Last reviewed by Dr. Raj MD on January 12th, 2022.
Women’s breasts consist of fat and breast tissues. Tissues in the breasts are made up of ducts and network of lobules. A connective tissue keeps everything in place. There is a condition called breast density.
What it does is it compares the amount of fat and tissues on mammogram. A dense breast means that it has more glandular and fibrous tissue that fatty tissue. Usually, younger women have dense breast. As a woman gets older, the density of breast decreases. It is the fat and fibrous tissue that determines the shape and size of the breast. Having a dense breast is common and normal. (1, 2)
Why is it important to find out if you have a dense breast? A study revealed that those who have dense breasts are more susceptible to breast cancer. They are five times more likely to have cancer than women with low breast density. How to measure the density of the breast? There are various ways to measure breast density. Breast density test is dependent on the mammogram result.
It is the doctor who will visually assess the result of the mammogram. The result is therefore subjective as it depends on the interpretation of the doctor. Further studies are made to thoroughly assess the density of the breast. A combination of mammography, magnetic resonance imaging (MRI), and ultrasound can help accurately detect the density of the breast.
Research also showed that digital mammography provides a more accurate result than film mammography. (1, 2, 3)
Breast density Pictures
Image 1: A diagnostic image of the breast showing the level of breast density
Picture Source: cdn.trustedpartner.com
Image 2: An image of a normal breast tissue and breast tumor tissue
Photo Source: www.urmc.rochester.edu
What causes dense breast tissue?
- Genetics – Dense breasts appear to run in families. If your mother or any member of your family has dense breast, then there is a high possibility that you will have a dense breast too. You could also pass it on to your children. (3)
- Early life exposures – The growth and development of women can also affect the density of the breast. Those with higher birth weight can lead to higher breast density in adulthood. If your body weight is high during adolescence, there is a likelihood that your breast density is low.
- Pregnancy – The density of the breast decreases in pregnant women. A woman who have given birth to more children has a less dense breast.
- Menopause – When a woman reaches her menopausal period hormonal changes take place. The breast tissue becomes less dense.
- Hormone therapy – Those women taking postmenopausal hormone such as estrogen and progestin have higher breast density than those who do not take the hormone. (4, 5)
Breast Density Classification (categories)
The BI-RADS Classification System is one of the commonly used systems for breast density classification. There are four classifications and they are the following:
- Type 1 – The breasts consist almost entirely of fat. There is glandular tissue but is less than 25%.
- Type 2 – The breasts contain about 25% to 50% of scattered fibroglandular tissues
- Type 3 – This is known as heterogeneously dense parenchyma, which ranges from 51% to 75%. What does it mean to have heterogeneously dense breasts? It means that the breast has a huge number of fibrous tissue but not clustered together.
- Type 4 – Women who fall under this category means that the breast contains more than 75% of glandular and fibrous tissue. (4, 5, 6, 7)
Why is it important to find out the density of the breast?
Research showed that women who have dense breast tissue are at high risk for breast cancer. The exact reason as to why the dense breast tissue is linked with breast cancer is still unknown up to this time.
What researchers know is dense breast tissues make it difficult for radiologist to detect cancer cells. On mammogram, dense breast tissue appears white. It is somewhat confusing because the tumor or breast mass looks white too.
On the other hand, fatty tissues on the breast look black, which makes it easier for the radiologist to detect cancer cells. If women have dense breast tissues, a mammogram procedure is less accurate in detecting cancer cells. (8, 9)
Do you still need to undergo a regular mammogram even if you have dense breast? Yes! The mammogram procedure can help save your life. It helps detect any unusual changes in your breast. However, if you have dense breast, you should not only rely on mammogram procedure.
If you are suspecting abnormalities in your breast, you also need to undergo further procedures like magnetic resonance imaging (MRI). It helps detect cancer cells, especially cells that cannot be accurately seen on mammogram. However, MRI and other related procedures can be costly and usually not covered by your health insurance. (7, 10)
What you should do if you have dense breast tissues?
If your mammogram report showed that you have dense breast tissue, you should contact your health care provider right away. Your doctor will conduct a thorough past medical and surgical history to find out whether there are other factors that make you susceptible for breast cancer.
If you have a family history of breast cancer, you should have a yearly mammogram along with other diagnostic procedures such as magnetic resonance imaging (MRI). It is important to know your risk and get screened.
Feel free to ask your doctor as to what screening test is perfect for you. Once you reach the age of 40, you should have a yearly mammogram, especially if you have a family history of breast cancer. (4, 6, 9)
If you reach the age of 20, you should have a clinical breast examination every three years. Self-breast examination is also helpful in detecting any abnormalities in the breast. If you notice an abnormal change in the size of the breast along with swelling, pain, puckering of the skin, or itchy or scaly sore in the nipple, you have to see your doctor immediately.
Preventive measures are important too. You should maintain a healthy weight. You should maintain a healthy lifestyle. Limit your intake of alcoholic beverages. If you can, stay away from using postmenopausal hormones. Exercise regularly. Breastfeeding can also help in preventing breast cancer. (4, 5, 9)
- Digital Breast Tomosynthesis: A Practical Approach edited by Alberto Tagliafico, Nehmat Houssami, Massimo Calabrese