Table 1 Clinical characteristics of patients in the full cohort, the Right-sided cohort, and the Left-sided cohort
Patients characteristics | Full cohort (N = 63,243 | Right-sided (N = 39,024) | Left-sided (N = 24,219) | |||
|---|---|---|---|---|---|---|
Total number of lymph nodes < 12 | Total number of lymph nodes ≥12 | Total number of lymph nodes < 12 | Total number of lymph nodes ≥12 | Total number of lymph nodes < 12 | Total number of lymph nodes ≥12 | |
| Â | 16,127 (25.5%) | 47,116 (74.5%) | 8370 (21.4%) | 30,654 (78.6%) | 7757 (32.0%) | 16,462 (68.0%) |
Age at diagnosis | ||||||
  < 40 | 277 (1.7%) | 1800 (3.8%) | 93 (1.1%) | 885 (2.9%) | 184 (2.4%) | 915 (5.6%) |
 40–49 | 872 (5.4%) | 3631 (7.7%) | 291 (3.5%) | 1792 (5.8%) | 581 (7.5%) | 1839 (11.2%) |
 50–59 | 2473 (15.3%) | 8658 (18.4%) | 889 (10.6%) | 4658 (15.2%) | 1584 (20.4%) | 4000 (24.3%) |
 60–69 | 3664 (22.7%) | 10,934 (23.2%) | 1719 (20.5%) | 6984 (22.8%) | 1945 (25.1%) | 3950 (24.0%) |
  > 70 | 8841 (54.8%) | 22,093 (46.9%) | 5378 (64.3%) | 16,335 (53.3%) | 3463 (44.6%) | 5758 (35.0%) |
Gender | ||||||
 Male | 8011 (49.7%) | 22,422 (47.6%) | 3828 (45.7%) | 13,797 (45.0%) | 4183 (53.9%) | 8625 (52.4%) |
 Female | 8116 (47.6%) | 24,694 (52.4%) | 4542 (54.3%) | 16,857 (55.0%) | 3574 (46.1%) | 7837 (47.6%) |
Race | ||||||
 Black | 2144 (13.3%) | 5796 (12.3%) | 1113 (13.3%) | 3805 (12.4%) | 1031 (34.1%) | 1991 (12.1%) |
 White | 12,446 (77.2%) | 37,081 (78.7%) | 6691 (79.9%) | 24,651 (80.4%) | 5755 (74.2%) | 12,430 (75.5%) |
 Hispanic/Latino | 119 (0.7%) | 296 (0.6%) | 69 (0.8%) | 181 (0.6%) | 50 (0.6%) | 115 (0.7%) |
 Asian or Pacific Islander and others | 1378 (8.5%) | 3784 (8.0%) | 484 (5.8%) | 1922 (6.3%) | 894 (11.5%) | 1862 (11.3%) |
 Unknown | 40 (0.2%) | 159 (0.3%) | 13 (0.2%) | 95 (0.3%) | 27 (0.3%) | 64 (0.4%) |
Hispanic | ||||||
 No | 14,460 (89.7%) | 42,480 (90.2%) | 7579 (90.5%) | 27,800 (90.7%) | 6881 (88.7%) | 14,680 (89.2%) |
 Yes | 1667 (10.3%) | 4636 (9.8%) | 791 (9.5%) | 2854 (9.3%) | 876 (11.3%) | 1782 (10.8%) |
T stage | ||||||
 T0–T2 (0, 2, 3) | 2723 (16.9%) | 5553 (11.8%) | 1144 (13.7%) | 3437 (11.2%) | 1579 (20.4%) | 2116 (12.9%) |
 T3–T4 (4, 5) | 13,376 (82.9%) | 41,503 (88.1%) | 7216 (86.2%) | 27,181 (88.7%) | 6160 (79.4%) | 14,322 (87.0%) |
 TX (6) | 28 (0.2%) | 60 (0.1%) | 10 (0.1%) | 36 (0.1%) | 18 (0.2%) | 24 (0.1%) |
N stage | ||||||
 N1 | 12,005 (74.4%) | 29,678 (63.0%) | 6057 (72.4%) | 19,100 (62.3%) | 5948 (76.7%) | 1809 (23.3%) |
 N2 | 4122 (25.6%) | 17,438 (37.0%) | 2313 (27.6%) | 11,554 (37.7%) | 10,578 (64.3%) | 5884 (35.7%) |
Chemotherapy | ||||||
