Table 2.
Simulated trial results for hazard ratios and 95% confidence intervals associated with distant recurrence-free survival at 9 years and 20 years for endocrine vs chemoendocrine therapy by 21-gene expression recurrence score (RS) and age
| Category | Age group, y | Sample size, mean* | Mean hazard ratio (SD)† | Trials showing noninferiority‡ in omission of chemo, % | 9-year distant recurrence-free survival rates |
20-year distant recurrence-free survival rates |
||
|---|---|---|---|---|---|---|---|---|
| Endocrine therapy, mean (SD), % | Chemoendocrine therapy, mean (SD), % | Endocrine therapy, mean (SD), % | Chemoendocrine therapy, mean (SD), % | |||||
| RS 11–25 | ||||||||
| 18–75 | 6711 | 1.15 (0.42) | 75 | 94.0 (0.02) | 94.4 (0.01) | 89.7 (0.07) | 90.7 (0.07) | |
| ≤50 | 2449 | 1.55 (0.74) | 59 | 94.4 (0.02) | 95.9 (0.01) | NA | NA | |
| >50 | 3970 | 1.17 (0.37) | 73 | 95.0 (0.02) | 95.1 (0.01) | NA | NA | |
| RS 16–25 | ||||||||
| 18–75 | 2601 | 1.71 (0.82) | 45 | 91.0 (0.03) | 94.1 (0.01) | 88.3 (0.07) | 90.6 (0.05) | |
| ≤50 | 2155 | 1.79 (0.94) | 43 | 91.6 (0.04) | 94.8 (0.01) | NA | NA | |
| >50 | 3970 | 1.18 (0.73) | 70 | 92.1 (0.04) | 92.8 (0.01) | NA | NA | |
| RS 16–20 | ||||||||
| 18–75 | 4437 | 1.72 (0.88) | 34 | 90.8 (0.04) | 94.2 (0.01) | 85.6 (0.10) | 88.0 (0.08) | |
| ≤50 | 3771 | 1.73 (0.88) | 35 | 91.7 (0.04) | 94.9 (0.01) | NA | NA | |
| >50 | 4866 | 1.15 (0.70) | 70 | 92.3 (0.04) | 92.9 (0.01) | NA | NA | |
| RS 21–25 | ||||||||
| 18–75 | 2473 | 1.76 (0.93) | 30 | 90.7 (0.04) | 94.2 (0.01) | 85.5 (0.10) | 88.1 (0.08) | |
| ≤50 | 2155 | 1.77 (0.97) | 26 | 91.7 (0.04) | 94.9 (0.01) | NA | NA | |
| >50 | 2694 | 1.17 (0.73) | 65 | 92.3 (0.04) | 92.9 (0.01) | NA | NA | |
| RS 26–30 | ||||||||
| 18–75 | 1372 | 1.60 (0.83) | 62 | 91.6 (0.03) | 93.9 (0.01) | 89.7 (0.06) | 91.0 (0.05) | |
| RS 0–100 | ||||||||
| 0–25 | 18–75 | 4310 | 1.14 (0.39) | 75 | 94.2 (0.02) | 94.8 (0.01) | 89.8 (0.06) | 90.5 (0.07) |
| >25 | 18–75 | 1078 | 2.94 (2.03) | 20 | 93.1 (0.01) | 96.5 (0.02) | 88.5 (0.08) | 89.3 (0.08) |
Based on the original TAILORx protocol. NA = data inadequate to model long-term outcomes beyond 9 years in these subgroups; TAILORx = Trial Assigning Individualized Options for Treatment.
Mean (SD) across 1000 trial replications.
Noninferiority was interpreted based on whether the confidence interval on the hazard ratio comparing endocrine vs chemoendocrine therapy contained the noninferiority margin (1.61) or no difference (1.00) according to the TAILORx protocol. The column provides the percentage of trials (out of 1000 simulations) that found noninferiority in the omission of chemotherapy on distant recurrence-free survival under each scenario.