Table 1.
Age and tumor characteristics of patients whose sentinel lymph nodes stained negative by hematoxylin and eosin (H&E) and were subsequently examined by immunohistochemistry (IHC).
| Variable | Tumor Status of Sentinel Lymph Node | P value | |
|---|---|---|---|
|
| |||
| Negative by H&E and IHC (N=2977) | Positive by IHC (N=349) | ||
|
| |||
| Age, in years | |||
| median (min, max) | 57 (23, 95) | 54 (27, 87) | |
| ≤ 50, n (%) | 835(28.1) | 125(35.8) | .003 |
| > 50, n (%) | 2141(71.9) | 224(64.2) | |
| missing, n | 1 | 0 | |
|
| |||
| Tumor type, n (%) | |||
| ductal | 2387 (80.3) | 262 (75.1) | |
| lobular | 226 (7.6) | 45 (12.9) | |
| both | 77 (2.6) | 14 (4.0) | .002 |
| other | 284 (9.6) | 28 (8.0) | |
| missing | 3 | 0 | |
|
| |||
| Lymphovascular invasion, n (%) | |||
| absent | 1921 (90.4) | 217(83.1) | .0003 |
| present | 205(9.6) | 44(16.9) | |
| missing | 851 | 88 | |
|
| |||
| Tumor size, in cm | |||
| median (minimum, maximum) | 1.2 (0,19) | 1.5 (0.1,5.0) | |
| ≤ 1.0, n (%) | 1260 (45.1) | 101 (30.7) | |
| 1.1 to 2.0, n (%) | 1202 (43.1) | 161 (48.9) | <.0001 |
| > 2.0, n (%) | 330 (11.8) | 67 (20.4) | |
| missing, n | 185 | 20 | |
|
| |||
| Estrogen receptor status, n (%) | |||
| positive | 2225 (81.1) | 268 (83.5) | .30 |
| negative | 518 (18.9) | 53 (16.5) | |
| missing | 234 | 28 | |
|
| |||
| Progesterone receptor status, n (%) | |||
| positive | 1828 (67.6) | 219 (70.0) | .40 |
| negative | 875(32.4) | 94 (30.0) | |
| missing | 274 | 36 | |