Table 1:

Clinical and Surgeon Characteristics in pMRI and no pMRI Cohorts

		Preoperative Breast MRI*
Variable		Yes (N=332)	No (N=41)	P-value
Age (Mean)		55.7 ± 11.2	53.8 ± 11.8	0.29
Pre-Menopausal		116 (34.9%)	20 (48.8%)	0.088
Family history†		144 (44.2%)	15 (38.5%)	0.61
Dense breasts†		227 (68.6%)	25 (62.5%)	0.47
DCIS ER positive†		264 (83.8%)	29 (85.3%)	>0.99
DCIS Necrosis present†		273 (83.2%)	32 (88.9%)	0.48
DCIS Grade†	Low	37 (11.1%)	4 (10.0%)	0.79
	Intermediate	125 (37.7%	13 (32.5%)
	High	170 (51.2%)	23 (57.5%)
Year of index CNB	2004-2008	159 (47.9%)	17 (41.5%)	0.51
	2009-2013	173 (52.1%)	24 (58.5%)
Surgeon	Surgeon 1	97 (29.2%)	9 (22.0%)	0.53
	Surgeon 2	71 (21.4%)	10 (24.4%)
	Surgeon 3	85 (25.6%)	8 (19.5%)
	Surgeon 4	62 (18.7%)	11 (26.8%)
	Others‡	17 (5.1%)	3 (7.3%)

CNB = core needle biopsy

^*Values are mean ± SD or no. (%);

^†Subjects were excluded from the summary due to missing values: family history (n=8), breast density (n=2), DCIS ER status (n=24), DCIS necrosis (n=9), and DCIS grade (n=1);

^‡Three surgeons treated 20 patients total, so these three surgeons were grouped together to facilitate the statistical comparison between pMRI and no-pMRI groups.