Table 1. Baseline demographic and disease characteristics before propensity score matching.
| Characteristic | Overall (N=1,091) | BUS (n=764) | SLN-CEUS (n=327) | P value* |
|---|---|---|---|---|
| Age, mean (SD) | 50.98 (11.35) | 51.53 (11.40) | 49.68 (11.15) | 0.013 |
| Patients underwent NAT, n (%†) | 207 (18.97) | 98 (12.83) | 109 (33.33) | <0.001 |
| T stage, n (%) | 0.372 | |||
| 0 | 226 (20.71) | 158 (20.68) | 68 (20.80) | |
| 1 | 620 (56.83) | 422 (55.24) | 198 (60.55) | |
| 2 | 218 (19.98) | 164 (21.47) | 54 (16.51) | |
| 3 | 13 (1.19) | 10 (1.31) | 3 (0.92) | |
| 4 | 14 (1.28) | 10 (1.31) | 4 (1.22) | |
| N stage, n (%) | 0.286 | |||
| 0 | 794 (72.78) | 546 (71.47) | 248 (75.84) | |
| 1 | 177 (16.22) | 128 (16.75) | 49 (14.98) | |
| 2 | 90 (8.25) | 65 (8.51) | 25 (7.64) | |
| 3 | 30 (2.75) | 25 (3.27) | 5 (1.53) | |
| Tumor stage group, n (%) | 0.124 | |||
| 0 | 225 (20.62) | 162 (21.20) | 63 (19.27) | |
| I | 459 (42.07) | 306 (40.05) | 153 (46.79) | |
| II | 278 (25.48) | 197 (25.79) | 81 (24.77) | |
| III | 129 (11.82) | 99 (12.96) | 30 (9.17) |
*, P values are from the t-test, comparing BUS group and SLN-CEUS group; †, percentages are rounded to 2 decimal places. BUS, B-mode ultrasound; SLN-CEUS, contrast-enhanced ultrasound of sentinel lymph node; NAT, neoadjuvant treatment.