Table 1. Baseline characteristics of breast cancer and immune-mediated disease cohorts according to immunosuppressive therapy use.
| Characteristic | Group | Methotrexate | Thiopurine | Anti-TNF | |||
|---|---|---|---|---|---|---|---|
| User(n=892) | Nonuser(n=892) | User(n=52) | Nonuser(n=208) | User(n=291) | Nonuser(n=1164) | ||
| Age (y) | <65 y | 121 (13.6%) | 154 (17.3%) | <11a | 30 (14.4%) | 55 (18.9%) | 174 (14.9%) |
| 65 to <70 | 178 (20.0%) | 137 (15.4%) | 16 (30.8%) | 34 (16.3%) | 71 (24.4%) | 207 (17.8%) | |
| 70 to <75 | 206 (23.1%) | 229 (25.7%) | 11 (21.2%) | 55 (26.4%) | 71 (24.4%) | 285 (24.5%) | |
| 75 to <80 | 192 (21.5%) | 176 (19.7%) | 11 (21.2%) | 41 (19.7%) | 60 (20.6%) | 242 (20.8%) | |
| 80+ | 195 (21.9%) | 196 (22.0%) | <11 | 48 (23.1%) | 34 (11.7%) | 256 (22.0%) | |
| Raceb | White | 767 (86.0%) | 718 (80.5%) | 46 (88.5%) | 189 (90.9%) | 262 (90.0%) | 977 (83.9%) |
| Black | 89 (10.0%) | 124 (13.9%) | <11 | <11 | 16 (5.5%) | 132 (11.3%) | |
| Other | 36 (4.0%) | 50 (5.6%) | <11 | 11 (5.3%) | 13 (4.5%) | 55 (4.7%) | |
| Rheumatologic disease | RA | 892 (100.0%) | 892 (100.0%) | -- | -- | 273 (93.8%) | 1092 (93.8%) |
| IBD | -- | -- | 52 (100.0%) | 208 (100.0%) | 18 (6.2%) | 72 (6.2%) | |
| Methotrexate | Never | -- | 320 (35.9%) | 50 (96.2%) | 198 (95.2%) | 99 (34.0%) | 322 (27.7%) |
| New use at start of follow-up | 128 (14.3%) | -- | -- | -- | -- | -- | |
| Priorc | 23 (2.6%) | 569 (63.8%) | <11 | <11 | 64 (22.0%) | 387 (33.2%) | |
| Concurrentd | 741 (83.1%) | <11 | -- | -- | 128 (44.0%) | 455 (39.1%) | |
| Thiopurines | Never | 883 (99.0%) | 813 (91.1%) | -- | 193 (92.8%) | 269 (92.4%) | 1104 (94.8%) |
| New use at start of follow-up | -- | -- | <11 | -- | -- | -- | |
| Prior | <11 | 53 (5.9%) | <11 | 15 (7.2%) | 15 (5.2%) | 40 (3.4%) | |
| Concurrent | <11 | 26 (2.9%) | 48 (92.3%) | <11 | <11 | 20 (1.7%) | |
| Anti-TNF | Never | 664 (74.4%) | 595 (66.7%) | 43 (82.7%) | 189 (90.9%) | -- | 950 (81.6%) |
| New use at start of follow-up | -- | -- | -- | -- | <11 | -- | |
| Prior | 111 (12.4%) | 183 (20.5%) | <11 | 11 (5.3%) | <11 | 214 (18.4%) | |
| Concurrent | 117 (13.1%) | 114 (12.8%) | <11 | <11 | 280 (96.2%) | <11 | |
| Other biologicse | Never | 840 (94.2%) | 817 (91.6%) | 52 (100.0%) | 208 (100.0%) | 278 (95.5%) | 1078 (92.6%) |
| Prior | 32 (3.6%) | 41 (4.6%) | -- | -- | 12 (4.1%) | 41 (3.5%) | |
| Concurrent | 20 (2.2%) | 34 (3.8%) | -- | -- | <11 | 45 (3.9%) | |
