Table 3.

Multivariable cox regression model to test the association between MRI use and local/distant recurrence-free survival, among the women (age ≤ 50) diagnosed in 2006–2013.

	Local recurrence		Distant recurrence
	HR (95% CI)	P-value	HR (95% CI)	P-value
MRI (reference, none N = 182)
MRI performed N = 330	1.03 (0.53, 1.99)	0.94	0.89 (0.43, 1.84)	0.74
Age	1 (0.94, 1.06)	0.94	0.98 (0.92, 1.04)	0.56
Race (reference, non-Hispanic whites N = 379)
Non-Hispanic black N = 70	1.47 (0.64, 3.40)	0.37	1.6 (0.71, 3.6)	0.25
Hispanic N = 30	1.46 (0.42, 5.00)	0.55	1.47 (0.33, 6.6)	0.62
Asian N = 16	0.79 (0.10, 6.05)	0.82	2.17 (0.47, 10.11)	0.32
Tumor size	1.16 (0.91, 1.48)	0.23	1.47 (1.19, 1.82)	<0.001
Grade (reference, Grade 1 N = 117)
Grade 2 N = 212	1.98 (0.63, 6.16)	0.24	4.79 (0.62, 37.33)	0.13
Grade 3 N = 183	2.00 (0.54, 7.36)	0.30	3.11 (0.34, 28.73)	0.32
Nodal status (reference, Negative N = 296)
Positive N = 145	1.36 (0.68, 2.73)	0.38	2.14 (1.01, 4.53)	0.05
Histology (reference, IDC N = 379)
DCIS N = 110	0.57 (0.11, 2.82)	0.49	1.45 (0.18, 11.77)	0.73
ILC N = 23	0.59 (0.07, 4.80)	0.62
ER (reference, Negative N = 89)
Positive N = 415	0.69 (0.28, 1.71)	0.43	0.3 (0.11, 0.85)	0.02
HER2 (reference, Negative N = 355)
Positive N = 49	1.34 (0.53, 3.40)	0.54	0.74 (0.22, 2.52)	0.63
P53 (reference, Negative N = 246)
Positive N = 89	1.53 (0.70, 3.37)	0.29	0.91 (0.38, 2.2)	0.84
Systemic therapy (reference, none N = 58)
Performed N = 454	0.63 (0.19, 2.12)	0.46	0.48 (0.1, 2.23)	0.35

Adjusted for age, race/ethnicity, tumor size, tumor grade, lymph node status, ER status, HER2 status, P53 status, and systemic therapy status (including chemotherapy and endocrine therapy). Number of local recurrences among the 512 women was 41 (8.0%). Number of distant recurrences among the 512 women was 33 (6.4%).