Table 1.
Patient characteristics.
| Initial DCIS treatment | ||||
|---|---|---|---|---|
| BCS only, N = 2647 | BCS + RT, N = 2604 | Mastectomy, N = 4794 | Total, N = 10,045 | |
| Follow-up (years), median (IQR) | 17.0 (9.7–24.4) | 14.5 (9.9–19.1) | 16.0 (9.0–22.9) | 15.7 (9.2–22.3) |
| Age at DCIS diagnosis (years), median (IQR) | 58.9 (43.0–74.8) | 57.2 (43.2–71.2) | 57.2 (40.6–73.8) | 57.6 (41.9–73.3) |
| Age <50 | 474 (17.9) | 457 (17.5) | 1212 (25.3) | 2143 (21.3) |
| Age ≥50 | 2173 (82.1) | 2147 (82.5) | 3582 (74.7) | 7902 (78.7) |
| DCIS grade (1999–2004a) | ||||
| Low (1) | 302 (40.9%) | 215 (13.7%) | 190 (10.2%) | 707 (16.9%) |
| Intermediate (2) | 234 (31.7%) | 578 (36.7%) | 553 (29.7%) | 1365 (32.7%) |
| High (3) | 202 (27.4%) | 780 (49.6%) | 1121 (60.1%) | 2103 (50.4%) |
| Unknown | 240 | 285 | 342 | 867 |
| Subsequent iIBC | 445 | 240 | 89 | 774 |
| Subsequent iDCIS | 352 | 145 | NA | 497 |
iIBC ipsilateral invasive breast cancer, iDCIS ipsilateral ductal carcinoma in situ, BCS breast-conserving surgery, RT radiotherapy, N number, IQR interquartile range, DCIS ductal carcinoma in situ, NA not available.
aData on grade are presented for patients diagnosed with primary DCIS from 1999 to 2004 (n = 5042).