Table 3. Independent predictive factors for biochemical recurrence by multivariate analysis.

Variable	Univariate		Multivariate
	HR (95% CI)	p-value	HR (95% CI)	p-value
Clinical stage
cT1	Reference		Reference
cT2	1.318 (0.764-2.276)	0.321	1.418 (0.781-2.575)	0.251
cT3	2.384 (1.448-3.928)	0.001	1.792 (1.067-3.008)	0.027
% Cores positive on biopsy
<33	Reference		Reference
33-66	1.812 (1.055-3.114)	0.031	1.194 (0.659-2.164)	0.559
>66	3.427 (1.985-5.917)	<0.001	1.601 (0.816-3.140)	0.171
Nerve-sparing procedure
None	Reference		Reference
Unilateral	0.925 (0.386-2.219)	0.861	1.099 (0.431-2.803)	0.843
Bilateral	0.718 (0.464-1.112)	0.138	0.978 (0.605-1.580)	0.926
Pathologic stage
pT2	Reference		Reference
pT3a	5.061 (2.536-10.099)	<0.001	3.396 (1.633-7.061)	0.001
pT3b	7.260 (3.614-14.585)	<0.001	3.586 (1.543-8.333)	0.003
Pathologic GS
≤7	Reference		Reference
8-10	2.328 (1.525-3.553)	<0.001	1.677 (1.061-2.650)	0.027
Lymph node metastasis	2.905 (1.665-5.068)	<0.001	1.249 (0.620-2.515)	0.534
RRP vs. RARP
RRP	Reference		Reference
RARP 1-250	0.830 (0.467-1.477)	0.527	1.064 (0.583-1.942)	0.839
RARP 251-500	0.924 (0.519-1.646)	0.789	0.857 (0.453-1.622)	0.635
RARP 501-750	0.491 (0.222-1.084)	0.078	0.523 (0.229-1.196)	0.125
RARP 751-1,000	0.459 (0.142-1.478)	0.192	0.683 (0.200-2.335)	0.216
Percent tumor volume	1.020 (1.013-1.028)	<0.001	1.007 (0.996-1.019)	0.216
Positive surgical margin (vs. negative)	2.424 (1.603-3.664)	<0.001	1.077 (0.644-1.803)	0.777

Univariate analyses were performed with all of the pre- and postoperative variables that are presented in Table 1. Multivariate analysis was performed with the statistically significant variables found in the univariate analysis.

HR, hazard ratio; CI, confidence interval; GS, Gleason score; RRP, retropubic radical prostatectomy; RARP, robot-assisted radical prostatectomy.