Assessment of disease extent on contrast-enhanced MRI in breast cancer detected at digital breast tomosynthesis versus digital mammography alone.
OBJECTIVE
To compare the utility of breast magnetic resonance imaging (MRI) in determining the extent of disease in patients with newly diagnosed breast cancer detected on combination digital breast tomosynthesis (DBT) versus digital screening mammography (DM).


METHODS
Review of 24,563 DBT-screened patients and 10,751 DM-screened patients was performed. Two hundred and thirty-five DBT patients underwent subsequent MRI examinations; 82 to determine extent of disease after newly diagnosed breast cancer. Eighty-three DM patients underwent subsequent MRI examinations; 23 to determine extent of disease. MRI examinations performed to assess disease extent were considered true positives if additional disease was discovered in the contralateral breast or >2 cm away from the index malignancy. Differences in cancer subtypes and MRI outcomes between the DM and DBT cohorts were compared using chi-squared tests and post-hoc Bonferroni-adjusted tests for equal proportions.


RESULTS
No differences in cancer subtype findings were observed between the two cohorts; however, MRI outcomes were found to differ between the DBT and DM cohorts (p=0.024). Specifically, the DBT cohort had significantly (p=0.013) fewer true-positive findings (7/82, 8.5%) than did the DM cohort (7/23; 30%), whereas the false-positive rate was similar between the cohorts (not statistically significant). When stratifying by breast density, this difference in true-positive rates was primarily observed when evaluating women with non-dense breasts (p=0.001).


CONCLUSIONS
In both the DM- and DBT-screened populations with new cancer diagnoses, MRI is able to detect additional cancer; however, in those patients who have DBT screen-detected cancers the positive impact of preoperative MRI is diminished, particularly in those women with non-dense breasts.
Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street/1 Silverstein, Philadelphia, PA 19104-4283, USA.
A V
AV
Chudgar
Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street/1 Silverstein, Philadelphia, PA 19104-4283, USA.
E F
EF
Conant
Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street/1 Silverstein, Philadelphia, PA 19104-4283, USA.
S P
SP
Weinstein
Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street/1 Silverstein, Philadelphia, PA 19104-4283, USA.
B M
BM
Keller
Division of General Internal Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
M
M
Synnestvedt
Division of General Internal Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
P
P
Yamartino
Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street/1 Silverstein, Philadelphia, PA 19104-4283, USA. Electronic address: elizabeth.mcdonald@uphs.upenn.edu.
E S
ES
McDonald
D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods; D008327:Mammography; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies
D003287:Contrast Media