Breast Cancer Screening and Dense Breasts: What Are My Options?

Guides you through breast cancer screening choices if you have dense breasts. Discusses the benefits and risks of choosing more testing after a mammogram, such as ultrasound or MRI. Includes interactive tool to help you make your decision.

Top of the pageDecision Point

Breast Cancer Screening and Dense Breasts: What Are My Options?

You may want to have a say in this decision, or you may simply want to follow your doctor’s recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.

Breast Cancer Screening and Dense Breasts: What Are My Options?

Get the facts

Your options

  • Have a mammogram to screen for breast cancer.
  • Have an MRI or ultrasound with your mammogram.

Key points to remember

  • The more dense your breast tissue is, the harder it is to see cancer on a mammogram image. That’s because dense tissue looks white onscreen, just like cancer does.
  • Having dense breasts may slightly increase your risk for breast cancer. But your risk depends on many things.
  • When deciding about breast cancer screening, you’ll need to think in terms of your total breast cancer risk. Ask your doctor to go over your breast cancer risk factors with you, so you can decide what screening is right for you.
  • Screening tests for breast cancer include mammogram, breast ultrasound, and magnetic resonance imaging (MRI). Each type of test shows breast tissue differently and finds things that the others don’t. Depending on your risk level, insurance may pay only for a mammogram.
  • Cancer screening comes with the risk of finding things that look like cancer, but aren’t. This “false-positive” problem can lead to unneeded tests, biopsy, and sometimes treatment. When deciding about screening, weigh this risk against the possible benefits of detection, especially with the MRI. Breast MRI is very good at finding cancer. But it’s also more likely than other tests to mistake non-cancer breast changes as possible cancer.
FAQs

What are dense breasts?

Dense breast tissue is made up of thick fibrous tissue and milk glands.

Most women have breasts with a mix of dense tissue and fatty tissue. Some women have very dense or very fatty breasts. All of these breast types are normal.

There are four levels of breast density:

  • Almost all fatty tissue (1 out of 10 women)
  • Scattered areas of dense tissue, but mostly fatty tissue (4 out of 10 women)
  • Mixed dense and fatty tissue, also called heterogeneous (4 out of 10 women)
  • Extremely dense tissue (1 out of 10 women)

You can’t tell how dense your breasts are by looking in the mirror or feeling them. The mammogram report sent to your doctor tells how dense your breasts are. It’s written by the radiologist who reads your mammogram.

Why do I need to know about dense breasts?

Having dense breasts may affect your plans for breast cancer screening. The more dense a breast is, the harder it is to see cancer on a mammogram image. That’s because dense tissue looks white onscreen, just like cancer does.

Breast cancer tends to grow in dense breast tissue more often than in fatty breast tissue. So having dense breasts may slightly increase your risk for breast cancer.

What about my breast cancer risk?

Having dense breasts may slightly increase your risk for breast cancer. But your risk for breast cancer depends on many things.

Sometimes women think that their breast cancer risk is higher than it really is. If you don’t know how high your risk actually is, talk to your doctor to find out.

If there’s a high risk of breast cancer in your family, talk to your doctor about getting genetic testing and genetic counseling.

To learn more about your risk level, go to www.cancer.gov/bcrisktool.

What tests are commonly used to screen dense breasts for breast cancer?

There are several breast cancer screening tests. Each type of test shows breast tissue differently and finds things that the others don’t.

  • Mammogram only. Mammograms are recommended for all women who need breast cancer screening. A mammogram is the only test that can show tiny bits of calcium that can be a sign of cancer, even in dense breast tissue.
  • Mammogram and breast ultrasound. These tests work well together for screening dense breast tissue. An ultrasound can show if a lump seen on a mammogram is a harmless fluid-filled cyst or something solid that could be a problem.
  • Mammogram and MRI. MRI shows clear detail of breast tissue, but often can’t tell you what is cancer and what isn’t. Many “abnormal” spots on MRI turn out to not be cancer, especially in women with a low risk for breast cancer.

