Research findings show patient age and existing mammogram studies play a role in assessment.
Older patients and those who have prior mammogram screenings are more likely to receive a cancer diagnosis from an initial “probably benign” BI-RADS 3 assessment, according to new research.
In a poster presented during the American Roentgen Ray Society (ARRS) 2021 Virtual Annual Meeting, a team led by Cindy Lee, M.D., a radiologist and clinical assistant professor with New York University Langone Health, examined the results of the National Mammography Database (NMD) and determined that both age and the existence of prior mammogram screenings should be considered with BI-RADS 3 assessments.
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“We sought to determine the effect of patient age and availability of prior mammograms on cancer yield and cancer staging of BI-RADS 3 findings in the National Mammography Database,” the team said. “[Based on our results,] discussions with patients should include the estimated risk of cancer.”
Overall, the NMD includes 31,905,228 mammograms collected from 690 facilities throughout 45 states. For their retrospective study, Lee’s team analyzed data gathered between 2009 and 2018 from 471 NMD facilities, including 19,675,062 mammograms from 8,296,728 patients. Their patient population included women who were recalled from screening mammograms for a follow-up diagnostic evaluation that yielded a BI-RADS 3 assessment who either had a biopsy or an imaging follow-up after two or more years. The team stratified their data into 10-year intervals.
For their evaluations, they concentrated on age, the existence of prior mammograms, and lesion type, looking at cancer yield, PPV3, biopsy rate, and the percentage of invasive cancers.
Of the study population, they identified 43,628 women – with an average age of 55 – who had BI-RADS 3 assessments. In the group, the overall cancer yield was 1.86 percent, the PPV3 was 16.6 percent, and the biopsy rate was 11.2 percent. The team did determine the cancer yield was higher among the 25,160 women who had prior mammograms – 2.24 percent.
All total, they pinpointed 810 cancers, 545 of which (67.3 percent) were invasive. From their analysis, they saw the rate of ductal carcinoma in situ was much higher for women in their 40s than older women, 41.3 percent and 31.1 percent, respectively.
When the team drilled down on the data, they made several additional discoveries. Information on lesion type was available for 10,804 women (24.8 percent). Based on that data, the team said, breast cancer mass is the most common type of lesion (1.11 percent), but it also has the lowest cancer yield among women of all ages (0.47 percent). Architectural distortions are rarer, but they have a much higher cancer yield (3.21 percent). However, the team noted, when prior mammograms were available, the cancer yield for masses jumped significantly for older women – up to 5.1 percent.
While there were few asymmetries, the team said, those that were presumed to be developing consistently had a cancer yield rate of more than 2 percent for women between ages 60 and 90.
Ultimately, the team said, they found no clear relationship between cancer staging and age or between prior mammogram availability and cancer staging or cancer type. But, still women with prior mammograms who had BI-RADS 3 findings still had significantly higher cancer yield. In fact, they said, cancer yield exceeded 2 percent at age 60 for baseline and actually reached 4.6 percent for women ages 80-to-89.
Based on these outcomes, they said, surveillance may still be a reasonable option for findings with a slightly higher cancer yield, such as 3 percent instead of 1 percent or 2 percent.
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