Patient characteristics
| Training set | Test set | Total | ||||
|---|---|---|---|---|---|---|
| n | Percentage | n | Percentage | n | Percentage | |
| Treatment response | ||||||
| Non-pCR | 88 | 87.13% | 22 | 66.67% | 110 | 82.09% |
| Achieved pCR | 13 | 12.87% | 11 | 33.33% | 24 | 17.91% |
| Miller-Payne grade | ||||||
| G1-G3 | 62 | 61.39% | 13 | 39.39% | 75 | 55.97% |
| G4 | 22 | 21.78% | 8 | 24.24% | 30 | 22.39% |
| G5 | 17 | 16.83% | 12 | 36.36% | 29 | 21.64% |
| Ki-67 index (percent) | ||||||
| ≤ 20 | 17 | 16.83% | 4 | 12.12% | 21 | 15.67% |
| > 20 | 84 | 83.17% | 29 | 87.88% | 113 | 84.33% |
| HER2 status | ||||||
| Positive | 46 | 45.54% | 23 | 69.70% | 69 | 51.49% |
| Negative | 53 | 52.48% | 10 | 30.30% | 63 | 47.01% |
| Unknown | 2 | 1.98% | 0 | 0.00% | 2 | 1.49% |
| Subtype | ||||||
| TNBC | 53 | 52.48% | 10 | 30.30% | 63 | 47.01% |
| HR-HER2+ | 43 | 42.57% | 22 | 66.67% | 65 | 48.51% |
| HR-HER2+ (at surgery) | 3 | 2.97% | 1 | 3.03% | 4 | 2.99% |
| HR-HER2 unknown | 2 | 1.98% | 0 | 0.00% | 2 | 1.49% |
| ypN | ||||||
| ypN0 | 52 | 51.49% | 19 | 57.58% | 71 | 52.99% |
| ypN1 | 21 | 20.79% | 8 | 24.24% | 29 | 21.64% |
| ypN2 | 13 | 12.87% | 2 | 6.06% | 15 | 11.19% |
| ypN3 | 15 | 14.85% | 4 | 12.12% | 19 | 14.18% |
| cT | ||||||
| cT1 | 7 | 6.93% | 2 | 6.06% | 9 | 6.72% |
| cT2 | 72 | 71.29% | 28 | 84.85% | 100 | 74.63% |
| cT3 | 20 | 19.80% | 2 | 6.06% | 22 | 16.42% |
| Unknown | 2 | 1.98% | 1 | 3.03% | 3 | 2.24% |
| Chemotherapy regimen | ||||||
| Chemo (TEC/TAC) | 77 | 76.24% | 10 | 30.30% | 87 | 64.93% |
| H/HP-chemo | 24 | 23.76% | 23 | 69.70% | 47 | 35.07% |
HER2, human epidermal growth factor receptor 2; TNBC, triple-negative breast cancer; pCR, pathologic complete response; ypN, pathologic N stage after NAT; H, trastuzumab; P, pertuzumab; T, taxanes; E, epirubicin; A, adriamycin; C, cyclophosphamide; chemo, chemotherapy (including TEC/TAC).