| Disease-free survival | Cancer-specific survival | ||||
---|---|---|---|---|---|---|
 | P-value | Hazard ratio | 95 % CI | P-value | Hazard ratio | 95 % CI |
Metformin | Â | Â | Â | Â | Â | Â |
 Metformin |  | 1 |  |  | 1 |  |
 Non-metformin versus metformin | 0.05 | 1.50 | 1.0 to 2.25 | 0.02 | 1.69 | 1.07 to 2.68 |
 Non-DM versus metformin | 0.39 | 0.87 | 0.64 to 1.19 | 0.29 | 0.83 | 0.58 to 1.18 |
Age, years | Â | Â | Â | Â | Â | Â |
 ≤50 | 0.652 | 0.97 | 0.87 to 1.09 | 0.023 | 0.83 | 0.73 to 0.96 |
BMI, kg/m2 | Â | Â | Â | Â | Â | Â |
 High |  | 1 |  |  | 1 |  |
 Low versus high | 0.141 | 1.24 | 0.94 to 1.64 | 0.362 | 1.17 | 0.84 to 1.64 |
 Normal versus high | 0.132 | 0.91 | 0.80 to 1.03 | 0.064 | 0.87 | 0.75 to 1.01 |
Tumor size, cm | Â | Â | Â | Â | Â | Â |
 T ≥2 | <0.001 | 2.59 | 2.30 to 2.91 | <0.001 | 3.10 | 2.68 to 3.59 |
Node metastasis | Â | Â | Â | Â | Â | Â |
 Node-positive | <0.001 | 2.79 | 0.49 to 3.13 | <0.001 | 3.58 | 3.10 to 4.13 |
Estrogen receptor status | Â | Â | Â | Â | Â | Â |
 Positive | 0.026 | 0.78 | 0.63 to 0.97 | <0.001 | 1.85 | 1.62 to 2.11 |
Progesterone receptor status | Â | Â | Â | Â | Â | Â |
 Positive | 0.001 | 0.72 | 0.60 to 0.87 | <0.001 | 1.93 | 1.69 to 2.21 |
HER2 status | Â | Â | Â | Â | Â | Â |
 Positive | <0.001 | 1.44 | 1.28 to 1.62 | <0.001 | 1.56 | 1.37 to 1.79 |
Chemotherapy | Â | Â | Â | Â | Â | Â |
 Yes | 0.098 | 0.82 | 0.65 to 1.04 | <0.001 | 0.38 | 0.31 to 0.46 |
Endocrine therapy | Â | Â | Â | Â | Â | Â |
 Yes | 0.108 | 0.83 | 0.67 to 1.04 | <0.001 | 1.78 | 1.56 to 2.03 |