TABLE 2.
Patient characteristics (n = 137,324).
| Variables | Median (range) or frequency (%) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Autoimmmune disease breast cancer cohort | Autoimmune disease stage I–III breast cancer | Autoimmmune disease stage IV breast cancer | |||||||
| No (n = 100,677) | Yes (n = 36,647) | p value | No (n = 91,526) | Yes (n = 33,932) | p value | No (n = 5330) | Yes (n = 1351) | p value | |
| Age (range) | 62 (58, 72) | 68 (63, 75) | <0.001 | 62 (21, 90) | 68 (23, 90) | <0.0001 | 66 (58, 76) | 69 (64, 77) | <0.001 |
| Sex (%) | <0.001 | 0.0004 | 1 | ||||||
| Female | 99,877 (99.2) | 36,425 (99.4) | 90,830 (99.2) | 33,738 (99.4) | 5268 (98.8) | 1335 (98.8) | |||
| Male | 800 (0.8) | 222 (0.6) | 696 (0.8) | 194 (0.6) | 62 (1.2) | 16 (1.2) | |||
| Race (%) | <0.001 | <0.0001 | 0.005 | ||||||
| Black | 10,842 (10.8) | 3875 (10.6) | 9573 (10.5) | 3492 (10.4) | 805 (15.1) | 211 (15.6) | |||
| White | 81,486 (80.9) | 30,757 (83.9) | 74,292 (81.6) | 28,577 (84.6) | 4195 (78.7) | 1090 (80.7) | |||
| Others | 8349 (8.3) | 2015 (5.4) | 7209 (7.9) | 1700 (5) | 330 (6.2) | 50 (3.7) | |||
| Rural/Urban (%) | <0.001 | <0.0001 | 0.612 | ||||||
| All urban | 65,815 (65.4) | 23,309 (63.6) | 59,975 (65.5) | 21,547 (63.5) | >3400 (>63.8) a | >850 (>62.9) a | |||
| Mostly urban | 21,074 (20.9) | 8102 (22.1) | 19,143 (20.9) | 7551 (22.2) | 1116 (20.9) | 271 (20.1) | |||
| Mostly rural | 7158 (7.1) | 2659 (7.3) | 6482 (7.1) | 2485 (7.3) | 375 (7.0) | 92 (6.8) | |||
| All rural | 6483 (6.4) | 2506 (6.8) | 5815 (6.4) | 2299 (6.8) | 389 (7.3) | 89 (6.6) | |||
| Unknown | 147 (0.1) | 71 (0.2) | 111 (0.1) | 50 (0.2) | <50 (<0.9) a | <50 (<3.7) a | |||
| Poverty (%) | <0.001 | <0.0001 | 0.147 | ||||||
| 0%–5% | 24,547 (24.4) | 9003 (24.6) | 22,627 (24.7) | 8451 (24.9) | 1081 (20.3) | 280 (20.7) | |||
| 5%–10% | 27,652 (27.5) | 9817 (26.8) | 25,361 (27.7) | 9117 (26.9) | 1319 (24.7) | 366 (27.1) | |||
| 10%–20% | 28,965 (28.8) | 10,300 (28.1) | 26,232 (28.7) | 9539 (28.1) | >1600 (>30.0) a | >350 (>26.0) a | |||
| 20%–100% | 19,348 (19.2) | 7451 (20.3) | 17,171 (18.8) | 6767 (19.9) | 1315 (24.7) | 334 (24.7) | |||
| Unknown | 165 (0.2) | 76 (0.2) | 135 (0.1) | 58 (0.2) | <15 (<0.3) a | <21 (<1.6) a | |||
| ER (%) | <0.001 | <0.0001 | 0.407 | ||||||
| Positive | 76,573 (76.1) | 28,370 (77.4) | 71,011 (77.6) | 26,677 (78.6) | >3550 (>66.6) a | >900 (>66.6) a | |||
| Negative | 16,319 (16.2) | 53,70 (14.7) | 14,816 (16.2) | 4932 (14.5) | 1027 (19.3) | 259 (19.2) | |||
| Bordeline | 118 (0.1) | 36 (0.1) | 103 (0.1) | 31 (0.1) | <37 (<0.7) a | <28 (<2.1) a | |||
| Unknown | 7667 (7.6) | 2871 (7.8) | 5596 (6.1) | 2292 (6.8) | 716 (13.4) | 164 (12.1) | |||
