When Should You Get a Mammogram?
When it comes to detecting breast cancer, regular testing matters. But precisely how early and how often you should get screened isn’t so straightforward. Medical guidance can seem bewilderingly inconsistent. Some agencies recommend annual checks from age 40 onward, for example, while others have said to wait until age 50. There is no “generalizable” age that can be applied to everyone, says Vivian Bea, section chief of breast surgical oncology at New York–Presbyterian Brooklyn Methodist Hospital.
“I think we need a more personalized approach for each individual in determining when they should actually start screening—not this bucketed start age,” Bea says. “We’re clearly missing people.”
Not only have breast cancer rates been climbing in the past decade, but people are being diagnosed younger. And now several medical regulatory boards and organizations are saying that if you’re age 40, it’s time to get regular mammograms. Last month the U.S. Preventive Services Task Force (USPSTF), an independent group of clinicians and researchers, proposed that people ages 40 to 74 receive mammograms every two years—an update from previous guidelines that recommended starting at age 50. These recommendations apply to people assigned female at birth, including cisgender women, transgender men and nonbinary people. Task force members also noted data showing disproportionate rates of late-stage breast cancer diagnoses and death among people in certain racial and ethnic communities, especially Black women.
“We have new and more inclusive evidence that getting breast cancer screening starting at age 40, every other year, will save lives,” says task force member John Wong, who helped draft the proposal and is a primary care clinician at Tufts Medical Center. “That will help women who are Black even more and reduce some of the health inequity.”
Why does age matter for mammograms?
Generally, breast cancer is more likely to develop with age because the risk of genetic mutations increases, and the mutations become harder to repair. Natural shifts in hormones can also play a role. “Breast cancer is more likely to occur when we’re older, but we do know a lot of people who are getting breast cancer in their 40s and younger,” says Laurie Margolies, a radiologist and the director of breast imaging for the Mount Sinai Health System in New York City.
For its proposal, the USPSTF applied newer and more inclusive data to a comparative model that showed what the survival outcomes would be for average-risk 40-year-olds in the U.S. if they did or did not receive breast cancer screenings. “We say more inclusive because these data include more racially, ethnically diverse populations than the original randomized controlled trials done for breast cancer screening over roughly 20 or more years ago,” Wong says. What the data showed was “more women than ever before in their 40s have been developing breast cancer.”
Long-term data from the National Cancer Institute show that breast cancer rates increased 2.7 percent annually among women under the age of 50 between 2016 and 2019—compared with a 0.3 percent annual increase between 1994 and 2016. Getting tested is an important step in improving survival and avoiding invasive treatments, Margolies says. “If you detect cancer by screening, you’re less likely to need a mastectomy, you’re less likely to need chemotherapy, and you’re less likely to need to have all the lymph nodes under your arm removed,” she adds. “So it’s so important.”
Many medical organizations have already been guiding practitioners to screen people for breast cancer earlier than age 50. The American College of Radiology has been recommending mammograms as early as age 40 for average-risk women. The American Cancer Society says women between ages 40 and 44 should have the option to get mammograms and that screening should start for all women by age 45. “A large percentage, if not the majority, of physicians in the United States have been recommending [screening around age 40] to their patients,” Margolies says. But she adds that some insurance companies, particularly those supplying government insurance plans, as well as some public health departments and legislators, often lean on the USPSTF’s recommendations to guide practice and policy.
Most insurance plans cover mammogram screenings, but additional tests such as ultrasounds or magnetic resonance imaging (MRI) may vary by state or require insurance authorization. Wong says the task force recognizes that insurance coverage and screening costs are important—but he notes that these decisions are not under the task force’s control and remain at the jurisdiction of payers, insurers and legislators.
How do you know if you’re at high risk for breast cancer?
Starting screening at 40 can “save more lives—assuming you’re not at high risk,” Margolies says.
Medical organizations such as the American College of Radiology, along with breast specialists such as Margolies and Bea, encourage people to receive a breast cancer risk assessment at age 25. Practitioners use a risk assessment tool, which is like a “calculator” that crunches a patient’s medical, family and reproductive history. If the result is above a certain percentage, a person is deemed at high risk for breast cancer.
People at high risk “may need more than screening mammography. They may need to start earlier. They may need to have supplemental MRI or supplemental ultrasound,” Margolies says. “So it’s a complicated message.”
Two-dimensional-image mammograms are the cornerstone of breast cancer screening tests. Additionally, three-dimensional mammograms, or digital breast tomosyntheses, use several x-ray images to create a more complete picture of the breast, Wong says. Additional screening technologies look at tissues differently. Ultrasound machines bounce acoustic waves off body tissues to create an image, and MRI involves injecting a dye that helps visualize tissues and blood vessels in greater detail. “If you did just the ultrasound, you would see some cancers that you wouldn’t have found on the mammogram. And if you do MRI, that’s going to find even more cancers,” Margolies explains. “For our highest-risk women, we recommend MRI.”
