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The massive recent study published in the British Medical Journal shows that death rates from breast cancer are the same among women who get mammograms and those who don't. It's just one more study in a recent surge of research trying to answer the question: Who needs mammograms, and how often?

The 25-year study followed nearly 90,000 Canadian women, half of whom received regular mammogram screenings, and half of whom performed self-exams or received exams from health care professionals. And while this is the third time this group of researchers has published results from this study (once at 5 years and once at 15 years), researchers feel since the mortality rates are so similar between both groups, mammograms appear to have little benefit for women ages 40-59. (You can avoid cancer just by living a healthy lifestyle. Check out our 20 simple habits to lower your risk.)

Worse, the mammograms seem to actually pose a threat themselves: According to the study, one in five cancers found via mammograms and then treated with procedures such as chemotherapy and biopsies didn't need to be, points out The New York Times. According to the Times, an editorial accompanying the study compared mammography to prostate-specific antigen screening for prostate cancer--and found both tests are nearly idential in overdiagnosis rate and the same slight reduction in deaths.

The study, large as it may be, was met with criticism by breast imaging experts like Donna Plecha, MD, director of Breast Imaging at University Hospitals Case Medical Center in Cleveland, who argues the data is flawed because the machines and quality of technologists used in the 25-year BMJ study are not indicative of what we have today. "In my mind, this means bad mammography is no better than no mammography," she says. (Prevent breast cancer when you follow these 10 steps.)

Dr. Plecha is just one investigator who has published research during the past six months that contributes to the polarizing debate around mammograms. Her study, published in American Journal of Roentgenology, found that women ages 40 to 49 who underwent routine screening mammography were diagnosed at earlier stages with smaller tumors and were less likely to require chemotherapy.

Previous clinical trials have found mammography reduces the death rate from breast cancer by at least 15% for women in their 40s and by at least 20% for older women, says Richard C. Wender, MD, chief of cancer control for the American Cancer Society, who is penning new mammography guidelines this year based on these studies and others.

Dr. Plecha's findings contradict the controversial guidelines set out by the U.S. Preventive Services Task Force in 2009, which only recommends mammograms for women ages 50 to 74 every 2 years. What is it about the 50th year that determines the need for a mammogram? In an attempt to assign some sort of starting point, researchers and policy makers are interested in mortality rate, which rises after 50. "It's not that women in their 40s don't develop cancer, and it's not that they don't develop serious cancers," says Laura Esserman, MD, director of the Carol Franc Buck Breast Care Center at University of California-San Francisco, who adds these guidelines don't apply to women with higher risk factors. "The data simply isn't there to prove that screening in your 40s makes a difference on your mortality." (What is surviving breast cancer really like? Meet 13 women who've battled breast cancer--and lived to tell about it.)

But survival rate, or how long you can live with the disease, is different from mortality rate and something Dr. Plecha thinks is worth waiting on before deeming mammograms unnecessary. "If we're looking at the patients we're going to save and the number of years of life saved, it's more important to screen patients in their 40s," she says. "Your biggest risk is in your 70s. But in the 40s, the cancer can be more aggressive, it grows quicker, you're more likely to save more years of life if you catch it early enough to cure it."

One thing most experts can agree on: You shouldn't try to create a blanket screening recommendation for a cancer that is so different between patients. "It matters in terms of frequency, because we can't predict how aggressive a cancer will develop," says Jean Weingert, MD, FACR, director of breast imaging for the hospitals of central Connecticut. Tumors can take years to become invasive, or just a matter of months--which makes the current guidelines recommending mammograms every 2 years after the age of 50 seem arbitrary. "With a grade three cancer, we don't have two years to wait. I've seen them pop up in a matter of 6 months," she says. (No matter how diligently you see the doctor and keep up with regular screenings and exams, the realm of cancer checks can be confusing. We've got the lowdown that'll keep you healthy.)

That's why Dr. Esserman is looking toward a future of risk-based screening. She hopes that determining a screening schedule based on your individual risks like family history, breast density, and genetic factors will reduce the amount of unnecessary biopsies, chemotherapy, and patient worry. "There's enough doubt about it that we simply must rethink our approach and think about how to use modern tools to narrow down the population that might need them," she says.

So where does this leave you? "Your ob/gyn should talk you through the benefits and limitations of mammograms generally--and as they relate to you specifically," says Mary Jane Minkin, MD, Prevention advisor and clinical professor of obstetrics and gynecology at the Yale School of Medicine. You and your doctor should also consider how concerned you are about cancer, false-positives, and finances, she says: "Most likely, she won't try to talk you into or out of any particular choice, but she'll want you to decide based on real evidence and information. I personally recommend mammograms every 1 to 2 years starting at age 40, but it's your decision."

Learn more about breast cancer and what you can do to help prevent it with this comprehensive guide.

Source: The New York Times