TABLE 6.

Multivariate Analyses for nPSA12 as a Dichotomous Covariate (n = 1000; Cutpoint for nPSA12 = 2.0)

	HR (95% CI)	P
Biochemical failure (n = 260)*
Increasing iPSA	1.018 (1.015-1.022)	<.0001
Gleason score ≥7	1.958 (1.491-2.570)	<.0001
Increasing RT dose	0.919 (0.885-0.955)	<.0001
T3	2.130 (1.419-3.199)	.0003
Distant metastasis (n = 50)*
Gleason score ≥7	3.205 (1.782-5.767)	.0001
T3	5.657 (2.918-10.969)	<.0001
nPSA12 >2 ng/mL	3.400 (1.930-5.988)	<.0001
Increasing RT dose	0.904 (0.827-0.988)	.0262
Cause-specific mortality (n = 17)*
nPSA12 >2 ng/mL	3.881 (1.429-10.536)	.0078
T3	4.037 (1.312-12.428)	.0150
Overall mortality (n = 126)*
Gleason score ≥7	1.657 (1.113-2.466)	.0129
Increasing RT dose	0.913 (0.863-0.967)	.0019
Age	1.059 (1.030-1.089)	<.0001

HR indicates hazard ratio; CI, 95% confidence interval; iPSA, initial PSA; RT Dose, radiotherapy dose in Gy; nPSA12, nadir PSA within 12 months.

^*Number of events for each endpoint in parentheses.