What is breast density and why do you need to know yours?

A new one FDA rule on mammography reporting came into effect in September. Among the changes is a new standard for the way doctors talk to patients about breast density after breast cancer screening.

From now on, your doctor will tell you whether your breast tissue is ‘dense’ or ‘not dense’ after a mammography or mammography, which involves taking an X-ray of the breast. But what does this mean? We spoke to two doctors about how breast density is measured, whether it increases your risk of breast cancer and why this may change over your life.

Regardless of your breast density, Breast Cancer Awareness Month is a good time to schedule a mammogram. The advises the American Cancer Society that people with an average risk of breast cancer should be screened at the age of 40. You can also have yourself regularly checked for breast cancer at home at any age.

What is breast density?

Breast density refers to the way your breast tissue looks on a mammogram. Dense tissue is difficult to see through on the mammogram, while less dense tissue is more transparent. Many people have dense breast tissue (approx 4 in 10 women if you have heterogeneous dense breast tissue), and if your doctor tells you that you are one of them, it does not mean that something is wrong.

There are four categories used to measure breast density. The categories are based on descriptions of the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS). You may see a category listed as A through D on your bust report.

• A: Almost all fat. There will be very little dense breast tissue.
• B: Scattered areas of density. The breast tissue is still mostly fatty, but there are some areas of dense tissue.
  
• C: Heterogeneous density. This breast tissue is usually dense, but there are some areas of fatty tissue.
  
• D: Extremely dense. In this case, most of the tissue is dense and very little fatty tissue shows up on the mammogram.
  

What does dense breast tissue mean?

Having breasts three types of tissue: fibrous, glandular and greasy. Fibrous tissue holds your breast together, while glandular tissue contains the lobes or parts of the breast necessary for lactation or lactation. As for fatty tissue, it provides the shape and size of the breast. Combined fibrous and glandular tissue is called fibroglandular tissue.

We asked Dr. Michelle Townsend Daychief of breast imaging for MedStar Union Memorial and MedStar Good Samaritan Hospitals in Baltimore, Maryland, what this means for interpreting mammograms. She explained that practitioners who review mammogram results look at both “adipose tissue, which is black on mammograms, and fibroglandular tissue, which is white on mammograms.”

Fibroglandular tissue appears white on a mammogram because it is denser than fatty tissue.

How much of your tissue must be white on the mammogram before it is considered compact? Dr. Townsend-Day says, “Dense breast tissue means that the breast is made up of 50% to 100% fibroglandular tissue.”

If your breast tissue is dense, it may be easier for a radiologist to miss an abnormality. That said, there’s no cause for immediate alarm. Breast tissue can be either dense or completely healthy.

Causes of dense breast tissue

It is quite common for patients to be told that they have a lot of fibroglandular breast tissue, especially if they are premenopausal. Dr. Anna Cabeca from The Girlfriend Doctor, says there are several reasons why your breast tissue may be compact. She told us that the following four factors are the most common:

Heredity: Genetics can influence breast density. Some people are more predisposed to dense breast tissue than others, simply because of genes.

Age: Younger people may have dense breast tissue because they have more glandular tissue, which is necessary for lactation or lactation. As these people age, especially after menopause, this glandular tissue is often replaced by fat, which is less dense.

Weight: People with a lower BMI tend to have denser breast tissue.

Hormones: Higher hormone levels in younger people can also increase breast density. Hormone replacement therapy (HRT) can also increase breast density in menopausal people.

How do you find out if you have dense breast tissue?

You cannot measure your breast density at home. You will need professional imaging to determine how much fatty tissue you have in your breast tissue versus fibroglandular tissue.

In recent years, some organizations have changed their recommendations for when people should start getting mammogram scans. For example, the US Preventive Services Task Force, a non-governmental organization made up of volunteer medical experts, recently lowered their recommendation from 50 to 40 years.

The American Cancer Society (ACS) still says mammograms are optional between ages 40 and 44but all people at average risk should start regular screenings at age 45.

If you have a family history of breast cancer or other risk factors, your doctor may want you to start screenings earlier. The ACS notes that people at high risk should get breast MRIs and mammograms by age 30.

