• Mammograms are X-rays of the breasts used to screen for breast cancer or check for a recurrence of breast cancer.
• Mammograms carry the risks of false-positive or false-negative results and exposure to a small amount of radiation.
• Having regular mammograms on the recommended schedule helps your care team create a history of your breast health and spot any concerning changes early.

A mammogram is an X-ray picture of the breast. It uses a tiny amount of radiation to produce detailed images of the breast. Although mammograms cannot be used to diagnose breast cancer, they are valuable tools for helping detect the early signs of breast cancer before a person starts to develop symptoms. If a radiologist finds any potential signs of breast cancer in a mammogram, they’ll order more tests to confirm the diagnosis.

Here is what you need to know about the use of mammograms to detect breast cancer, including what they involve and how to prepare for this test.

Types of Mammograms

Mammograms are often one of the most important types of breast imaging screening tests. There are two general types of mammograms, based on their purpose: screening mammograms and diagnostic mammograms. A newer type of mammogram, known as a 3D mammogram, can also be used to produce detailed images of breast tissue.

Screening Mammograms

Regular screening mammograms can be used to identify the early signs of breast cancer (pre-cancer), sometimes years before someone has any apparent symptoms. These X-rays can often detect breast cancer long before a lump can be felt through a breast self-exam or a clinical breast exam. Early detection gives doctors the chance to diagnose and treat cancer before it spreads.

In addition to detecting cancer and pre-cancer, screening mammograms can detect benign (noncancerous) tumors and cysts, including the two most common types of changes found on a mammogram: masses (lumps) and calcifications (calcium deposits).

The American Cancer Society recommends annual mammograms for women ages 45 to 54. After age 55, women can switch to mammograms every two years, or continue annual mammograms if desired. Those with a genetic predisposition to breast cancer, a family history of breast cancer, or other specific risk factors will most likely require additional testing, such as a breast MRI.

Diagnostic Mammograms

A doctor may recommend a diagnostic mammogram if a screening mammogram indicates abnormalities or changes to a person’s breast tissue. Diagnostic mammograms may also be used if radiologists find signs of potential breast cancer and need to check the tissue further. These X-rays use special techniques to provide a more detailed picture of the breast, as well as more images of the breast tissue.

3D Mammograms

A newer type of mammogram is called a 3D mammogram — also known as digital breast tomosynthesis or breast tomosynthesis. In a 3D mammogram, each breast is compressed once. A machine takes multiple low-dose X-rays, moving in an arc over each breast. This type of imaging allows doctors to see the breast tissues much more clearly and in three dimensions.

Multiple studies have suggested that 3D mammography lessens the chance of needing follow-up testing. More breast cancers appear to be found when this technique is used, and several studies show 3D mammography may be helpful for people with higher breast density.

How Are Mammograms Used?

Mammograms are used to detect abnormalities in breast tissue. They can be used for the early detection of signs of breast cancer and further investigation of changes in the breasts.

Early Detection of Breast Cancer

Screening mammography is used to detect breast cancer in those who have no known breast problems or symptoms. Early detection can lead to early treatment, which may lead to better outcomes for individuals who are diagnosed with breast cancer.

Mammography alone cannot determine whether any abnormalities in the breasts are cancerous or provide a breast cancer diagnosis. If a doctor suspects breast cancer based on the mammogram results, they may order a breast biopsy. This entails the removal of a small sample of breast tissue for lab analysis.

Diagnosis of Changes to the Breasts

Diagnostic mammograms provide additional images that aren’t included in screening mammograms. These tests can be used if an abnormality — such as pain or nipple discharge — or a mass (lump) is found during a breast self-exam or clinical breast exam. These mammograms can also be used if someone is experiencing other symptoms of breast cancer.

Being told you have an abnormal mammogram test result doesn’t necessarily mean you have cancer. An abnormal mammogram just means that your radiologist has found a change or abnormality that should be investigated with further testing. Mammograms alone cannot diagnose breast cancer.

What Are the Risks of Breast Cancer Screening?

Mammography has been recommended by the American Cancer Society since 1976. Recently, technological advancements have considerably improved the results and techniques used in mammograms. Mammograms today produce high-quality images of the breasts with X-rays that are low in radiation. However, there are some things to consider before choosing to undergo mammography.

