Breast cancer detected with screening US: reasons for nondetection at mammography.
OBJECTIVE
To retrospectively review the mammograms of women with breast cancers detected at screening ultrasonography (US) to determine the reasons for nondetection at mammography.


METHODS
This study received institutional review board approval, and informed consent was waived. Between 2003 and 2011, a retrospective database review revealed 335 US-depicted cancers in 329 women (median age, 47 years; age range, 29-69 years) with Breast Imaging Reporting and Data System breast density type 2-4. Five blinded radiologists independently reviewed the mammograms to determine whether the findings on negative mammograms should be recalled. Three unblinded radiologists re-reviewed the mammograms to determine the reasons for nondetection by using the reference location of the cancer on mammograms obtained after US-guided wire localization or breast magnetic resonance imaging. The number of cancers recalled by the blinded radiologists were compared with the reasons for nondetection determined by the unblinded radiologists.


RESULTS
Of the 335 US-depicted cancers, 63 (19%) were recalled by three or more of the five blinded radiologists, and 272 (81%) showed no mammographic findings that required immediate action. In the unblinded repeat review, 263 (78%) cancers were obscured by overlapping dense breast tissue, and nine (3%) were not included at mammography owing to difficult anatomic location or poor positioning. Sixty-three (19%) cancers were considered interpretive errors. Of these, 52 (82%) were seen as subtle findings (46 asymmetries, six calcifications) and 11 (18%) were evident (six focal asymmetries, one distortion, four calcifications).


CONCLUSIONS
Most breast cancers (81%) detected at screening US were not seen at mammography, even in retrospect. In addition, 19% had subtle or evident findings missed at mammography.
From the Department of Radiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea (M.S.B., W.K.M., J.M.C., H.R.K., W.H.K., N.C., B.L.Y., S.H.L., E.B.R., M.S.); Department of Radiology, Seoul Metropolitan Government Seoul National University, Boramae Medical Center, Seoul, Korea (A.Y.); and Department of Radiology, Konkuk University Medical Center, Seoul, Korea (M.Y.K.).
Min Sun
MS
Bae
Woo Kyung
WK
Moon
Jung Min
JM
Chang
Hye Ryoung
HR
Koo
Won Hwa
WH
Kim
Nariya
N
Cho
Ann
A
Yi
Bo La
BL
Yun
Su Hyun
SH
Lee
Mi Young
MY
Kim
Eun Bi
EB
Ryu
Mirinae
M
Seo
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008327:Mammography; D008403:Mass Screening; D008875:Middle Aged; D012189:Retrospective Studies; D016217:Ultrasonography, Mammary