J Reprod Endocrinol.  2012 Oct;4(2):91-98.

An Association between Estrogen-alone Postmenopausal Hormone Therapy and Breast Cancer

• Kim H
• Kim JG

Abstract

Exposure to endogenous and exogenous hormone has been reported to be associated with the risk of breast cancer. The prevalence of breast cancer has increased continuously in Korea, therefore, the risk factor for breast cancer may catch the attention. Elevated blood levels of estrogen has been found to be related to the risk of breast cancer in many studies and several surrogate markers for endogenous estrogen, such as age at menarche, menopause or 1st birth are probably associated with breast cancer. After the report of Women's Health Initiative (WHI), estrogen- only hormone therapy seems not to increase the incidence of breast cancer. Recent research issues of hormone therapy (HT) include the type of hormone therapy, especially inclusion of progestin or gap time, i.e., interval from menopause to the initiation of HT. In the early report of WHI estrogen-alone arm, there was a trend for decreased breast cancer incidence although it was not statistically significant. Recently, further analysis of WHI revealed significant decrease of breast cancer in subgroups with no prior history of HT or benign breast disease. Moreover, in vitro studies have observed apoptosis in long-term estrogen-deprivated breast cancer cell lines. However, many issues need to be addressed before the statement that estrogen-only HT is a safe regimen for breast cancer.

Keyword

Breast cancer; Estrogen; Hormone therapy; Menopause

MeSH Terms

Apoptosis
Arm
Biomarkers
Breast
Breast Diseases
Breast Neoplasms
Cell Line
Estrogens
Female
Incidence
Korea
Menarche
Menopause
Parturition
Prevalence
Risk Factors
Women's Health
Estrogens