- A new study links skipping first and subsequent mammograms to a higher chance of dying from breast cancer.
- It highlights the importance of getting mammograms at the recommended times.
- It also highlights the importance of assessing individual breast cancer risk.
Breast cancer accounts for about 30% of all cancers diagnosed in females, and is the second leading cause of cancer death in women, according to the American Cancer Society. One of the key ways to control these statistics is to promote and implement breast cancer screening via timely mammograms—key word, timely. A new study emphasizes just how important that latter aspect is.
Meet the Experts: Eric Brown, M.D., breast surgeon at the Barbara Ann Karmanos Cancer Institute; John Lewin, M.D. chief of the Breast Imaging Division at Smilow Cancer Hospital and Yale Cancer Center researcher; Alit Yousif, M.D., diagnostic radiologist and director of breast imaging at Barbara Ann Karmanos Cancer Institute; Angela Wilson, M.D., obgyn at Montefiore Einstein Advanced Care.
The study, published in The BMJ, found that women who skipped their first mammogram were more likely to forego subsequent screenings and therefore, had a 40% higher chance of dying of breast cancer. Keep reading to learn more about the findings, mammogram recommendations, and understanding breast cancer risk.
What did the study find?
The observational study looked at mammogram attendance, breast cancer incidence, tumor characteristics, and breast cancer mortality of over 400,000 women in Sweden using various national health register databases. Researchers followed the participants’ data over a period of 29 years.
Among the participants, 32% did not have their first mammogram at the recommended time, and were persistently less likely to attend subsequent screenings. After a three year follow-up period, 16,059 new cases of breast cancer were documented, and those who missed their initial screenings were more likely to have had noticeable breast cancer symptoms, be diagnosed with advanced stages, and die from breast cancer.
Both groups (first screening attendees and early absentees) had relatively similar breast cancer incidence, however, the early absentees had a 40% higher rate of breast cancer mortality—a ratio of 9.9 per 1000 compared to 7.0 per 1000—meaning the absentees were more prone to dying of breast cancer, likely because they missed the window for early detection.
What limitations did the study have?
A couple of caveats here: The age recommendation for mammograms in Sweden changed from 50 to 40 (circa 2005) during the study, and are now advised to occur every 18 months. Related, some early study data “doesn’t control for variables such as which patients were screened using old film mammography versus digital screening versus three-dimensional mammography,” explains Eric Brown, M.D., breast surgeon at the Barbara Ann Karmanos Cancer Institute. “Because these technologies were not implemented at the same time everywhere, the results may be related to a patient’s risk, but also related to their access to better, or worse, imaging.”
It’s also worth noting that the journal published an expression of concern after the study released that raised eyebrows at its causal link between missing mammograms and breast cancer deaths. Skipping a mammogram increases the likelihood of breast cancer going undetected, which can lead to mortality. Still, all of our experts agree with the main takeaway here and noted that this is not the first study to highlight the life-saving importance of on-time mammograms.
What the findings mean
In Sweden, even though there are clear guidelines for mammograms, over 1/4 of study participants missed their first. This goes to show that: “People do not always want to follow medical guidelines for preventive care, whether that is vaccines, colonoscopy or mammography,” notes John Lewin, M.D. chief of the Breast Imaging Division at Smilow Cancer Hospital and Yale Cancer Center researcher.
In the United States, such hesitancy could be conflated by the general public confusion about mammogram screening guidelines. “Unfortunately, there is no absolute standard recommendation, so patients sometimes are not sure which one to follow,” says Alit Yousif, M.D., diagnostic radiologist and director of breast imaging at Barbara Ann Karmanos Cancer Institute. “There is also a significant amount of incorrect information circulating on social media. Some people post unfounded claims about breast imaging, and patients are not always able to tell who is trustworthy and who is not.”
When should you get a mammogram?
Dr. Yousif follows mammogram screening guidelines from the American College of Radiology (ACR), which recommend them for average-risk women beginning at age 40. “There are different guidelines from various medical societies, but all data points to earlier detection and lives saved with regular screening starting at 40,” she adds.
Both the ACR and the American Society of Breast Surgeons also recommend that every woman have a formal breast cancer risk assessment by age 25. “This assessment can identify women who may be at higher-than-average risk and might benefit from earlier screening,” Dr. Yousif explains. “Some data suggest that the incidence of breast cancer in women younger than 40 is rising, so this assessment could lead to earlier detection in these younger folks.” The ACR presses this recommendation particularly for Black and Ashkenazi Jewish women, who statistically experience higher risk at younger ages.
In general, according to Dr. Lewin, the main takeaway from the findings should be: “If you miss having a mammogram at 40, just get one as soon as you can. The problem with the women in the study is that they missed many mammograms.”
Understanding breast cancer risk
“For anyone uncertain when they should start screening, a visit to your general practitioner or gynecologist would allow for the opportunity to discuss their history to determine risk,” says Angela Wilson, M.D., obgyn at Montefiore Einstein Advanced Care.
Risk is determined by personal and family medical history, history of smoking, history of childbirth, history of chest radiation, and genetic predispositions, adds Dr. Wilson. In addition to discussing those factors with a provider, you can also asses your risk with various tools online including the Tyrer-Cuzick method or the Gail model calculator, she says. It’s important to take whatever you might learn from those assessments to an in-person provider, who may recommend “any possible lifestyle changes or screening plans that would be helpful,” she concludes.
Above all, the best understanding of your breast cancer risk will come from an initial mammogram, which is why they’re so important. The screening measures breast density, Dr. Lewin explains, which determines how future screenings should be adjusted for optimal readings.
Are mammograms safe?
Yes. “The radiation dose is low and considered safe. It’s roughly equivalent to the radiation dose one would expect from a round-trip flight between the Midwest U.S. and Europe,” explains Dr. Yousif. She adds that the compression of tissue during the procedure does not promote cancer growth. “Although it may be uncomfortable, it is not dangerous to the breast tissue,” she says.
It’s also important to note that women with dense breasts (which can make imaging tricky) still benefit from annual mammograms, “even if they receive adjunct screening such as ultrasound or MRI,” Dr. Yousif adds. “Radiologists can detect changes on a mammogram that may not yet be visualized with other modalities.”
The bottom line
“Sticking with guidelines to initiate screening at 40 is the most important factor that can lead to better cancer survivability,” says Dr. Brown. “There is no debate about it—mammograms save lives.”
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