Table 4

Univariate analysis of relapse-free survival for immunohistochemical biomarkers in the test and validation sets
Set
 Biomarker
 +/-
 n/total
 n
 Median RFS, years (95% CI)
 HR (95% CI)
 P
Test
 ER
 -
 308/313
 100
 2.9 (1.7–4.1)
 1


+
208
 6.1 (4.1–8.1)
 0.70 (0.52–0.93)
 0.02

PR
 -
 279/313
 143
 3.0 (2.1–3.8)
 1


+
136
 8.2 (5.0–11.4)
 0.58 (0.43–0.78)
 0.0003

HER2
 -
 300/313
 240
 6.0 (4.4–7.6)
 1


+
60
 3.6 (2.1–5.1)
 1.33 (0.94–1.89)
 0.1

EGFR
 -
 271/313
 239
 6.0 (4.0–8.0)
 1


+
32
 1.6 (0.9–2.3)
 2.30 (1.49–3.56)
 0.0002

Ki-67
 -
 308/313
 140
 11.0 (6.5–15.6)
 1


+
168
 3.6 (2.8–4.4)
 1.93 (1.44–2.60)
 0.00001

p53
 -
 307/313
 235
 6.4 (4.3–8.6)
 1


+
72
 2.6 (1.9–3.3)
 1.59 (1.16–2.18)
 0.004

CA IX
 -
 281/313
 234
 5.7 (4.0–7.4)
 1


+
47
 2.5 (1.4–3.6)
 1.81 (1.26–2.62)
 0.002

CK5/6
 -
 260/313
 238
 5.2 (3.8–6.6)
 1


+
22
 2.5 (0.6–4.3)
 1.60 (0.94–2.73)
 0.08
Validation
 ER
 -
 288/289
 100
 2.6 (1.5–3.8)
 1


+
188
 7.2 (5.8–8.5)
 0.68 (0.50–0.92)
 0.01

PR
 -
 268/289
 143
 3.8 (2.1–5.5)
 1


+
125
 7.2 (6.1–8.3)
 0.73 (0.54–1.00)
 0.05

HER2
 -
 273/289
 206
 7.0 (5.8–8.2)
 1


+
67
 2.4 (1.5–3.2)
 1.55 (1.11–2.18)
 0.01

EGFR
 -
 257/289
 219
 6.6 (4.9–8.3)
 1


+
38
 2.1 (1.3–2.8)
 1.81 (1.21–2.70)
 0.004

Ki-67
 -
 289/289
 134
 7.2 (5.6–8.8)
 1


+
155
 4.8 (3.0–6.6)
 1.27 (0.94–1.70)
 0.12

p53
 -
 286/289
 223
 6.7 (5.1–8.2)
 1


+
63
 2.7 (0.5–4.9)
 1.40 (0.99–1.97)
 0.06

CA IX
 -
 271/289
 227
 7.1 (5.4–8.6)
 1


+
44
 2.3 (1.3–3.2)
 1.79 (1.23–2.61)
 0.002

CK5/6
 -
 252/289
 237
 6.0 (4.3–7.6)
 1


+
15
 2.4 (1.7–3.1)
 1.81 (1.00–3.27)
 0.05

ER, estrogen receptor; PR, progesterone receptor; HER2, human epidermal growth factor receptor 2; EGFR, human epidermal growth factor receptor 1; CA IX, carbonic anhydrase IX; CK5/6, cytokeratin 5/6; RFS, relapse-free survival; CI, confidence interval; HR, hazard ratio; P, significance for comparison of hazard ratio.

Crabb et al. Breast Cancer Research 2008 10:R6   doi:10.1186/bcr1847