What is a mammogram?
A mammogram is the most effective test for detecting breast cancer. It is a special X-ray of the breast that can reveal tumors that are often too small to be felt or noticed on a physical examination. It can also show other changes in the breast that doctors believe may suggest breast cancer.
“Breast cancer is an important health issue for women. A screening mammography is an exam for women without any breast complaints that can detect breast cancer that may not be found on physical examination,” says Sona Chikarmane, MD, associate chair of Faculty Development at Dana-Farber/Brigham and Women’s Cancer Center. “Having regular screening mammograms will detect breast cancers when they are small, with a good prognosis.”
When should I have a mammogram?
Experts and medical organizations offer different timelines for when women should begin and stop routine screening mammography and how often screening mammography should be performed. Recommendations have evolved over time as more information has become available to guide these decisions. To determine when and how to screen for breast cancer, you should have a discussion with your health care team about your risk of developing breast cancer, your preferences, and your team’s recommendations.
For women deciding when to start having regular mammograms for early detection of breast cancer, the American Cancer Society (ACS), American College of Radiology (ACR), the National Comprehensive Cancer Network (NCCN), and U.S. Preventive Services Task Force (USPSTF) each offer useful guidelines.
The ACS recommendations, which were updated in 2015, state that:
- Women age 40-44 should have the option to start annual mammograms if they wish to do so
- Women age 45-54 who are at average risk of breast cancer should have yearly mammograms
- Women age 55 and older should have mammograms every other year
The ACR guidelines and NCCN guidelines recommend annual screening mammograms beginning at age 40 and continuing as long as you are in good health with a life expectancy of at least five to seven years.
New guidelines from the USPSTF, issued in May 2023, recommend that women at average risk for breast cancer get regular mammograms every other year starting at age 40. The organization’s previous recommendations called for beginning routine mammograms at age 50 with a personalized approach for those ages 40-49. In making the change, the USPSTF cited an increase in breast diagnoses among younger women and persistently high death rates among Black women. (The updated guidelines are not final, as the USPSTF continues to review evidence from research.)
“Although the guidelines from these organizations continue to shift over time and will continue to do so, it’s important to remember that one thing has never changed (nor will likely change): Women should talk with their clinicians about what works best for them when it comes to screening for breast cancer, with an individualized decision that incorporates one’s anticipated risk of breast cancer and preferences,” says Rachel A. Freedman, MD, MPH, a breast cancer specialist in Dana-Farber’s Susan F. Smith Center for Women’s Cancers.
Women at higher risk of breast cancer
You may be at an increased risk of developing breast cancer if you:
- Have cancer-susceptibility genes such as BRCA1 and BRCA2 or other inherited gene abnormalities
- Have had certain benign breast conditions
- Have a family history of breast cancer
- Had had chest irradiation as prior treatment
Women with gene mutations that predispose them develop to breast cancer typically begin regular screening at an early age, which usually involves a breast Magnetic Resonance Imaging (MRI) test in addition to mammography. In general, women at increased risk may even begin screening earlier than age 40. Be sure to talk to your doctor about what might be right for you.
Learn more: Take Dana-Farber’s AssessYourRisk Quiz to learn more about your personal risk of breast and ovarian cancer.
At what age can women safely stop having a regular mammogram?
There currently isn’t enough evidence to claim that mammograms benefit women later in life, particularly if other medical conditions are likely to limit their life expectancy. Life expectancy can be very hard to estimate, but in general, if a woman’s overall health is poor, the benefits of mammography in later years may be outweighed by the risks that may come with mammograms — false positives (having additional tests when there is no cancer), discomfort, anxiety, and over-treatment, in which a woman would undergo treatment for a cancer that would not have affected her longevity.
Women of all ages should talk with their health care team on what might be right for them, because these decisions should be very individualized.
A recent study involving women 75 and older provided additional information on whether women in this age group can benefit from annual mammograms. The researchers reported that in women age 75 to 84, mammograms were not associated with lowering the risk of dying from breast cancer. The findings, if confirmed by further research, may begin to change how many women continue screening as they age.
“The decision on when and how to start and stop having mammograms, regardless of age, should be one that is individualized, based on a patient’s concerns, risks, and other health priorities,” says Freedman. “However, as we age, the benefits will lessen and there will be a ‘right’ time to stop this testing.”