Table 1.
Characteristics of cohorts, women with breast cancer stage I–III and IV, diagnosed 2006–2012
| Stage I–III | Stage IV | |
|---|---|---|
| (n = 21,414) | (n = 621) | |
| Age at diagnosis | ||
| < 40 years | 883 (4.1) | 17 (2.8) |
| 40–49 years | 3114 (14.5) | 63 (10.1) |
| 50–59 years | 4597 (21.5) | 109 (17.6) |
| 60–69 years | 6546 (30.6) | 132 (21.3) |
| 70–79 years | 3679 (17.2) | 154 (24.8) |
| ≥ 90 years | 2595 (12.1) | 146 (23.6) |
| Age (years), median (range) | 63 (19–102) | 68 (29–97) |
| Region | ||
| Stockholm-Gotland | 9068 (42.4) | 235 (37.8) |
| Uppsala-Örebro | 8868 (41.4) | 263 (42.4) |
| North | 3478 (16.2) | 123 (19.8) |
| Education | ||
| < 10 years | 5367 (25.1) | 227 (36.6) |
| 10–12 years | 8682 (40.5) | 230 (37.0) |
| > 12 years | 7119 (33.2) | 147 (23.7) |
| Missing | 246 (1.2) | 17 (2.7) |
| Stage | ||
| I | 12,546 (58.6) | na |
| II | 7879 (36.8) | na |
| III | 989 (4.6) | na |
| IV | na | 621 |
| HER2 status | ||
| Positive | 2407 (11.2) | 50 (8.1) |
| Negative | 15,848 (74.0) | 147 (23.7) |
| Missing | 3159 (14.8) | 424 (68.3) |
| ER status | ||
| Positive | 17,514 (81.8) | 166 (26.7) |
| Negative | 2907 (13.6) | 60 (9.7) |
| Missing | 993 (4.6) | 395 (63.6) |
| Breast cancer subtype | ||
| Luminal (ER+, HER2–/HER2+) | 15,529 (72.5) | 141 (22.7) |
| Nonluminal HER2 (ER–, HER2+) | 857 (4.0) | 34 (5.5) |
| ER–HER2– | 1739 (8.1) | 18 (2.9) |
| Missing | 3289 (15.4) | 428 (68.9) |
| Neoadjuvanta/adjuvant breast cancer treatment | ||
| Chemotherapy | 8401 (39.2) | 97 (15.6) |
| Endocrine therapy | 16,160 (75.5) | 141 (22.7) |
| Radiotherapy | 15,036 (70.2) | 82 (13.2) |
| Trastuzumab | 1858 (8.7) | 21 (3.4) |
| Aspirin | ||
| Before breast cancer diagnosis (from 9 to 3 months) | 2660 (12.4) | 100 (16.1) |
| After breast cancer diagnosis (3–9 months) | 2813 (13.1) | na |
| During entire follow up | 4091 (19.1) | na |
| Aspirin treatment, duration (total, at end of follow-up) | ||
| < 6 months | 485 (2.3) | na |
| 6 months–2 years | 1552 (7.2) | na |
| > 2 years | 2054 (9.6) | na |
| Dose of aspirin (total, at end of follow-up) | ||
| < 75 mg/day | 24 (0.1) | na |
| 75 mg/day | 3486 (16.3) | na |
| > 75 to < 160 mg/day | 258 (1.2) | na |
| 160 mg/day | 223 (1.0) | na |
| > 160 mg/day | 100 (0.5) | na |
Data presented as n (%) unless indicated otherwise. ER estrogen receptor, HER2 human epidermal growth factor receptor 2, na not applicable
aNeoadjuvant radiotherapy, 41 women (0.2%); neoadjuvant chemotherapy, 891 women (4.1%); neoadjuvant endocrine therapy, 691 women (3.2%)