Table 1. Baseline demographic, clinical, and pathologic characteristics and local and systemic treatments of breast cancer patients with autoimmune disease (AD) and a matched cohort of breast cancer patients without AD.
| Patients with autoimmune disease (AD) N (%) | Comparison group N (%) | p-value | |
|---|---|---|---|
| All patients | 279 (100) | 558 (100) | |
| Type of AD | |||
| endocrine | 149 (53.4) | – | – |
| rheumatic | 66 (23.7) | ||
| systemic | 43 (15.4) | ||
| vasculitis | 7 (2.5) | ||
| neurologic | 14 (5.0) | ||
| Year of surgery | matching variable | ||
| < 1998 | 9 (3.2) | 14 (2.5) | |
| 1998–2001 | 48 (17.2) | 97 (17.4) | |
| 2002–2004 | 50 (17.9) | 106 (19) | |
| 2005–2007 | 97 (34.8) | 199 (35.7) | |
| 2008–2010 | 75 (26.9) | 142 (25.4) | |
| Age at surgery | matching variable | ||
| < 35 | 9 (3.2) | 15 (2.7) | |
| 35–50 | 109 (39.1) | 220 (39.4) | |
| 51–65 | 116 (41.6) | 230 (41.2) | |
| > 65 | 45 (16.1) | 93 (16.7) | |
| Menopausal status | matching variable | ||
| Peri-Pre | 125 (44.8) | 250 (44.8) | |
| Post | 154 (55.2) | 308 (55.2) | |
| Histology | 0.58 | ||
| Ductal | 225 (80.6) | 437 (78.3) | |
| Lobular | 25 (9) | 63 (11.3) | |
| Mixed/Other | 29 (10.4) | 58 (10.4) | |
| Tumor size (pT) | 0.46 | ||
| pT1 | 179 (64.2) | 374 (67.1) | |
| pT2 | 91 (32.6) | 164 (29.4) | |
| pT3/pT4 | 9 (3.2) | 20 (3.6) | |
| No. of positive lymph nodes | matching variable | ||
| pNx | 7 (2.5) | 14 (2.5) | |
| None | 154 (55.2) | 308 (55.2) | |
| 1–3 | 75 (26.9) | 150 (26.9) | |
| 4+ | 43 (15.4) | 86 (15.4) | |
| Grade | 0.16 | ||
| Unknown | 12 (4.3) | 15 (2.7) | |
| 1–2 | 168 (60.2) | 356 (63.8) | |
| 3 | 99 (35.5) | 187 (33.5) | |
| Surrogate intrinsic subtype | matching variable | ||
| Luminal A | 85 (30.5) | 171 (30.6) | |
| Luminal B (Her2 negative) | 104 (37.3) | 212 (38) | |
| Luminal B (Her2 positive) | 27 (9.7) | 49 (8.8) | |
| Her2 positive | 14 (5) | 28 (5) | |
| Triple Negative | 26 (9.3) | 52 (9.3) | |
| Missing | 23 (8.2) | 46 (8.2) | |
| Perivascular Invasion | 0.71 | ||
| Absent | 203 (72.8) | 391 (70.1) | |
| Focal | 46 (16.5) | 103 (18.5) | |
| Diffuse | 30 (10.8) | 64 (11.5) | |
| Surgery | 0.82 | ||
| Conservative | 213 (76.3) | 430 (77.1) | |
| Mastectomy | 66 (23.7) | 128 (22.9) | |
| Radiotherapy | 0.24 | ||
| No | 54 (19.4) | 83 (14.9) | |
| Yes-External | 143 (51.3) | 309 (55.4) | |
| Yes-Intraoperative | 82 (29.4) | 166 (29.7) | |
| Systemic adjuvant therapy | 0.39 | ||
| Nil | 21 (7.5) | 27 (4.8) | |
| Endocrine therapy alone | 147 (52.7) | 310 (55.6) | |
| Chemotherapy alone | 39 (14) | 70 (12.5) | |
| Chemotherapy and endocrine therapy | 72 (25.8) | 151 (27.1) |