Expert groups differ on when and how often women should have mammograms. So many groups now say that a woman in her 40s should talk to her doctor about the pros and cons of mammography as well as her individual risk in order to make the decision that's right for her.
Except that none of my 40-something friends I've spoken with have had that kind of conversation with a physician. Instead they've heard: "You're 40, here's a prescription for a mammogram." End of discussion.
Next year I'm determined to actually talk over the screening decision with my doctor rather than slink out the door with my questions unanswered. An online decision tool that launched earlier this year may make that conversation easier.
The online tool, called Breast Screening Decisions, grew out of a blog post written by Margaret Polaneczky, a gynecologist at Weill Cornell Medical College, back in 2009. That's when the U.S. Preventive Services Task Force first recommended that average-risk women in their 40s shouldn't be automatically be screened for breast cancer. (The task force is currently updating those recommendations, though the draft released earlier this year sticks to that same basic message.)
"I found myself really wondering how I'd address this in my practice," says Polaneczky. So she dug into the data used by the USPSTF and wrote about the controversy. In short, mammograms starting at 40 do save lives across a population of women, but not many, and at the cost of false positive results and the overdiagnosis of breast cancers that never would have threatened a woman's life if left undetected.
Polaneczky got good feedback on her explanation and wanted to help women and their physicians sort all this out with some kind of evidence-based screening decision aid. "I wanted women to decide not as a gut reaction to a horror story they've heard, either pro or con," she says.
There are plenty of online tools to calculate risk, but Polaneczky wanted to also give an estimate of the effects of screening and help women think about their own values.
She collaborated with Elena Elkin, a health outcomes researcher at Memorial Sloan Kettering Cancer Center. "We wanted this to be based on the best available evidence on mammography, and to use the best ways to communicate with people about risk," says Elkin. The tool is based on the data the USPSTF used to formulate its 2009 recommendations, which is a mix of information from large registries, analyses of the many studies done of mammography and predictive models.
The tool gives a woman in her 40s (it's not meant for older or younger women) an individual breast cancer risk assessment by asking questions about ethnicity, age at first menstrual period, personal history of breast abnormalities and family medical history, among other factors. Then it uses easy-to-understand infographics to show what is likely to happen across a population of similar-risk women if they have regular mammograms.
For example, after providing my own information, I learned I was at low to average risk of breast cancer, with a five-year risk of developing the disease at 0.9 percent. Or put another way, nine of 1,000 women like me will develop breast cancer in that time period.
I learned that if 1,000 low-to-average-risk women of my age have a mammogram, 900 will get a normal result, though one of them will actually have breast cancer that is missed by the test. The other 100 will have an abnormal mammogram that requires further testing or biopsies, but only two of them will actually have breast cancer.
What I found most illuminating were the scenarios for starting mammograms at different ages and intervals. If 1,000 women of my age and risk profile have annual mammograms starting at 40, over a lifetime, 22 will die of breast cancer. On the other end of the spectrum, if those women start mammography at age 50 and are screened every other year, 25 will die of breast cancer. That's not a big difference — unless of course, you or someone you care about is among those three additional deaths.
My tour of the tool ended with a series of questions intended to clarify what's important to me. For example, am I willing to do anything to detect breast cancer as early as possible? How worried am I about the harms of screening? (The tool provides information about unnecessary biopsies or overdiagnosis, but doesn't quantify them because the exact numbers are controversial, says Elkin.)
Those values questions are important, say the tool's creators. "Some women will say, 'My mother had a breast biopsy and developed an abscess, and I never want an unnecessary biopsy,' " says Polaneczky. "Another will say, 'My mother had breast cancer at 45 and I will do anything to catch it early.' "
Unpublished data show that most initial users of the tool came away with an accurate gauge of their risk and of the benefits and limitations of screening. Deanna Attai, assistant clinical professor of surgery at UCLA's David Geffen School of Medicine, says she recommends the decision aid to her patients. Given a doctor's limited time, it's nice to have something women can complete on their own, then bring in for discussion, says Attai, who is also the president of the American Society of Breast Surgeons. (The group recently revised its own mammography consensus statement.)
Doctors know they're supposed to having this kind of conversation with their patients, says Christine Gunn, a research assistant professor at the Boston University School of Medicine. But "how that looks in practice hasn't been spelled out," and clinicians tell her they don't always know what to do, she says. Her own research has shown that just 31 percent of women under 50 feel they are being given a choice to undergo screening.
The creators of the decision aid say their aim isn't to drive women toward or away from mammography, but to help them make an informed choice. "The mere fact that there's inconsistency should tell us that not even the experts agree on the best thing for an individual to do," says Elkin. When a woman makes her choice, "we should respect that," she says.
Katherine Hobson is a freelance health and science writer based in Brooklyn, N.Y. She's on Twitter: @katherinehobson