For decades, the mammogram calendar has felt like a fixed rule: show up every year starting at 40, no questions asked. But when given the choice, 89% of women in a new clinical trial picked something different. They chose a screening schedule tailored to their actual risk rather than their birthday.
That preference, buried in the observational data of the WISDOM trial, suggests something about what happens when you give women information about their own bodies and let them make decisions with it. The trial itself, coordinated by UCSF and published December 12 in JAMA, was testing whether this risk-based approach could be as safe as annual mammography. Turns out it was.
The study enrolled 46,403 women across the United States, ages 40 to 74. Of those, 28,372 agreed to randomization, half going to annual screening, half to a personalized schedule built from genetics, health history, lifestyle factors, and breast density. The primary safety question was straightforward: would matching screening intensity to risk lead to more advanced cancers? Based on over 28,000 participants, the answer was no.
What Risk-Based Actually Looked Like
Women in the personalized arm got sorted into tiers. Lowest risk meant waiting, at least until you hit 50 or your risk crossed a threshold. Highest risk, about 2% of participants, meant alternating mammography and MRI every six months. In between were biennial and annual schedules depending on where you landed.
That top tier is worth pausing on. Women with a 5-year risk of 6% or greater, or carrying a high-penetrance genetic variant, got the most intensive monitoring the trial offered. And in that group? Zero stage 2B or higher cancers reported. That’s the kind of result that makes you wonder how many high-risk women are currently on annual schedules designed for average risk.
The whole system ran through an online platform. Genetic testing kits went out by mail, mammogram data came back through uploads or directly from imaging centers. Laura Esserman, director of the UCSF Breast Care Center and first author, described the shift this way:
“The personalized approach begins with risk assessment, incorporating genetic, biological, and lifestyle factors, which can then guide effective prevention strategies.”
The Part That Didn’t Work
The trial had a secondary goal: reduce biopsy rates as a way of measuring screening harm. It failed. Biopsy rates in the risk-based group were not significantly lower than in the annual group, even though the risk-based group had fewer mammograms overall.
But here’s the thing, biopsies concentrated where risk concentrated. As women moved up the risk tiers, their rates for cancer detection, biopsies, and mammograms all climbed. The procedures landed on the people most likely to need them, which isn’t the same as doing fewer procedures total, but it’s also not nothing.
The genetic testing turned up something unexpected. Thirty percent of women who tested positive for a variant that increases breast cancer risk had no reported family history of the disease. Under current guidelines, most of them wouldn’t have been offered testing. The sequencing covered nine genes including BRCA1 and BRCA2, plus a polygenic risk score, which is essentially your genetic hand of cards for breast cancer, adding up lots of small effects.
Allison Fiscalini, who directs both the Athena Breast Health Network and the WISDOM study, pointed to the broader implications:
“When used as part of a comprehensive risk assessment, these results could have a real impact on improving the safety and effectiveness of screening and prevention.”
The rate of stage 2B or higher cancers, the study’s main safety measure, was noninferior in the risk-based group compared to annual screening. Rate difference: minus 18.0 per 100,000 person-years. Which is to say, tailoring screening schedules to individual risk didn’t lead to more late-stage diagnoses. And for a lot of women, that might be all the permission they need to stop showing up every single year.
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