Digital breast tomosynthesis, sometimes called DBT or 3-D mammogram, is a test that uses new technology. It may be used alone or with a digital mammogram. DBT seems to work better than mammogram alone to find cancer in dense breast tissue. But it is still being studied to see how well it works.

What are the risks of getting less testing versus the risks of getting more testing?

No screening test is perfect. Each carries the risk of doing too little or too much.

  • The risk of less testing is missing a cancer that needs treatment (called a false-negative result). With dense breast tissue, missing a cancer is most likely with a mammogram-only screening.
  • The risk of more testing is:
    • Finding something that looks like a cancer when it’s not (called a false-positive result). This can lead to unneeded tests or biopsy. False-positives are more common with MRI screening, since it shows the most detail.
    • Finding cancer that would never cause a problem, such as a cancer that grows so slowly that even without treatment it would never affect a woman’s health. But since there is no way to know which breast cancers will cause harm, any cancer is usually treated.

What are the benefits of getting less testing versus the benefits of getting more testing?

Different breast imaging tests can detect cancer in different ways. No single test can find every cancer.

  • The benefit of getting less testing (a mammogram-only screening) is that it raises your chances of finding cancer without the added risks of more testing.
  • The benefit of getting more testing (a mammogram plus another screening test) is that you may further raise your chances of finding cancer. But having more testing means that your chances for a false-positive result are higher. You may end up having tests that you don’t need, such as a biopsy.

What might a doctor recommend?

If you have dense breasts but no other risk factors for breast cancer, a mammogram is the recommended test. There isn’t enough evidence from studies to show that having other tests will help you.footnote 1

If you have dense breasts and other risk factors for breast cancer, talk with your doctor to decide about screening. In some cases, if further screening is needed, a breast ultrasound or MRI may be done.

Team up with your doctor to decide what makes the most sense for you.

Compare your options

Compare

What is usually involved?

What are the benefits?

What are the risks and side effects?

Get a mammogram only Get a mammogram only

  • You get a screening mammogram and breast exam.
  • If the mammogram is hard to read or looks abnormal, you may be called in for another test, such as a breast ultrasound.
  • If you notice any changes in your breasts between mammograms, you see your doctor.
  • A mammogram can show cancer that is too small for you or your doctor to feel. Even in dense breast tissue, it is the only test that can show tiny bits of calcium that can be a sign of cancer.
  • A screening mammogram is a proven early-detection test for breast cancer.
  • It can be hard to see cancer on a mammogram of dense breast tissue.
  • A mammogram may miss some cancers (called a false-negative result). This is most likely to happen with dense breast tissue.
  • A mammogram can find cancers that will never cause a problem. And it can show something that looks like a cancer when it’s not (called a false-positive result). This can lead to unneeded tests (like a biopsy).
Get an MRI or ultrasound with your mammogram Get an MRI or ultrasound with your mammogram

  • An ultrasound can show if a lump seen on a mammogram is a harmless fluid-filled cyst or if it’s something solid that might need a biopsy.
  • Mammograms show tiny calcium signs of cancer that ultrasound and MRI do not.
  • MRI shows breast tissue in detail and can find cancers that might not be seen on a mammogram.
  • The chance of finding something that looks like cancer, but is not, is higher than with mammogram alone. This false-positive result can lead to unneeded tests, like a biopsy. False-positives are more common with MRI screening.
  • The chance of finding cancer that will never cause a problem is higher than with a mammogram alone. This can lead to unneeded tests and even treatments.
  • Breast cancer imaging may miss some cancers (called a false-negative result).

Personal stories about considering how to screen dense breasts for cancer

These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.

