TABLE 1.
Clinicopathologic Characteristics of All ILC Patients, and Stratified by Pre- or Post-Guideline Era of Treatment
MMG, mammogram; US, ultrasound; LCIS, lobular carcinoma in situ; DCIS, ductal carcinoma in situ; ER, estrogen receptor; LVI, lymphovascular invasion
| Characteristic | All n = 745 |
Pre-guideline n = 312 |
Post-guideline n = 433 |
P |
|---|---|---|---|---|
| Age, years | 62 (53, 70) | 61 (52, 69) | 63 (53, 70) | 0.35 |
| Breast density | 0.10 | |||
| Fatty | 43 (5.8%) | 19 (6.1%) | 24 (5.5%) | |
| Scattered fibroglandular | 233 (31.3%) | 83 (26.6%) | 150 (34.6%) | |
| Heterogenous | 392 (52.6%) | 172 (55.1%) | 220 (50.8%) | |
| Extremely dense | 77 (10.3%) | 77 (10.3%) | 39 (9.0%) | |
| MMG/US size, cm* | 1.1 (0.8, 1.7) | 1.2 (0.8, 1.6) | 1.1 (0.8, 1.7) | 0.46 |
| MRI performed | 382 (51.3%) | 151 (48.4%) | 231 (53.3%) | 0.20 |
| MRI size, cm | 1.6 (1.1, 2.4) | 1.5 (1.1, 2.3) | 1.7 (1.1, 2.5) | 0.25 |
| Pathologic tumor size, cm | 1.4 (0.9, 2.1) | 1.4 (0.9, 2.0) | 1.3 (0.9, 2.1) | 0.99 |
| Associated LCIS | 686 (92.1%) | 298 (95.5%) | 388 (89.6%) | 0.004 |
| Associated DCIS | 117 (15.7%) | 54 (17.3%) | 63 (14.5%) | 0.31 |
| Receptor subtype | 0.64 | |||
| ER+/HER2− | 713 (95.7%) | 296 (94.9%) | 417 (96.3%) | |
| ER+/HER2+ | 17 (2.3%) | 7 (2.2%) | 10 (2.3%) | |
| ER−/HER2+ | 4 (0.5%) | 3 (1.0%) | 1 (0.2%) | |
| ER−/HER2− | 7 (0.9%) | 3 (1.0%) | 4 (0.9%) | |
| Unknown | 4 (0.5%) | 3 (1.0%) | 1 (0.2%) | |
| Type | 0.42 | |||
| Classic | 596 (80.0%) | 248 (79.5%) | 348 (80.4%) | |
| Pleomorphic | 133 (17.9%) | 60 (19.2%) | 73 (16.9%) | |
| Alveolar | 14 (1.9%) | 4 (1.3%) | 10 (2.3%) | |
| Unknown | 2 (0.3%) | 0 (0%) | 2 (0.3%) | |
| LVI** | 80 (10.7%) | 50 (16.0%) | 30 (6.9%) | < 0.001 |
| Pathologic T classification | 0.45 | |||
| T1 | 553 (74.2%) | 236 (75.6%) | 317 (73.2%) | |
| T2 | 183 (24.6%) | 74 (23.7%) | 109 (25.2%) | |
| T3 | 9 (1.2%) | 2 (0.6%) | 7 (1.6%) | |
| Pathologic N classification | 0.002 | |||
| N0 or N0(i+) | 593 (79.6%) | 236 (75.6%) | 357 (82.4%) | |
| N1 | 109 (14.6%) | 62 (19.9%) | 47 (10.9%) | |
| NX€ | 43 (5.8%) | 14 (4.5%) | 29 (6.7%) | |
| Pathologic stage | 0.43 | |||
| I | 485 (65.1%) | 195 (62.5%) | 290 (67.0%) | |
| IIA | 210 (28.2%) | 94 (30.1%) | 116 (26.8%) | |
| IIB | 50 (6.7%) | 23 (7.4%) | 27 (6.2%) |
Values presented as median (interquartile range) or n (%)
*
Size not stated or occult in n = 91
**
Unknown in n = 14
€
No axillary surgery performed in n = 43 patients due to age