6 Answers About Mammograms and Breast Cancer
Cut through the confusion about when and how often to get mammograms.
Oct. 6, 2012— -- If you're among the millions of women concerned about the new guidelines on mammogram screenings from the United States Preventive Services Task Force (USPSTF), well, join the club. It's no wonder we're alarmed, given the conflicting responses from reputable medical organizations like the American Cancer Society, as well as health insurers and government policymakers.
"If there's one thing women should take away from all this, it's that no one disagrees with the fact that fewer women die from breast cancer because of mammograms, and no one is saying women shouldn't get mammograms," says Therese Bevers, MD, medical director of Cancer Prevention at M.D. Anderson Cancer Center. "The debate is over the potential downside of mammograms, and how that affects how frequently women should get them."
What do these recommendations mean for you and your health? We sifted through the research and spoke to top experts to help explain.
What are the new rules for getting mammograms?
After commissioning two studies that reviewed the risks and benefits of breast cancer screening, the USPSTF announced changes to the current mammogram guidelines, which the same group instituted in 2002. For average-risk women, they recommend:
No routine mammograms for women ages 40 to 49
Every-other-year mammograms for women ages 50 to 74
No need for clinicians to teach women to do breast self-exams
The task force concluded there is not enough evidence to recommend for or against mammograms in women 75 and older. The same goes for breast exams performed by doctors (clinical breast exams) for women of all ages. None of these guidelines apply to women at increased breast cancer risk due to genetic mutations or those who have a history of chest radiation.
Why did this government task force announce new mammogram guidelines?
First, it's important to know something about the group that issued the guidelines. The USPSTF is a government-appointed committee of scientists whose job it is to impartially interpret available scientific evidence to make recommendations for a number of health issues, like the benefit of vaccines or heart disease prevention.
"Their guidance is about 'just the facts, ma'am' with as little overlay of judgment and interpretation as possible," says Prevention advisor David Katz, MD, director of the Prevention Research Center, Yale University School of Medicine.
The group's goal: to determine the ideal breast cancer-screening schedule based on what would save the most lives while causing the fewest side effects.
"When you look strictly at the data, it's very clear mammograms should start at age 50 and be given every other year," says breast cancer surgeon Susan Love, MD.
The reason is that, based on the findings, giving mammograms to women every other year from ages 50 to 69 reduces breast cancer deaths by 16.5 percent over a lifetime. If screening is started at age 40 and continued every other year, there's a 19.5 percent lifetime reduction in deaths from breast cancer. That 3 percent difference translates roughly to saving one woman's life for every 1,000 who are screened but also causing hundreds of false positive results (when an abnormality is detected that isn't really cancer) and dozens of unnecessary biopsies.
The Task Force paper says that while mammograms save lives, "the additional benefit gained by screening at age 40 years rather than at age 50 years is small, and that moderate harms from screening remain at any age."
"We're not trying to give women whiplash, but we've become more realistic about what mammograms can and can't do," says Love. "Medicine is an ongoing process; we tend to present things as the truth when, really, they're the best guess of the moment."
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What's the downside of getting tested anyways isn't early cancer detection the most important thing?
That mammograms aren't perfect is old news. What is news, according to this panel, is that they've identified the age where science shows that the benefits of mammograms outweigh the risks. The main issues, according to the Task Force paper, are that false positive results lead to unnecessary follow-up mammograms and breast biopsies, as well as the stress associated with those procedures.
Another possibility, especially for women in their 60s, is overdiagnosis--detecting a cancer that would otherwise have never been symptomatic or life-threatening--and the treatment (surgery, chemo, radiation, etc.) that comes with it. Some experts also believe that cumulative exposure to radiation from annual mammograms (the x-ray gives off low levels) could cause health problems, including cancer, but others say this risk is small and largely theoretical.
Perhaps most troublesome is that mammograms aren't lifesaving for all women, though many people assume they are. Statistics vary, but at best, they only reduce the risk of dying from breast cancer by up to 20 percent.
"We've made it sound like every cancer can be found early and cured, and that's not true," says Love. Mammograms miss many cancers, particularly the fast-growing, aggressive ones that are most likely to strike women under age 50. "Mammograms are best at finding the slow-growing, low-grade cancers, not the worst ones," she says.
Why do other groups disagree with the new guidelines?
Medical organizations such as the American Cancer Society, the American College of Obstetricians and Gynecologists, the American College of Radiologists, and others have all said that women should stick to current recommendations of annual mammograms starting at age 40.
"The fact is, there are conflicting guidelines out there, and they're all based on the exact same data, but it's how we each interpret that data," says Carole Lee, MD, chair of the commission on breast imaging of the American College of Radiology and an attending radiologist at Sloan-Kettering Memorial Cancer Center in New York City.
Most of the groups that do not support the new guidelines are clinicians on the front line, who treat women with cancer and see fewer of them dying because of early detection, says Bevers. (M.D. Anderson also maintains annual screenings for women 40 and older). "Although the net benefit of saving lives through mammograms is small, it's still saving lives," she says. "I don't think it's fair to compare the anxiety of a false-positive test result with a woman dying of breast cancer." If you go for yearly screenings, recognize the risk: that you may have an abnormal result and need a biopsy, says Lee. "I think most of us would gladly accept that tradeoff in exchange for the possibility of a cancer being found early."
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What if I still want to get mammograms in my 40s or annually?
You can still get a mammogram if your doctor agrees; it's up to your insurance company to decide if it will pay for it. Secretary of Health and Human Services Kathleen Sebelius said government programs would continue to offer mammograms to women 40 and older, and according to a recent New York Times article, all of the big health insurance providers (Aetna, Cigna, UnitedHealth Group) said their policies are not changing.
What should I know before I talk to my doctor about this?
Unfortunately, for most average-risk women, there's no simple answer, says Victor Vogel, MD, national vice president for research for the American Cancer Society. Because up to 80% of women who get breast cancer have no known risk factors, it's hard to figure out who should be screened in her 40s and who can skip it. That said, discuss your risk factors with your doctor, says Katz, as well as your personal preferences, risk tolerance/aversion, etc.
Bottom line
For the general population, routine mammography in women under 50 does enough harm--because of false-positive results, unnecessary procedures, and the fact that the tests don't often catch the most lethal breast cancers anyway--to outweigh the good. "But that equation is very different for an individual woman," says Katz. You and your doctor should discuss pros and cons to personalize these one-size-fits-all recommendations.
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