When my sister got cancer, we learned that she and I both have the BRCA1 gene. That means that I have a high risk of getting breast cancer—bad breast cancer—like my sister and other women in our family have. It makes my dense breasts seem like nothing, especially since I get a mammogram and an MRI every year, anyway. I had a biopsy after one screening, which got me absolutely terrified. But so far, there’s no cancer.

Shawna, age 47

When I learned from my mammogram results that I have dense breasts, I freaked out. I thought, “That’s it. I’m going to get cancer.” See, I’m one of those people who expects the worst. But thanks to my doctor, I’ve settled down on this one. My breasts aren’t that dense, and the radiologist had no trouble seeing everything she needed to on the mammogram. If there’s any trouble with reading my next mammogram, they’ll just do an ultrasound afterward. Hopefully, it’ll be that easy.

Joelle, age 44

A couple of years ago, I had a biopsy that shows a kind of cell change that could lead to cancer. Until I learned I have dense breasts, I figured that a mammogram every year was all I needed to keep an eye on it. My doctor and I read over my past mammogram reports and decided that I can have a breast ultrasound with my next mammogram and see if that gives a clear enough picture. If not, we’ll go from there and talk about whether I need another test.

Lisa, age 65

What matters most to you?

Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.

Reasons to have a mammogram only

Reasons to have a mammogram plus other testing

I’m not too worried about breast cancer. I do have dense breasts, but my doctor says I don’t have any important risk factors.

I have a mother, sister, or daughter who’s had breast cancer, so my cancer risk is high.

More important
Equally important
More important

My radiology report says that my breasts only have scattered areas of dense tissue, so I think a mammogram can do the job.

My radiology report says that my breasts are very dense, so I’m worried.

More important
Equally important
More important

I feel like getting mammograms and doing self-exams of my breasts are enough screening for me.

I want as much breast cancer screening as I can have, even if it means getting some false-positives.

More important
Equally important
More important

I’m concerned about the cost of the screening tests.

I’m not concerned about the cost of testing.

More important
Equally important
More important

My other important reasons:

My other important reasons:

More important
Equally important
More important

Where are you leaning now?

Now that you’ve thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.

Having a mammogram only

Having a mammogram plus other screening testing

Leaning toward
Undecided
Leaning toward

What else do you need to make your decision?

Check the facts

1, Having dense breasts makes me high-risk for breast cancer.
2, A mammogram is a good test for finding breast cancer if I have dense breasts.
3, The more dense my breasts are, the more testing I need to screen for breast cancer.
4, An MRI is the best way for to screen women for breast cancer.

Decide what’s next

1,Do you understand the options available to you?
2,Are you clear about which benefits and side effects matter most to you?
3,Do you have enough support and advice from others to make a choice?

Certainty

1. How sure do you feel right now about your decision?

Not sure at all
Somewhat sure
Very sure

Your Summary

Here’s a record of your answers. You can use it to talk with your doctor or loved ones about your decision.

Your decision

Next steps

Which way you’re leaning

How sure you are

Your comments

Your knowledge of the facts

Key concepts that you understood

Key concepts that may need review

Getting ready to act

Patient choices

Credits and References

Credits
Author Healthwise Staff
Primary Medical Reviewer Sarah Marshall MD – Family Medicine
Primary Medical Reviewer Kathleen Romito MD – Family Medicine
Primary Medical Reviewer E. Gregory Thompson MD – Internal Medicine
Primary Medical Reviewer Wendy Y. Chen MD, MPH MD, MPH – Medical Oncology, Hematology

References
Citations
  1. American College of Obstetricians and Gynecologists (2015). Management of women with dense breasts diagnosed by mammography. ACOG Committee Opinion No. 625. Obstetrics and Gynecology, 125(3): 750–751. DOI: 10.1097/01.AOG.0000461763.77781.79. Accessed April 3, 2015.

You may want to have a say in this decision, or you may simply want to follow your doctor’s recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.

Breast Cancer Screening and Dense Breasts: What Are My Options?

