Reassessment of Breast Cancers Missed During Routine Screening Mammography

OBJECTIVE: The purpose of this study was to have a series of screening mammograms from routine practice, including false-negative results, reviewed by peer community-based experienced radiologists to determine the percentage of these false-negative findings that might be considered detectable. MATERIALS AND METHODS: All screening cases for 1997 and 1998 were identified from the Carolina Mammography Registry. Mammographic assessments from community mammography practices were linked with population-based cancer outcomes. The findings of four community-based radiologists who reviewed the mammograms of 339 asymptomatic women were 93 false-negatives, 180 true-negatives, and 66 false-positives. The percentage of false-negative, true-negative and false-positive findings on breast films that reviewers evaluated was determined. The findings of the reviewers were compared with the original interpreting radiologists' assessments. RESULTS: The overall breast-specific workup rate by the reviewing radiologists was 21%. The average workup rate for the false-negative findings was 42% (range, 35-51%). Adjusting for the 13% workup rate in the cancer-free breasts, the percentage of false-negative findings that were detectable was estimated to be 29%. CONCLUSION: This peer review of screening mammograms from a population-based screening registry estimated a missed detectable cancer rate of 29%. Thus, 71% of cancers missed at screening would not have been worked up by peers in the same community.