Breast Screening Guidelines Vary: One Doctor Explains Why
Though guidelines differ, a doctor says you should start annual mammograms in your 40s — and tells why.
For a test with a high rate of success, mammography — used to spot breast cancer — also carries a surprisingly high rate of confusion and conflict. When should women start getting mammograms? At age 40? 50? Should they get them every year? Every other year? The answers, oddly, depend on whom you ask.
Dr. Weinberg Calls Proposed Guidelines "Disturbing"
“Screening guidelines from different groups are really inconsistent, and that is very confusing,” says Susan Weinberg MD, a diagnostic radiologist with TriHealth. And things stand to get even more confusing if proposed guidelines from the United States Preventive Services Task Force (USPSTF ) are approved. Dr. Weinberg calls these recommendations “very disturbing.”
The USPSTF is proposing that “women should not be screened at all between ages 40 and 50, unless there is a family history of breast cancer,” says the doctor, “and only every other year from 50 to 75.” USPSTF guidelines are particularly important because many health insurance carriers base their coverage on them.
Dr. Weinberg and many others in her field are aghast at the recommended guidelines, and major medical groups are fighting back during the “open comment” phase of the guideline proposal process. There is currently legislation in Congress called Protect Access to Lifesaving Screenings, which would place a two-year moratorium on implementing the USPSTF breast cancer screening recommendations. More information can be found at stoptheguidelines.com.
One justification offered for the new recommendations, says Dr. Weinberg, is fear of “overdiagnosis” — findings of small and possibly insignificant cancers that may be overtreated, or of false-positive results, which cause needless fear, anxiety and potential overtreatment. Dr. Weinberg concedes that there are such cases and that they’re a problem. “But it’s unknown what their actual number is,” she says. “And the belief that anxiety from false-positive results outweighs the benefits from picking up cancers early doesn’t make a lot of sense.”
The proposed recommendations appear to cast doubt on the importance of mammography screening for women without a family history of breast cancer, says the doctor. “But we know that 75 percent of breast cancer cases are in women without any family history, so how is that logical?” she asks.
Dr. Weinberg adds that the new proposed guidelines also fail to endorse breast tomosynthesis, a three-dimensional imaging system that is better at separating suspicious from benign growths and is useful in women with dense breast tissue. “The recs say there is insufficient evidence that this tool picks up more cancer, and that is absolutely not true,” she says.
The Recommended Guidelines Discrepancy Explained
How does she explain such a discrepancy between these proposals and the beliefs widely held in her profession? “There are no radiologists or breast surgeons or oncologists on the panel that drew up the USPSTF guidelines,” she says. “We saw the names on the list — they excluded anybody with any experience in diagnosing or caring for breast cancer, which makes no sense.” The panel also based its findings in part on a Canadian study, the Canadian National Breast Screening, that, she says, used “flawed data.” The mammograms used in the study were of poor quality, and the statistical estimate of overdiagnosis was off by a wide margin — it was calculated at 22 percent, when all other evidence suggests the usual rate is closer to 4 percent, she says.
What do the USPSTF panelists have to say about all this? Little if anything — they are notoriously tight-lipped about their process and procedures, says Dr. Weinberg. And there is no way to know when the new recommendations will be approved — or rejected. “We are all in limbo, waiting with bated breath,” she says.
Until the final results are released, she continues to follow guidelines from the American College of Radiology. “After many, many years of doing mammography and studying its benefit, the ACR recommends that screening mammography begin at 40 and continue yearly until the woman’s health indicates it is no longer a good idea,” she says.
How Dr. Weinberg Recommends Handling the Issue of False-Positives
As for the admittedly real issue of overdiagnosis, she suggests setting up solid, randomized trials to study different treatments for women with early-stage breast cancer. “The onus is on us as a society to figure out which breast cancer cases may be insignificant and overtreated and how to avoid this so we can make more educated decisions down the road,” says Dr. Weinberg. “You don’t stop screening entirely because 4 or 5 percent may be overdiagnosed. Why throw out the baby with the bathwater, when we also know from years of experience that early screening saves lives? If we do, we could have a situation like in China, where there is no screening. Breast cancers there are usually caught only when women can feel them, when most are already at stage 3 or higher.
“Mammography is the best tool we have for picking up breast cancer in women in their most productive years — those with young families, who are a significant part of our society,” says Dr. Weinberg.
Last Updated: January 13, 2016