Here’s a record of your answers. You can use it to talk with your doctor or loved ones about your decision.
  1. Get the facts
  2. Compare your options
  3. What matters most to you?
  4. Where are you leaning now?
  5. What else do you need to make your decision?

1. Get the Facts

Your options

  • Have a mammogram to screen for breast cancer.
  • Have an MRI or ultrasound with your mammogram.

Key points to remember

  • The more dense your breast tissue is, the harder it is to see cancer on a mammogram image. That’s because dense tissue looks white onscreen, just like cancer does.
  • Having dense breasts may slightly increase your risk for breast cancer. But your risk depends on many things.
  • When deciding about breast cancer screening, you’ll need to think in terms of your total breast cancer risk. Ask your doctor to go over your breast cancer risk factors with you, so you can decide what screening is right for you.
  • Screening tests for breast cancer include mammogram, breast ultrasound, and magnetic resonance imaging (MRI). Each type of test shows breast tissue differently and finds things that the others don’t. Depending on your risk level, insurance may pay only for a mammogram.
  • Cancer screening comes with the risk of finding things that look like cancer, but aren’t. This “false-positive” problem can lead to unneeded tests, biopsy, and sometimes treatment. When deciding about screening, weigh this risk against the possible benefits of detection, especially with the MRI. Breast MRI is very good at finding cancer. But it’s also more likely than other tests to mistake non-cancer breast changes as possible cancer.
FAQs

What are dense breasts?

Dense breast tissue is made up of thick fibrous tissue and milk glands.

Most women have breasts with a mix of dense tissue and fatty tissue. Some women have very dense or very fatty breasts. All of these breast types are normal.

There are four levels of breast density:

  • Almost all fatty tissue (1 out of 10 women)
  • Scattered areas of dense tissue, but mostly fatty tissue (4 out of 10 women)
  • Mixed dense and fatty tissue, also called heterogeneous (4 out of 10 women)
  • Extremely dense tissue (1 out of 10 women)

You can’t tell how dense your breasts are by looking in the mirror or feeling them. The mammogram report sent to your doctor tells how dense your breasts are. It’s written by the radiologist who reads your mammogram.

Why do I need to know about dense breasts?

Having dense breasts may affect your plans for breast cancer screening. The more dense a breast is, the harder it is to see cancer on a mammogram image. That’s because dense tissue looks white onscreen, just like cancer does.

Breast cancer tends to grow in dense breast tissue more often than in fatty breast tissue. So having dense breasts may slightly increase your risk for breast cancer.

What about my breast cancer risk?

Having dense breasts may slightly increase your risk for breast cancer. But your risk for breast cancer depends on many things.

Sometimes women think that their breast cancer risk is higher than it really is. If you don’t know how high your risk actually is, talk to your doctor to find out.

If there’s a high risk of breast cancer in your family, talk to your doctor about getting genetic testing and genetic counseling.

To learn more about your risk level, go to www.cancer.gov/bcrisktool.

What tests are commonly used to screen dense breasts for breast cancer?

There are several breast cancer screening tests. Each type of test shows breast tissue differently and finds things that the others don’t.

  • Mammogram only. Mammograms are recommended for all women who need breast cancer screening. A mammogram is the only test that can show tiny bits of calcium that can be a sign of cancer, even in dense breast tissue.
  • Mammogram and breast ultrasound. These tests work well together for screening dense breast tissue. An ultrasound can show if a lump seen on a mammogram is a harmless fluid-filled cyst or something solid that could be a problem.
  • Mammogram and MRI. MRI shows clear detail of breast tissue, but often can’t tell you what is cancer and what isn’t. Many “abnormal” spots on MRI turn out to not be cancer, especially in women with a low risk for breast cancer.

Digital breast tomosynthesis, sometimes called DBT or 3-D mammogram, is a test that uses new technology. It may be used alone or with a digital mammogram. DBT seems to work better than mammogram alone to find cancer in dense breast tissue. But it is still being studied to see how well it works.

