Table 3. Univariate Cox regression analysis of prognostic factors influencing the survival of stage IV breast cancer patients.
| Characteristic | BCSS | OS | ||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P value | HR | 95% CI | P value | |
| Age (years) | ||||||
| <35 | 1 | 1 | ||||
| 35-50 | 1.280 | 1.003-1.633 | 0.047 | 1.320 | 1.044-1.671 | 0.021 |
| >50 | 1.900 | 1.506-2.398 | < 0.001 | 2.065 | 1.649-2.585 | < 0.001 |
| Race | ||||||
| White | 1 | 1 | ||||
| Black | 1.279 | 1.172-1.396 | < 0.001 | 1.295 | 1.194-1.405 | < 0.001 |
| Other | 0.848 | 0.737-0.975 | 0.021 | 0.851 | 0.747-0.969 | 0.015 |
| Grade | ||||||
| Well differentiated | 1 | 1 | ||||
| Moderately differentiated | 1.445 | 1.202-1.738 | < 0.001 | 1.328 | 1.125-1.566 | 0.001 |
| Poorly/undifferentiated | 2.078 | 1.735-2.489 | < 0.001 | 1.863 | 1.585-2.189 | < 0.001 |
| Tumor size (cm) | ||||||
| ≤2 | 1 | 1 | ||||
| >2-5 | 1.042 | 0.928-1.171 | 0.487 | 1.003 | 0.902-1.116 | 0.952 |
| >5 | 1.315 | 1.168-1.481 | < 0.001 | 1.229 | 1.102-1.371 | < 0.001 |
| Nodal stage | ||||||
| N0 | 1 | 1 | ||||
| N1 | 0.946 | 0.862-1.039 | 0.246 | 0.864 | 0.793-0.941 | 0.001 |
| N2 | 0.831 | 0.731-0.945 | 0.005 | 0.777 | 0.690-0.876 | < 0.001 |
| N3 | 0.920 | 0.819-1.034 | 0.164 | 0.846 | 0.759-0.943 | 0.002 |
| Breast cancer subtype | ||||||
| HR+/HER2- | 1 | 1 | ||||
| HR+/HER2+ | 0.856 | 0.770-0.952 | 0.004 | 0.840 | 0.761-0.928 | 0.001 |
| HR-/HER2+ | 1.185 | 1.047-1.342 | 0.007 | 1.187 | 1.057-1.331 | 0.004 |
| HR-/HER2- | 2.534 | 2.324-2.763 | < 0.001 | 2.491 | 2.298-2.701 | < 0.001 |
| Marital status | ||||||
| Unmarried | 1 | 1 | ||||
| Married | 0.701 | 0.652-0.754 | < 0.001 | 0.678 | 0.633-0.725 | < 0.001 |
| Surgery | ||||||
| No | 1 | 1 | ||||
| Yes | 0.480 | 0.443-0.520 | < 0.001 | 0.478 | 0.444-0.515 | < 0.001 |
BCSS, breast cancer-specific survival; CI, confidence interval; HER2, human epidermal growth factor receptor; HR, hormone receptor; HR, hazard ratio; OS, overall survival.