Biomarkers in Prostate CancerCurrent clinical implications and

future perspectives

Rui HenriqueServiço de Anatomia Patológica e Centro de Investigação

Instituto Português de Oncologia do Porto Francisco Gentil, E.P.E.

&Departamento de Patologia e Imunologia Molecular

Instituto de Ciências Biomédicas Abel Salazar

Universidade do Porto

Conflicts of interest statement

For the purposes of this presentation and its content, I declare that I have no conflicts of interest

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• Biomarkers in prostate cancer• Why?

• Clinically silent disease at early, curable stages

• Considerable heterogeneity

• Limitation of currently available clinical and pathological parameters

• What for?• Early detection / Diagnosis

• Prognosis

• Prediction of response to therapy

4Li & Dahiya, 2007Mitchell & Neal, 2015

Prostate carcinogenesis: the source for biomarkers?

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Molecular taxonomy of prostate cancer

Barbieri & Tomlins, 2014

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Biomarcador Indicações / desempenho

Prostate Health Index (phi)Distinção entre PCa e condições benignas da próstata em pacientes com PSA entre 4

e 10ng/ml com toque rectal negativo

Progensa PCA3Previsão do resultado de re-biópsia após biópsia negativa; potencial associação com

a agressividade da doença

Mi-Prostatic Score Deteção de PCa em pacientes com níveis de PSA ligeiramente aumentados.

Oncotype DX Preditor independente de doença mais agressiva

ProlarisEstratificação de acordo com risco de progressão da doença quando da realização de

biópsia

DecipherPreditor do risco de metástases a 5 anos ou de recorrência bioquímica, após

prostatectomia radical

ProstarixAuxilio na estratificação pacientes com PSA ligeiramente aumentado com toque

rectal negativo

PAM50 / ProsignaClassificação molecular do PCa (luminal A, luminal B e tipo basal), com implicações

prognósticas e terapêuticas

ConfirmMDxEstimativa de risco de diagnóstico de PCa em re-biopsia após biopsia prostática

negativa

ProCaMEstratificação de risco de diagnóstico de PCa significativo, em pacientes com valores

de PSA entre 2-10ng/ml

Clinically tested biomarkers

Torres-Ferreira, Henrique & Jerónimo, 2016

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• Prostate Health Index (FDA approved)• Its an algorithm based on serum levels of Pro-PSA, free PSA and total PSA:

(p2PSA/fPSA) × PSA½

• Indicated for men with serum PSA of 4-10ng/mL to determine the risk offinding PCa in biopsy

• Using the reference value 27.0, PHI provides 90% clinical sensitivity and31.1% clinical specificity, avoiding 1 in 3 prostate biopsies and detecting90% of prostate neoplasms

• Higher values associate with high risk pathological features and biochemicalrecurrence following prostatectomy

• In the context of active surveillance, it is predictive of PCa reclassificationin subsequent biopsy

Detection / Diagnosis

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• PRoGensa / PCA3 score (FDA approved)• Non-coding RNA, overexpressed specifically in PCa, comparatively with

normal prostate tissue and other urological cancers

• Measured in urine (quantitative RT-PCR, using PSA mRNA PSA as normalizer for input), requiring previous prostatic massage

• Using reference value 25, it displays 77.5% sensitivity and 57.1%specificity for PCa diagnosed in biopsy, reducing up to 50% the numberof unnecessary repeat prostate biopsies

• In the context of active surveillance, it might identify PCa patients withincreased risk of progression

• It increases the identification of “clinically insignificant” and smallvolume PCa

Detection / Diagnosis

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• Mi-Prostate Score – MiPS (CLIA certified)• This test combines serum PSA levels and urine levels of PCA3 and

TMPRSS2-ERG fusion transcript

• It quantitatively predicts the risk of detecting PCa in biopsy, being usedas continuous variable without a cutoff value for reference, and theperformance estimates are 80% sensitivity and 90% specificity

• It is estimated that its use might reduce by 50% the number of prostatebiopsies

• MiPS HG (high-grade, i.e., GS > 6) associates with detection of high-riskPCa in biopsy

• There is no evidence of usefullness in the context of active surveillance

Detection / Diagnosis

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• Prostarix (CLIA certified)• It is based on the analysis of urinary levels of 4 metabolites (sarcosine,

alanine, glycine and glutamate) by means of mass spectometry andliquid chromatography, requiring previous prostatic massage

• It aims to aid in the decision of selecting candidates for prostate biopsythat have negative DRE and slightly elevated serum PSA levels

• This metabolic profile might augment the ability to predict organ-confined PCa as well as the risk of recurrence at 5 years.

Detection / Diagnosis

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• ProCaM• It is based on the quantification of GSTP1, APC and RARB-2 gene

promoter methylation levels, in urine samples

• Indicated for individuals with serum PSA levels between 2.0 and 10.0 ng/ml, displaying 80% sensitivity and 60% specificity for predicting thehistopathological diagnosis of PCa in biopsy

• It outperforms DRE and serum PSA-based tests for predicting PCa in biopsy and it identifies a larger proportion of cases with higher Gleason score (≥ 7)

GS ≥ 7

No PCa

Baden et al., 2011

Detection / Diagnosis

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• ConfirmMDx (CLIA certified)• This test evaluates GSTP1, APC and RASSF1A gene promoter

methylation levels in prostate biopsy tissues (FFPE)

• Owing to the presence of molecular alterations in morphologically normal cells adjacent to tumor foci (“halo effect”), allows for the identification of PCa in tissue samples with normal/benign morphology

• Indicated for cases with negative prostate biopsy, discriminatingindividuals without PCa from those with occult PCa, providing a negative predictive value of 88-90%

• In a study that evaluated the potencial clinical impact of this test, from138 PCa suspects with negative biopsy, only 6 (4%) were re-biopsed.However, there are no long-term follow-up data to assess the real clinical impact.