What are the risks of getting less testing versus the risks of getting more testing?

No screening test is perfect. Each carries the risk of doing too little or too much.

  • The risk of less testing is missing a cancer that needs treatment (called a false-negative result). With dense breast tissue, missing a cancer is most likely with a mammogram-only screening.
  • The risk of more testing is:
    • Finding something that looks like a cancer when it’s not (called a false-positive result). This can lead to unneeded tests or biopsy. False-positives are more common with MRI screening, since it shows the most detail.
    • Finding cancer that would never cause a problem, such as a cancer that grows so slowly that even without treatment it would never affect a woman’s health. But since there is no way to know which breast cancers will cause harm, any cancer is usually treated.

What are the benefits of getting less testing versus the benefits of getting more testing?

Different breast imaging tests can detect cancer in different ways. No single test can find every cancer.

  • The benefit of getting less testing (a mammogram-only screening) is that it raises your chances of finding cancer without the added risks of more testing.
  • The benefit of getting more testing (a mammogram plus another screening test) is that you may further raise your chances of finding cancer. But having more testing means that your chances for a false-positive result are higher. You may end up having tests that you don’t need, such as a biopsy.

What might a doctor recommend?

If you have dense breasts but no other risk factors for breast cancer, a mammogram is the recommended test. There isn’t enough evidence from studies to show that having other tests will help you.1

If you have dense breasts and other risk factors for breast cancer, talk with your doctor to decide about screening. In some cases, if further screening is needed, a breast ultrasound or MRI may be done.

Team up with your doctor to decide what makes the most sense for you.

2. Compare your options

Get a mammogram only Get an MRI or ultrasound with your mammogram
What is usually involved?
  • You get a screening mammogram and breast exam.
  • If the mammogram is hard to read or looks abnormal, you may be called in for another test, such as a breast ultrasound.
  • If you notice any changes in your breasts between mammograms, you see your doctor.
What are the benefits?
  • A mammogram can show cancer that is too small for you or your doctor to feel. Even in dense breast tissue, it is the only test that can show tiny bits of calcium that can be a sign of cancer.
  • A screening mammogram is a proven early-detection test for breast cancer.
  • An ultrasound can show if a lump seen on a mammogram is a harmless fluid-filled cyst or if it’s something solid that might need a biopsy.
  • Mammograms show tiny calcium signs of cancer that ultrasound and MRI do not.
  • MRI shows breast tissue in detail and can find cancers that might not be seen on a mammogram.
What are the risks and side effects?
  • It can be hard to see cancer on a mammogram of dense breast tissue.
  • A mammogram may miss some cancers (called a false-negative result). This is most likely to happen with dense breast tissue.
  • A mammogram can find cancers that will never cause a problem. And it can show something that looks like a cancer when it’s not (called a false-positive result). This can lead to unneeded tests (like a biopsy).
  • The chance of finding something that looks like cancer, but is not, is higher than with mammogram alone. This false-positive result can lead to unneeded tests, like a biopsy. False-positives are more common with MRI screening.
  • The chance of finding cancer that will never cause a problem is higher than with a mammogram alone. This can lead to unneeded tests and even treatments.
  • Breast cancer imaging may miss some cancers (called a false-negative result).

Personal stories

Personal stories about considering how to screen dense breasts for cancer

These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.

“When my sister got cancer, we learned that she and I both have the BRCA1 gene. That means that I have a high risk of getting breast cancer—bad breast cancer—like my sister and other women in our family have. It makes my dense breasts seem like nothing, especially since I get a mammogram and an MRI every year, anyway. I had a biopsy after one screening, which got me absolutely terrified. But so far, there’s no cancer.”

