Table 1.

Patient demographic and primary invasive tumor characteristics among WCHS cases included in the DSP assay. PR, progesterone receptor. Four staging categories, I–IV, from the American Joint Committee on Cancer were examined, stage 0 patients were not included in this study. Low tumor grade denotes well‐differentiated tumors, intermediate denotes moderately differentiated, and high grade denotes poorly differentiated tumors. Tumor size (cm) was classified into three categories: < 1.0 cm, 1.0–2.0 cm, and > 2.0 cm. LN, lymph node status was defined as the presence (positive) or no (negative) cancer cells in axillary lymph nodes.

Variable	Categories	Overall	Black	White	P‐value
Overall		159 (100%)	94 (59.1%)	65 (40.9%)
Age	Mean/(SD)	52.6/(10.2)	53.0/(10.7)	52.1/(9.6)	0.597
BMI	< 25	46 (29.3%)	19 (20.2%)	27 (42.9%)	0.009
	25–29	40 (25.5%)	27 (28.7%)	13 (20.6%)
	30+	71 (45.2%)	48 (51.1%)	23 (36.5%)
Subtype	Luminal A	97 (61.8%)	52 (56.5%)	45 (69.2%)	0.005
	HER2‐positive	26 (16.6%)	12 (13%)	14 (21.5%)
	Triple‐negative	34 (21.7%)	28 (30.4%)	6 (9.2%)
ER status	POS	112 (70.4%)	59 (62.8%)	53 (81.5%)	0.018
	NEG	47 (29.6%)	35 (37.2%)	12 (18.5%)
PR status	POS	92 (57.9%)	46 (48.9%)	46 (70.8%)	0.010
	NEG	67 (42.1%)	48 (51.1%)	19 (29.2%)
HER2 status	POS	26 (16.6%)	12 (13%)	14 (21.5%)	0.233
	NEG	131 (83.4%)	80 (87%)	51 (78.5%)
Stage	I	65 (41.1%)	31 (33%)	34 (53.1%)	0.028
	II	72 (45.6%)	47 (50%)	25 (39.1%)
	III/IV	21 (13.3%)	16 (17%)	5 (7.8%)
Grade	LOW	22 (14.1%)	9 (9.8%)	13 (20.3%)	0.001
	MED	53 (34%)	24 (26.1%)	29 (45.3%)
	HIGH	81 (51.9%)	59 (64.1%)	22 (34.4%)
Tumor size	< 1.0	18 (11.5%)	8 (8.6%)	10 (15.6%)	0.056
	1–1.9	60 (38.2%)	31 (33.3%)	29 (45.3%)
	≥ 2.0	79 (50.3%)	54 (58.1%)	25 (39.1%)
LN status	POS	63 (41.2%)	42 (46.7%)	21 (33.3%)	0.138
	NEG	90 (58.8%)	48 (53.3%)	42 (66.7%)

P‐values in bold are statistically significant.