Table 1.
Age and clinicopathologic variables at diagnosis by breast cancer subtype in untreated patients
| Variable/subtype | Total (n = 301) | HR+/HER2− (n = 224) | HR+/HER2+ (n = 21) | TNBC (n = 43) | HER2+ (n = 13) | P value* |
|---|---|---|---|---|---|---|
| No. (%) | No. (%) | No. (%) | No. (%) | No. (%) | ||
| Age at diagnosis | 0.047 | |||||
| ≤ 50 | 61 (20.3%) | 38 (17.0%) | 7 (33.3%) | 14 (32.6%) | 2 (15.4%) | |
| > 50 | 240 (79.7%) | 186 (83.0%) | 14 (66.7%) | 29 (67.4%) | 11 (84.6%) | |
| Histology | 0.344 | |||||
| Ductal | 267 (88.7%) | 195 (87.1%) | 20 (95.2%) | 39 (90.7%) | 13 (100%) | |
| Lobular | 34 (11.3%) | 29 (12.9%) | 1 (4.76%) | 4 (9.3%) | 0 (0%) | |
| T stage | 0.793 | |||||
| T1 | 226 (75.1%) | 172 (76.8%) | 17 (81%) | 29 (67.4%) | 8 (61.5%) | |
| T2 | 52 (17.3%) | 37 (16.5%) | 3 (14.3%) | 9 (20.9%) | 3 (23.1%) | |
| T3 | 16 (5.32%) | 10 (4.46%) | 1 (4.76%) | 4 (9.3%) | 1 (7.69%) | |
| T4 | 7 (2.33%) | 5 (2.23%) | 0 (0%) | 1 (2.33%) | 1 (7.69%) | |
| N stage | 0.076 | |||||
| N0 | 241 (80.1%) | 186 (83%) | 15 (71.4%) | 33 (76.7%) | 7 (53.8%) | |
| N1 | 55 (18.3%) | 34 (15.2%) | 5 (23.8%) | 10 (23.3%) | 6 (46.2%) | |
| N2 | 5 (1.66%) | 4 (1.79%) | 1 (4.76%) | 0 (0%) | 0 (0%) | |
| Tumor size | 0.378 | |||||
| ≤ 2 | 226 (75.1%) | 172 (76.8%) | 17 (81.0%) | 29 (67.4%) | 8 (61.5%) | |
| 2–5 | 57 (18.9%) | 42 (18.8%) | 3 (14.3%) | 9 (20.9%) | 3 (23.1%) | |
| > 5 | 18 (5.98%) | 10 (4.46%) | 1 (4.76%) | 5 (11.6%) | 2 (15.4%) | |
| N of positive nodes | 0.025 | |||||
| 0 | 241 (80.1%) | 186 (83.0%) | 15 (71.4%) | 33 (76.7%) | 7 (53.8%) | |
| 1–3 | 39 (13.0%) | 25 (11.2%) | 3 (14.3%) | 7 (16.3%) | 4 (30.8%) | |
| 4–9 | 10 (3.3%) | 4 (1.8%) | 1 (4.8%) | 3 (7.0%) | 2 (15.4%) | |
| ≥ 10 | 11 (3.7%) | 9 (4.0%) | 2 (9.5%) | 0 (0%) | 0 (0%) | |
| Tumor grade | < 0.001 | |||||
| I | 92 (30.6%) | 86 (38.4%) | 5 (23.8%) | 1 (2.33%) | 0 (0%) | |
| II | 136 (45.2%) | 109 (48.7%) | 10 (47.6%) | 13 (30.2%) | 4 (30.8%) | |
| III | 73 (24.3%) | 29 (12.9%) | 6 (28.6%) | 29 (67.4%) | 9 (69.2%) | |
| Stage | 0.361 | |||||
| I | 197 (65.4%) | 153 (68.3%) | 14 (66.7%) | 25 (58.1%) | 5 (38.5%) | |
| II | 80 (26.6%) | 56 (25%) | 5 (23.8%) | 13 (30.2%) | 6 (46.2%) | |
| III | 24 (7.97%) | 15 (6.7%) | 2 (9.52%) | 5 (11.6%) | 2 (15.4%) | |
| ER status | < 0.001 | |||||
| Negative | 71 (23.6%) | 15 (6.7%) | 0 (0%) | 43 (100%) | 13 (100%) | |
| Positive | 230 (76.4%) | 209 (93.3%) | 21 (100%) | 0 (0%) | 0 (0%) | |
| PR status | < 0.001 | |||||
| Negative | 90 (29.9%) | 28 (12.5%) | 6 (28.6%) | 43 (100%) | 13 (100%) | |
| Positive | 211 (70.1%) | 196 (87.5%) | 15 (71.4%) | 0 (0%) | 0 (0%) | |
| HER2 status | < 0.001 | |||||
| Negative | 267 (88.7%) | 224 (100%) | 0 (0%) | 43 (100%) | 0 (0%) | |
| Positive | 34 (11.3%) | 0 (0%) | 21 (100%) | 0 (0%) | 13 (100%) | |
CI confidence interval, ER estrogen receptor, HER2 human epidermal growth factor receptor 2, HR hazard ratio, PR progesterone receptor, No. number, OS overall survival, TNBC triple-negative breast cancer
*P < 0.05 was considered statistically significant