— Shawna, age 47

“When I learned from my mammogram results that I have dense breasts, I freaked out. I thought, “That’s it. I’m going to get cancer.” See, I’m one of those people who expects the worst. But thanks to my doctor, I’ve settled down on this one. My breasts aren’t that dense, and the radiologist had no trouble seeing everything she needed to on the mammogram. If there’s any trouble with reading my next mammogram, they’ll just do an ultrasound afterward. Hopefully, it’ll be that easy.”

— Joelle, age 44

“A couple of years ago, I had a biopsy that shows a kind of cell change that could lead to cancer. Until I learned I have dense breasts, I figured that a mammogram every year was all I needed to keep an eye on it. My doctor and I read over my past mammogram reports and decided that I can have a breast ultrasound with my next mammogram and see if that gives a clear enough picture. If not, we’ll go from there and talk about whether I need another test.”

— Lisa, age 65

3. What matters most to you?

Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.

Reasons to have a mammogram only

Reasons to have a mammogram plus other testing

I’m not too worried about breast cancer. I do have dense breasts, but my doctor says I don’t have any important risk factors.

I have a mother, sister, or daughter who’s had breast cancer, so my cancer risk is high.

More important
Equally important
More important

My radiology report says that my breasts only have scattered areas of dense tissue, so I think a mammogram can do the job.

My radiology report says that my breasts are very dense, so I’m worried.

More important
Equally important
More important

I feel like getting mammograms and doing self-exams of my breasts are enough screening for me.

I want as much breast cancer screening as I can have, even if it means getting some false-positives.

More important
Equally important
More important

I’m concerned about the cost of the screening tests.

I’m not concerned about the cost of testing.

More important
Equally important
More important

My other important reasons:

My other important reasons:

More important
Equally important
More important

4. Where are you leaning now?

Now that you’ve thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.

Having a mammogram only

Having a mammogram plus other screening testing

Leaning toward
Undecided
Leaning toward

5. What else do you need to make your decision?

Check the facts

1. Having dense breasts makes me high-risk for breast cancer.

  • True
  • False
  • I’m not sure
You’re right. If you have dense breasts only—and no other risk factors—you are not at high risk for breast cancer.

2. A mammogram is a good test for finding breast cancer if I have dense breasts.

  • True
  • False
  • I’m not sure
Yes, it’s true. Although a mammogram of dense tissue can be hard to read, it’s the only imaging test that can show tiny bits of calcium—which can be a sign of cancer.

3. The more dense my breasts are, the more testing I need to screen for breast cancer.

  • True
  • False
  • I’m not sure
You’re right. Experts say to use total breast cancer risk, not just breast density, to guide screening decisions.

4. An MRI is the best way for to screen women for breast cancer.

  • True
  • False
  • I’m not sure
You’re right. An MRI shows such detail that it raises unanswered questions and worry, often leading to a biopsy. Most of these “abnormal” spots turn out to not be cancer.

Decide what’s next

1. Do you understand the options available to you?

2. Are you clear about which benefits and side effects matter most to you?

3. Do you have enough support and advice from others to make a choice?

Certainty

1. How sure do you feel right now about your decision?

Not sure at all
Somewhat sure
Very sure

2. Check what you need to do before you make this decision.

  • I’m ready to take action.
  • I want to discuss the options with others.
  • I want to learn more about my options.

Credits
By Healthwise Staff
Primary Medical Reviewer Sarah Marshall MD – Family Medicine
Primary Medical Reviewer Kathleen Romito MD – Family Medicine
Primary Medical Reviewer E. Gregory Thompson MD – Internal Medicine
Primary Medical Reviewer Wendy Y. Chen MD, MPH MD, MPH – Medical Oncology, Hematology

References
Citations
  1. American College of Obstetricians and Gynecologists (2015). Management of women with dense breasts diagnosed by mammography. ACOG Committee Opinion No. 625. Obstetrics and Gynecology, 125(3): 750–751. DOI: 10.1097/01.AOG.0000461763.77781.79. Accessed April 3, 2015.

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