Table 2.
Univariate and multivariate analysis of disease‐specific survival (DSS)
| Variables | Univariate analysis | Multivariate analysis | |||
|---|---|---|---|---|---|
| HR (95% CI) | P | HR (95% CI) | P | ||
| Year of diagnosis | 1990–1999 | Reference | – | Reference | – |
| 2000–2009 | 0.840 (0.831–0.848) | <0.01 | 0.923 (0.907–0.938) | <0.01 | |
| Age at diagnosis | 15–49 | Reference | – | Reference | – |
| 50–85+ | 2.120 (2.092–2.147) | <0.01 | 2.330 (2.299–2.361) | <0.01 | |
| Race | White | Reference | – | Reference | – |
| Black | 1.398 (1.377–1.419) | <0.01 | 1.244 (1.225–1.263) | <0.01 | |
| Othera | 0.694 (0.680–0.708) | <0.01 | 0.729 (0.715–0.744) | <0.01 | |
| Marital status | Married | Reference | – | Reference | – |
| Unmarriedb | 1.010 (0.996–1.025) | 0.159 | 1.014 (0.999–1.029) | 0.066 | |
| Laterality | Left | Reference | – | Reference | – |
| Right | 0.991 (0.982–1.001) | 0.068 | 1.000 (0.991–1.009) | 0.965 | |
| Histologic type | PLC | Reference | – | Reference | – |
| IDC | 0.691 (0.534–0.893) | <0.01 | 0.815 (0.630–1.055) | 0.120 | |
| Grade | I | Reference | – | Reference | – |
| II | 1.2947 (1.274–1.315) | <0.01 | 1.154 (1.136–1.172) | <0.01 | |
| III | 1.667 (1.642–1.693) | <0.01 | 1.365 (1.342–1.387) | <0.01 | |
| AJCC stage | I | Reference | – | Reference | – |
| II | 1.350 (1.334–1.366) | <0.01 | 1.604 (1.553–1.656) | <0.01 | |
| III | 2.699 (2.662–2.736) | <0.01 | 2.423 (2.327–2.523) | <0.01 | |
| IV | 10.760 (10.561–10.963) | <0.01 | 4.469 (4.331–4.613) | <0.01 | |
| LN status | Negative | Reference | – | Reference | – |
| Positive | 1.833 (1.813–1.853) | <0.01 | 1.188 (1.170–1.206) | <0.01 | |
| ER status | Negative | Reference | – | Reference | – |
| Positive | 0.804 (0.795–0.813) | <0.01 | 0.944 (0.930–0.959) | <0.01 | |
| PR status | Negative | Reference | – | Reference | – |
| Positive | 0.758 (0.750–0.767) | <0.01 | 0.868 (0.855–0.880) | <0.01 | |
| Surgery type | No surgery | Reference | – | Reference | – |
| Lumpectomy | 0.145 (0.142–0.148) | <0.01 | 0.604 (0.590–0.619) | <0.01 | |
| Mastectomy | 0.226 (0.221–0.230) | <0.01 | 0.690 (0.674–0.706) | <0.01 | |
| Radiation | No | Reference | – | Reference | – |
| Yes | 0.590 (0.584–0.595) | <0.01 | 0.688 (0.681–0.695) | <0.01 | |
Multivariate analysis included year of diagnosis, age at diagnosis, race, marital status, laterality, grade, histology, LN status, ER/PR status, surgery type and radiation. HR, hazard ratio; CI, confidence interval; ER, estrogen receptor; PLC, Pleomorphic lobular breast carcinoma; IDC, infiltrating ductal carcinoma; LN, lymph node; PR, progesterone receptor. The bold number of p‐value is statistically significant
a
Including American Indian, Alaska Native, Asian, Pacific Islander and others–unspecified.
b
Including divorced, separated, single (never married), and widowed.