Table 6 

Coefficients of the linear predictor in the final Cox regression model (N = 196) 

Variable 
B 
exp(B) 
P 
95% CI for exp(B) 


Stage 

II^{a} 
0.72 
2.06 
0.14 
0.79–5.36 
III^{a} 
1.69 
5.4 
0.001 
1.97–14.74 
IV^{a} 
3.25 
25.68 
<0.001 
6.72–98.17 
Estrogen receptor (pos. versus neg.) 
0.58 
1.79 
0.039 
1.03–3.11 
cerbB2 (pos. versus neg.) 
0.82 
2.26 
0.0036 
1.31–3.93 
Topoisomerase IIα (pos. versus neg.) 
0.39 
1.48 
0.005 
0.77–2.83 
Grading (3 versus {1,2}) 
t0.62 
0.54 
0.15 
0.23–1.25 
Topoisomerase IIα × grading^{b} 
1.21 
3.35 
0.035 
1.09–10.36 


^{a}The hazard ratio exp(B) of the stage given is the relative risk of this stage with respect to stage I. ^{b}The effect of the interaction term on survival can be described as follows: if grading equals G1 or G2, the hazard ratio of topoisomerase IIα positive versus negative is 1.48 (95% confidence interval (CI) 0.77 to 2.83); if grading equals G3, this hazard ratio is 4.96 (95% CI 2.00 to 12.29). 

Fritz et al. Breast Cancer Research 2005 7:R374R384 doi:10.1186/bcr1012 