. Author manuscript; available in PMC: 2017 Oct 1.

Published in final edited form as: Ann Surg Oncol. 2016 Jul 12;23(10):3239–3246. doi: 10.1245/s10434-016-5397-7

TABLE 1.

Clinical factors by time period in the pre- and post-guideline study periods

Factors	Overall	Pre-Study Period (n = 504)	Post-Study Period (n = 701)	p-value
Age in years (range)^*	58.5 (29.0, 90.4)	57.9 (29.0, 86.7)	58.7 (30.1, 90.4)	0.330
Breast density^†				0.750
- Fatty	91 (7.6)	42 (8.3)	49 (7.0)
- Scattered	451 (37.4)	191 (37.9)	260 (37.1)
- Heterogeneous	570 (47.3)	231 (45.8)	339 (48.4)
- Extremely Dense	93 (7.7)	40 (7.9)	53 (7.6)
Chemotherapy/Anti-HER2 therapy	542 (45.9)	236 (46.9)	306 (45.1)	0.555
Radiation therapy	1065 (89.6)	453 (90.2)	612 (89.1)	0.565
Endocrine therapy	908 (84.5)	404 (83.5)	504 (85.4)	0.397

Continuous variables reported as a median (range)

^†

Categorical variables reported as N, %