| Breast cancer surgery | Bilateral mastectomy | 11 (1.2%) | 11 (1.2) | <11 | <11 | <11 | 20 (1.7%) |
| Mastectomy | 371 (41.6%) | 371 (32.7%) | 17 (32.7%) | 68 (32.7%) | 113 (38.8%) | 452 (38.8%) | |
| Lumpectomy | 510 (57.2%) | 510 (65.4%) | 34 (65.4%) | 136 (65.4%) | 173 (59.5%) | 692 (59.5%) | |
| Radiation therapyf | 420 (47.1%) | 420 (47.1%) | 31 (59.6%) | 124 (59.6%) | 147 (50.5%) | 588 (50.5%) | |
| Adjuvant chemotherapyf | 91 (10.2%) | 91 (10.2%) | <11 | 20 (9.6%) | 28 (9.6%) | 112 (9.6%) | |
| Hormonal therapyf | 518 (58.1%) | 446 (50.0%) | 32 (61.5%) | 136 (65.4%) | 164 (56.4%) | 645 (55.4%) | |
| HER2 therapyf | 26 (2.9%) | 23 (2.6%) | <11 | <11 | <11 | 34 (2.9%) | |
| Prior NSAIDsg | 295 (33.1%) | 227 (25.4%) | <11 | 31 (14.9%) | 90 (30.9%) | 320 (27.5%) | |
| Diabetes mellitus | 222 (24.9%) | 263 (39.5%) | <11 | 49 (23.6%) | 68 (23.4%) | 320 (27.5%) | |
| Chronic kidney disease | 43 (4.8%) | 72 (8.1%) | <11 | 23 (11.1%) | 16 (5.5%) | 75 (6.4%) | |
| Chronic liver disease | <11 | 40 (4.5%) | <11 | <11 | <11 | 31 (2.7%) | |
| Congestive heart failure | 98 (11.0%) | 146 (16.4%) | <11 | 24 (11.5%) | 35 (12.0%) | 158 (13.6%) | |
| Coronary artery disease | 188 (21.1%) | 278 (31.2%) | <11 | 44 (21.2%) | 61 (21.0%) | 305 (26.2%) | |
| Carotid artery disease | 21 (2.4%) | 18 (2.0%) | <11 | <11 | <11 | 29 (2.5%) | |
| Time from breast cancer surgery to follow-up start | 1 y | 752 (84.3%) | 834 (93.5%) | 48 (92.3%) | 186 (89.4%) | 283 (97.3%) | 1021 (87.7%) |
| 1 to 1.5 y | 35 (3.9%) | 12 (1.3%) | <11 | <11 | <11 | 38 (3.3%) | |
| 1.5 to 2 y | 28 (3.1%) | 18 (2.0%) | <11 | <11 | <11 | 28 (2.4%) | |
| 2+ y | 77 (8.6%) | 28 (3.1%) | <11 | <11 | <11 | 77 (6.6%) | |
| Follow-up time | Median (IQR) | 2.4 (1.6-3.1) | 2.5 (1.5-3.3) | 3.4 (1.7-4.8) | 3.2 (1.9-3.5) | 2.7 (1.7-3.7) | 2.5 (1.7-4.4) |
Abbreviations: y, years; RA, rheumatoid arthritis; IBD, inflammatory bowel disease; TNF, tumor necrosis factor, HER2, human epidermal growth factor receptor 2; NSAID, non-steroidal anti-inflammatory drug.
a
Results not reported where <11 subjects were exposed to a therapy
b
Other race includes Hispanics, Asian/Pacific Islander, Native American, unknown.
c
Use >90 days prior to the start of follow-up
d
Use in the 90 days prior to start of follow-up
e
Biologics assessed included abatacept, rituximab, tocilizumab
f
Within 365 days after breast surgery
g
Use in the 90 days prior to start of follow-up