Table 4. Cox proportional hazards analysis of various clinical and pathological characteristics and PSA kinetic parameters in predicting OS.

		Univariate analysis		Multivariate analysis
		P-value	HR (95% CI)	P-value	HR (95% CI)
Age at diagnosis	≤ 70 vs. > 70	0.269	0.61 (0.25–1.47)
Initial PSA	≤ 100 vs. > 100	0.567	1.27 (0.56–2.88)
T stage	T1+T2 vs. T3+T4	0.394	1.74 (0.49–6.25)
N stage	N0 vs. N1	0.220	1.96 (0.67–5.76)
M stage	M0 vs. M1	0.149	2.47 (0.72–8.40)
Biopsy Gleason score	< 8 vs. ≥ 8	0.072	2.62 (0.92–7.48)
Castration method	LH-RHa vs. surgical	0.526	0.73 (0.27–1.95)
PSAVd	≤ 20 vs. > 20	0.980	1.01 (0.42–2.44)
PSAHL	≤ 0.5 vs. > 0.5	0.026	3.10 (1.15–8.37)	0.026	3.41 (1.16–10.06)
Nadir PSA	≤ 0.4 vs. > 0.4	0.041	8.06 (1.09–59.8)	0.024	10.20 (1.37–76.17)
First PSA at HRPC	≤ 10 vs. > 10	0.229	1.65 (0.73–3.72)
Chemotherapy	Docetaxel vs. mitoxantrone	0.092	0.48 (0.20–1.13)
PSAV	≤ 5.0 vs. > 5.0	0.143	1.52 (0.81–3.73)
PSADT	≤ 2.0 vs. > 2.0	0.001	5.70 (2.01–15.56)	< 0.001	8.12 (2.73–24.16)

Abbreviations: CI, confidence interval; HR, hazard ratio; HRPC, hormone-refractory prostate cancer; LH-RHa, luteinizing hormone-releasing hormone agonist; OS: overall survival; PSA, prostate-specific antigen; PSADT, prostate specific antigen doubling time; PSAHL, prostate-specific antigen half-life during the first hormonal therapy; PSAV, prostate-specific antigen increasing velocity; PSAVd, prostate-specific antigen decreasing velocity during the first hormonal therapy.

Long PSAHL (> 0.5 months), high nadir PSA (> 0.4 ng mL⁻¹) and short PSADT (≤ 2.0 months) were positively correlated with short OS, P < 0.05.