Table 3 –
Kaplan-Meier analysis and multivariate Cox regression of clinical outcomes.
| Kaplan-Meier analysisa | Multivariate Cox regression | ||||
|---|---|---|---|---|---|
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|
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| Clinical outcome | 5-yr | 10-yr | HR | 95% CI | p value |
| Biochemical recurrence | |||||
|
| |||||
| EBRT vs RP (%) | 28.2% vs 73.6a | 39.7% vs 83.8b | 0.21 | (0.14, 0.32) | <0.0001 |
|
| |||||
| EBRT + BT vs EBRT (%) | 17.1% vs 28.2 | 30.0% vs 39.7 | 0.76 | (0.44, 1.32) | 0.33 |
|
| |||||
| EBRT + BT vs RP (%) | 17.1% vs 73.6a | 30.0% vs 83.8b | 0.16 | (0.09, 0.28) | <0.0001 |
|
| |||||
| Distant metastasis | |||||
|
| |||||
| EBRT vs RP (%) | 21.3 vs 20.9 | 33.3 vs 38.5 | 0.78 | (0.45, 1.35) | 0.37 |
|
| |||||
| EBRT + BT vs EBRT (%) | 5.4 vs 21.3a | 10.2 vs 33.3a | 0.30 | (0.12, 0.72) | 0.008 |
|
| |||||
| EBRT + BT vs RP (%) | 5.4 vs 20.9a | 10.2 vs 38.5a | 0.23 | (0.09, 0.6) | 0.003 |
|
| |||||
| Prostate cancer specific mortality | |||||
|
| |||||
| EBRT vs RP (%) | 8.4%vs 8.3 | 19.5 vs 21.5 | 0.75 | (0.34, 1.65) | 0.47 |
|
| |||||
| EBRT + BT vs EBRT (%) | 4.4 vs 8.4 | 11.9 vs 19.5 | 0.64 | (0.24, 1.71) | 0.37 |
|
| |||||
| EBRT + BT vs RP (%) | 4.4 vs 8.3 | 11.9 vs 21.5 | 0.48 | (0.16, 1.4) | 0.18 |
|
| |||||
| Overall survival | |||||
|
| |||||
| EBRT vs RP (%) | 79.9 vs 90.3 | 65.3 vs 72.1 | 1.07 | (0.58, 1.98) | 0.82 |
|
| |||||
| EBRT + BT vs EBRT (%) | 84.7 vs 79.9 | 59.2 vs 65.3 | 0.99 | (0.58, 1.69) | 0.98 |
|
| |||||
| EBRT + BT vs RP (%) | 84.7 vs 90.3 | 59.2 vs 72.1 | 1.06 | (0.53, 2.12) | 0.86 |
CI = confidence interval; BT = brachytherapy; EBRT = external beam radiotherapy; HR = hazard ratio; RP = radical prostatectomy; RT = radiotherapy.
The Kaplan-Meier analysis was not adjusted for age, Gleason score, clinical T stage, or initial prostate-specific antigen, and comparisons between cohorts was performed using the log-rank test. The multivariate Cox regression model derived-hazard ratios are adjusted for age, Gleason score, clinical T-stage, 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 (Cox analysis for outcomes through 5 yr of follow-up can be found in Supplementary Table 2). For example, a hazard ratio <1 for the comparison external beam radiotherapy versus radical prostatectomy suggests that the given outcome (eg, biochemical recurrence) has a lower hazard of occurring with external beam radiotherapy versus with radical prostatectomy.
These comparisons showed statistically significant differences on Kaplan-Meier survival analysis.