When Should I Start Getting Mammograms?

For women older than age 40, mammogram screening schedules, including when to start and how often to get them, may vary widely.

woman getting a mammogram

Medically reviewed in March 2020

In 2019 alone, the American Cancer Society estimates that more than 300,000 American women were diagnosed with breast cancer, and almost 42,000 died of the disease. Hands down, mammograms are the best method for early detection, when there are more options for treatment and a better chance of survival. And while experts agree that screening is essential, there’s some disagreement among major medical organizations regarding the age to begin and how often to have it done.

“As with all screening tests, mammography has both benefits and adverse consequences,” says Samantha Bunting, DO, an OBGYN affiliated with Plantation General Hospital and Westside Regional Hospital in Plantation, Florida. Each organization weighs these benefits and harms a bit differently, she explains, and that influences their recommendations. But it can lead to some confusion.

Understanding why the guidelines differ can help women discuss mammography with their healthcare providers (HCPs). Together, they can make informed choices about screenings. Here’s what you should know to make the best decision for you.

Getting to know the guidelines
For women with an average breast cancer risk, none of the four organizations in question advise starting regular mammograms before age 40. The disease isn’t as common during those years, and it’s largely agreed upon that the potential harms (more on those below) significantly offset the benefits. The recommendations are as follows:

  • American Cancer Society (ACS): Women can start screening between ages 40 and 45 if they so choose. Beginning at 45, the ACS recommends annual mammograms. From 55 to 74, getting screened every one or two years is recommended.
  • American College of Obstetricians and Gynecologists (ACOG): At age 40, average-risk women should be offered the option. By 50, all women should be screened every one or two years.
  • National Comprehensive Cancer Network (NCCN): Yearly mammograms should start at 40.
  • United States Preventive Services Task Force (USPSTF): Women may choose to begin screening at 40. Between 50 and 74, they should have mammograms every two years.

Keep in mind, mammography recommendations are different for women at a higher risk of breast cancer, such as those with certain genetic mutations or a personal or family history of the disease. These women should typically begin regular screenings earlier and may have them more frequently. Speak with your HCP about assessing your own risk for the disease.

How long should you keep getting mammograms?
In short, there’s no absolute age that screening should be discontinued. Instead, the organizations generally advise that women review their screening decisions when they turn 75 or when life expectancy is 10 years or less. If it’s anticipated that a woman will live another decade, it may be beneficial to keep up with regular imaging.

“It should be a shared decision between the patient and the physician about whether to continue screening or not,” says Dr. Bunting. “This is usually based on a discussion including the information about the risks and benefits, as well as the values of the patient, their concerns, their priorities and their current health status.”

The basics of benefits and harms
In creating their guidelines for average-risk women, the ACS, ACOG, NCCN and USPSTF tried to balance the potential benefits of mammograms with their possible harms.

The benefits of mammograms are significant and well-known: Regular screening can prolong and save lives. Between 1989 and 2016, the American breast cancer death rate fell 40 percent, likely due in part to the wider awareness and implementation of mammography.

Mammogram harms may be less familiar to the general public, which is why it’s important to discuss these with your doctor. One common harm is the potential for a false positive. False positives are mammograms that appear abnormal at first but turn out to be non-cancerous. Whenever a woman receives abnormal results from a screening, she’s called back for further testing, which can be costly and anxiety-inducing. They happen in about 1 of 10 mammograms.

Other possible harms include overdiagnosis and overtreatment. Overdiagnosis occurs when a mammogram detects a relatively minor cancer—one that would never progress into a critical, symptomatic problem, and may even disappear on its own eventually. Overtreatment is the unnecessary treatment of these cancers, which can cause serious, otherwise avoidable mental and physical side effects. It’s difficult to tabulate the number of women overdiagnosed and overtreated annually, since doctors can’t predict exactly which tumors will become potentially life-threatening.  

Mammogram radiation may also be considered a harm. However, the chance that the X-ray exposure itself could lead to cancer is very low. The benefit of early detection, Bunting says, “far outweighs the risk of dying from any kind of cancer that could be induced from mammography radiation.”

Deciding what’s right for you
As women discuss screenings with their HCP, they should take these benefits and harms into account. For those between 40 and 49, who tend to have lower breast cancer rates than older women, the benefits of mammography may be significant, but so is the risk for false positives, overtreatment and overdiagnosis—as well as the anxiety and stress that these outcomes may cause. For most women age 50 to 74, on the other hand, the benefits of regular screening tend to outweigh the harms. Your HCP can help you determine the frequency at which you should be screened.

Ultimately, choosing whether to initiate regular mammograms before age 50 is up to each woman. Mammography guidelines serve as excellent references, and should be important factors in the decision, along with your individual risk, personal preferences and the advice of your HCP.

“This is another shared decision-making process with a patient and physician,” says Bunting. Together, you can make the screening choice that serves you best.

Article sources open article sources

Centers for Disease Control and Prevention. “United States Cancer Statistics: Data Visualizations: Leading Cancer Cases and Deaths, Male and Female, 2016,” “What Is a Mammogram?” “What Are the Risk Factors for Breast Cancer?” “What Are the Benefits and Risks of Screening?”
UpToDate.com. “Patient education: Breast cancer screening (Beyond the Basics),” “Screening for breast cancer: Strategies and recommendations.”
American Cancer Society. “Mammogram Basics,” “American Cancer Society Guidelines for the Early Detection of Cancer,” “How Common Is Breast Cancer?”
The American College of Obstetricians and Gynecologists. “ACOG Practice Bulletin: Breast Cancer Risk Assessment and Screening in Average-Risk Women.”
National Comprehensive Cancer Network. “Breast Cancer Screening and Diagnosis.” Version 1.2019 — May 17, 2019.
U.S. Preventive Services Task Force. “Final Recommendation Statement: Breast Cancer: Screening.”
National Cancer Institute. “Breast Cancer Screening–Patient Version.”
Hoffman RM, Lewis CL, et al. “Decision-making processes for breast, colorectal, and prostate cancer screening: the DECISIONS survey.” Medical Decision Making. 2010 Sep-Oct;30(5 Suppl):53S-64S.

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