Table 2.

Analysis of prognostic factors related to breast cancer recurrence and metastasis in cases of low-positive HER2 expression.

	Univariate analysis		Multivariate analysis
Variable	Hazard ratio (95% CI)	P value	Hazard ratio (95% CI)	P value
HER2 status
HER2 2+ (ISH-) vs. HER2 1+	0.925 (0.770–1.111)	0.403
Age
35 years vs. ≤35 years	0.595 (0.443–0.800)	0.001	0.747 (0.472–1.185)	0.747
Menstrual status
Menopausal vs. premenopausal	1.007 (0.840–1.207)	0.938
T stage
T3–T4 vs. T0–T2	4.720 (3.731–5.970)	<0.001	3.142 (2.181–4.526)	<0.001
N stage
N1–N3 vs. N0	2.838 (2.340–3.440)	<0.001	1.289 (0.894–1.860)	0.174
Histological grade
G2–G3 vs. G1	1.575 (1.210–2.051)	0.001	1.005 (0.725–1.394)	0.974
Lymphvascular invasion
Yes vs. No	2.418 (1.930–3.031)	<0.001	1.684 (1.260–2.251)	<0.001
Ki67 index
>30% vs. ≤30%	1.668 (1.334–2.085)	<0.001	1.411 (1.067–1.867)	0.016
HR status
HR negative vs. HR positive	1.622 (1.297–2.028)	<0.001	1.100 (0.765–1.581)	0.606
TNM staging
Stage II–III vs. Stage I	4.095 (3.407–4.922)	<0.001	2.069 (1.438–2.978)	<0.001
Prognostic staging
Stage II–III vs. Stage I	3.537 (2.739–4.568)	<0.001	1.478 (1.016–2.150)	0.041

CI: Confidence interval; HER2: Human epidermal growth factor receptor 2; HR: Hormone receptor; ISH: In situ hybridization.