Radiation

Ask your doctor about the radiation used in mammography — particularly, whether exposure to this level of radiation poses a risk to you, given your overall health. Keep a record of your previous history of exposure to radiation, including other X-rays and radiographic scans, so your doctor will have a better idea of the risks you may face.

Overall, scientists have determined that radiation risks associated with mammographies are minimal. However, if you’re pregnant or think you may be, tell your doctor. Exposure to radiation while pregnant can lead to birth defects. If you’re pregnant and you must have a mammogram, you and your doctor can take special precautions to minimize radiation exposure to the fetus.

False-Positive Test Results

False-positive results occur when a radiologist mistakenly believes a benign growth or abnormality to be cancerous. These results may lead to further tests and procedures, such as repeated X-rays, breast ultrasounds, or breast biopsy. Further testing will usually clarify the result before your doctor recommends treatments, such as radiation therapy or surgery (e.g., a mastectomy). Overdiagnosis, as well as additional tests and procedures, can be invasive, anxiety-provoking, expensive, and time-consuming.

False-Negative Test Results

Radiologists can sometimes miss certain types of breast cancer. These incidents are called false-negative test results. A false-negative result may delay the detection and treatment of breast cancer.

Breast Cancer Screening Guidelines

Different cancer research institutions offer different breast cancer screening guidelines. For people under 50 years who are at average risk of breast cancer, most health organizations advocate letting the individual decide if the potential benefits of getting a mammogram outweigh any risks.

Individuals with an increased or high risk of breast cancer are generally given a separate set of screening recommendations. People in the following groups should discuss with their doctor the best time to start mammograms:

• Those who’ve undergone genetic testing that has identified mutations in their BRCA1 or BRCA2 genes
• Those who have a 20 percent or greater lifetime breast cancer risk due to family history
• Those who have had exposure to chest or mantle radiation before the age of 30

It’s important to undergo regular mammography as recommended by your doctor based on your age and breast cancer risk. Having regular mammograms allows your doctor to create a history of your breasts over the years. A radiologist can compare each past mammogram to current ones to look for any suspicious changes, which can help them detect breast cancer as early as possible.

Preparing for a Mammogram

If you are 40 or older, have a family history of breast cancer, or have a genetic predisposition for breast cancer, your health care provider will likely notify you when it is time for a mammogram and refer you to mammography facilities.

Communicating With Your Care Team

If you’re going to a mammogram appointment after a breast cancer diagnosis, make sure that all of your doctors are aware of your medical history. One MyBCTeam member asked, “I’ll be going for my mammogram soon (about one year after diagnosis). Should I expect or request an ultrasound also?” Another replied, “Request an ultrasound! Because we’ve had cancer, they may want to use ultrasound too.”

When you schedule your appointment, be sure to inform the office if it’s your first mammogram and ask what you need to know to be prepared for the appointment.

Certain factors can affect the results of a mammogram. For instance, wearing creams, lotions, deodorant, or talcum powder on your breasts or under your arms can interfere with the images produced. Having dense breast tissue — a risk factor for breast cancer — can also make it more difficult for radiologists to read the results of a mammogram.

Breast implants can also hide some of the breast tissue and obscure mammography images. Make sure to inform the radiology office if you have implants before your appointment. They’ll be able to assign you a technologist who has experience performing mammograms on people with implants.

Discuss with your provider and insurance company what kinds of scans your insurance will cover. One MyBCTeam member who was going to receive a postdiagnosis mammography said, “My copay covered the diagnostic mammogram, the ultrasound, and the biopsy, all done in one day.” However, another member reported, “If I’m getting a diagnostic mammogram, my insurance deductible applies.”

Ask how you’ll receive your results and approximately how long it will take. Your radiologist is also there to help you understand the results of your mammography if you have any questions.

Find Your Support

MyBCTeam is the social network for people with breast cancer. On MyBCTeam, more than 58,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Do you have any tips for people undergoing their first screening or diagnostic mammogram? Share your experiences and thoughts in the comments below or by posting on MyBCTeam.