Dense breast have less fatty tissue and more non-fatty tissue compared to breast that are not dense. The American College of Radiology developed a system called the Breast Imaging Reporting and Data System (BI-RADS) to help delineate normal breast from cancers of the breast with a 1 to 5 system - 1 being normal and 5 indicating a high risk of cancer. They have recently developed a new reporting system for measuring breast density:
- BI-RADS 1 less than 25% density
- BI-RADS 2 26-50% density
- BI-RADS 3 51-75% density
- BI-RADS 4 greater than 75% density
Breast density is now considered the strongest reason for the mammogram to fail in detecting breast cancer. It has been estimated that 50% of women younger than age 50 have dense breast and one third of women over 50 will continue to have dense breast. One recent study suggested that up to half of the women who have breast cancer were not diagnosed until the cancer was advanced due to the cancer being masked by the density of the breast. Breast density can only be determined by mammogram. While some studies have suggested that density is a risk factor for developing breast cancer, the risk is typically low. The problem that exists is that most of the women diagnosed with breast cancer have no family history or significant risk factors - only up to 10% of breast cancers are caused by mutations of the BRCA gene.
On May 20, 2013, Alabama became one of several states to pass breast density legislation. Congressional bills have also been introduced to require the reporting of breast density. Alabamas law at this time does not require insurers to pay for additional testing for density as some states have required. The law will go into effect Aug. 1, 2013, and requires radiologists to include a report to the patient that her breast are dense and that the density may make diagnosis of cancer more difficult. The difficulty with the state law is that it does not define and standardize the assessment of density.
A current criterion that has been suggested is as follows:
- Dense breast with no family history and no other risk factors breast ultrasound might be appropriate. Ultrasound is like any other screening test with possible false negatives and false positives that might lead to the need for other testing.
- Dense breast with moderate risk factors this is a combination of history of personal breast problems and family history. Patients with a calculated life time risk of breast cancer with the National Cancer Institute Gail model above 15% might benefit from bilateral breast MRI.
- Dense breast with significant family history and risk factors this includes a Gail model score of lifetime risk greater than 20%. It has been recommended that these patients should have a bilateral breast MRI.
- Significant family history and risk factors without dense breast this woman will be a candidate for annual MRI.
If you are diagnosed with dense breast, you can choose a lifestyle that might keep the risk of breast cancer as low as possible:
- Exercise regularly
- Maintain a healthy weight
- Limit the use of alcohol
- No smoking
- Eat foods that are nutritious
- Do monthly self breast exam
- Have a yearly breast exam by a physician
- Schedule a mammography yearly after age 40
You should discuss these concerns with your physician. It is your responsibility to help maintain your health. If you are diagnosed with dense breast, talk with your doctor and plan out a means to monitor not only now, but also for the future.