Table 2.
The clinical characteristics between early-onset and late-onset breast cancer participants
| Characteristics, n (%) |
Early-onset (≤ 40 years old) (n = 131) |
Late-onset (> 40 years old) (n = 644) |
P-valuesa | P-values after Bonferroni correction |
|---|---|---|---|---|
| Breast density | < 0.001 | 0.0048 | ||
| Fatty + Mildly dense | 10 (7.9) | 99 (16.5) | ||
| Moderately | 84 (66.7) | 426 (71.0) | ||
| Extremely | 32 (25.4) | 75 (12.5) | ||
| Molecular subtype | 0.322 | 1.000 | ||
| Luminal A | 78 (65.5) | 379 (62.0) | ||
| Luminal B | 22 (18.5) | 107 (17.5) | ||
| HER2-enriched | 7 (5.9) | 71 (11.6) | ||
| Triple negative | 12 (10.1) | 54 (8.8) | ||
| TNM stage | 0.822 | 1.000 | ||
| 0/I/II | 108 (84.4) | 529 (83.6) | ||
| III/IV | 20 (15.6) | 104 (16.4) | ||
| Grade | 0.761 | 1.000 | ||
| Well differentiated | 16 (13.7) | 85 (13.8) | ||
| Moderately differentiated | 65 (55.6) | 321 (52.1) | ||
| Poorly differentiated | 36 (30.8) | 210 (34.1) | ||
| Tumor size | 0.251 | 1.000 | ||
| ≤ 2 cm | 68 (54.4) | 371 (59.9) | ||
| > 2 cm | 57 (45.6) | 248 (40.1) | ||
| Invasive | 0.055 | 1.000 | ||
| None | 9 (8.9) | 91 (16.4) | ||
| Yes | 92 (91.1) | 465 (83.6) | ||
| ER status | 0.272 | 1.000 | ||
| ER-negative | 22 (17.5) | 138 (21.8) | ||
| ER-positive | 104 (82.5) | 494 (78.2) | ||
| PR status | 0.270 | 1.000 | ||
| PR-negative | 37 (29.8) | 220 (35.0) | ||
| PR-positive | 87 (70.2) | 409 (65.0) | ||
| HER2 status | 0.292 | 1.000 | ||
| HER2-negative | 90 (75.6) | 433 (70.9) | ||
| HER2-positive | 29 (24.4) | 178 (29.1) |
TNM stage TNM classification of malignant tumors, ER Estrogen receptor, PR Progesterone receptor, HER2 Human epidermal growth factor receptor 2. aP-values were calculated for categorical variables by Chi-square test