Table 3. Cox regression analysis including conventional prognostic markers and groups 1–3 and the HER2-positive group of cohort C based on our four-gene algorithm.

	HR	95% CI	P
(a) OAS
Grade
I–II	1
III—undifferentiated	1.72	0.92–3.30	0.086
Positive nodes
0–3	1
⩾4	3.21	1.14–9.01	0.027
Algorithm classification
Group 1+3+HER2 positive.	1
Group 2	3.94	1.92–8.09	<0.001
Treatment group
E-T-CMF	1
E-CMF	1.18	0.64–2.17	0.603
(b) DFS
Grade
I–II	1
III–undifferentiated	1.45	0.87–2.42	0.157
Positive nodes
0–3	1
⩾4	2.21	1.05–4.65	0.038
Algorithm classification
Group 1+3+HER2 positive.	1
Group 2	2.18	1.10–4.34	0.026
Treatment group
E-T-CMF	1
E-CMF	1.08	0.65–1.80	0.767

Abbreviations: CI=confidence interval; DFS=disease-free survival; E-CMF=epirubicin-cyclophosphamide, methotrexate and fluorouracil; E-T-CMF=epirubicin-paclitaxel-cyclophosphamide, methotrexate and fluorouracil; HER2=human epidermal growth factor 2; HR=hazards ratio; OAS=overall survival.

Only the presented algorithm and the number of positive nodes (⩾4) are independent predictors of outcome in this cohort.