Breast Density is the strongest indicator for assessing a woman's risk of developing breast cancer, even more than family history.
Breast density is detected on a mammogram; it does not necessarily have anything to do with 'lumpy', 'stiff' or 'tender' breasts.
There are two types of breast tissue
- Active (glandular fibrous)
- Inactive (fat)
Ideally by the time a woman enters her peri-menopausal years, her breast tissue will be almost completely 'fat replaced'. That means that most of the breast tissue will be inactive; and when this is the case, she has a low risk of developing breast cancer.
Unfortunately, many women have active or dense breast tissue. According to the American Cancer Society 43% of the women in the US, aged between 40-65, have dense breast tissue. Although and analysis has not been done for Australian women, we do know that it should be about the same statistic for women living in any industrialised nation. The American Cancer Society states that dense breast tissue is a normal phenomenon, just like high blood pressure is associated with cardiovascular (heart) disease. Although many people have high blood pressure, it is not a 'normal' state. Just like there are many factors that contribute to dense breast tissue.
For example we know that the combination of an elevated oestrogen to lowered testosterone ratio will cause breast tissue to become dense. The cause of elevated oestrogen to lowered testosterone ratio, and consequent breast density, is linked to a variety of things; including the birth control pill, toxins in the environment, combination HRT, and genetics.