Table 4.

Multivariable Analysis Predicting OS in Stage IV Breast Cancer Patients

Variable	N	HR (95% CI)	P value
Surgery (yes vs no)	243	0.56 (0.32–0.78)	0.000
Age (<50 vs ≥50 yr)	243	1.01(0.73–1.33)	0.812
Bone metastasis	243	0.79 (0.54–1.26)	0.062
Visceral organ metastasis	243	2.38 (1.37–3.35)	0.000
Number of metastases(continuous)	243	1.05 (0.72–1.48)	0.069
ER(+ vs.-)	243	0.54 (0.41–0.85)	0.000
PR(+ vs.-)	243	0.68 (0.55–0.82)	0.002
HER2(+ vs.-)	243	1.52 (0.81–1.66)	0.553

Abbreviations: HR, hazard ratio; ER, estrogen receptor; PR, progesterone receptor; HER2, human epidermal growth factor 2.