Table. Multivariable Cox Proportional Hazards Regression Models of Treatment Interruption and Recurrence-Free Survival.
| Variable | No. (%) | Unadjusted HR (95% CI) | P value | Adjusted HRa (95% CI) | P value | |
|---|---|---|---|---|---|---|
| Total patients | Total events | |||||
| Model 1 | <.001 | .01 | ||||
| Trastuzumab interruption | ||||||
| No | 1212 (87) | 153 (78) | 1 [Reference] | 1 [Reference] | ||
| Yes | 184 (13) | 44 (22) | 1.94 (1.39-2.72) | 1.56 (1.10-2.21) | ||
| Model 2 | ||||||
| Trastuzumab interruption (by indication) | ||||||
| No | 1212 (87) | 153 (78) | 1 [Reference] | 1 [Reference] | ||
| Yes, cardiac | 124 (9) | 29 (15) | 1.83 (1.23-2.72) | .003 | 1.47 (0.98-2.20) | .07 |
| Yes, noncardiac | 60 (4) | 15 (8) | 2.21 (1.30-3.75) | .003 | 1.78 (1.03-3.08) | .04 |
| Model 3 | ||||||
| Trastuzumab interruption (by dose) | ||||||
| No | 1212 (87) | 153 (78) | 1 [Reference] | 1 [Reference] | ||
| Yes, ≤56 mg/kg | 60 (4) | 16 (8) | 2.24 (1.34-3.76) | .002 | 1.96 (1.16-3.33) | .01 |
| Yes, >56 mg/kg | 124 (9) | 28 (14) | 1.81 (1.21-2.70) | .004 | 1.39 (0.92-2.11) | .12 |
Abbreviation: HR, hazard ratio.
a
All models were adjusted for age, estrogen receptor status, progesterone receptor status, anthracycline exposure, cancer stage, hypertension, and diabetes.