Table 4.
Multivariable Cox Proportional Hazards Model for Patients With HER2-Positive BC (n = 1,142) According to Trastuzumab-Based Therapy Who Were Diagnosed With Stage I to III BC Between 1997 and 2011 and Were Treated With Adjuvant Chemotherapy
| TTC (days) | OS |
RFS |
DRFS |
||||||
|---|---|---|---|---|---|---|---|---|---|
| HR | 95% CI | P | HR | 95% CI | P | HR | 95% CI | P | |
| Patients treated with trastuzumab (n = 591) | |||||||||
| 31-60 v 0-30 | 0.74 | 0.35 to 1.54 | .41 | 0.98 | 0.6 to 1.62 | .95 | 0.81 | 0.48 to 1.38 | .44 |
| 61+ v 0-30 | 3.09 | 1.49 to 6.39 | .002 | 1.78 | 0.99 to 3.21 | .06 | 1.72 | 0.94 to 3.15 | .08 |
| Patients not treated with trastuzumab (n = 551) | |||||||||
| 31-60 v 0-30 | 1.04 | 0.76 to 1.42 | .82 | 0.84 | 0.63 to 1.11 | .22 | 0.94 | 0.7 to 1.26 | .66 |
| 61+ v 0-30 | 0.86 | 0.57 to 1.29 | .46 | 0.92 | 0.65 to 1.3 | .65 | 0.94 | 0.65 to 1.36 | .73 |
NOTE. Variables in the model include age, race/ethnicity, axillary node involvement, tumor size, tumor grade, surgery, lymphovascular invasion, and number of comorbidities (0, 1-2, 3-4, 5+).
Abbreviations: BC, breast cancer; DRFS, distant relapse-free survival; HER2, human epidermal growth factor receptor 2; HR, hazard ratio; OS, overall survival; RFS, relapse-free survival; TTC, time to initiation of adjuvant chemotherapy.