Talking About Breast Density and Cancer Risk

In the last blog I mentioned that breast density has been in the news; recently 5 states in the US (New York, California, Connecticut, Texas and Virginia) have passed legislation, and a dozen more are considering similar laws requiring patients be notified if they have highly dense breasts.  Canada’s Parliament is reviewing proposed Bill C-314 as breast density notification legislation.

What is perhaps as not well known is that the medical and research community has been thinking and studying the connection between breast density, risk, detection and incidence of cancer for over the last 20 years.

OK what exactly is it? Breast density is described as a comparison of the amount of fatty to the amount of glandular (milk producing and ductal) and connective in the tissue breast. High Density breasts typically have a greater percentage of glandular and connective tissue. Conversely, a Low Density breast will have more fatty tissue.

Important points of the density conversation gleaned from research, the web and recent journal articles:

- Recent scientific studies have shown that women with high density breasts dont have a greater risk of breast cancer death compared to women with fatty (low) density breasts;

- Density in breast tissue is a challenge for traditional screening techniques and can mask breast abnormalities; therefore it could be a greater risk for cancer.

- Changes in density (such as an increase) could indicate the need for further evaluation.

- Proponents believe that density notification laws will raise awareness and potentially encourage women to follow up or maintain a follow-up/regular screening schedule to increase the probability of early detection.

- Some criticism of the density notification laws is the potential for unnecessary patient anxiety or increased medical expenses.

- In the majority of women that are of screening age, density is not an issue for traditional screening methods, or supplemental follow-up can address concerns.

- Younger women have higher density breasts than menopausal and post-menopausal women

- Breast composition is determined by a complicated relationship between ethnic, hereditary, environmental (diet, geography), reproductive (age at first pregnancy, number of children) and hormonal factors.

Anecdotal conversations with the women in my life about breast density include most admitting they don’t really understand what it means to have a dense breast in a mammogram, just that their doctor told them they have dense breasts.  A quick search will find some images online, but I asked our collaborators at the University of Michigan if they would share some images. In the video below, I share the images and try to point out the differences for you.  Please let me know if you have any questions.

In the coming weeks, we’ll talk about some emerging technologies and research with them, so stay tuned!

- Andrea

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1 Comment

  1. Maggie

    Great article! It reminds me of a great TED talk on new technology for improved screening in women with high density breasts. http://on.ted.com/pJ2E