Estrogen-only hormone replacement therapy may benefit younger postmenopausal women who do not have a uterus, a Canadian researcher said Thursday at the annual meeting of the San Antonio Breast Cancer Symposium.
Dr. Joseph Ragaz, an oncologist at the University of British Columbia, presented a re-analysis of the Women's Health Initiative -- which originally concluded that both long-term estrogen-only and estrogen-plus-progestin hormone replacement were too risky for most women.
But Ragaz said his take on the data suggests that using only estrogen -- for women who do not have a uterus and do not need progestin -- protects against breast cancer. He found that subsets of women, such as younger postmenopausal women and those with no strong family history of breast cancer or benign breast disease, had a lower risk of breast cancer after using estrogen-only therapy and reaped other health benefits, such as a lower risk of heart disease.
Ragaz says studies are needed to determine whether estrogen produced by the body, called endogenous estrogen and which is known to fuel cancer growth, and outside sources of estrogen (called exogenous) have different effects on breast-cancer risk.