Adding to the debate about the benefits of mammography screening before age 50, a new research review find “limited” evidence that screening prevents breast cancer deaths among women in their 40s.
The results come from the International Agency for Research on Cancer, which asked experts from 16 countries to look at the latest evidence on breast cancer screening.
What they found largely confirmed what experts have long said: For women ages 50 to 75, routine mammograms reduce the risk of dying form breast cancer.
The report, published in the June 4 issue of the New England Journal of Medicine, reflects a longstanding debate.
In 2009, the U.S. Preventive Services Task Force ignited a controversy when it changed its recommendations on mammograms – which had long advised women to have screening every one to two years, starting at age 40.
The revised guidelines now say routine screening should begin at age 50 and be done every two years. The panel said women in he 40s should discuss the pros and cons of mammography screening with their doctors, then make an informed decision.
However, the cancer society and the American Collage of Obstetricians and Gynecologists still urge women to get yearly mammograms, starting at age 40.
The problem, the task force said, is that breast cancer screening can cause harm, so there should be strong evidence that the benefits outweigh those risks.
The risks include false-positive results that trigger further, sometime invasive tests, and needless anxiety. But the bigger concern, experts say, is over-diagnosis and overtreatment.
Mammography catches tiny tumors, some of which may never progress to the point of threatening a woman’s life. But because there is no way to predict which tumors are dangerous, women almost always go through treatment.
The average 40-year-old has a 1.5% chance of developing the disease in the next 10 years, while a 60-year-old has a 3.5% chance, according to the U.S. Centers for Disease Control and Prevention.
The greatest risk from mammography is from the ionizing radiation. Statistically, we create more breast cancer from x-ray then we detect. However, if you are one of those who has a tumor detected early, it could save your life.
To mitigate the risks, the 2009 recommendations reduced the frequency of mammograms from 1 to every 2 years, and moved the starting age from 40 to 50 years of age. That cut the amount of radiation more than 50%.
There are other testing alternatives – ultrasound, MRI, and themography – that can reveal tumors earlier than x-ray and even find some that don’t show on x-ray. These three testing procedures are non-invasive and do not damage tissue or cause mutations like x-ray.
The Bottom Line:
Follow the recommendations of the U.S. Preventive Services Task Force. If you feel you are at high risk, add alternative imaging and run the BRCA1 and 2 genetic tests to access your risk factors.
Source: June 3, 2015 National Institutes of Health