Table 3.
Hazard ratio and estimates of survival according to mammographic breast density reduction stratified by treatment groups.
| TAM-only (n=476) | TAM + OFS (n=468) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Survival | MDR | 8-year survival rate | HRa (95% CI) | P | MDR | 8-year survival rate | HRa (95% CI) | P | P interaction |
| DFS | MDR-negative (n=370) | 80.2% | Ref. | MDR-negative (n=379) | 82.0% | Ref. | 0.039 | ||
| MDR-positive (n=106) | 80.2% | 1.03 (0.64–1.63) | 0.917 | MDR-positive (n=89) | 93.1% | 0.37 (0.16–0.85) | 0.019 | ||
| OS | MDR-negative (n=370) | 95.6% | Ref. | MDR-negative (n=379) | 96.4% | Ref. | NA | ||
| MDR-positive (n=106) | 97.1% | 0.88 (0.33–2.39) | 0.809 | MDR-positive (n=89) | 100% | NA | NA | ||
| RFS | MDR-negative (n=370) | 83.7% | Ref. | MDR-negative (n=379) | 85.0% | Ref. | 0.054 | ||
| MDR-positive (n=106) | 82.3% | 1.19 (0.73–1.95) | 0.489 | MDR-positive (n=89) | 92.7% | 0.43 (0.18–1.00) | 0.050 | ||
| DMFS | MDR-negative (n=370) | 85.0% | Ref. | MDR-negative (n=379) | 87.5% | Ref. | 0.108 | ||
| MDR-positive (n=106) | 87.2% | 0.97 (0.55–1.72) | 0.924 | MDR-positive (n=89) | 95.4% | 0.35 (0.12–0.97) | 0.043 | ||
| LRRFS | MDR-negative (n=370) | 90.2% | Ref. | MDR-negative (n=383) | 92.3% | Ref. | 0.081 | ||
| MDR-positive (n=106) | 91.1% | 0.96 (0.49–1.89) | 0.900 | MDR-positive (n=87) | 97.4% | 0.21 (0.05–0.86) | 0.030 | ||
a
Hazard ratio with its associated 95% CI was estimated using the Cox regression model adjusted for age, tumor size, lymph node status, tumor grade, and HER2 status.
DFS, disease-free survival; DMFS, distant metastasis-free survival; HR, hazard ratio; LRRFS, locoregional-free survival; MDR, mammographic breast density reduction; OS, overall survival; RFS, recurrence-free survival; TAM + OFS, tamoxifen plus ovarian function suppression group; TAM-only, tamoxifen-only group.