Table 1.
Clinicopathological characteristics.
| Number of Tumors (n = 45,881) | ||||
|---|---|---|---|---|
| One (n = 40,662) | Two (n = 3639) | Three or More (n = 1580) | p-Value | |
| Age, years | <0.001 | |||
| <30 | 378 (0.9) | 30 (0.8) | 19 (1.2) | |
| 30–50 | 21,861 (53.8) | 2245 (61.7) | 1041 (65.9) | |
| ≥50 | 18,423 (45.3) | 1364 (37.5) | 520 (32.9) | |
| Largest tumor size (cm) | 1.243 ± 1.048 | 1.244 ± 0.681 | 1.243 ± 0.766 | 0.999 |
| Surgery | <0.001 | |||
| Breast-conserving | 28,784 (70.8) | 1793 (49.3) | 554 (35.1) | |
| Mastectomy | 11,878 (29.2) | 1846 (50.7) | 1026 (64.9) | |
| N stage | <0.001 | |||
| N0 | 31136 (76.7) | 2635 (72.6) | 1052 (66.8) | |
| N1 | 7956 (19.6) | 833 (22.9) | 403 (25.6) | |
| N2 | 1079 (2.7) | 109 (3.0) | 76 (4.8) | |
| N3 | 429 (1.1) | 53 (1.5) | 44 (2.8) | |
| Unknown | 62 | 9 | 5 | |
| Hormonal receptor | <0.001 | |||
| Positive | 30,942 (76.2) | 2900 (79.8) | 1239 (78.6) | |
| Negative | 9667 (23.8) | 735 (20.2) | 337 (21.4) | |
| Unknown | 53 | 4 | 4 | |
| HER2 | <0.001 | |||
| Positive | 11,346 (27.9) | 1086 (29.9) | 554 (35.2) | |
| Negative | 29,263 (72.1) | 2549 (70.1) | 1022 (64.8) | |
| Unknown | 53 | 4 | 4 | |
| Chemotherapy | <0.001 | |||
| No | 18097 (44.6) | 1452 (40.0) | 549 (34.8) | |
| Yes | 22505 (55.4) | 2179 (60.0) | 1029 (65.2) | |
| Unknown | 60 | 8 | 2 | |