Several large studies, including a review by the U.S. Preventive Services Task Force in 2009 and a study on the causes of death in the United Kingdom in 2013, have questioned the value of screening mammograms.
Doctors who question the value of mammograms say that while mammograms do save lives, for each breast cancer death prevented, three to four women are overdiagnosed. Overdiagnosis means either:
- a screening mammogram finds a suspicious area that would have been eventually diagnosed as cancer by other means, without any effect on prognosis
- a screening mammogram finds a suspicious area that never would have affected a woman’s health if it hadn’t been found or treated
False positive results from screening mammograms also have helped fuel the debate about the value of breast cancer screening. When a mammogram shows an abnormal area that looks like a cancer but turns out to be normal, it’s called a false positive. Ultimately the news is good: no breast cancer. But the suspicious area usually requires follow-up with more than one doctor, extra tests, and extra procedures, including a possible biopsy. There are psychological, physical, and economic costs that come with a false positive.
These studies and the resulting stories in the media have fueled an ongoing debate about the value of screening mammograms, especially for women ages 40 to 49.
Some experts have suggested that women in their 40s should get mammograms based on their risk of breast cancer. This idea is called risk-based screening. In risk-based screening, a woman in her 40s who likely has a higher risk of breast cancer based on family history or having dense breasts would get a mammogram, while a woman with no family history or who didn’t have dense breasts wouldn’t get a mammogram.
A small study suggests that more than 75% of women ages 40 to 49 diagnosed with breast cancer didn’t meet the criteria for risk-based screening. In other words, they didn’t have a strong family history or didn’t have dense breasts, so wouldn’t have gotten a mammogram. If the women didn’t have a mammogram, it’s likely the breast cancer wouldn’t have been detected early, when it’s most treatable.
The research was presented at the Radiological Society of North America (RSNA) annual meeting on Dec. 2, 2014. While the abstract of “The Potential Impact of Risk-based Screening Mammography in Women Age 40-49 Years” isn’t available through a direct link, a media release from the RSNA on the study is available.
In the study, the researchers looked at the medical records of 136 women ages 40 to 49 who were diagnosed with breast cancer based on a screening mammogram result. The women were diagnosed between 1997 and 2012.
The researchers looked at the women’s:
- family history of breast cancer
- breast density
As well as the:
- type of breast cancer
- lymph node status
- hormone receptor status of the cancer
Of the 136 breast cancers:
- 50% were invasive; 90% of the invasive cancers were hormone-receptor-positive
- 50% were DCIS (ductal carcinoma in situ); 88% of the DCIS cases were intermediate or high grade
The researchers also looked to see if the women met the criteria for risk-based screening:
- 90% of the women didn’t have a strong family history of breast cancer
- 86% of the women didn’t have dense breasts
- 78% of the women had neither a strong family history nor dense breasts
In fact, 79% of the women diagnosed with invasive breast cancer had neither a strong family history nor dense breasts.
“Our results show that by exclusively using a risk-based approach to screening mammography, we could potentially miss more than 75% of breast cancers in women in their 40s, thereby eliminating most of the survival benefit from screening mammography that has been previously shown in randomized controlled trials,” said Bonnie Joe, M.D., Ph.D., chief of women’s imaging at the University of California-San Francisco, one of the researchers who did the study.
If you're 40 or older and have an average risk of breast cancer, yearly screening mammograms should be part of your healthcare. If your breast cancer risk is higher than average, you should talk to your doctor about a more aggressive breast cancer screening plan that makes the most sense for your particular situation.
There's only one of you and you deserve the best care possible. Don't let any obstacles get in the way of your regular screening mammograms:
- If you're worried about cost, talk to your doctor, a local hospital social worker, or staff members at a mammogram center. Ask about free programs in your area.
- If you're having problems scheduling a mammogram, call the National Cancer Institute (800-4-CANCER) or the American College of Radiology (800-227-5463) to find certified mammogram providers near you.
- If you find mammograms painful, ask the mammography center staff members how the experience can be as easy and as comfortable as possible for you.
For more information, visit the Breastcancer.org Mammograms pages.