Table 3. Multivariate logistic regression analysis of factors associated with de novo metastasis.

Variable	B	S.E.	Sig.	Exp(B)	95% CI for Exp(B)
Race: black (contrast: white)	0.179	0.072	0.013	1.196	1.037–1.375
Histology: invasive lobular carcinoma (contrast: invasive ductal carcinoma)	0.400	0.084	<0.001	1.492	1.262–1.756
Primary site: upper-outer quadrant (contrast: nipple and central portion)	−0.381	0.116	0.001	0.683	0.546–0.861
Tumor grade: undifferentiated, anaplastic (contrast: well differentiated)	1.491	0.287	<0.001	4.440	2.474–7.657
Laterality: bilateral (contrast: left side)	2.783	0.473	<0.001	16.176	6.665–43.674
Regional lymph nodes status: N1 (contrast: N0)	1.431	0.073	<0.001	4.183	3.629–4.825
ER status: ER (+) [contrast: ER(−)]	0.244	0.086	0.005	1.276	1.078–1.509
PR status: PR (+) [contrast: PR(−)]	−0.293	0.073	<0.001	0.746	0.646–0.862
Her-2 status: Her-2(+) [contrast: Her-2(−)]	0.245	0.069	<0.001	1.278	1.114–1.463
Tumor size	0.006	0.001	<0.001	1.006	1.005–1.008
Bloom-Richardson (Nottingham) score	−0.083	0.025	<0.001	0.921	0.878–0.967
Number of positive ipsilateral axillary lymph nodes	−0.165	0.011	<0.001	0.848	0.830–0.866
Lymph node ratio (LNR)	0.525	0.121	<0.001	1.691	1.332–2.136

B, coefficient values; S.E., standard error; Sig., significant value; Exp(B), odds ratio; CI, confidence interval.