Should You Have Additional Screenings If You Have Dense Breast Tissue?

Dense breast tissue does not automatically require additional testing, but doctors may suggest it in some cases.

Like Dr. Cabeca reminds us, “It is more difficult to read a mammogram on breasts with dense tissue, because they appear white on the images. That makes the plain tissue more difficult to distinguish from potential masses, which also appear in white.” Because of this common problem, the doctor says that people “with dense breast tissue may be called back more often for additional testing.”

If you are called back for more testing, it will likely be for another non-invasive screening. Dr. Townsend-Day states, “Additional screening modalities such as breast ultrasound and breast MRI are useful in patients with dense breasts to improve cancer detection.”

Ultrasound of the breasts: An ultrasound is possible help a doctor examine a lump that can be felt but not detected on a mammogram, or that can determine whether the lump is a cyst or a solid mass.

Breast MRI: An MRI is sometimes used in combination with mammography can find some cancers missed by mammograms. If breast cancer has already been diagnosed, a breast MRI can also provide more information about the size and location of the cancer.

The Affordable Care Act (ACA) requires health insurers coverage of annual breast cancer screenings for people over 40 at no out-of-pocket costs. If you are high risk and your doctor recommends screenings before age 40, your insurer will likely still cover it with a co-pay.

What should you do if you have dense breast tissue?

Dr. Townsend-Day told us there is nothing patients can do to change their breast tissue. Dr. Cabeca agrees, explaining, “Breast density is a moving target; it’s not the same throughout your life. As things change in your body and your hormonal balance shifts, the density in your breasts will change too.”

If you have dense breast tissue and think you might be a good candidate for more frequent mammograms, discuss your concerns with your doctor. In the meantime, you can still be proactive about staying cancer-free. The American Cancer Society suggests that the following steps can help people lower their risk of breast cancer:

Exercise regularly: Physical activity is linked to a lower risk of breast cancer. Aim for at least 75 minutes of vigorous activity or at least 150 minutes of moderate physical activity per week.

Limit alcohol intake: Even small amounts of alcohol have been linked to an increase in the risk of breast cancer. Do not drink more than an average of one drink per day to prevent an increased risk.

For those at increased risk of breast cancer, you may also consider:

Undergo genetic testing: Genetic counseling and genetic testing can help you determine if you are susceptible to breast cancer, including carrying the BRCA1 or BRCA2 gene. If you are at increased risk, your doctor may recommend more screenings.

Consider estrogen blockers: Some people at increased risk for breast cancer may benefit from medications that block estrogen in the breast tissue.

Does dense breast tissue increase your risk of breast cancer?

Having dense breast tissue increases the risk of breast cancer. Researchers are still working to gain a clearer understanding of this causal relationship, but there is a general consensus among experts. The suggests ACS that dense breast tissue simply contains more cells that can turn into abnormal (cancer) cells. This is stated by the Breast Cancer Research Foundation breast cancer tends to develop in glandular tissueSo having denser glandular tissue than fatty tissue can increase your risk of breast cancer.

Dr. Townsend-Day says dense breast tissue increases your chances of developing breast cancer 1.5 times as much during your lifetime. She also reiterated that dense breast tissue can better hide breast cancer because dense breast mammograms are more difficult to interpret.

People with dense breast tissue “need to be a little more vigilant,” Dr. Cabeca said. She says glandular tissue makes people more vulnerable to cancer, but adds: ‘Of course you also have oestrogen-based cancer, which is a completely different type of breast cancer. I wouldn’t say that lower density in the breast tissue means you won’t get cancer, but as a rule, density makes your breast more glandular and harder to read on a mammogram.”

The bottom line

Dense breast tissue is more difficult to interpret on a mammogram film, which makes detecting breast cancer more difficult. Most premenopausal people suffer from dense tissue. This makes regular screening important.

If you are at average risk for breast cancer, consider having your first mammogram at age 40 to give your doctor a baseline. People at all risk levels should perform monthly self-breast examinations. Tell your doctor if you notice any changes in your breast tissue, including lumps.