How to find out “mammographic density” and dense breast tissue
- Detailed cancer.org guide to breast cancer detection, including dense breast tissue” discussion.
Hints from a radiologist.
You can ask for a copy of the radiologist’s report from your last mammograms
Sometimes your mammogram report will say whether or not you have dense breast tissue. Indeed, If the report says that your breast tissue is’very’ dense, then you are probably in 75% to 100% density category. If the report says they are ‘somewhat’ or ‘moderately’ dense, then the breast tissue is probably in the 50% to 74% category. But if the report says the breasts are ‘entirely fatty’ they are probably in the 0% category. If the report says they are ‘mostly’ or ‘somewhat’ or ‘partially’ fatty, they are probably in the 1% to 24% category. Note: Some radiologists are not required to describe the mammographic density in their reports. Many radiologists do not mention anything about mammographic density, unless the density is great enough to interfere with their ability to interpret the mammograms.
What if the mammograms were taken as part of an organized screening program?
In this case, there may not be a written radiologists report, but some screening result data must be recorded somewhere. You can ask the screening program administrators if mammographic density is recorded in their databases. Many (but not all) screening programs do this, and they may be able to tell you your mammographic density.
You can ask the radiologist
who reported the mammograms, to estimate your mammographic density percentage. You can just ask “Do I have dense breast tissue?” Some radiologists would happily do this for you. Others might be too busy or hard to reach.
You can ask to see your mammo films
and judge for yourself. Some mammography centers will loan you your mammograms. Others may offer to charge you a fee to make copies of the films. Without taking your mammograms away from the mammography center, you should at least be able to look at them for free. When you look at your mammograms you can judge the density for yourself.
See these examples of what mammograms look like
|1% to 24% density|
|25% to 49% density|
|50% to 74% density|
|75% to 100% density|
The Risks of the Mammogram reports
- The risk of doctors not noticing a cancer on the mammogram report. This may be because the report is too wordy and includes information about breast density and birads numbers. Sometimes the reports even include which society or government set the guidelines, and so on.
- The risk of having more people die due to annoyance and confusion about mammograms
Here is a real life Example
I live and work as a radiologist in the province of Alberta, Canada. If a government sets a clear guideline that women should get mammograms ever 1 year, what happens? Women tend to come for a mammogram every 2 years. Some women will develop a cancer during those 2 years and some will even die because of it. Furthermore, if a government sets a guideline that women over 50 can have mammograms annually and the rest can have mammograms every 2 years, what happens? Women tend to come every 5 years. During those 5 years there will be more cancers and more deaths.
By the way, the above information is factual and let me reference it. This is data from the Alberta Breast Cancer Screening Program, presented to the Alberta Society of Radiologists meeting in 2013 or 2014.
Major screening programs and governments find the subject embarrassing, (and financially beneficial). So data like this does not get publicity or published in journals.
Another example. Every few years there will be some scientific study published somewhere, saying that mammography does not prevent cancer deaths. A flurry of scientific rebuttals and arguments will appear in medical journals for months afterwards. But most normal people see none of that. Instead, normal people see a TV reporter telling women that mammograms are of no benefit and they may see 2 doctors arguing about it on TV.
The result? Women stop coming for mammograms for around 5 years. Furthermore, during those 5 years, cancers happen and go undiagnosed for too long. Indeed, early diagnosis is key to breast cancers and undetected tumors can grow big and involve lymph nodes. As a result, more women die.
Dense Breast Tissue and Mammograms
Some of you may know that a patchwork of states in the USA have new laws regarding the reporting of breast density. Below is a map from 2014.
In a yellow-color state, like Colorado, here is the kind of message that goes in a letter to women:-
The dense breast tissue Letter
“Your mammogram shows that your breast tissue is dense. Dense breast tissue is common and is not abnormal. However, dense breast tissue can make it harder to evaluate the results of your mammogram and may also be associated with an increased risk of breast cancer. This information about the results of your mammogram is given to you to raise your awareness and to inform your conversations with your doctor. Together, you can decide which screening options are right for you. A report of your results was sent to your physician.”
However, the letter above will confuse women and family doctors. I believe that the states that send confusing letters about mammography will lead to women having fewer mammograms and therefore cause more cancer deaths in those states.
My other website Breast-cancer.ca is where most of my breast cancer information has been accumulating.
- Vachon CM, van Gils CH, et al. Mammographic density, breast cancer risk and risk prediction. Breast Cancer Res. 2007 9:217.
- Assi V, Massat NJ, et al. A case-control study to assess the impact of mammographic density on breast cancer risk in women aged 40-49 at intermediate familial risk. Int J Cancer 2014: