Survival Outcome and Impact of Chemotherapy in T1 Node-Negative Triple-Negative Breast Cancer: A SEER Database Analysis

Table 3

Univariate and multivariate analyses of overall survival.

Variables	Univariate analysis			Multivariate analysis
	HR	95% CI		HR	95% CI
Age (years)
>50 vs. ≤ 50	2.272	1.543–3.345	<0.001	2.227	1.507–3.289	<0.001
Histologic subtype
Lobular vs. ductal	0.905	0.337–2.429	0.843	0.864	0.317–2.356	0.775
Tumor size
T1a	1			1
T1b	1.415	0.846–2.369	0.186	1.680	0.998–2.829	0.051
T1c	2.105	1.321–3.355	0.002	2.742	1.702–4.418	<0.001
Grade
3 vs. 1–2	1.213	0.946–1.555	0.128	1.153	0.891–1.491	0.278
Chemotherapy
No/unknown vs. yes	2.445	1.938–3.085	<0.001	2.766	2.185–3.501	<0.001

Abbreviations: HR, hazard ratio; CI, confidence interval.