Table 1.
Characteristics of breast cancer patients by stage at diagnosis
| Characteristic | Overall | Stage | P valueb | ||||
|---|---|---|---|---|---|---|---|
| I | II | III | IV | Unknowna | |||
| Total | 4640 | 1334 | 2180 | 573 | 100 | 453 | |
| Age (years) | 52.9 ± 11.3 | 53.1 ± 11.5 | 52.9 ± 11.3 | 52.6 ± 11.0 | 53.3 ± 11.0 | 55.7 ± 13.6 | 0.85 |
| BMI | 25.0 ± 3.8 | 24.5 ± 3.6 | 25.2 ± 3.9 | 25.5 ± 4.0 | 25.0 ± 3.5 | 25.2 ± 3.9 | < 0.01 |
| Menopausal status | 0.03 | ||||||
| Premenopausal | 2017 (43.5) | 616 (46.2) | 956 (43.9) | 244 (42.6) | 36 (36.0) | 165 (36.4) | |
| Postmenopausal | 2510 (54.1) | 691 (51.8) | 1175 (53.9) | 318 (55.5) | 62 (62.0) | 264 (58.3) | |
| Unknowna | 113 (2.4) | 27 (2.0) | 49 (2.2) | 11 (1.9) | 2 (2.0) | 24 (5.3) | |
| Histological grade | < 0.01 | ||||||
| Well differentiated | 349 (7.5) | 147 (11.0) | 136 (6.2) | 20 (3.5) | 5 (5.0) | 41 (9.1) | |
| Moderately differentiated | 2549 (54.9) | 714 (53.5) | 1257 (57.7) | 311 (54.3) | 48 (48.0) | 219 (48.3) | |
| Poorly differentiated | 899 (19.4) | 224 (16.8) | 461 (21.1) | 140 (24.4) | 15 (15.0) | 59 (13.0) | |
| Unknowna | 843 (18.2) | 249 (18.7) | 326 (15.0) | 102 (17.8) | 32 (32.0) | 134 (29.6) | |
| Histological type | 0.28 | ||||||
| Ductal | 4031 (86.9) | 1161 (87.0) | 1928 (88.4) | 509 (88.8) | 88 (88.0) | 345 (76.2) | |
| Lobular | 149 (3.2) | 43 (3.2) | 60 (2.8) | 23 (4.0) | 3 (3.0) | 20 (4.4) | |
| Others | 460 (9.9) | 130 (9.8) | 192 (8.8) | 41 (7.2) | 9 (9.0) | 88 (19.4) | |
| Molecular subtype | < 0.01 | ||||||
| Luminal A | 2387 (51.4) | 775 (58.1) | 1122 (51.5) | 267 (46.6) | 32 (32.0) | 191 (42.2) | |
| Luminal B | 535 (11.5) | 144 (10.8) | 246 (11.3) | 72 (12.6) | 18 (18.0) | 55 (12.1) | |
| HER2 | 365 (8.0) | 78 (5.9) | 178 (8.2) | 67 (11.7) | 11 (11.0) | 31 (6.9) | |
| Triple-negative | 517 (11.1) | 130 (9.7) | 241 (11.1) | 81 (14.1) | 10 (10.0) | 55 (12.1) | |
| Unknowna | 836 (18.0) | 207 (15.5) | 393 (18.0) | 86 (15.0) | 29 (29.0) | 121 (26.7) | |
Continuous data are expressed as mean ± standard deviation (SD). Categorical data are expressed as number of cases (percent)
aUnknown data were not included in the statistical tests
b P values were calculated using one-way analysis of variance (ANOVA) test (continuous variables) and Chi square or exact test (categorical variables)