Table 4.
Multivariate Cox proportional hazards model for disease-free survival by immunohistochemical staining of ER, PR and HER2
| 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 |
HER2, human epidermal growth factor receptor-2. DM, diabetes mellitus