Table 4.

Univariate and multivariate analyses of risk factors and OS in the validation cohort.

Variables	HR (95% CI)	P-Value
Univariate analyses
Age (years) (>60 vs. ≤ 60)	1.393 (0.899–2.159)	0.138
Race
Black or African American vs. White	1.401 (0.641–3.061)	0.398
Asian vs. White	1.190 (0.163–8.674)	0.864
Other vs. White	0.543 (0.075–3.928)	0.545
Anatomic subdivision (Bilateral vs. Unilateral)	0.760 (0.474–1.218)	0.254
Neoplasm histologic grade (G3–4 vs. G1–2)	1.567 (0.631–3.890)	0.333
Clinical stage (III and IV vs. I and II)	1.628 (0.399–6.640)	0.497
Chemotherapy (No vs. Yes)	4.806 (2.241–10.307)	<0.001
Hormone therapy (Yes vs. No)	0.768 (0.405–1.454)	0.417
Targeted molecular therapy (Yes vs. No)	0.524 (0.227–1.213)	0.131
Immunotherapy (Yes vs. No)	0.400 (0.055–2.890)	0.364
Risk score (high-risk vs. low-risk)	1.931 (1.235–3.018)	0.004
Multivariate analyses
Chemotherapy (No vs. Yes)	4.552 (2.124–9.756)	<0.001
Risk score (high-risk vs. low-risk)	1.884 (1.204–2.950)	0.006

HR, hazard ratio; CI, confidence interval; OS, overall survival; AJCC, American Joint Committee on Cancer.