| PR (%) | <0.001 | <0.0001 | 0.791 | ||||||
| Positive | 64,396 (64.0) | 24,138 (65.9) | 59,965 (65.5) | 22,769 (67.1) | 2778 (52.1) | >700 (>51.8) a | |||
| Negative | 27,084 (26.9) | 9204 (25.1) | 24,547 (26.8) | 8475 (25) | 1766 (33.1) | 435 (32.2) | |||
| Bordeline | 362 (0.4) | 126 (0.3) | 314 (0.3) | 114 (0.3) | 25 (0.5) | <21 (<1.6) a | |||
| Unknown | 8835 (8.8) | 3179 (8.7) | 6700 (7.3) | 2574 (7.6) | 761 (14.3) | 185 (13.7) | |||
| HER2/HR (%) | <0.001 | <0.0001 | 0.001 | ||||||
| HER2+/HR+ | 4030 (4.0) | 1115 (3.0) | 3478 (3.8) | 997 (2.9) | 427 (8.0) | 74 (5.5) | |||
| HER2+/HR‐ | 1827 (1.8) | 482 (1.3) | 1572 (1.7) | 422 (1.2) | 202 (3.8) | 40 (3.0) | |||
| HER2‐/HR+ | 29,002 (28.8) | 9184 (25.1) | 26,923 (29.4) | 8604 (25.4) | 1404 (26.3) | 343 (25.4) | |||
| Triple Negative | 4221 (4.2) | 1258 (3.4) | 3892 (4.3) | 1146 (3.4) | 229 (4.3) | 77 (5.7) | |||
| Unknown | 61,597 (61.2) | 24,608 (67.1) | 55,661 (60.8) | 22,753 (67.1) | 3068 (57.6) | 817 (60.5) | |||
| CKD (%) | <0.001 | <0.0001 | <0.001 | ||||||
| No | 86,239 (85.7) | 26,753 (73.0) | 79,334 (86.7) | 25,044 (73.8) | 3984 (74.7) | 767 (56.8) | |||
| Yes | 14,438 (14.3) | 9894 (27.0) | 12,192 (13.3) | 8888 (26.2) | 1346 (25.3) | 584 (43.2) | |||
| CTX (%) | <0.001 | <0.0001 | <0.001 | ||||||
| No | 90,737 (90.1) | 29,878 (81.5) | 83,499 (91.2) | 28,014 (82.6) | 3883 (72.9) | 801 (59.3) | |||
| Yes | 9940 (9.9) | 6769 (18.5) | 8027 (8.8) | 5918 (17.4) | 1447 (27.1) | 550 (40.7) | |||
| Surgery (%) | <0.001 | <0.001 | 0.3 | ||||||
| No | 8486 (8.4) | 2486 (6.8) | 2911 (3.2) | 957 (2.8) | 3546 (66.5) | 878 (65.0) | |||
| Yes | 92,191 (91.6) | 34,161 (93.2) | 88,615 (96.8) | 32,975 (97.2) | 1784 (33.5) | 473 (35.0) | |||
| Radiation (%) | 0.114 | 0.0002 | 0.275 | ||||||
| No | 49,970 (49.6) | 18,416 (50.3) | 43,141 (47.1) | 16,400 (48.3) | 3667 (68.8) | 908 (67.2) | |||
| Yes | 50,707 (50.4) | 18,231 (49.7) | 48,385 (52.9) | 17,532 (51.7) | 1663 (31.2) | 443 (32.8) | |||
| Stage (%) | <0.001 | ||||||||
| 1 | 55,870 (55.5) | 21,467 (58.6) | |||||||
| 2 | 26,035 (25.9) | 9453 (25.8) | |||||||
| 3 | 9621 (9.6) | 3012 (8.2) | |||||||
| 4 | 5330 (5.3) | 1351 (3.7) | |||||||
| Unknown | 3821 (3.8) | 1364 (3.7) | |||||||
Note: Characteristics of patients with breast cancer (n = 137,324), stage I‐III breast cancer (n = 125,458) and stage IV breast cancer (n = 6681) with and without autoimmune diagnosis.
Abbreviations: CKD, chronic kidney disease; CTX, chemotherapy; ER, estrogen receptor; HER2+, human epidermal growth factor receptor 2 positive; HR+, hormone receptor positive; PR, progesterone receptor.
a
Data in cell coarsened as per SEER‐Medicare data use agreement to protect patient identity.