ON THIS PAGE: You will find out more about screening for breast cancer. You will also learn the risks and benefits of screening. Use the menu to see other pages.
Screening is used to look for cancer before you have any symptoms or signs. Scientists have developed, and continue to develop, tests that can be used to screen a person for specific types of cancer. The overall goals of breast cancer screening are to:
Detect the cancer at an earlier stage of disease, which is when the cancer is most curable
Lower the number of people who die from the disease, or eliminate deaths from cancer altogether
Identify people with a higher risk of developing a specific type of cancer who may need screening more often or a different type of screening due to genetic mutations or diseases
Learn more about the basics of cancer screening.
Screening information for breast cancer
Mammography is the best tool doctors have to screen healthy people for breast cancer, as it has been shown to lower deaths from the disease. Like any medical test, mammography involves risks, such as the possibility of additional testing and anxiety if the test falsely shows a suspicious finding, called a "false-positive" result. Up to 10% to 15% of the time, mammography will not show an existing cancer, called a "false-negative" result.
Digital mammography may be better able to find breast cancers, particularly in dense breasts. A newer type of mammogram is called tomosynthesis or 3D mammography. It may improve the ability to find small cancers and reduce the need to repeat tests due to false-positives. However, there is also the risk of diagnosing problems in the breast that would otherwise go unnoticed and would not lead to any negative consequences. This is called "overdiagnosis" and may lead to overtreatment with a potential for harm. This method is approved by the U.S. Food and Drug Administration (FDA), though research on it is ongoing.
Other breast cancer screening methods
Other ways to examine the breasts, such as an ultrasound and/or a magnetic resonance imaging (MRI) scan, are not regularly used to screen for breast cancer in many women at average risk. However, these tests may be helpful when there is a very high risk of breast cancer, those with dense breast tissue, or when a lump or mass is found during a breast examination. The use of ultrasound screening is controversial because it has a high false-positive rate. This means that the test often wrongly identifies potential cancers. However, ultrasounds can be very useful in diagnosing breast cancer when an abnormality is found on mammogram (see Diagnosis). MRI use in routine screening is also controversial, although there are very high-risk populations in which it is recommended.
According to the American Cancer Society (ACS), women who have BRCA gene mutations, who have a very strong family history of breast cancer, or who had prior radiation therapy to the chest should consider mammography and MRI each year.
Women at moderate risk of breast cancer, such as women with precancerous changes on a biopsy or mutations in other genes that increase risk of breast cancer, can talk with their doctor about whether MRI screening should be considered.
MRI may be better than mammography and ultrasound at finding a small mass in the breast, especially when there is very dense breast tissue. However, an MRI has a higher rate of false-positive test results, which may mean more biopsies, surgeries, and other tests that may lead to overdiagnosis. In addition, an MRI does not show small spots of calcium called calcifications that can be found on a mammogram. Calcifications can be a sign of non-invasive breast cancer (ductal carcinoma in situ, or DCIS). However, MRI can still be used to detect DCIS.
Ultrasound and/or MRI may also be used for a suspicious breast finding on physical examination or mammography. Studies have shown mammography combined with whole breast ultrasound may find slightly more breast cancers than mammography alone in women with dense breasts. If a lump or mass is found during a physical examination, further testing with ultrasound or mammography may be needed.
Sometimes, a mammogram and sonogram are staggered with an MRI 6 months apart as part of screening surveillance.
Talk with your doctor about the method of screening recommended for you and how often screening is needed.
Different organizations have looked at the evidence, risks, and benefits of mammography and have developed different screening recommendations. Decisions about screening for breast cancer are becoming increasingly individual. It is important to talk with your doctor about how often you should receive screening and which tests are most appropriate.
The U.S. Preventive Services Task Force (USPSTF) recommends that women ages 50 to 74 have mammography every 2 years. They recommend that mammography be considered in women ages 40 to 49 after evaluating the risks and benefits of this test with a doctor.
ACS recommends that women ages 40 to 44 have the choice to start yearly mammography. They recommend that women ages 45 to 54 receive mammography every year and that women 55 and older can switch to having a mammogram every 2 years or continue yearly screening if they choose or as long as they are in good health.
Other groups also provide recommendations regarding screening, including the American College of Radiology and the Society of Breast Imaging. Both recommend annual mammography starting at age 40. Some international groups do not recommend routine population-based screening for any age, but instead recommend an individualized approach.
The controversy about screening mammography is related to the risks versus the benefits associated with it. The benefit of this screening is finding a cancer early that could result in a better chance of a cure. The risk is a finding that leads to additional tests when cancer isn't present and how much harm those additional tests have on the patient. In many parts of the world, the controversy around screening mammography is also about feasibility and costs. Breast cancers detected by mammography are often small. In contrast, rapidly growing, aggressive cancers are more commonly found in between screening mammograms. They are called interval cancers. Interval cancers are more aggressive than screen-detected cancers and lead to more deaths compared to screen-detected cancers. They are also more frequently found in younger women.
If you have a higher risk of developing breast cancer, screening may be recommended at an earlier age and more often than the schedules listed above. Some older women may stop screening at some point, especially if they have significant health problems that limit the length of their life or ability to go through the physical demands of breast cancer treatment.
There are also different screening recommendations by groups for breast cancer survivors. Guidelines published in JAMA Oncology recommend that mammography be stopped for breast cancer survivors age 75 and older if they are expected to live less than 5 years. Meanwhile, they recommend that mammography be continued for breast cancer survivors age 75 and older who are expected to live more than 10 years.
This is why it is important to talk with your doctor about breast cancer screening and decide on an appropriate screening schedule for you.
The USPSTF and ACS also differ on their recommendations for clinical breast examinations. A clinical breast examination is when a doctor or other health care professional performs a physical examination of your breasts to check for abnormalities or lumps. The USPSTF recommends a clinical breast examination along with mammography. The ACS does not recommend a clinical breast examination for women with an average risk of developing breast cancer, as they say there is very little evidence that it helps find breast cancer early when women are also getting mammograms. However, the ACS notes that this does not mean these examinations should never be done.
Finally, although breast self-examination has not been shown to lower deaths from breast cancer, it is important to become familiar with your breasts so that you can be aware of any changes and report these to the doctor. Cancers that are growing more quickly are often found through breast examinations in between regular mammograms.
The next section in this guide is Symptoms and Signs. It explains what changes or medical problems breast cancer can cause. Use the menu to choose a different section to read in this guide.