Table 1. Patient characteristics (n = 6,597).
| Characteristics | Number | % | |
|---|---|---|---|
| Age at operation (yr) | |||
| < 40 | 1,285 | 19.5 | |
| 40–49 | 2,540 | 38.5 | |
| 50–59 | 1,977 | 30.0 | |
| ≥ 60 | 795 | 12.0 | |
| Sex | |||
| Male | 3 | 0.1 | |
| Female | 6,594 | 99.9 | |
| Clinical T stage | |||
| cT1 | 528 | 9.5 | |
| cT2 | 3,778 | 67.8 | |
| cT3 | 1,268 | 22.7 | |
| Unknown | 1,023 | NA | |
| Clinical N stage | |||
| cN0 | 1,539 | 27.7 | |
| cN1 | 2,976 | 53.6 | |
| cN2 | 1,036 | 18.7 | |
| Unknown | 1,046 | NA | |
| Breast operation | |||
| BCS | 3,538 | 53.6 | |
| TM | 3,059 | 46.4 | |
| Axillary operation | |||
| SLNB | 3,101 | 47.0 | |
| ALND | 3,495 | 53.0 | |
| Unknown | 1 | NA | |
| Nuclear grade | |||
| Low | 299 | 6.1 | |
| Intermediate | 2,321 | 47.5 | |
| High | 2,233 | 46.4 | |
| Unknown | 1,744 | NA | |
| Histologic grade | |||
| Well differentiated | 587 | 11.4 | |
| Moderate differentiated | 2,846 | 55.3 | |
| Poorly differentiated | 1,711 | 33.3 | |
| Unknown | 1,453 | NA | |
| Pathologic T stage | |||
| ypT0 (No residual tumor) | 915 | 13.9 | |
| ypTis | 512 | 7.8 | |
| ypT1 | 2,912 | 44.3 | |
| ypT2 | 1,875 | 28.5 | |
| ypT3 | 360 | 5.5 | |
| Unknown | 23 | NA | |
| Pathologic N stage | |||
| ypN0 | 3,929 | 59.6 | |
| ypN1 | 1,986 | 30.2 | |
| ypN2 | 662 | 10.2 | |
| Unknown | 20 | NA | |
| ER status | |||
| Negative | 2,591 | 40.5 | |
| Positive | 3,806 | 59.5 | |
| Unknown | 200 | NA | |
| PR status | |||
| Negative | 3,395 | 56.7 | |
| Positive | 2,595 | 43.3 | |
| Unknown | 607 | NA | |
| HER2 status | |||
| Negative | 4,268 | 71.8 | |
| Positive | 1,527 | 25.7 | |
| Equivocal | 153 | 2.5 | |
| Unknown | 649 | NA | |
| Subtype | |||
| HR-positive/HER2-negative | 2,329 | 39.3 | |
| HR-positive/HER2-positive | 1,122 | 18.9 | |
| HR-negative/HER2-positive | 405 | 6.8 | |
| HR-negative/HER2-negative | 2,072 | 35.0 | |
| Unknown | 669 | NA | |
| Breast response | |||
| BpCR | 1,427 | 21.6 | |
| Non-BpCR | 5,147 | 79.0 | |
| Unknown | 23 | NA | |
| Axillary response | |||
| ApCR | 3,929 | 59.7 | |
| Non-ApCR | 2,648 | 40.3 | |
| Unknown | 20 | NA | |
| ypCR | |||
| ypCR | 1,285 | 19.4 | |
| Non-ypCR | 5,289 | 80.6 | |
| Unknown | 23 | NA | |
NA = not available; BCS = breast-conserving surgery; TM = total mastectomy; SLNB = sentinel lymph node biopsy; ALND = axillary lymph node dissection; ER = estrogen receptor; PR = progesterone receptor; HER2 = human epidermal growth factor-2; HR = hormone receptor; BpCR = breast pathologic complete response; ApCR = axillary pathologic complete response; ypCR = pathologic complete response.