Table 4 –
Multivariate Cox regression of clinical outcomes by subgroups.
Clinical outcome | HR | 95% CI | p value |
---|---|---|---|
Biochemical recurrencea | |||
Total RT dose | 0.95 | (0.91, 0.98) | 0.0043 |
ADT duration | 1.00 | (0.99, 1.01) | 0.48 |
Distant metastasis | |||
Total RT dose | 0.91 | (0.87, 0.96) | 0.0001 |
ADT duration | 1.01 | (1, 1.02) | 0.26 |
Salvage RT | 0.47 | (0.19, 1.15) | 0.099 |
Adjuvant RT | 0.86 | (0.2, 3.72) | 0.84 |
Prostate cancer specific mortality | |||
Total RT dose | 0.93 | (0.87, 0.99) | 0.020 |
ADT duration | 1.01 | (1, 1.02) | 0.051 |
Salvage RT | 0.53 | (0.19, 1.5) | 0.23 |
Adjuvant RT | 0.55 | (0.07, 4.23) | 0.57 |
Overall survival | |||
Total RT dose | 0.98 | (0.95, 1.01) | 0.23 |
ADT duration | 1.00 | (0.99, 1.01) | 0.53 |
Salvage RT | 0.47 | (0.19, 1.15) | 0.099 |
Adjuvant RT | 0.86 | (0.2, 3.72) | 0.84 |
ADT = androgen deprivation therapy; CI = confidence interval; HR = hazard ratio; RT = radiotherapy.
The multivariate Cox regression model derived-hazard ratios are adjusted for age, Gleason score, clinical T-stage, and initial prostate-specific antigen, year of treatment, local salvage (with time to salvage as a covariate), and systemic salvage (with time to salvage as a covariate) and refer to outcomes through 10 yr of follow-up. Hazard ratios <1 suggest the outcome (eg, distant metastasis) has a lower hazard of occurring with higher values of continuous variables (total radiotherapy dose or androgen deprivation therapy duration) or “yes” for binary variables (salvage radiotherapy or adjuvant radiotherapy).