Table 1.
Baseline demographic and clinical characteristics of patients in the whole cohort and those included in this study
| Characteristics | Patients in the whole cohort (n= 1,462) | Patients included in this study (n= 1,112) | P-value |
|---|---|---|---|
| Age, mean ± SD, year | 51.9±9.1 | 52.2±8.8 | 0.408 |
| Education level, n (%) | |||
| High school or below | 1,230 (84.1) | 948 (85.3) | 0.441 |
| Collage or above | 232 (15.9) | 164 (14.7) | |
| Marital status, n (%) | |||
| Married or cohabitation | 1,039 (71.1) | 800 (71.9) | 0.628 |
| Unmarried or divorced or widowed | 423 (28.9) | 312 (21.8) | |
| Menopausal status, n (%) | |||
| Pre-/perimenopausal | 782 (53.5) | 584 (52.2) | 0.633 |
| Postmenopausal | 680 (46.5) | 528 (47.5) | |
| BMI, kg/m2, n (%) | |||
| Underweight (< 18.5) | 78 (5.3) | 54 (4.9) | 0.977 |
| Normal (18.5-22.9) | 709 (48.5) | 540 (48.6) | |
| Overweight (23-24.9) | 287 (19.6) | 221 (19.9) | |
| Obese (≥25) | 388 (26.5) | 297 (26.7) | |
| Number of comorbid condition, n (%) | |||
| None | 901 (61.6) | 685 (61.2) | 0.998 |
| 1 | 371 (25.4) | 284 (25.5) | |
| 2 | 146 (10.0) | 109 (9.8) | |
| ≥3 | 44 (3.0) | 34 (3.1) | |
| AJCC stage at diagnosis, n (%) | |||
| 0-I | 523 (35.8) | 399 (35.9) | 0.358 |
| II | 652 (44.6) | 518 (46.6) | |
| III | 276 (18.9) | 191 (17.2) | |
| Missing | 11 (0.8) | 4 (0.4) | |
| Histology, n (%) | |||
| IDC | 1,227 (83.9) | 938 (84.4) | 0.600 |
| ILC | 42 (2.9) | 33 (3.0) | |
| DCIs | 92 (6.3) | 63 (5.7) | |
| Others | 101 (6.9) | 78 (7.0) | |
| Estrogen receptor status, n (%) | |||
| Negative | 363 (24.8) | 269 (24.2) | 0.552 |
| Positive | 1,057 (72.3) | 818 (73.6) | |
| Missing | 42 (2.9) | 9 (2.2) | |
| Progesterone receptor status, n (%) | |||
| Negative | 605 (41.4) | 449 (40.4) | 0.465 |
| Positive | 810 (55.4) | 635 (57.1) | |
| Missing | 47 (3.2) | 28 (2.5) | |
| HER2 status, n (%) | |||
| Negative | 966 (66.1) | 747 (67.2) | 0.300 |
| Positive | 381 (26.1) | 299 (26.9) | |
| Missing | 115 (7.9) | 66 (5.9) | |
| Treatment, n (%) | |||
| surgery | 1,461 (99.9) | 1,113 (100.0) | 0.903 |
| Chemotherapy | 1,100 (75.2) | 856 (77.0) | 0.306 |
| Radiotherapy | 1,032 (70.6) | 789 (71.0) | 0.840 |
| Endocrine therapy | 1,054 (72.1) | 833 (74.9) | 0.082 |
Abbreviations: AJCC, American Joint Committee on Cancer; BMI, body mass index; DCIS, ductal carcinoma in situ; IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; HER2, human epidermal growth factor receptor 2.