Should you get a preventive mammogram?
If you don’t know the answer, you’re not alone.
It’s not that women aren’t aware of the risks of breast cancer. It’s that guidelines for mammography are confusing.
The big push for regular mammograms began in the 1980s. A lot of data has been gathered since then. As we learn more about the pros and cons of mammography, recommendations change. Each change brings renewed controversy over women’s healthcare. That leaves many women unsure of what to do.
Much of the debate has to do with the potential benefits and harms of routine mammography. It doesn’t help that experts disagree.
It’s also about money. When guidelines change, so do insurance rules. That can affect access to preventive care.
On April 21, the U.S. Preventive Services Task Force (USPSTF) released a draft recommendation statement for breast cancer screening. The USPSTF panel is made up of independent experts in preventive care and evidence-based medicine. The panel strives to update all recommendations every five to seven years.
In the draft, the USPSTF does not recommend for or against routine screening for average-risk women aged 40 to 49. After analyzing the data, they determined that a small number of deaths might be avoided. They also found a higher rate of false positives leading to more procedures.
The result is a small “net benefit” for this age group. The panel calls on doctors and patients to make informed decisions about the benefits and harms of preventive screening. They say these decisions should be based on values, preferences, and health history.
For women between 50 and 74 years old, the USPSTF recommends a mammogram every two years. This age group benefits the most from mammography. Women from 60 to 69 are the most likely to avoid death from breast cancer due to mammogram screening.
The USPSTF made no recommendations for women aged 75 and up, due to lack of adequate science. It made no recommendation for or against 3-D mammography. It also did not change its 2009 recommendation against doctors teaching patients about self-exams.
These recommendations are for women at average risk. Women at higher risk should discuss screening with their doctors.
Public input on the draft closed May 18. Final guidelines will be drawn up after a review.
Potential Benefits and Risks of Mammogram Screening
The clear benefit of a mammogram is it can detect breast cancer in its earliest stages. This is important so the cancer can be treated before it becomes life threatening.
There are a few risks of routine mammography. One is overdiagnosis.
This occurs when a woman is diagnosed and treated for a breast cancer that would not otherwise have become a threat to her health during her lifetime, according to Dr. Kirsten Bibbins-Domingo, vice chair of the USPSTF.
“Currently, it is not possible to know for any individual woman whether or not her cancer will progress,” said Bibbins-Domingo. “As a result, almost all women diagnosed with breast cancer are treated. The discovery of an overdiagnosed cancer, therefore, can result in overtreatment, including invasive procedures, chemotherapy, and radiation, that can have significant harms.”
Dr. Laurie Margolies, director of breast imaging at the Dubin Breast Center, Mount Sinai Hospital in New York City and an associate professor of radiology at the Icahn School of Medicine at Mount Sinai, looks at it another way.
“Just as we all wear seatbelts to prevent a few from getting injured, we must screen all women so that no one dies unnecessarily from breast cancer. That is a cost that society should bear,” said Margolies.
Mammogram results aren’t always clear. That means more tests, increased healthcare costs, and higher anxiety levels.
There is also some concern about the safety of the test itself. The USPSTF noted a slightly higher risk of developing breast cancer from lifelong exposure to radiation from mammography. They also point out that no first-hand studies have directly measured this effect.
The panel made no recommendation for or against extra mammogram screening for women with dense breast tissue. In some states, the law requires providers to notify women who have this condition.
Dense tissue makes it harder to read a mammogram. It also increases the risk of developing breast cancer. The USPSTF says more research is needed. In the meantime, there’s no clear strategy for women with dense tissue.
A Difference of Opinion
Some organizations disagree with the task force. The American Cancer Society continues to recommend yearly mammograms for women age 40 and older. The American College of Radiology calls the USPSTF recommendations “untrustworthy” due to lack of transparency and adherence to Institute of Medicine methodology standards.
Margolies believes the task force has done a disservice to women.