 No | 8200 (50.8%) | 19,558 (41.5%) | 4640 (55.4%) | 13,549 (44.6%) | 3560 (45.9%) | 6009 (36.5%) |
 Yes | 7927 (49.2%) | 27,558 (58.5%) | 3730 (44.6%) | 17,105 (55.8%) | 4197 (54.1%) | 10,453 (63.5%) |
Radiotherapy | ||||||
 No | 37 (0.2%) | 88 (0.2%) | 18 (0.2%) | 57 (0.2%) | 19 (0.2%) | 31 (0.2%) |
 Yes | 343 (2.1%) | 868 (1.8%) | 107 (1.3%) | 298 (1.0%) | 236 (3.0%) | 570 (3.5%) |
 Unknown | 15,747 (97.6%) | 46,160 (98.0%) | 8245 (98.5%) | 30,299 (98.8%) | 7502 (96.7%) | 15,861 (96.3%) |
Marital status | ||||||
 Single, separated, divorced, | 3574 (22.2%) | 11,237 (23.8%) | 1734 (20.7%) | 6932 (22.6%) | 1840 (23.7%) | 4305 (26.2%) |
 Married (including common law) | 8568 (53.1%) | 25,176 (53.4%) | 4223 (50.5%) | 15,937 (52.0%) | 4345 (56.0%) | 9239 (56.1%) |
 Widowed | 3362 (20.8%) | 8714 (18.5%) | 2053 (24.5%) | 6469 (21.1%) | 1309 (16.9%) | 2245 (13.6%) |
 Unknown | 623 (3.9%) | 1989 (4.2%) | 360 (4.3%) | 1316 (4.3%) | 263 (3.4%) | 673 (4.1%) |
Pathology grade | ||||||
 Well-differentiated | 999 (6.2%) | 2440 (5.2%) | 483 (5.8%) | 1539 (5.0%) | 516 (6.7%) | 901 (5.5%) |
 Moderately differentiated | 10.677 (66.2%) | 29,917 (63.5%) | 5042 (60.2%) | 18,005 (58.7%) | 5635 (72.6%) | 11,912 (72.4%) |
 Poorly differentiated | 3619 (22.4%) | 11,956 (25.4%) | 2338 (27.9%) | 8995 (29.3%) | 1281 (16.5%) | 2961 (18.0%) |
 Undifferentiated | 401 (2.5%) | 1802 (3.8%) | 274 (3.3%) | 1431 (4.7%) | 127 (1.6%) | 371 (2.3%) |
 Unknown | 431 (2.7%) | 1.001 (2.1%) | 233 (2.8%) | 684 (2.2%) | 198 (2.6%) | 317 (1.9%) |
Positive lymph node | ||||||
 0 | 421 (2.6%) | 971 (2.1%) | 193 (2.3%) | 576 (1.9%) | 228 (2.9%) | 395 (2.4%) |
 1 | 6032 (37.4%) | 14,198 (30.1%) | 3050 (36.4%) | 9165 (29.9%) | 2982 (38.4%) | 5033 (30.6%) |
 2–3 | 5483 (34.0%) | 14,244 (30.2%) | 2776 (33.2%) | 9176 (29.9%) | 2707 (34.9%) | 5068 (30.8%) |
 4–6 | 3023 (18.7%) | 9226 (19.6%) | 1621 (19.4%) | 6008 (19.6%) | 1402 (18.1%) | 3218 (19.5%) |
  ≥ 7 | 1168 (7.2%) | 8477 (18.0%) | 730 (8.7%) | 5729 (18.7%) | 438 (5.6%) | 2748 (16.7%) |
Lymph nodes ratio | ||||||
  < 0.07 | 421 (2.6%) | 14,484 (30.7%) | 193 (2.3%) | 9518 (31.0%) | 228 (2.9%) | 4966 (30.2%) |
 0.07–0.25 | 7089 (44.0%) | 20,189 (42.8%) | 3673 (43.9%) | 12,965 (42.3%) | 3416 (44.0%) | 7224 (43.9%) |
 0.25–0.50 | 4645 (28.8%) | 7954 (16.9%) | 2361 (28.2%) | 5172 (16.9%) | 2284 (29.4%) | 2782 (16.9%) |
 0.50–1.0 | 3972 (24.6%) | 4489 (9.5%) | 2143 (25.6%) | 2999 (9.8%) | 1829 (23.6%) | 1490 (9.1%) |
Tumor site | ||||||
 Right-sided | 8370 (51.9%) | 30,654 (65.1%) |  |  |  |  |
 Left-sided | 7757 (48.1%) | 16,462 (34.9%) |  |  |  |  |