Mammograms are a special kind of x-ray used to look at breast tissue for the purpose of diagnosing breast cancer. By the time most women reach the age of 35 you should have had at least one experience with a mammogram. However, the diagnosis of breast cancer relies on a three pronged approach which includes a mammogram, self-examination and an annual clinical examination by your gynecologist. Sometimes all three of these examinations can be hindered by dense breast tissue.
Breast density refers to the proportion of fat and tissue in the breast as it is seen on a mammogram. Women who have high density breasts have a higher proportion of tissue to fat. Low density breasts have a greater proportion of fat then tissue. (1)
When women are young their breasts are often more dense and made up of specialized tissue that produces milk during lactation. As a woman ages this breast tissue will change and become less dense with more fat. This thick breast tissue has the potential to cause problems with mammograms and self-examinations because it makes it more difficult to identify abnormalities. On x-ray film dense tissue and tumors will show up as white, which makes it more difficult to discern what is a potential tumor and which is breast tissue. (2)
Dense breast tissue will also make a difference on what women feel when they do their self breast exams once a month. Normally, breasts are rather lumpy but tissue which is dense makes it more difficult to distinguish between a normal lump and a new one. If breast tissue remains dense as women grow older this presents a significant disadvantage to the woman. Women over 50 are at an increased risk of breast cancer which makes having tissue that is more difficult to diagnose a higher risk.
However, there is another risk for women who have dense breast tissue. In 2007, published in the New England Journal of Medicine, researchers suggested that women who develop breast cancer had more known risk factors than women who didn’t and mammography density was 5.8 percentage points greater in women who had breast cancer than in those who did not develop breast cancer. (3)
In another study published in Current Biology researchers found that the cells which make up dense breast tissue may actually provide more fertile ground for cancer cells. This suggested a possible link between tissue density and tumor aggressiveness. (4)
If you have dense breast tissue it is important to take care of yourself using preventative measures and tools for early diagnosis. Get to know your breasts during self breast examinations on the monthly basis. When you recognize or notice that there is something different, reported to your gynecologist or primary care practitioner immediately.
Be sure to request a digital mammogram because digital technology can see abnormalities within dense breast tissue much more clearly and dependably then can regular mammograms. If your mammogram is unclear and your physician believes that an ultrasound will not give you good results, you may request a magnetic resonance imaging scan. These are not a substitute for mammography and only done in addition to a mammogram when a lump is present.
Premenopausal women who have never been pregnant will oftentimes have the most dense breast tissue. They are normally dense because tissue does not turn to fat until a woman has been pregnant and potentially breast-fed.
The key to treatment of any disease is early diagnosis and early treatment. Give yourself the best advantage possible by performing monthly breast self examination, insisting on annual mammograms and scheduling that clinical evaluation once a year.
(1) U-Systems: Know Your Breast Density Classification
(2) National Cancer Institute: Breast Density in Mammography and Cancer Risk
(3) New England Journal of Medicine: Mammographic Density and the Risk and Detection of Breast Cancer
(4) Current Biology: Dense Tissue Promotes Aggressive Cancers