TABLE 2.
Multivariable Cox Proportional Hazards Analysis Models predicting Biochemical recurrence‐free survival, Distant metastasis‐free survival, and Overall survival following EBRT treatment (n = 405 a – c )
| Patient characteristic | Biochemical recurrence‐free survival (BRFS) | Distant metastasis‐free survival (DMFS) | Overall survival (OS) | |||
|---|---|---|---|---|---|---|
| HR (95% CI) | p‐value | HR (95% CI) | p‐value | HR (95% CI) | p‐value | |
| Age at EBRT (years) | 1.01 (0.96, 1.06) | 0.84 | 0.98 (0.9, 1.1) | 0.64 | 1.05 (1.02, 1.08) | 0.001 |
| Prostate volume b (cubic centimeters, cc) | NA | NA | NA | NA | ||
| 28.4–36.4 vs. <28.4 | 1.8 (0.6, 5.8) | 0.31 | ||||
| 36.5–48.06 vs. <28.4 | 2.5 (0.8, 7.8) | 0.13 | ||||
| ≥48.07 vs. <28.4 | 4.2 (1.3, 13.9) | 0.02 | ||||
| Self‐reported race | ||||||
| African American vs. Caucasian American | 1.3 (0.6, 2.7) | 0.58 | 2.3 (0.6, 9) | 0.24 | 1.3 (0.8, 2) | 0.29 |
| NCCN risk stratum | ||||||
| Favorable‐Intermediate vs. Low | 1.1 (0.5, 2.3) | 0.84 | 4.2 (1.1, 16.3) | 0.04 | 1.6 (1.1, 2.4) | 0.016 |
| PSA Nadir (ng/ml) | ||||||
| ≥0.2 vs. <0.2 | 4.3 (1.7, 10.6) | 0.002 | 1.6 (0.3, 8.5) | 0.56 | 1.1 (0.7, 1.6) | 0.82 |
| Time to PSA nadir c (years) | ||||||
| <2.3 vs. ≤2.3 | 4.9 (2.3, 10.5) | <0.001 | 0.8 (0.2, 3.8) | 0.76 | 1.7 (1.2, 2.5) | 0.004 |
| PSADT (months) | ||||||
| ≥10 vs. No BCR | NA | NA | 2.8 (0.6, 13.9) | 0.20 | NA | NA |
| <10 vs. No BCR | 33.9 (4.1, 277.5) | 0.001 | ||||
| Major comorbidities | ||||||
| Yes vs. No | 2.1 (1.4, 3.1) | <0.001 | ||||
a
Exclusion of study subjects was made for the following reasons: receipt of secondary HT (n = 68), missing PSA nadir or missing prostate volume information (n = 33).
b
The model was also adjusted for primary treatment year, primary treatment type, and primary treatment technique.
c
Time to PSA nadir was categorized using the median split for time from RT to PSA nadir (in years).
Bold indicates significant values of p < 0.05.