Table 1.
Baseline characteristics of the Z0011-compable patients selected from the Surveillance, Epidemiology, and End Results (SEER) database.
| Characteristis | Total | SLND (ALN 1–2) | SLND Plus (ALN 3–9) | SLND + ALND (ALN ≥10) | p-Value |
|---|---|---|---|---|---|
| No. (%) | No. (%) | No. (%) | No. (%) | ||
| Subject number | 23,138 | 7077 | 9441 | 6620 | |
| Year | <0.001 | ||||
| 2010 | 3614 | 595 | 1157 | 1862 | |
| 2011 | 3831 | 1051 | 1524 | 1256 | |
| 2012 | 3731 | 1227 | 1515 | 989 | |
| 2013 | 3841 | 1281 | 1678 | 882 | |
| 2014 | 3986 | 1423 | 1708 | 855 | |
| 2015 | 4135 | 1500 | 1859 | 776 | |
| Patient age, years (range) | 60 (20–101) | 62 (23–98) | 60 (24–101) | 59 (20–97) | <0.001 |
| ≤50 | 5227 (22.6) | 1300 (18.4) | 2146 (22.7) | 1781 (26.9) | |
| >50 | 17,911 (77.4) | 5777 (81.6) | 7295 (77.3) | 4839 (73.1) | |
| Tumor size, median (cm) | 1.8 | 1.8 | 1.8 | 2.0 | <0.001 |
| T category | <0.001 | ||||
| T1 | 13,674 (59.1) | 4448 (62.9) | 5641 (59.8) | 3585 (54.2) | |
| T2 | 9464 (40.9) | 2629 (37.1) | 3800 (40.2) | 3035 (45.8) | |
| No. of positive ALN(s) | <0.001 | ||||
| 1 | 17,677 (76.4) | 6439 (91.0) | 7029 (74.5) | 4209 (63.6) | |
| 2 | 5461 (23.6) | 638 (9.0) | 2412 (25.5) | 2411 (36.4) | |
| Histologic type | <0.001 | ||||
| IDC | 18,643 (80.6) | 5538 (78.3) | 7631 (80.8) | 5474 (82.7) | |
| ILC | 1545 (6.7) | 562 (7.9) | 659 (7.0) | 324 (4.9) | |
| IDC and ILC | 1508 (6.5) | 510 (7.2) | 618 (6.5) | 380 (5.7) | |
| others | 1442 (6.2) | 467 (6.6) | 533 (5.6) | 442 (6.7) | |
| Histologic grade | <0.001 | ||||
| 1 | 4316(18.7) | 1536 (21.7) | 1830 (19.4) | 950 (14.4) | |
| 2 | 10,849 (46.9) | 3523 (49.8) | 4492 (47.6) | 2834 (42.8) | |
| 3 | 7452 (32.2) | 1846 (26.1) | 2913 (30.9) | 2693 (40.7) | |
| unknown | 521 (2.3) | 172 (2.4) | 206 (2.2) | 143 (2.2) | |
| ER status | <0.001 | ||||
| positive | 19,927 (86.1) | 6365 (89.8) | 8184 (86.7) | 5378 (81.2) | |
| borderline | 5 (0.0) | 1 (0.0) | 2 (0.0) | 2 (0.0) | |
| negative | 2957 (12.8) | 634 (9.0) | 1160 (12.3) | 1163 (17.6) | |
| unknown | 249 (1.1) | 77 (1.1) | 95 (1.0) | 77 (1.2) | |
| PR status | <0.001 | ||||
| positive | 17,845 (77.1) | 5760 (81.4) | 7404 (78.4) | 4681 (70.7) | |
| borderline | 26 (0.1) | 7 (0.1) | 9 (0.1) | 9 (0.1) | |
| negative | 4982 (21.5) | 1224 (17.3) | 1920 (20.3) | 1838 (27.8) | |
| unknown | 285 (1.2) | 86 (1.2) | 108 (1.1) | 91 (1.4) | |
| HER2 status | <0.001 | ||||
| positive | 2917 (12.6) | 699 (9.9) | 1184 (12.5) | 1034 (15.6) | |
| borderline | 433 (1.9) | 133 (1.9) | 177 (1.9) | 123 (1.9) | |
| negative | 19,377 (83.7) | 6130 (86.6) | 7922 (83.9) | 5325 (80.4) | |
| unknown | 411 (1.8) | 115 (1.6) | 158 (1.7) | 138 (2.1) | |
| Molecular subtype | <0.001 | ||||
| HR+, HER2− | 17,354 (75.0) | 5691 (80.4) | 7141 (75.6) | 4522 (68.3) | |
| HR+, HER2+ | 2220 (9.6) | 546 (7.7) | 897 (9.5) | 777 (11.7) | |
| HR−, HER2+ | 691 (3.0) | 153 (2.2) | 286 (3.0) | 252 (3.8) | |
| triple negative | 2004 (8.7) | 431 (6.1) | 772 (8.2) | 801 (12.1) | |
| unknown | 869 (3.8) | 256 (3.6) | 345 (3.7) | 268 (4.0) | |
| Adjuvant therapy | |||||
| chemotherapy | 13,449 (58.1) | 3467 (49.0) | 5367 (56.8) | 4615 (69.7) | <0.001 |
| radiation therapy | 17,082 (73.8) | 5299 (74.9) | 7033 (74.5) | 4750 (71.8) | <0.001 |
| Median follow-up, months (IQR) | 41 (24–61) | 37 (22–55) | 39 (23–58) | 50 (30–70) | |
| Deaths | 1760 (7.6) | 515 (7.3) | 656 (6.9) | 589 (8.9) | |
| breast cancer | 865 (3.7) | 219 (3.1) | 334 (3.5) | 312 (4.7) | |
| other cause | 895 (3.9) | 296 (4.2) | 322 (3.4) | 277 (4.2) |
Abbreviations: Abbreviations: axillary lymph node (ALN); axillary lymph node dissection (ALND); confidence interval (CI); estrogen receptor (ER); human epidermal growth factor receptor 2 (HER2); hazard ratio (HR); invasive ductal carcinoma (IDC); invasive lobular carcinoma (ILC); progesterone receptor (PR); sentinel lymph node dissection (SLND).