Clinical utility of emerging biomarkers in prostate cancer liquid biopsies

Figures & data

Table 1. Clinically (commercially) available urinary liquid biomarker tests for PCa.

Biomarkers	Test	Value	Available as	References
Ratio of PCA3 and KLK3 RNA	Progensa PCA3	PCA3 score is associated with risk of positive (TRUS) biopsy. NPV = 90% (AUC = 0.71).	CE-IVD, FDA-approved	[12–14]
Urinary levels of DLX1 and HOXC6 and clinical parameters*	SelectMDx	SelectMDx score is good predictor of clinically significant PCa (Gleason score ≥7). NPV = 98% (AUC = 0.83).	CLIA-certified LDT, CE-IVD	[15,16]
PCA3 and TMPRSS-ERG RNA levels in urine	Michigan Prostate Score (MiPS)	MiPS score is good predictor of clinically significant PCa (Gleason score ≥7). NPV = 97% (AUC = 0.77).	CLIA-certified LDT	[17–19]
Exosomal RNA in urine	ExoDx Prostate (IntelliScore*)	The Intelliscore is good predictor of clinically significant PCa (Gleason score ≥7). NPV = 94% (AUC = 0.74).	CLIA-certified LDT	[20]

AUC = Area Under the (Receiver Operating Characteristic) Curve. CE-IVD = European Conformity-in vitro Diagnostics. CLIA-certified LDT = Clinical laboratory Improvement Amendments-based clinical laboratory-developed test. FDA = US Food and Drug administration. NPV = Negative Predictive Value. *clinical parameters used in SelectMDx = age, DRE, family history of PCa, prostate volume, sPSA.

Figure 1. Liquid biopsies contain a variety of clinically informative components. Blood samples can be analyzed for circulating tumor cells (CTCs (§3.1), tumor educated platelets (§3.2), exosomes (§3.3) and cell-free nucleic acids (§3.4) with each of them providing valuable numerical and molecular information. Adapted with permission from: Mader & Pantel. Oncol Res Treat 2017; 40: 404–8. S. Karger AG, Basel.

Table 2. Clinically available blood based liquid biomarker tests for PCa.

Biomarker	Source	Assay(s)	Value	Available as	References
CTC enumeration	CTCs	CellSearch	Prognostic and monitoring treatment response.	FDA approved	[23–28]
AR-v7	CTCs	AdnaTest Epic Sciences	Predictive: resistance to abiraterone and enzalutamide.	CLIA-certified LDT	[46]
cfDNA somatic mutations	cfDNA	Multi-gene NGS* panels (e.g. UW-OncoPlex and 73 PCa driver gene panel)	Prognostic and predictive: guiding treatment selection.	CLIA-certified CAP accredited	[111,112]

CAP = College of American Pathologists. CE-IVD = European Conformity-in vitro Diagnostics. CLIA-certified LDT = Clinical laboratory Improvement Amendments-based clinical laboratory-developed test. FDA = US Food and Drug administration. *NGS = next-generation sequencing.

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