Table 3. Comparison of Clinicopathological Features Between Metformin and Control Groups.
| Clinicopathological features | Metformin group | Control group (N = 56) | χ2 | P |
|---|---|---|---|---|
| Tumor size | ||||
| T ≤ 2 cm | 7 (21.2%) | 10 (17.9%) | 0.151 | 0.697 |
| T > 2 cm | 26 (78.8%) | 46 (82.1%) | ||
| Lymph node | ||||
| Negative | 16 (48.5%) | 12 (16.1%) | 7.049 | 0.008* |
| Positive | 17 (51.5%) | 44 (78.6%) | ||
| Clinical stage | ||||
| I | 6 (18.2%) | 9 (16.1%) | 0.066 | 0.797 |
| II, III | 27 (81.8%) | 47 (83.9%) | ||
| Histological grade | ||||
| I | 8 (24.2%) | 8 (14.3%) | 1.396 | 0.237 |
| II, III | 25 (75.8%) | 48 (85.7%) | ||
| ER status | ||||
| Negative | 14 (42.4%) | 31 (55.4%) | 2.796 | 0.095 |
| Positive | 19 (57.6%) | 25 (44.6%) | ||
| PR status | ||||
| Negative | 13 (39.4%) | 34 (60.7%) | 3.787 | 0.052 |
| Positive | 20 (60.6%) | 22 (39.3%) | ||
| HER-2 status | ||||
| Negative | 28 (84.8%) | 41 (73.2%) | 1.613 | 0.204 |
| Positive | 5 (15.2%) | 15 (26.8%) | ||
| Ki-67 | ||||
| < 14% | 21 (63.6%) | 21 (37.5%) | 5.692 | 0.017* |
| ≥ 14% | 12 (36.4%) | 35 (62.5%) | ||
| Molecular typing | ||||
| Luminal | 25 (75.8%) | 30 (53.6%) | 4.329 | 0.037* |
| Others | 8 (24.2%) | 26 (46.4%) |
ER: estrogen receptor; PR: progesterone receptor; HER-2: human epidermal growth factor receptor-2. *P < 0.05.