Table 4.
Cox Proportional Hazards Model of Breast Cancer‐Specific Death in an Institutional Cohort of Patients With Stage IV Breast Cancer, 1990 to 2011 (n = 261)
| By Order of Entry into the Model: | HzR (95% CI) | P |
|---|---|---|
| Surgery | ||
| No | Reference | <.001 |
| Yes | 0.51 (0.37, 0.71) | |
| Diagnosis year | ||
| 1990‐1998 | Reference | |
| 1999‐2004 | 0.63 (0.42, 0.94) | .001 |
| 2005‐2011 | 0.55 (0.39, 0.78) | |
| Age, y | ||
| ≥70 | Reference | .018 |
| <70 | 0.62 (0.41, 0.92) | |
| Chemotherapy | ||
| No | Reference | .036 |
| Yes | 0.71 (0.52, 0.98) | |
| Radiation therapy | ||
| No | Reference | NS |
| Yes | 0.75 (0.52, 1.07) | |
| Hormone receptor status | ||
| Negative | Reference | NS |
| Positive | 0.76 (0.51, 1.13) | |
| Race | ||
| Nonwhite | Reference | NS |
| White | 0.95 (0.64, 1.40) |
Abbreviations: HzR, hazard ratio; NS, nonsignificant.