Table 1 Patients’ baseline characteristics of the study population (n = 4398)
From: The effect of postmastectomy radiotherapy in node-positive triple-negative breast cancer
Variables | N (%) | PMRT (%) | No PMRT (%) | P value |
|---|---|---|---|---|
Median follow-up (months) | 41.4 (1–83) | 41.7 (5–83) | 40.8 (1–83) |  |
Age (years) | ||||
 < 50 | 1713 (38.9) | 1098 (41.4) | 615 (35.2) | < 0.001 |
 ≥ 50 | 2685 (61.1) | 1551 (58.6) | 1134 (64.8) |  |
Ethnicity | ||||
 White | 3097 (70.4) | 1848 (69.8) | 1249 (71.4) | 0.044 |
 Black | 948 (21.6) | 601 (22.7) | 347 (19.8) |  |
 Other | 353 (8.0) | 200 (7.6) | 153 (8.7) |  |
Grade | ||||
 Well-differentiated | 25 (0.6) | 13 (0.5) | 12 (0.7) | 0.318 |
 Moderately differentiated | 609 (13.8) | 353 (13.3) | 256 (14.6) |  |
 Poorly/undifferentiated | 3764 (85.6) | 2283 (86.2) | 1481 (84.7) |  |
Histology | ||||
 IDC1 | 4036 (91.8) | 2443 (92.2) | 1593 (91.1) | 0.314 |
 ILC2 | 71 (1.6) | 43 (1.6) | 28 (1.6) |  |
 Other | 291 (6.6) | 163 (6.2) | 128 (7.3) |  |
T3 stage | ||||
 T1 | 883 (20.1) | 420 (15.9) | 463 (26.5) | < 0.001 |
 T2 | 2070 (47.1) | 1237 (46.7) | 833 (47.6) |  |
 T3 | 833 (18.9) | 558 (21.1) | 275 (15.7) |  |
 T4 | 612 (13.9) | 434 (16.4) | 178 (10.2) |  |
N4 stage | ||||
 N1 | 2812 (63.9) | 1534 (57.9) | 1278 (73.1) | < 0.001 |
 N2 | 937 (21.3) | 648 (24.5) | 289 (16.5) |  |
 N3 | 649 (14.8) | 467 (17.6) | 182 (10.4) |  |
Staging subgroup | ||||
 T1–2N1 | 2055 (46.7) | 1007 (38.0) | 1048 (59.9) | < 0.001 |
 T3–4N1 | 757 (17.2) | 527 (19.9) | 230 (13.2) |  |
 T1-4N2 | 937 (21.3) | 648 (24.5) | 289 (16.5) |  |
 T1-4N3 | 649 (14.8) | 467 (17.6) | 182 (10.4) |  |