Impact of Surveillance Mammography Intervals Less Than One Year on Performance Measures in Women With a Personal History of Breast Cancer

Objective@#When multiple surveillance mammograms are performed within an annual interval, the current guidance for oneyear follow-up to determine breast cancer status results in shared follow-up periods in which a single breast cancer diagnosis can be attributed to multiple preceding examinations, posing a challenge for standardized performance assessment. We assessed the impact of using follow-up periods that eliminate the artifactual inflation of second breast cancer diagnoses. @*Materials and Methods@#We evaluated surveillance mammograms from 2007–2016 in women with treated breast cancer linked with tumor registry and pathology outcomes. Second breast cancers included ductal carcinoma in situ or invasive breast cancer diagnosed during one-year follow-up. The cancer detection rate, interval cancer rate, sensitivity, and specificity were compared using different follow-up periods: standard one-year follow-up per the American College of Radiology versus follow-up that was shortened at the next surveillance mammogram if less than one year (truncated follow-up). Performance measures were calculated overall and by indication (screening, evaluation for breast problem, and short interval follow-up). @*Results@#Of 117971 surveillance mammograms, 20% (n = 23533) were followed by another surveillance mammogram within one year. Standard follow-up identified 1597 mammograms that were associated with second breast cancers. With truncated follow-up, the breast cancer status of 179 mammograms (11.2%) was revised, resulting in 1418 mammograms associated with unique second breast cancers. The interval cancer rate decreased with truncated versus standard follow-up (3.6 versus 4.9 per 1000 mammograms, respectively), with a difference (95% confidence interval [CI]) of -1.3 (-1.6, -1.1). The overall sensitivity increased to 70.4% from 63.7%, for the truncated versus standard follow-up, with a difference (95% CI) of 6.6% (5.6%, 7.7%). The specificity remained stable at 98.1%. @*Conclusion@#Truncated follow-up, if less than one year to the next surveillance mammogram, enabled second breast cancers to be associated with a single preceding mammogram and resulted in more accurate estimates of diagnostic performance for national benchmarks.

Screening women with a personal history of breast cancer: overview of the evidence on breast imaging surveillance

This work reviews the evidence on breast imaging for screening (surveillance) in women with a history of breast cancer (BC). Early detection of second BCs in these women improves their prognosis based on studies using mammography (usually with clinical examinations) for surveillance. Cohort studies have estimated that mammography surveillance has moderate sensitivity (65.4%) and good specificity (98.3%), and have shown that these women are at a higher risk of interval BC than age- and breast density-matched women without a history of BC. Studies of adjunct imaging (ultrasound, magnetic resonance imaging) for surveillance that have reported detection and accuracy measures have generally shown that adjunct imaging detected more second BCs than mammography and added substantially to the amount of false-positive results; however, little evidence exists regarding screening efficacy of adjunct imaging as part of routine surveillance.