Table 2.

Multivariable analysis for overall survival (OS) in patients who received at least one line of palliative systemic therapy

	HER2 + total N = 493, events = 352			HR + /HER2 + N = 330, events = 242			HER2 + total N = 493, events = 352
	Hazard ratio	95% CI	P	Hazard ratio	95% CI	P	Hazard ratio	95% CI	P
Incidence period
2008–2012	Ref			Ref			Ref
2013–2017	0.85	0.66–1.08	0.17	0.87	0.72–1.32	0.86	0.59	0.38–0.92	0.02
Age at diagnosis ABC
Age per year	1.01	1.01–1.02	0.002	1.02	1.01–1.03	0.001	1.00	0.98–1.02	0.97
WHO performance status
0–1	Ref			Ref			Ref
≥ 2	2.29	1.58–3.32	< 0.001	2.89	1.83–4.57	< 0.001	1.34	0.68–2.64	0.40
Unknown	1.61	1.27–2.05	< 0.001	1.74	1.30–2.33	< 0.001	1.48	0.95–2.30	0.08
Hormone receptor
Positive	Ref			NA			NA
Negative	0.86	0.68–1.08	0.19	NA			NA
Number initial metastatic sites
Single organ	Ref			Ref			Ref
Multiple organs	1.68	1.25–2.25	0.001	1.46	1.02–2.09	0.04	2.14	1.30–3.53	0.003
Initial metastatic sites
Bone only	Ref			Ref			Ref
Soft tissue without visceral or CNSa	0.80	0.49–1.31	0.38	0.94	0.53–1.65	0.82	0.71	0.25–2.02	0.52
Visceral without CNSb	1.23	0.85–1.78	0.26	1.31	0.86–2.00	0.21	1.27	0.55–2.92	0.58
CNSc	1.36	0.84–2.20	0.21	1.94	1.10–3.42	0.02	1.06	0.38–2.92	0.91
Metastatic-free interval
< 3 months/ de novo	Ref			Ref			Ref
3–23 months	1.56	1.12–2.19	0.009	1.84	1.20–2.84	0.005	1.46	0.79–2.70	0.23
≥ 24 months	1.07	0.83–1.37	0.61	1.14	0.84–1.54	0.39	0.91	0.56–1.47	0.69

ABC advanced breast cancer, CI confidence interval, CNS central nervous system, HR hormone receptor, HER2 human epidermal growth factor receptor 2, NA not applicable

^aLymph nodes, skin and eye

^bLiver, lung, pleura, peritoneum, gastrointestinal track, kidney, and ovaries

^cBrain and leptomeningeal