Table 2.

Univariate and multivariate analyses of clinicopathological factors for failure-free survival

Parameter	Cutoff	Univariate	Multivariate
		P	HR (95 % CI)	P
Age	≥65 years vs <65 years†	0.2151
Initial PSA	≥20 ng/mL vs <20 ng/mL	0.9923
Pathological T stage	≥T3 vs ≤ T2	0.5521
Pathological GS	≥8 vs ≤7	0.0558
Gleason pattern 5	Yes vs no	0.0004*	4.166 (1.351 to 12.76)	0.0133*
Extraprostatic extension	Yes vs no	0.4370
Lymphovascular invasion	Yes vs no	0.0101*	1.005 (0.323 to 3.130)	0.9935
Positive surgical margin	Yes vs no	0.2967
Seminal vesicle invasion	Yes vs no	0.1506
Perineural invasion	Yes vs no	0.0157*	5.876 (1.139 to 107.5)	0.0316*
Timing of SRT	ueSRT vs eSRT vs dSRT	0.0364*	–	–‡
	ueSRT + eSRT vs dSRT	0.0108*	3.117 (1.141 to 7.880)	0.0280*
	ueSRT vs eSRT + dSRT	0.2991
SRT technique	3DCRT vs IMRT	0.4964
Total dose	≥66 Gy vs <66 Gy	0.6278
Concomitant ADT	Yes vs no	0.3118
PSA doubling time	≥6 months vs <6 months	0.0071*	–	–‡

HR hazard ratio, CI confidence interval, PSA prostate-specific antigen, GS Gleason score, SRT salvage radiotherapy, ueSRT ultra-early salvage radiotherapy, eSRT early salvage radiotherapy, dSRT delayed salvage radiotherapy, 3DCRT 3-dimensional conformal radiation therapy, IMRT intensity-modulated radiotherapy, ADT androgen deprivation therapy

†median; *statistically significant; ‡these covariates were excluded from the multivariate analysis (see text)