TABLE 4. Cox Proportional Hazard Estimates for Bone Metastasis-Free Survival.
| Univariate Model | Multivariate Model | |||||
|---|---|---|---|---|---|---|
| Full Model | Reduced Model | Reduced Model + TD Covariate | ||||
| Variable | RR (95% CI) p | pH | RR (95% CI) p | pH | RR (95% CI) p | RR (95% CI) p |
| Age (1 yr increase) | 0.96 (0.94,0.98) < 0.001 | 0.97 (0.94,0.99) 0.007 | 0.96 (0.94,0.99) < 0.001 | 0.96 (0.94,0.98) < 0.001 | ||
| 0 kg/m2 ≤ BMI < 25 kg/m2 | ||||||
| 25 kg/m2 ≤ BMI < 30 kg/m2 | 0.97 (0.62,1.51) 0.890 | 0.077 | 0.96 (0.61,1.51) 0.854 | 0.120 | ||
| 30 kg/m2 ≤ BMI | 1.40 (0.89,2.21) 0.147 | 1.37 (0.85,2.19) 0.195 | ||||
| Prior Prostatectomy | 1.49 (1.01,2.19) 0.046 | 1.49 (0.98,2.28) 0.064 | ||||
| Prior Orchiectomy | 1.16 (0.83,1.61) 0.390 | 1.17 (0.83,1.66) 0.376 | ||||
| Gleason Score < 7 | ||||||
| Gleason Score ≥ 7 | 0.81 (0.59,1.12) 0.210 | 0.79 (0.57,1.10) 0.163 | ||||
| KPS 90 – 100 | ||||||
| KPS ≤ 80 | 1.37 (0.70,2.69) 0.359 | 1.21 (0.60,2.45) 0.594 | ||||
| PSA < 13.1 ng/mL | ||||||
| PSA ≥ 13.1 ng/mL | 2.02 (1.48,2.76) < 0.001 | 2.08 (1.51,2.89) < 0.001 | 1.98 (1.45,2.70) < 0.001 | |||
| ≤ 1 yr from study entry | 3.11 (1.92,5.04) < 0.001 | |||||
| > 1 yr from study entry | 1.33 (0.86,2.06) 0.196 | |||||
| Ntx < 13.6 nmol BCE/L | ||||||
| Ntx ≥ 13.6 nmol BCE/L | 1.24 (0.92,1.68) 0.165 | 1.28 (0.93,1.77) 0.125 | ||||
| BAP < 13.2 ng/mL | ||||||
| BAP ≥ 13.2 ng/mL | 1.23 (0.91,1.67) 0.177 | 1.06 (0.76,1.47) 0.748 | ||||
| Albumin (1 g/dL increase) | 0.99 (0.60,1.65) 0.974 | 0.98 (0.58,1.67) 0.940 | ||||
| LDH (1 IU/L increase) | 0.999 (0.994,1.004) 0.606 | 0.999 (0.994,1.004) 0.784 | ||||
| HGB (1 g/dL increase) | 1.01 (0.88,1.16) 0.857 | 0.94 (0.81,1.09) 0.390 | ||||
Note: All models stratified by cancer duration < 7 yrs or ≥ 7 yrs.
pH: Test of homogeneity, p-value
BMI: Body mass index; KPS: Karnofsky performance score
PSA: Prostate specific antigen; Ntx: Serum N-telopeptides; BAP: Bone alkaline phosphatase; LDH: Lactic dehydrogenase; HGB: hemoglobin