Two of the factors considered during risk assessments are prior chest radiation exposure between the ages of 10 and 30 and breast tissue density. Around menopause, usually between ages 45 and 55, breast tissue typically becomes less dense and more fatty. Cancerous tissues are easier to spot in fatty tissue, where they appear as white spots or shadows on a mammogram. Denser tissue, on the other hand, masks some cancers on a mammogram. And cancers are more likely to develop in dense tissue (experts are still trying to figure out why). Wong says younger women tend to have denser breasts; about 50 percent of women in their 40s and 40 percent of women in their 50s are considered to be in this category.
A practitioner will also ask whether first-degree family members (such as parents or siblings) or extended relatives (such as aunts, grandparents or cousins) have had any type of cancer. More specifically, people with a family history of mutations in the BRCA1 and BRCA2 genes—which are important in suppressing tumors and curbing abnormal cell growth—are at higher risk for breast cancer. Certain populations, such as Ashkenazi Jewish people and Black people, are known to have higher percentages of BRCA mutations.
“Black women are twice as likely to be diagnosed with triple-negative breast cancer,” a fast-spreading, invasive cancer with few treatment options, Bea says. “Triple-negative breast cancer is linked to sub-Saharan and West African ancestry. That’s within your genes.”
According to a 2021 study in the journal Cancer, women in racial or ethnic minority groups are 127 percent more likely to die of breast cancer before age 50 than non-Hispanic white women. And research in 2019 found that Black women are also 42 percent more likely to die from breast cancer despite similar diagnosis rates and are more likely to be diagnosed with later stages of the disease. There are several reasons for these disparities, Bea says. On top of genetic and biological risk factors, Black women and other members of minority groups experience greater barriers to quality care. “Confusion leads to distrust, and systemic racism also leads to distrust,” Bea says. “Distrust, period, in the health care system leads to poor outcomes. We have to really have a unified approach to care that is more personalized.”
Bea also suggests that women who are uncomfortable or nervous about breast screenings or risk assessments to go with a trusted friend or family member. “Every woman should be empowered to know what their risks are and should start risk assessment at the age of 25,” Bea says. “It is absolutely imperative that whoever’s performing these assessments is aware of the intricate details of breast cancer and breast cancer inequalities in the U.S.”
The proposal from the USPSTF doesn’t currently include specific guidance on whether employing different strategies or screening earlier than age 40 would be beneficial for Black women, members of other racial groups or women with dense breast tissue.
How frequently should people get screened?
While several medical organizations recommend annual mammograms, the USPSTF’s proposal calls for average-risk women to get one every other year; the task force says there wasn’t enough evidence to show a benefit to annual screening for those in their 40s. Some experts, such as Bea and Margolies, say screening every two years is not enough. Lowering the starting screening age to 40 is a good first step, Margolies says, but she adds that younger women are more likely to develop aggressive, fast-growing breast cancers. “Screening every other year does not make sense,” Margolies says. “We’re lowering the screening age according to the task force to catch those fast-growing, more aggressive cancers. People in their 40s need it every year. Otherwise you’re missing that opportunity.”
Bea expresses similar concern for her patients: “I’m not going to [subscribe] to waiting for two years to use a perfectly invented tool—that we know works to catch it at its earliest stage—because there wasn’t sufficient evidence.”
Getting mammograms too early or too frequently has brought up concerns about false positives and overdiagnosis. For instance, if you are receiving imaging twice as often, you increase the risk of getting a false positive and of a clinician ordering costlier additional testing such as ultrasounds or MRI scans or even biopsies. “You do perhaps detect a few more cases of cancer [through screening every year], but we were not clear that that resulted in a lot of benefits,” Wong says. An incorrect diagnosis might also be “unsettling and anxiety-provoking,” he says.
Experts such as Margolies feel that temporary discomfort shouldn’t outweigh finding cancers more readily. “How can you possibly equate anxiety, whether it be a few minutes or a few days, to potentially dying of breast cancer? It doesn’t seem to make sense,” she says.
Wong emphasizes that the task force’s recommendations are meant to be built upon and that the group is calling for more research to determine if additional screening after a normal mammogram might be helpful. The USPSTF is taking public comments on its recent proposal for mammogram screenings until June 6. Task force members also plan to continue monitoring national data and trends as that information becomes available. Ultimately, they hope to answer the big question on researchers and clinicians’ minds: What is causing breast cancer rates to rise at younger ages than before?
“Our lifestyle, our weight, what’s in the environment—I think all those are combining to lead to increased risk of breast cancer. But we don’t know for sure,” Margolies says. “We might eventually find that maybe 35 is right. Maybe 40 is too old. These are questions that we’ll need to answer over the next decade or two.”