March 24, 2014
News Review From Harvard Medical School -- Value of Mammograms Over Age 70 Questioned
Mammograms can help detect breast cancer. But these screening tests did not reduce the number of advanced breast cancer cases diagnosed in older women. So says a study in the Netherlands. The study looked at the effect of extending regular screenings to women between the ages of 70 and 75. It included more than 25,000 women in this age group. All had been diagnosed with breast cancer between 1995 and 2011. While early stage breast cancer cases rose quite a bit in these women over those 16 years, advanced breast cancer cases did not show marked improvement. Researchers expected that, with increased detection of early breast cancer, advanced breast cancer diagnosis would significantly decrease. It did not. Regular mammograms in this older age group could do more harm than good, the researchers said. They could lead to overdiagnosis, overtreatment, harmful side effects and needless worry. The results of the study are yet to be published. They were presented at the European Breast Cancer Conference in Glasgow, Scotland. HealthDay News reported on it March 21.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Mammography has the potential to find small cancers early. Cancers that might become untreatable later on or cause premature death. However, most of the spots seen on mammograms are either not cancers or they are cancers that don’t hurt a woman’s health.
The value of using this tool to screen all women for breast cancer continues to spur much debate. Most experts agree that routine (regular) mammograms are appropriate for women ages 50 to 75 with an average risk for breast cancer. The main controversy is:
- How often should a woman have a mammogram, and
- Whether screening should start at age 50 rather than 40
The U.S. Preventive Services Task Force publishes advice about health screening and disease prevention. The advice is based on evidence evaluated by experts from different specialties. This way, it is less likely to have a bias than advice from a single specialty group.
For breast cancer screening, the task force recommends:
- A mammogram every 2 years for women ages 50 to 74.
- No routine screening mammograms for women in their 40s, unless they have an increased risk of breast cancer.
- Discussion between a woman and her doctor about whether to screen for breast cancer before age 50. Decisions would be based on a woman's risk of breast cancer. And on what she prefers after learning about the benefits and harms of breast cancer screening.
The American Cancer Society and other well respected medical groups disagree. They say that the task force guidelines would miss too many early cancers. They say that this could cost lives. Instead, the cancer society recommends a mammogram every year. And they say it should start at age 40 for women at average risk for breast cancer.
This new report suggests routine mammography might do more harm than good in women ages 70 to 75. The researchers found that mammograms don’t lead to a decreased risk of advanced breast cancer. But many women undergo unnecessary worry, testing and treatment as a result of spots seen on a mammogram.
What Changes Can I Make Now?
If you are 70 or older, talk with your doctor about the benefits and harms of breast cancer screening. If you are healthy and active, you may want to continue to get a mammogram every couple years, even beyond age 75. But if you are in poor health, it may not be worth your time, energy and resources to find and treat a cancer that may not affect how long you live.
It's important to remember that mammograms detect early cancer. They do not prevent cancer. But there are some things you can do to help lower your breast cancer risk:
- Maintain a healthy weight.
- Don't smoke.
- Either avoid alcohol, or drink an average of no more than one alcoholic beverage per day.
- Avoid binge drinking, even if the average amount of alcohol you drink is moderate.
- Eat a diet rich in vegetables, especially the green leafy ones. They are rich in folic acid. Folic acid may offset any increased risk of breast cancer if you drink alcohol.
- Stay physically active. Try to find time every day for dedicated exercise.
What Can I Expect Looking to the Future?
Experts will continue to debate what we expect from breast cancer screening. They will weigh the physical and emotional effects of treating non-threatening cancers against the value of finding some cancers early enough to save women's lives.
For the near future, we will continue to struggle with these difficult questions. Further in the future, advances in genetic testing will help a woman make a more informed personal decision about the benefits versus the harms of screening mammography.