Table 4.
Hazard ratio of contralateral breast cancer derived from univariate and multivariate cox regression model
| Variable | Univariate | Multivariate (including family history) | Multivariate (excluding family history) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| HR | [95% CI] | p value | HR | [95% CI] | p value | HR | [95% CI] | p value | |
| Age | |||||||||
| Age > 40 | 1 | 1 | 1 | ||||||
| Age ≤ 40 | 1.68 | [1.27, 2.22] | < 0.001 | 1.25 | [0.85, 1.84] | 0.26 | 0.98 | [0.85, 1.84] | 0.26 |
| TNBC | |||||||||
| Yes | 2.18 | [1.66, 2.87] | < 0.001 | 1.69 | [1.20, 2.40] | 0.003 | 1.44 | [1.02, 2.02] | 0.036 |
| Ovary cancer | |||||||||
| Yes | 1.06 | [0.15, 7.55] | 0.955 | ||||||
| First-degree relatives with BC | |||||||||
| Yes | 2.92 | [2.08, 4.08] | < 0.001 | 1.95 | [1.23. 3.08] | 0.004 | |||
| T stage | 0.95 | [0.79, 1.14] | 0.575 | ||||||
| N stage | 1.02 | [0.88, 1.19] | 0.796 | ||||||
| Histologic grade | 1.16 | [0.93, 1.44] | 0.182 | ||||||
| Endocrine therapy | |||||||||
| Yes | 0.48 | [0.37, 0.61] | < 0.001 | ||||||
| BRCA test | |||||||||
| Low risk | 1 | 1 | 1 | ||||||
| Not tested | 2.19 | [1.67, 2.86] | < 0.001 | 1.41 | [0.92, 2.16] | 0.115 | 1.88 | [1.29, 2.76] | 0.001 |
| BRCAx | 2.77 | [1.76, 4.35] | < 0.001 | 1.57 | [0.84, 2.91] | 0.154 | 2.6 | [1.56, 1.33] | < 0.001 |
| BRCA mutation | 7.3 | [4.11, 13.0] | < 0.001 | 3.2 | [1.44, 7.14] | 0.004 | 6.17 | [3.23, 11.8] | < 0.001 |
TNBC triple negative breast cancer, HR hazard ratio, CI confidence interval, BC breast cancer