Table 2.
Results of Multivariate Cox Proportional Hazards Regression Analysis of NSABP B-14 and TransATAC: Meta-Analysis of Evaluable Patients (n = 1,735)
| Covariate | NSABP B-14 (n = 647) |
TransATAC (n = 1,088) |
||
|---|---|---|---|---|
| Hazard Ratio | Wald Test P | Hazard Ratio | Wald Test P | |
| RS linear component | 5.344* | < .001 | 2.766* | .02 |
| RS nonlinear component | .004 | .37 | ||
| Tumor poorly differentiated | 2.845 | .008† | 2.477 | .012† |
| Tumor moderately differentiated | 1.223 | .50† | 1.625 | .14† |
| Tumor size | 1.266‡ | .006 | 1.72‡ | < .001 |
| Age at surgery | 0.892§ | .22 | 0.933§ | .53 |
| Treatment (anastrozole v tamoxifen) | — | — | 0.886 | .48 |
| 1-3 positive nodes (N1-3) | — | — | 1.429 | .083 |
| 4+ positive nodes (N4+) | — | — | 4.548 | < .001 |
Abbreviations: NSABP, National Surgical Adjuvant Breast and Bowel Project; RS, recurrence score; TransATAC, translational research cohort of Arimidex, Tamoxifen Alone or in Combination trial.
Hazard ratio for RS is the ratio of the hazards at 3rd and 1st quartiles of RS, estimated using both the linear and nonlinear components. Overall test for RS P < .001 for NSABP B-14 and for TransATAC.
Trend test for tumor grade P = .008 for NSABP B-14 and P = .023 for TransATAC. Overall test for tumor grade P < .001 for NSABP B-14 and P = .019 for TransATAC.
The hazard ratio for tumor size is for a 1-cm increase.
The hazard ratio for age is for a 10-year increase.