. 2014 Dec 10;14:929. doi: 10.1186/1471-2407-14-929

Table 4.

Cox proportional-hazards regression model for distant-metastasis-free survival (DMFS) and breast-cancer-specific survival (BCSS) in 692 patients with tissue HER2-positive breast cancer

Variable	DMFS			BCSS
	HR	95% CI	P	HR	95% CI	P
Model with dichotomized serum HER2 ECD level, elevated vs normal
Serum HER2 ECD level, >15.2 ng/ml	3.788	2.034–7.054	<0.001^a	2.564	1.230–5.343	0.012^a
Tumor size, >2 cm	1.731	0.859–3.487	0.125	1.134	0.515–2.497	0.754
Lymph node positive	2.614	1.011–6.756	0.047^a	2.428	0.812–7.257	0.112
Grade 3+	1.972	1.069–3.638	0.030^a	1.575	0.758–3.270	0.223
Lymphovascular invasion	2.625	1.419–4.855	0.002^a	2.740	1.315–5.709	0.007^a
Chemotherapy, yes	0.235	0.081–0.687	0.008^a	0.303	0.085–1.078	0.065
Hormone therapy, yes	1.576	0.841–2.951	0.156	1.032	0.494–2.156	0.933
Trastuzumab, received	1.734	0.902–3.332	0.099	1.969	0.903–4.292	0.089
Model with four subgroups classified by serum HER2 ECD levels, each quartile group vs lowest-quartile subgroup
Serum HER2 ECD level,
Lowest quartile (reference)	1			1
Second quartile	1.827	0.549–6.078	0.326	1.008	0.224–4.529	0.992
Third quartile	3.029	1.003–9.152	0.049^a	2.407	0.669–8.655	0.179
Highest quartile	4.746	1.591–14.160	0.005^a	2.826	0.785–10.176	0.112
Tumor size, >2 cm	1.741	0.864–3.507	0.121	1.146	0.519–2.534	0.736
Lymph node positive	2.502	0.982–6.376	0.055	2.407	0.804–7.211	0.117
Grade 3+	1.844	1.010–3.370	0.046^a	1.844	1.010–3.370	0.046^a
Lymphovascular invasion	2.303	1.250–4.240	0.007^a	2.550	1.223–5.317	0.012^a
Chemotherapy, yes	0.210	0.074–0.599	0.004^a	0.273	0.078–0.957	0.042^a
Hormone therapy, yes	1.443	0.784–2.655	0.238	1.038	0.501–2.150	0.920
Trastuzumab, received	1.930	1.013–3.677	0.045^a	2.098	0.968–4.549	0.061

^aSignificant at P < 0.05.