Table 4.
Characteristics of the patients in internal and external validation groups.
| Variable | Internal validation group (N = 467) | Patients from CHCAMS (n = 167) | Patients from BTH (n = 114) | χ 2 | P value |
| Age, years | 51.2 ± 0.39 | 56.4 ± 0.38 | 47.2 ± 0.82 | ||
| Clinical T stage | 34.200 | 0.002 | |||
| T1 | 9 (1.9) | 7 (4.2) | 10 (8.7) | ||
| T2 | 200 (42.8) | 69 (41.3) | 64 (56.1) | ||
| T3 | 156 (33.8) | 74 (44.3) | 29 (25.4) | ||
| T4 | 102 (21.8) | 17 (10.2) | 11 (9.6) | ||
| Pathological type | 0.519 | 0.771 | |||
| IDC | 449 (96.0) | 161 (96.4) | 111 (97.4) | ||
| Others∗ | 18 (4.0) | 6 (3.6) | 3 (2.6) | ||
| Histologic grade | 9.304 | 0.050 | |||
| I | 7 (1.5) | 9 (5.7) | 10 (8.7) | ||
| II | 329 (70.5) | 98 (58.8) | 65 (57.1) | ||
| III | 131 (28.1) | 60 (35.5) | 39 (34.2) | ||
| Primary tumor response | 20.160 | <0.001 | |||
| PR + SD | 392 (83.9) | 116 (69.5) | 81 (71.1) | ||
| CR | 75 (16.1) | 51 (30.5) | 33 (28.9) | ||
| Axillary response | 10.130 | 0.006 | |||
| Non-pCR | 352 (75.4) | 105 (62.9) | 79 (69.3) | ||
| pCR | 115 (24.6) | 62 (37.1) | 35 (30.7) | ||
| ER | 0.023 | 0.981 | |||
| Negative | 177 (37.9) | 63 (37.7) | 42 (36.8) | ||
| Positive | 290 (62.1) | 104 (62.3) | 72 (63.2) | ||
| PR | 0.089 | 0.965 | |||
| Negative | 187 (40.0) | 65 (38.9) | 44 (38.6) | ||
| Positive | 280 (60.0) | 102 (61.1) | 70 (61.4) | ||
| HER2 | 7.064 | 0.030 | |||
| Negative | 333 (71.3) | 100 (59.9) | 65 (57.0) | ||
| Positive | 134 (28.7) | 67 (40.1) | 49 (43.0) |
Data are presented as mean ± standard deviation and n (%).
∗
Others, invasive lobular carcinoma, invasive papillary carcinoma, mucinous carcinoma. ALN: Axillary lymph node; BTH: Beijing Tiantan Hospital Affiliated to Capital Medical University; CHCAMS: Cancer Hospital of Chinese Academy of Medical Sciences; CR: Complete response; ER: Estrogen receptor; HER2: Human epidermal growth factor receptor 2; IDC: Invasive ductal carcinoma; Clinical T stage: Clinical tumor stage; PR: Partial response; pCR: Pathological complete response; PR: Progesterone receptor; SD: Stable disease.