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Table 4 Multivariate Cox proportional hazards model for disease-free survival by immunohistochemical staining of ER, PR and HER2

From: Metformin increases survival in hormone receptor-positive, HER2-positive breast cancer patients with diabetes

  Disease-free survival Cancer-specific survival
P-value Hazard ratio 95 % CI P-value Hazard ratio 95 % CI
Hormone receptor-positive, HER2-negative
Metformin       
 Metformin   1    1  
 Non-metformin versus metformin 0.340 1.35 0.73 to 2.47 0.072 1.92 0.94 to 3.90
 Non-DM versus metformin 0.484 0.85 0.54 to 1.34 0.64 0.87 0.50 to 1.54
Age, years       
 ≤50 0.369 0.92 0.76 to 1.12 0.012 0.728 0.57 to 0.93
Body mass index, kg/m 2       
 High   1    1  
 Low versus high 0.034 1.62 1.04 to 2.54 0.009 2.11 1.20 to 3.68
 Normal versus high 0.772 0.97 0.80 to 1.18 0.87 0.98 0.76 to 1.26
Tumor stage       
 T ≥2 <0.001 2.10 1.73 to 2.54 <0.001 2.44 1.88 to 3.16
Node stage       
 Node-positive <0.001 2.13 1.76 to 2.58 <0.001 2.92 2.25 to 3.80
Hormone receptor-positive, HER2-positive
Metformin       
 Metformin   1    1  
 Non-metformin versus metformin 0.002 5.37 1.88 to 15.28 0.001 6.51 2.06 to 20.55
 Non-DM versus metformin 0.648 1.23 0.50 to 3.02 0.502 1.41 0.52 to 3.84
Age, years       
 ≤50 0.120 0.79 0.59 to 1.06 0.006 0.623 0.45 to 0.87
Body mass index, kg/m 2       
 High   1    1  
 Low versus high 0.050 2.15 1.00 to 4.63 0.446 1.50 0.53 to 4.30
 Normal versus high 0.053 1.41 1.00 to 1.99 0.085 1.41 0.95 to 2.09
Tumor stage       
 T ≥2 <0.001 1.81 1.33 to 4.27 0.004 1.72 1.19 to 2.47
Node stage       
 Node-positive <0.001 2.22 1.64 to 3.02 0.000 2.85 1.97 to 4.13
Hormone receptor-negative, HER2-positive
Metformin       
 Metformin   1    1  
 Non-metformin versus metformin 0.897 1.07 0.39 to 2.95 0.452 0.61 0.16 to 2.24
 Non-DM versus metformin 0.310 0.72 0.38 to 1.36 0.156 0.61 0.31 to 1.21
Age, years       
 ≤50 0.310 1.17 0.89 to 1.54 0.385 1.15 0.84 to 1.57
Body mass index, kg/m 2       
 High   1    1  
 Low versus high 0.06 1.81 0.98 to 3.35 0.189 1.63 0.79 to 3.38
 Normal versus high 0.615 0.93 0.68 to 1.25 0.471 0.88 0.63 to 1.24
Tumor stage       
 T ≥2 <0.001 1.98 1.45 to 2.71 <0.001 2.39 1.63 to 3.51
Node stage       
 Node-positive <0.001 3.03 2.24 to 4.11 <0.001 3.94 2.71 to 5.72
Hormone receptor-negative, HER2-negative
Metformin       
 Metformin   1    1  
 Non-metformin versus metformin 0.311 1.62 0.64 to 4.12 0.329 1.66 0.60 to 4.56
 Non-DM versus metformin 0.89 1.05 0.50 to 2.24 0.867 1.07 0.47 to 2.42
Age, years       
 ≤50 0.350 1.13 0.88 to 1.44 0.989 1.00 0.76 to 1.32
Body mass index, kg/m 2       
 High   1    1  
 Low versus high 0.993 1.00 0.54 to 1.83 0.629 1.17 0.62 to 2.23
 Normal versus high 0.750 1.04 0.81 to 1.34 0.583 1.08 0.82 to 1.43
Tumor stage, cm       
 T ≥2 <0.001 1.62 1.26 to 2.08 <0.001 1.76 1.32 to 2.34
Node stage       
 Node-positive <0.001 2.25 1.78 to 2.84 <0.001 2.45 1.88 to 3.19
  1. HER2, human epidermal growth factor receptor-2. DM, diabetes mellitus