Table 1. Tumour characteristics by allocated arm.
| Metformin (n=50) | Placebo (n=50) | Pa | |
|---|---|---|---|
| Age (median, IQR) |
50, 45–62 |
49, 45–57 |
0.5 |
| Body mass index (median, IQR) |
24.2, 20.8–26.8 |
24.7, 21.4–28.3 |
0.6 |
| HOMA index (median, IQR) |
2.18, 1.15–3.13 |
2.18, 1.72–3.15 |
0.4 |
| Ki67 LI (median, IQR) |
21, 12–38 |
20, 15–34 |
0.9 |
|
T stage (n, %) | |||
| pT1 | 12 (24) | 18 (36) | 0.2 |
| pT2 | 32 (64) | 30 (60) | |
| pT3 |
6 (12) |
2 (4) |
|
|
Nodal status(n, %) | |||
| pN0 | 19 (38) | 15 (30) | 0.2 |
| pN1 | 17 (34) | 24 (48) | |
| pN2 | 6 (12) | 8 (16) | |
| pN3 |
8 (16) |
3 (6) |
|
|
Mastectomy(n, %) | |||
| Yes | 28 (56) | 34 (68) | 0.2 |
| No |
22 (44) |
16 (32) |
|
|
Histology(n, %) | |||
| Ductal | 44 (88) | 45 (90) | 0.2 |
| Lobular | 5 (10) | 1 (2) | |
| Mixed | 0 (—) | 2 (4) | |
| Other |
1 (2) |
2 (4) |
|
|
Molecular subtype by IHC(n, %) | |||
| Luminal A | 13 (26) | 9 (18) | 0.3 |
| Luminal B | 25 (50) | 30 (60) | |
| HER 2+ | 8 (16) | 6 (12) | |
| Triple negative |
4 (8) |
5 (10) |
|
|
Grade(n, %) | |||
| 1 | 4 (8) | 3 (6) | 0.8 |
| 2 | 23 (46) | 26 (52) | |
| 3 |
23 (46) |
21 (42) |
|
|
Peritumoral vascular invasion(n, %) | |||
| 0 | 31 (62) | 23 (46) | 0.3 |
| 1 | 9 (18) | 9 (18) | |
| 2 | 9 (18) | 16 (32) | |
| 3 |
1 (2) |
2 (4) |
|
|
HER2 overexpression/amplification(n, %) | |||
| Yes | 8 (16) | 6 (12) | 0.6 |
| No | 42 (84) | 44 (88) | |
Abbreviations: IHC=immunohistochemistry; IQR=interquartile range, LI=labelling index.
a
Wilcoxon rank-sum or Pearson's χ2-test.