Table 2.
Changes in the patient characteristics in response to NAC in the SLNB-only or ALND groups, before and after PSM.
| Before PSM | After PSM | |||||
|---|---|---|---|---|---|---|
| SLNB-only | ALND | p-value | SLNB-only | ALND | p-value | |
| N (%) | N (%) | N (%) | N (%) | |||
| Pathological response | 0.660 | 0.686 | ||||
| pCR (ypT0/is) | 164 (56.0) | 132 (57.9) | 113 (56.5) | 117 (58.5) | ||
| No pCR | 129 (44.0) | 96 (42.1) | 87 (43.5) | 83 (41.5) | ||
| Total number of SLNB | < 0.001 | < 0.001 | ||||
| Mean (± SD) | 3.7 ± 1.7 | 1.8 ± 2.0 | 3.7 ± 1.7 | 1.9 ± 2.0 | ||
| Estrogen receptor status | 0.270 | 0.718 | ||||
| Negative | 71 (52.2) | 60 (59.4) | 53 (55.8) | 52 (58.4) | ||
| Positive | 65 (47.8) | 41 (40.6) | 42 (44.2) | 37 (41.6) | ||
| Unknown (pCR) | 157 | 127 | 105 | 111 | ||
| Progesterone receptor status | 0.231 | 0.998 | ||||
| Negative | 106 (77.9) | 85 (84.2) | 79 (83.2) | 74 (83.1) | ||
| Positive | 30 (22.1) | 16 (15.8) | 16 (16.8) | 15 (16.9) | ||
| Unknown (pCR) | 157 | 127 | 105 | 111 | ||
| HER2 status | 0.337 | 0.794 | ||||
| Negative | 85 (62.0) | 57 (55.9) | 54 (56.8) | 50 (54.9) | ||
| Positive | 52 (38.0) | 45 (44.1) | 41 (43.2) | 41 (45.1) | ||
| Unknown (pCR) | 156 | 126 | 105 | 109 | ||
| Ki-67 index | 0.004 | 0.182 | ||||
| < 20% | 76 (50.0) | 33 (32.0) | 46 (43.8) | 31 (34.4) | ||
| ≥ 20% | 76 (50.0) | 70 (68.0) | 59 (56.2) | 59 (65.6) | ||
| Unknown (pCR) | 141 | 125 | 95 | 110 | ||
| IMLN dissection | 133 (45.4)a | 79 (34.6)a | 0.312 | 96 (48.0) a | 74 (37.0) a | 0.128 |
| No | 130 (97.7) | 74 (93.7) | 94 (97.9) | 69 (93.2) | ||
| Yes | 3 (2.3) | 5 (6.3) | 2 (2.1) | 5 (6.8) | ||
| SCLN dissection | 61 (20.8) | 74 (32.5) | < 0.001 | 47 (23.5%)a | 69 (34.5%)a | 0.027 |
| No | 57 (93.4) | 56 (75.7) | 43 (91.5%) | 52 (75.4%) | ||
| Yes | 4 (6.6) | 18 (24.3) | 4 (8.5%) | 17 (24.6%) | ||
| Radiotherapy | 291 (99.3) | 222 (97.8) | 0.136 | 198 (99.0) | 199 (100.0) | 0.157 |
| Hormone therapy | 135 (60.0) | 90 (40.0) | 0.131 | 87 (43.5) | 81 (40.5) | 0.543 |
PSM propensity score matching, SLNB sentinel lymph node biopsy, ALND axillary lymph node dissection, ypT0/is pathological T0 or Tis after NAC, SD standard deviation, pCR pathological complete response, IMLN internal mammary lymph node, SCLN supraclavicular lymph node.
aThe number and rate of metastasis, proven radiologically or pathologically, in all patients.