TABLE 1.
Clinicopathologic characteristics for 7509 SLN procedures in 7302 patients, by use of FS
| Characteristic | SLN/no FS (n = 1182), n (%) | SLN/FS (n = 6327), n (%) | P valuea |
|---|---|---|---|
| Median age, year (range) | 59 (12–90) | 56 (19–91) | < 0.001 |
| Operation | < 0.001 | ||
| Breast conservation | 857 (72.6) | 4227 (66.9) | |
| Mastectomy | 323 (27.4) | 2093 (33.1) | |
| Missing | 2 | 7 | |
| Median tumor size, cm (range) | 0.7 (0.1–5.0) | 1.3 (0.1–17.0) | < 0.001 |
| Tumor size | < 0.001 | ||
| T1 (≤2 cm) | 1084 (93.1) | 4893 (78.9) | |
| T2 (2–5 cm) | 80 (6.9) | 1250 (20.2) | |
| T3 (> 5 cm) | 0 (0.0) | 59 (1.0) | |
| Tx (unknown) | 18 | 125 | |
| Histologic grade | < 0.001 | ||
| I | 123 (13.8) | 391 (7.3) | |
| II | 281 (31.5) | 1575 (29.6) | |
| III | 489 (54.8) | 3362 (63.1) | |
| Unknown | 289 | 999 | |
| Nuclear grade | < 0.001 | ||
| I | 100 (11.9) | 329 (6.4) | |
| II | 497 (59.2) | 2832 (55.0) | |
| III | 243 (28.9) | 1986 (38.6) | |
| Unknown | 342 | 1180 | |
| Positive SLN | 216 (18.3) | 2219 (35.1) | < 0.001 |
| LVI | |||
| Present | 161 (14.3) | 1554 (24.9) | < 0.001 |
| Missing | 60 | 84 | |
| Multicentric/multifocal tumor | |||
| Present | 280 (23.7) | 1502 (23.7) | 1.000 |
| Missing | 1 | 2 | |
| ER positive | |||
| Present | 852 (81.5) | 4584 (80.2) | 0.330 |
| Missing | 137 | 611 | |
| PR positive | |||
| Present | 621 (59.8) | 3395 (59.7) | 1.000 |
| Missing | 143 | 643 | |
| Tumor type | < 0.001b | ||
| Invasive ductal | 907 (76.8) | 5323 (84.2) | |
| Invasive lobular | 96 (8.1) | 684 (10.8) | |
| Microinvasive DCIS | 148 (12.5) | 96 (1.5) | |
| Other invasive carcinomas | 11 (0.9) | 94 (1.5) | |
| Invasive carcinoma with ductal and lobular features | 19 (1.6) | 128 (2.0) | |
| Missing | 1 | 2 | |
| Median year of surgery (range) | 2005 (1997–2006) | 2002 (1997–2006) | < 0.001 |
SLN sentinel lymph node, FS frozen section, LVI lymphovascular invasion, ER estrogen receptor, PR progesterone receptor, DCIS ductal carcinoma in situ
a
All P values are based on Fisher’s exact test (categorical covariates) or Wilcoxon rank sum test (continuous covariates), except where otherwise indicated
b
This P value is based on Pearson’s chi-square test