood swings and anxiety may affect the menopausal woman. Additionally, menopause may also be accompanied by increased urinary tract infections, incontinence, vaginal discomfort due to a lack of estrogen-based lubrication and decreased bone density. HRT has been effectively used to mitigate these side effects and is widely prescribed for women experiencing these unpleasant symptoms of menopause. Recent results from several clinical studies have demonstrated a correlation between the use of hormone therapy and the development of breast cancer. However, until now there has been no confirmatory evidence supporting an increased risk of death from breast cancer with the use HRT. HRT can contain estrogen alone, progesterone alone or a combination of the two hormones. Research continues in order to answers questions regarding different outcomes for patients who use specific combinations or single-agent HRT as well as duration of use.
Researchers from England recently evaluated data from over one million women between the ages of 50 and 64 years in an attempt to provide further information regarding HRT and breast cancer incidence as well as mortality from breast cancer. Results from this study indicated that women who used HRT with estrogen alone had a 32% increased incidence of breast cancer and those who used estrogen plus progestin HRT had a 65% increased incidence of breast cancer. The incidence of breast cancer increased with increased duration of use of HRT. Furthermore, patients currently being treated with HRT had an 22% increased mortality from breast cancer, compared to those who had never used HRT or had used HRT in the past. Patients using HRT for 5 and 10 years also have increased incidence of uterine cancer, by an increase of 4 cases per 1,000 with 5 years of use and 10 per 1,000 with 10 years of use.
The researchers concluded that HRT use not only increases the risk of developing breast or uterine cancer, but also increases the risk of mortality from breast cancer in postmenopausal women. However, a duration of HRT use of 6 months of less does not appear to increase risks of breast cancer. It remains important that women discuss the risks and benefits of HRT with their physician for their individual situation.
Reference: Million Women Collaborators. Breast Cancer and Hormonal-Replacement Therapy in the Million Women Study.
The Lancet. 2003;362:419-427.