Table 4. Multivariate 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 | 1.193 | 0.896-1.589 | 0.227 | 1.272 | 0.961-1.684 | 0.092 |
| >50 | 1.674 | 1.274-2.200 | < 0.001 | 1.871 | 1.432-2.445 | < 0.001 |
| Race | ||||||
| White | 1 | 1 | ||||
| Black | 1.112 | 0.989-1.251 | 0.075 | 1.121 | 1.004-1.250 | 0.041 |
| Other | 0.858 | 0.714-1.031 | 0.102 | 0.878 | 0.740-1.042 | 0.137 |
| Grade | ||||||
| Well differentiated | 1 | 1 | ||||
| Moderately differentiated | 1.426 | 1.137-1.787 | 0.002 | 1.270 | 1.040-1.551 | 0.019 |
| Poorly/undifferentiated | 2.032 | 1.620-2.550 | < 0.001 | 1.774 | 1.452-2.169 | < 0.001 |
| Tumor size (cm) | ||||||
| ≤2 | 1 | 1 | ||||
| >2-5 | 1.010 | 0.880-1.158 | 0.891 | 0.993 | 0.875-1.126 | 0.908 |
| >5 | 1.220 | 1.060-1.406 | < 0.001 | 1.166 | 1.023-1.328 | 0.021 |
| Nodal stage | ||||||
| N0 | 1 | 1 | ||||
| N1 | 0.827 | 0.735-0.931 | 0.002 | 0.752 | 0.675-0.837 | < 0.001 |
| N2 | 0.881 | 0.751-1.034 | 0.120 | 0.820 | 0.708-0.951 | 0.008 |
| N3 | 0.866 | 0.746-1.005 | 0.058 | 0.793 | 0.691-0.911 | 0.001 |
| Breast cancer subtype | ||||||
| HR+/HER2- | 1 | 1 | ||||
| HR+/HER2+ | 0.859 | 0.746-0.989 | 0.034 | 0.855 | 0.749-0.977 | 0.021 |
| HR-/HER2+ | 1.132 | 0.954-1.342 | 0.155 | 1.227 | 1.050-1.434 | 0.010 |
| HR-/HER2- | 2.618 | 2.324-2.950 | < 0.001 | 2.602 | 2.327-2.910 | < 0.001 |
| Marital status | ||||||
| Unmarried | 1 | 1 | ||||
| Married | 0.749 | 0.682-0.824 | < 0.001 | 0.715 | 0.654-0.782 | < 0.001 |
| Surgery | ||||||
| No | 1 | 1 | ||||
| Yes | 0.451 | 0.409-0.498 | < 0.001 | 0.457 | 0.416-0.501 | < 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.