SAN ANTONIO – Women who underwent surgical menopause and were receiving hormone replacement therapy (HRT) prior to breast cancer diagnosis had significantly less dense breasts than women who underwent natural menopause without HRT, a study presented at the 2016 San Antonio Breast Cancer Symposium (SABCS) has shown.1
“The use of HRT in postmenopausal women has been shown to result in increased breast density,” said Sarah Pivo, MD, Perlmutter Cancer Center, New York University Langone Medical Center, New York, NY. “Increased breast density is associated with increased risk of breast cancer and reduced sensitivity of mammography.”
Therefore, researchers sought to compare the mammographic breast densities of women after they underwent surgical menopause with and without HRT with women who underwent menopause naturally.
For the study, investigators analyzed data from 1106 postmenopausal women newly diagnosed with breast cancer from January 2010 through 2015 who were included in the institutional Breast Cancer Database. The researchers categorized the patients into the following 4 groups: natural menopause without HRT (88%), history of bilateral salpingo-oophorectomy (BSO) without HRT (6%), history of BSO with HRT use prior to cancer diagnosis (5%), and history of BSO with current HRT at the time of diagnosis (1%).
Results showed a non-statistically significant increase in breast density among women who had a prior BSO and were on HRT at the time of cancer diagnosis compared with those who had natural menopause with no HRT (69% vs 44% heterogeneously or extremely dense breasts).
“Women with a history of surgical menopause who were on HRT at the time of breast cancer diagnosis had a trend towards more dense breasts,” said Dr Pivo.
However, researchers found that women who had a prior BSO and were on HRT prior to cancer diagnosis had significantly less dense breasts than women who underwent natural menopause without HRT (67% vs 56%; P = .007).
There were no significant differences in tumor characteristics between the 4 groups, suggesting that variability in breast density did not correlate with stage of disease at the time of presentation.
“Surprisingly, women with BSO who were prior users of HRT had less dense breasts at the time of diagnosis than women who never use HRT,” Dr Pivo noted. “This may be related to their age at time of diagnosis.”
1. Pivo S, Schwartz S, Chun J, et al. Influence of hormone replacement therapy following bilateral salpingo-oophorectomy on mammographic breast density in women newly diagnosed with breast cancer. Poster presented at: 2016 San Antonio Breast Cancer Symposium; December 6-10, 2016; San Antonio, TX.