A very large, long-term Swedish study found that women who had regular screening mammograms were 31% less likely to die of breast cancer over nearly 30 years compared to women who didn't get regular screening mammograms.
The results were published in the June 2011 issue of the journal Radiology.
The value of routine mammogram screening was questioned in November 2009 when the U.S. Preventive Services Task Force (USPSTF) recommended that routine screening mammograms for women with an average risk of breast cancer should start at age 50 instead of age 40.
The recommended changes were very controversial and were not adopted. Much research supports the value of mammogram screening starting at age 40. U.S. guidelines call for all women age 40 and older to have screening mammograms every year. While not ideal, some women may choose to have a screening mammogram every other year.
Health care in Sweden is through a national health system. This makes it a little easier to track health outcomes and do large, long-term studies on the benefits of screening, including mammograms.
The Swedish Two County Trial started in 1977 and involved 133,000 women from two counties in Sweden. The women were aged 40 to 74 when the study started and were randomly assigned to get either routine care -- which didn't include regular mammogram screening -- or to get routine care and regular screening mammograms during the 7 years of the study:
- 56,000 women got routine care.
- 77,000 women got routine care and regular screening mammograms.
The women were followed for 28 to 29 years after the study started. During the follow-up period, fewer than 1% of the women died of breast cancer. Still, the likelihood of dying of breast cancer was 31% less likely among the women who had regular screening mammograms:
- 0.66% (367 women) of women who got routine care died of breast cancer.
- 0.46% (351 women) of women who got routine care and regular screening mammograms died of breast cancer.
For every 414 women screened over 7 years, one death from breast cancer was prevented.
The researchers noted that the study's very long follow-up period helped clarify just how much regular mammogram screening can reduce the risk of women dying from breast cancer. After 10 years the risk of dying of breast cancer was 27% lower in women who got regular screening; risk reduction increased to 30% lower after that. Many experts believe the true value of breast cancer screening starting at age 40 can only be determined by studies that follow women over a long period of time -- at least 20 years.
This study underscores other research showing that regular screening mammograms starting at age 40 save lives. Other studies also have found that women between the ages of 40 and 49 could have a worse prognosis after diagnosis if they don't get regular screening mammograms. Despite this evidence and current guidelines, many women between the ages of 40 and 50 don't get regular screening mammograms.
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.
There's only one of you and you deserve the best care possible. Don't let any obstacles get in the way of 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 breast cancer, visit the Breastcancer.org Screening and Testing pages.