Table 2.
Performance of 24 candidate post-biochemical failure risk categorization schemes (BFRC)* in univariable competing risk models for prostate cancer-specific mortality (PCSM) after biochemical failure.
| BFRC model | High risk† | Low risk† | Intermediate risk‡ | BFRC model performance§ | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | PSADT | TTBF | HR | (95% CI) | N | PSADT | TTBF | HR | N | HR | (95% CI) | c-Index | (95% CI) | Rank | P value# | |
| 1 | 97 | <3 | <1 | 6.1 | (3.8–9.8) | 231 | >9 | >4 | 1 | 157 | 2.7 | (1.8–4.3) | 0.724 | (0.685–0.763) | 7 | 0.32 |
| 2 | 113 | <3 | <1.5 | 5.1 | (3.3–7.7) | 267 | >6 | >4 | 1 | 105 | 2.7 | (1.8–4.2) | 0.719 | (0.678–0.760) | 8 | 0.28 |
| 3 | 129 | <3 | <1.5 | 5.6 | (3.5–9.0) | 222 | >9 | >4 | 1 | 134 | 2.7 | (1.7–4.3) | 0.718 | (0.679–0.757) | 9 | 0.15 |
| 4 | 163 | <3 | <2 | 5.2 | (3.2–8.5) | 212 | >9 | >4 | 1 | 110 | 2.8 | (1.6–4.7) | 0.705 | (0.668–0.743) | 13 | 0.013 |
| 5 | 166 | <3 | <2 | 5.1 | (3.2–8.3) | 221 | >12 | >3 | 1 | 98 | 2.9 | (1.7–4.9) | 0.697 | (0.658–0.736) | 17 | 0.007 |
| 6 | 171 | <3 | <2 | 7.3 | (3.9–13.7) | 183 | >12 | >4 | 1 | 131 | 3.9 | (2.1–7.5) | 0.695 | (0.657–0.733) | 19 | 0.004 |
| 7 | 119 | <4 | <1 | 5.7 | (3.7–8.8) | 246 | >9 | >3 | 1 | 120 | 2.6 | (1.7–4.2) | 0.732 | (0.695–0.769) | 1# | — |
| 8 | 119 | <4 | <1 | 7.0 | (4.3–11.3) | 225 | >12 | >3 | 1 | 141 | 3.1 | (1.9–5.1) | 0.730 | (0.693–0.767) | 2 | 0.70 |
| 9 | 120 | <4 | <1 | 8.2 | (4.8–14.1) | 208 | >24 | >3 | 1 | 157 | 3.5 | (2.0–6.0) | 0.729 | (0.692–0.767) | 3 | 0.68 |
| 10 | 188 | <4 | <2 | 8.1 | (4.2–15.5) | 180 | >12 | >4 | 1 | 117 | 3.7 | (1.9–7.3) | 0.705 | (0.669–0.741) | 14 | 0.019 |
| 11 | 196 | <4 | <2 | 7.4 | (3.8–14.7) | 163 | >18 | >4 | 1 | 126 | 2.9 | (1.4–5.9) | 0.697 | (0.661–0.733) | 16 | 0.005 |
| 12 | 196 | <4 | <2 | 8.0 | (3.9–16.4) | 159 | >24 | >4 | 1 | 130 | 3.1 | (1.4–6.5) | 0.697 | (0.660–0.733) | 18 | 0.005 |
| 13 | 150 | <5 | <1 | 7.6 | (4.4–13.0) | 201 | >24 | >3 | 1 | 134 | 3.4 | (1.9–6.0) | 0.727 | (0.691–0.762) | 4 | 0.55 |
| 14 | 149 | <5 | <1 | 5.2 | (3.4–7.9) | 239 | >9 | >3 | 1 | 97 | 2.5 | (1.5–4.1) | 0.726 | (0.691–0.762) | 5 | 0.41 |
| 15 | 149 | <5 | <1 | 6.3 | (3.9–10.3) | 218 | >12 | >3 | 1 | 118 | 3.1 | (1.8–5.1) | 0.726 | (0.690–0.762) | 6 | 0.45 |
| 16 | 201 | <5 | <2 | 8.4 | (4.3–16.6) | 173 | >12 | >4 | 1 | 111 | 3.9 | (1.9–7.9) | 0.700 | (0.665–0.735) | 15 | 0.007 |
| 17 | 209 | <5 | <2 | 7.8 | (3.8–15.9) | 156 | >18 | >4 | 1 | 120 | 3.0 | (1.4–6.4) | 0.693 | (0.658–0.728) | 20 | 0.002 |
| 18 | 209 | <5 | <2 | 8.5 | (4.0–18.2) | 152 | >24 | >4 | 1 | 124 | 3.2 | (1.4–7.2) | 0.693 | (0.658–0.728) | 21 | 0.002 |
| 19 | 141 | <6 | <1 | 5.0 | (3.3–7.7) | 235 | >18 | >2 | 1 | 109 | 2.4 | (1.5–3.9) | 0.714 | (0.676–0.753) | 10 | 0.18 |
| 20 | 184 | <6 | <1 | 6.8 | (3.9–11.8) | 190 | >24 | >3 | 1 | 111 | 2.7 | (1.5–5.0) | 0.713 | (0.679–0.748) | 11 | 0.07 |
| 21 | 140 | <6 | <1 | 4.7 | (3.1–7.1) | 242 | >12 | >2 | 1 | 103 | 2.4 | (1.5–3.8) | 0.712 | (0.674–0.751) | 12 | 0.12 |
| 22 | 220 | <6 | <2 | 7.7 | (3.9–15.0) | 167 | >12 | >4 | 1 | 98 | 3.3 | (1.6–6.9) | 0.691 | (0.657–0.725) | 22 | 0.001 |
| 23 | 228 | <6 | <2 | 7.0 | (3.5–14.3) | 150 | >18 | >4 | 1 | 107 | 2.4 | (1.1–5.3) | 0.685 | (0.651–0.719) | 23 | <0.001 |
| 24 | 228 | <6 | <2 | 7.7 | (3.6–16.4) | 146 | >24 | >4 | 1 | 111 | 2.6 | (1.1–6.0) | 0.685 | (0.651–0.719) | 24 | <0.001 |
PSA: prostate-specific antigen; BFRC: biochemical failure risk categorization; N: number of patients; PSADT: PSA doubling time (months); TTBF: time from biochemical (Phoenix) failure (years); HR: hazard ratio; CI: confidence interval; c-index: Harrell's concordance index.
*BFRC schemes presented include the best and worst three schemes for each high risk PSADT cutpoint from the 72 evaluable schemes.
†Risk is defined by PSADT and/or TTBF ranges specified.
‡PSADT and TTBF ranges are intermediate between the high and low risk ranges.
§Performance assessed by C-index, ranked highest (best) to lowest (worst). Performance against best BFRC compared using paired Student's t-test.
#The best BFRC scheme.
¶A P-value<0.05 for the paired Student's t-test indicates that the BFRC model is significantly worse (less predictive) than the best BRFC model.