These additional analyses will be hopefully forthcoming from registries and data resources like those of the [Kaiser Permanente Northwest] group and might allow new insights into how to use menopausal hormone therapy with the lowest risk of negative effects and to the greatest advantage, the editorialists write.
Postmenopausal Sex Hormones and Breast Density Are Each Associated with Breast Cancer Risk
Sex hormone levels and breast density are independent risk factors for breast cancer in postmenopausal women.
Breast density and hormone levels are both well-known predictors of breast cancer, but it is unclear whether hormone levels regulate breast density.
Rulla Tamimi, Sc.D., of Brigham and Womens Hospital in Boston and colleagues measured breast density and estrogen and testosterone levels in postmenopausal women who later developed breast cancer and those who did not. They found that sex hormone levels and breast density are strongly and independently associated with breast cancer risk.
Thus, levels of circulating sex steroid hormones and mammographic density may increase breast cancer risk through different mechanisms, the authors write.