No easy answers on frequency of mammograms

Nicole from New Jersey wrote to us about an issue that's on many women's minds this week. Her question: "I am a 44-year-old woman and am scheduled for my first mammogram in two weeks. Do the new recommendations mean I shouldn't get it or that my insurance won't pay?"

Our reply? There's not an easy answer to whether you should get one. Until last week, guidelines for screening were that women at average risk should get a mammogram every year starting at age 40; women at high risk due to family history or genetics were urged to start earlier and sometimes to get more-frequent checks.

That changed when the U.S. Preventive Services Task Force announced last week that mammograms should begin at age 50 for most women and be repeated every two years. (If you're at high risk for breast cancer, guidelines haven't changed.) The task force, made up of an independent panel of medical experts, makes recommendations to the Department of Health and Human Services. The panel's advice influences doctors and insurance companies but doesn't by itself change the rules.

Why the shift? For starters, screening younger women hasn't dramatically increased the number of lives saved. While mammograms have reduced the risk of breast-cancer deaths overall by about 15 percent, that risk is so low in women under age 50 that the screenings don't save significantly more lives. Research cited by the task force estimates that to spare the life of one woman in her 40s, 1,904 women would need annual mammograms for a decade. In contrast, one life is saved for every 1,339 women age 50 to 59 who get 10 years' worth of checks, and for every 377 women in their 60s. It's difficult to examine research like this because if the woman in her 40s with cancer is your sister, your wife, your daughter, these statistics won't mean much to you.

To delve deeper into the meaning of these statistics and address more about both sides of the controversy is more than we have room for here, so we are devoting a whole section of "The Dr. Oz Show" this Monday to this issue.

Mammograms are far from perfect for other reasons, too. They can miss aggressive, fast-growing cancers and have trouble spotting problems in dense breast tissue, and both challenges are more common in younger women. Younger women have a 1-in-10 chance of a false alarm — suspicious findings that scare people and trigger expensive, time-consuming and sometimes uncomfortable biopsies and other checks, yet turn out not to be cancer. About half of women in their 40s will have a false positive by the time they've had 10 mammograms. In addition, Danish researchers recently found that about 1-in-3 cancers detected by mammograms may be so slow-growing that they'll never be a problem. (But 2-in-3 aren't, so you see why there's no easy answer here).