“Their conclusions were based on data from analog mammography, yet in the United States, less than 4 percent of mammograms are analog,” she said. “The remainder are digital. Many are 3-D digital breast tomosynthesis. These new technologies were not available in the 1980s when the screening mammography trials were performed. It is absolutely inappropriate to suggest future care regimens based on old technology that is no longer in use.”
Bibbins-Domingo told Healthline this is not the case.
“For this draft recommendation, as with all of our recommendations, we always look at all new available evidence since the last time a recommendation was made for breast cancer screening,” she said.
Bibbins-Domingo noted that the task force specifically looked at newer screening methods, such as digital and 3-D mammography, MRI, and ultrasound.
“While 3-D mammography, MRI, and breast ultrasound are emerging technologies,” she said, “there is very little evidence available that examines the ultimate effectiveness of these newer screening methods. Therefore, the task force was unable to make a recommendation for or against these types of screening.”
Margolies said early detection remains a powerful tool.
“Chemotherapy still cannot cure stage 4 disease, despite years of advancements,” she said. “Yet, stage 0 or stage 1 disease is almost always cured when detected by mammography, ultrasound, or MRI.”
Others agree with the task force.
In a Washington Post commentary, Breast Cancer Action Executive Director Karuna Jaggar wrote, “Despite widespread mammography, breast cancer remains the second leading cause of death in women, killing about 40,000 every year in the United States. Any decline in the breast cancer mortality rate is likely the result of improved treatment – primarily the development of targeted therapies, like Herceptin – rather than widespread screening.”
Last year, the British Medical Journal published results of the Canadian National Breast Screening Study. Authors of the 25-year follow-up study concluded, “Annual mammography in women aged 40-59 does not reduce mortality from breast cancer beyond that of physical examination or usual care when adjuvant therapy for breast cancer is freely available.”
How Changing Mammogram Guidelines Affect Quality of Life
The Affordable Care Act requires insurers to cover mammograms every one or two years for women over 40. Still in the draft stage, the task force recommendations don’t affect those requirements. Yet. If the guidelines change, so could your coverage.
“Insurance companies lean on federal guidelines for determination of what tests are necessary, and therefore covered,” said New York obstetrician/gynecologist Jennie Freiman. “Reading the USPSTF recommendations highlights how the legislative war on women continues, unabated.”
For some women, insurance coverage equals access to care.
“Women with financial means will still get this test if they want it, covered or not,” Freiman told Healthline. “Those dependent on health insurance will be excluded from the opportunity.”
Then there’s the quality of life issue.
“Using mortality as an endpoint is disingenuous,” said Freiman. “The quality of life difference for a woman whose breast cancer is found early, with annual screening, is dramatically different than that of a woman who waits two years to have a mammogram, at which point her cancer might be stage 2, 3, or 4, instead of stage 1. USPSTF recommendations also throw in a good dose of ageism. ... Let's just forget about women after the age of 75.”
“As a gynecologist and a female, I find the latest USPSTF recommendations nothing less than outrageous,” Freiman added.
Bibbins-Domingo said the task force evaluated a number of factors related to the benefits and harms of breast cancer screening. These included the impact of potential harms, such as overtreatment, on quality of life.
“Fortunately, breast cancer is an uncommon disease for women under 50. Despite this, the task force recognizes that women in their 40s do get breast cancer, and that mammography can help women in their 40s reduce their risk of dying from breast cancer,” she said. “But in comparison to women in their 50s and 60s, the number of women in their 40s who will benefit is much smaller, and the harms are actually greater.”
So, do you need a mammogram? It’s not a one-size-fits-all answer. It depends on your personal and family health histories. It depends on your particular risk factors, including age. And it depends on how you feel about the pros and cons of mammography. It’s something each woman should discuss with her doctor during annual visits.
Whether your insurance will pay for it is another question. For some women, that takes the decision out of their hands.