Table 5.
Predictive impact of mammographic density reduction ratio (MDRR) on recurrence-free survival
| Variable | Hazard ratio | 95% Confidence interval | P-value |
|---|---|---|---|
| Age, yr (continuous) | 0.99 | 0.97-1.02 | 0.600 |
| MDRR (%)* | |||
| ≥ 25% | 1.00 | Referent | 0.078 |
| 10%-25% | 1.37 | 0.73-2.58 | 0.327 |
| 0%-10% | 2.09 | 1.07-4.06 | 0.030 |
| < 0% (increased) | 2.17 | 1.08-4.35 | 0.030 |
| Size, cm (continuous) | 1.19 | 1.05-1.35 | 0.007 |
| Lymph node positive | 1.98 | 1.18-3.34 | 0.010 |
| High histologic grade | 1.34 | 0.80-2.24 | 0.261 |
| Chemotherapy done | 0.79 | 0.39-1.60 | 0.519 |
| Ki-67 ≥ 10% | 0.60 | 0.33-0.94 | 0.029 |
Cox proportional hazard regression model for recurrence-free survival. Risk of recurrence was analyzed using the group with the greatest reduction (MDRR ≥ 25%) as the reference. *MDRR = (pre-treatment MD - post-treatment MD) × 100/pre-treatment MD.