Table 5.

Univariate and Multivariate Cox Regression for OS among patients of Breast Cancer with Liver Metastases in the FUSCC dataset

Variable	Overall Survival
	Univariate		Multivariate
	HR (95% CI)	P Value	HR (95% CI)	P Value
Age at diagnosis, y
21–40	1[Reference]		1[Reference]
41–60	1.34 (1.11–1.62)	0.003*	1.38 (1.09–1.74)	0.006*
> 60	1.39 (1.10–1.75)	0.005*	1.55 (0.86–2.80)	0.145
Histology
Infiltrating duct carcinoma	1[Reference]		1[Reference]
Lobular carcinoma	0.90 (0.56–1.43)	0.648	0.68 (0.41–1.14)	0.146
Other	0.72 (0.60–0.87)	< 0.001*	1.05 (0.85–1.29)	0.661
De novo metastatic diseases
No	1[Reference]		1[Reference]
Yes	0.40 (0.31–0.52)	< 0.001*	0.67 (0.29–1.52)	0.337
Surgery of primary site
No surgery	1[Reference]		1[Reference]
Yes	2.33 (1.83–2.98)	< 0.001*	1.02 (0.50–2.09)	0.947
Prior Chemotherapy
No	1[Reference]		1[Reference]
Yes	2.56 (1.99–3.28)	< 0.001*	1.51 (0.88–2.60)	0.135
Prior Radiotherapy
No	1[Reference]		1[Reference]
Yes	1.33 (1.17–1.51)	< 0.001*	1.20 (1.04–1.39)	0.014*
Unknown	0.77 (0.54–1.08)	0.122	0.67 (0.45–0.99)	0.046*
Recurrent sequence
First liver metastases	1[Reference]		1[Reference]
Subsequent liver metastases	2.16 (1.90–2.46)	< 0.001*	1.58 (1.33–1.87)	< 0.001*
Extrahepatic metastatic sites to lung, brain, bone and lymph nodes, No
0	1[Reference]		1[Reference]
1	1.54 (1.30–1.83)	< 0.001*	1.16 (0.95–1.41)	0.15
2	2.16 (1.80–2.59)	< 0.001*	1.56 (1.23–1.97)	< 0.001*
3	2.57 (2.08–3.18)	< 0.001*	2.05 (1.51–2.79)	< 0.001*
All 4	5.49 (3.56–8.47)	< 0.001*	4.59 (2.42–8.69)	< 0.001*
Subtype
HR+/HER2−	1[Reference]		1[Reference]
HR+/HER2+	0.82 (0.68–0.98)	0.033*	1.02 (0.83–1.25)	0.851
HR−/HER2+	0.84 (0.70–1.01)	0.067	1.13 (0.92–1.40)	0.242
Triple-negative	1.83 (1.53–2.20)	< 0.001*	2.17 (1.78–2.63)	< 0.001*
Unknown	1.11 (0.79–1.57)	0.544	1.63 (1.10–2.43)	0.015*

Notes: + denotes positive; − denotes negative; *denotes a statistically significant P-value; HER2, human epidermal growth factor receptor 2; HR, hormone receptor; CI confidence interval