Table 1.

Characteristics of study group. ABCB1 analysis group was involved in the ABCB1 gene expression and methylation analysis, while TLDA analysis group was profiled for the ABC transporter genes expression. NPT – noncancerous prostate tissue; PCa – prostate cancer; BCR – biochemical recurrence; PSA – prostate-specific antigen

Variable	ABCB1 analysis group		TLDA analysis group
	N = 93		N = 16
	NPT	PCa	NPT	PCa
	N = 15 + 10a	N = 78	N = 6	N = 10
Mean age in years ± SEM	62.13 ± 1.01	60.76 ± 0.85	61.33 ± 1.09	62.9 ± 2.04
Pathological stage
pT2		52		5
pT3		25		5
Gleason score
6		18		3
≥ 7		54		7
Unknown		1
BCR
Yes		20		5
No		53		5
Unknown		5
TMPRSS2-ERG status
Positive		51		6
Negative		27		4
Mean PSA level at diagnosis, ng/ml ± SEM		10.57 ± 1.25		11.07 ± 3.03
Methylation status of ABCB1 promoter
Methylated	4	56		5
Unmethylated	15	22		5
Unknown	6		6
Mean expression of ABCB1, ∆Cq ± SEM	7.50 ± 0.24	8.14 ± 0.13	5.01 ± 0.18	5.61 ± 0.17

^aTen additional samples were included in ABCB1 methylation analysis