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.
Since that time, the American Medical Association, the American College of Obstetricians and Gynecologists, the American College of Radiology, the American Cancer Society, the National Cancer Institute, and the National Comprehensive Cancer Network all have issued guidelines saying that all women should be eligible for screening mammograms starting at age 40.
A British study has found that when mammograms started at age 40 instead of age 50, more lives were saved.
The research was published online on July 20, 2015 by The Lancet Oncology. Read the abstract of “Effect of mammographic screening from age 40 years on breast cancer mortality in the UK Age trial at 17 years’ follow-up: a randomised controlled trial.”
In the study, called the UK Age trial, 160,921 British women ages 39-41 were randomly assigned to one of two groups:
- 53,883 women were offered annual mammograms up to and including the year of their 48th birthday (the intervention group)
- 106,953 women received the usual care, which meant they were invited to have their first mammogram at age 50 and additional mammograms every 3 years after that (the usual care group)
The researchers recorded how many women were diagnosed with breast cancer during the study period and continue to follow the women to record survival statistics.
When the researchers analyzed the results after 10 years of follow-up, there were no differences in survival rates.
Now the researchers have 17 years of follow-up information. The results show that fewer women in the intervention group died from breast cancer compared to women in the usual care group. So starting screening at age 40 instead of age 50 saved more lives.
It’s likely that the researchers found the survival difference after 17 years of follow-up rather than after 10 years of follow-up because more women died during years 11 through 17.
“If a woman’s life is to be saved by early detection, it happens during the first 10 years after diagnosis, not after,” said Brian Wojciechowski, M.D., a medical oncologist in Pennsylvania and Breastcancer.org’s medical adviser. “The first 10 years after diagnosis is the critical time period.”
At Breastcancer.org, we believe that 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 may want to talk to your doctor about a more aggressive breast cancer screening plan that makes the most sense for your particular situation.
The Mayo Clinic, the American Medical Association, the American College of Obstetricians and Gynecologists, the American College of Radiology, the American Cancer Society, the National Cancer Institute, and the National Comprehensive Cancer Network all recommend that screening mammograms should start at age 40.
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 on mammograms and other tests to detect and diagnose breast cancer, visit the Breastcancer.org Screening and Testing section.