Biomarkers for Prostate Cancer: Present Challenges and Future Opportunities

Figures & data

Figure 1.  Proposed algorithm for prostate cancer management.

MRI: Magnetic resonance imaging; PCA3: Prostate cancer antigen 3; PSA: Prostate specific antigen; PSAD: PSA density; PSADT: PSA doubling time; PSAV: PSA velocity; TRUS: Transrectal ultrasound.

Table 1.  Description of prostate-specific antigen-based markers utilized in clinical practice for prostate cancer diagnosis.

Marker	Description
Age-adjusted PSA	Age-specific reference limits for serum total PSA stratified by race (i.e., Caucasian, African–American)
PSA doubling time	Time in months or years for the total PSA to double
PSA velocity	The rate of change of PSA measured in ng/ml per year (change in PSA over time)
Free PSA	Serum PSA unbound to alpha-1-anti-chymotrypsin
Percent-free PSA	Ratio of free PSA to total PSA
ProPSA	The precursor of PSA, which is an inactive 224-amino acid protein secreted by prostatic cells
PSA density	Total PSA divided by PSA volume (length × width × height × π/6) in ml or cc

PSA: Prostate-specific antigen.

Table 2.  Commercially available biomarkers utilized in clinical practice for prostate cancer diagnosis.

Panel	Specimen	Description	AUC for PCa detection	Sensitivity (%)	Specificity (%)	Ref.
PCA3	Urine	Measures noncoding RNA only expressed in human prostate tissue	0.658	66	76	[34]
PHI	Serum	Combines total, free and (-2)proPSA	0.703	80	45	[35]
4Kscore^®	Serum	Consists of total PSA, free PSA, intact PSA and KLK2	0.711	–	–	[36]
ConfirmMDx^®	Prostate biopsy tissue	Measures the degree of methylation of GSTP1, APC and RASSF1	–	68	64	[37]

AUC: Area under curve; PCa: Prostate cancer; PHI: Prostate health index; PSA: Prostate-specific antigen.

Table 3.  Commercially available RNA-based gene panels utilized in clinical practice for prostate cancer prognosis.

Panel	Company	Tissue type	Number of genes	End point	Ref.
Prolaris^®	Myriad Genetics	Radical prostatectomy, prostate biopsy	31	BCR, DSS, MFS	[140]
Oncotype DX^®	Genomic Health Inc.	Radical prostatectomy, prostate biopsy	17	BCR, adverse RP pathology, MFS	[148]
Decipher^®	GenomeDX Biosciences	Radical prostatectomy	22	BCR, DSS, MFS	[149]

BCR: Biochemical recurrence; DSS: Disease-specific survival; MFS: Metastasis-free survival; RP: Radical prostatectomy.

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