Detection / Diagnosis

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• Circulating Tumor Cells Test (FDA approved)• It is based on the identification and enumeration of circulating tumor

cells (CTCs) using epithelial markers(EpCAM, CK8/18, CK19)

• Enumeration of CTCs correlates with disease progression, as well as overall and progression-free survival

• In castration-resistant PCa patients, high CTC count (> 5CTCs/7.5ml) isan independent predictive factor of poor prognosis and of higher riskof metastatic spread

• The FDA approved test (CellSearch™) is indicated for monitoring ofpatients with metastasized PCa

Prognosis

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• Oncotype DX Genomic Prostate Score (CLIA certified)• Based on the expression levels of 12 target genes (involved in androgen

signalling, cell organization, proliferation and stromal response) and 5 reference genes, in prostate biopsy tissue samples (FFPE)

• It estimates the risk of high-grade (GS≥4+3) and/or stage (≥pT3) PCa in the prostatectomy specimen, with a predictive value that isindependent of clinicopathological parameters and CAPRA score

• It improves the discrimination among “very low”, “low” and“intermediate” risk Pca, aiding in the selection of candidates for activesurveillance

• It is an independent prognostic factor (adjusted for risk) of time to biochemical recurrence and metastatic progression after radical prostatectomy

Prognosis

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• Prolaris (CLIA certified)• Evaluates the expression levels of 31 genes involved in cell cycle progression

and 15 reference genes, in tissue samples from prostate biopsy or radical prostatectomy (FFPE)

• The CCP (cell cycle progression) score correlates with tumor agressivenessand it is an independent prognostic factor for biochemical recurrence andmetastatic progression

• It predicts for the mortality risk due to PCa at 10 years (< 0.0: 7%; 0.0-1.0: 15%; 1.0-2.0: 36%; > 2.0: 59%)

• In a study that evaluated the potential clinical impact of this test (n=305), in 65% of cases the therapeutic strategy was changed (in 40% of cases it wasaltered from interventional to non-interventional). However, there are no long-term follow-up data to assess the real clinical impact.

Prognosis

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• Decipher (CLIA certified)• It is based on the expression levels of 22 mRNAs involved in several

signalling pathways that are relevant PCa, which are evaluated in tissuesamples from prostate biopsy or radical prostatectomy (FFPE)

• It allows for risk stratification after surgery, predicting the likelihood ofmetastization and of disease-specific mortality, and determine the needfor salvage vs. adjuvant therapy

• In patients with biochemical recurrence, it might be useful for aiding in thedecision of early salvage/multimodal therapy vs. salvage therapy only

• In a study that evaluated the potential clinical impact (12 patients candidate for adjuvant therapy and 12 patients candidate for salvage therapy andexternal beam RT) there was a change in treatment recommendation in 43% and 53% of cases, respectively

Prognosis

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• PAM50 / Prosigna (CLIA certified)• It makes use of the classifier developed for breast cancer, categorizing PCa

into 3 subtypes: luminal A, luminal B and basal type

• The preliminar results (recently published) indicate na association betweenPCa subtype and biology, validating this aproach

• Luminal B subtype displays the worse prognosis:

• However, response to androgen-deprivation therapy seems to besignificantly better in luminal B PCa

Prognosis

10-year bRFS DMFS PCSS OS

Luminal A 41% 73% 89% 82%

Luminal B 29% 53% 78% 69%

Basal 39% 73% 86% 80%

10-year biochemical recurrence-free survival [bRFS]; distant metastasis-free

survival [DMFS]; prostate cancer-specific survival [PCSS]; overall survival [OS]

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• Cell proliferation (Ki67) index• Assessed by immunohistochemistry in tissue samples from prostate

biopsy or radical prostatectomy (FFPE)

• Low cost and easy to implement as immunohistochemistry is a widelyavailable technique in most Pathology Departments/Laboratories

• Several studies have demonstrated independent prognostic value for high Ki67 levels, which have been associated with worse overall, disease-specific and disease-free survival, as well as biochemicalrecurrence-free survival and rate of distant metastases after curativeintent treatment

• There is, however, a wide variability in the results from the severalstudies published to date and a lack of agreement about the mostsignificant cutoff value (5-10%)

Prognosis

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Lobo et al., 2017

Lobo et al., 2017

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• High Ki67, EZH2 and SMYD3 immunoexpression independently predicted PCa patient

outcome, adjusted for standard clinicopathological parameters

• This assessment might assist in discriminating indolent from aggressive PCa, improving

treatment selection

Lobo et al., 2017

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Early detection Diagnosis Therapeutic decision

Prognosis

Monitoring

ProCaM

Prostate Health Index

PRoGensa PCA3

Mi-Prostate Score

Prostarix

ConfirmMDx

Oncotype Dx

Prolaris

Decipher

PAM50

Ki67 index

Prostate Health Index

CTCs

Clinical usefulness of biomarkers in prostate cancer

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• Biomarkers in prostate cancer

– Most of them (if not all!) are complementary of routineclinical and pathological parameters

– They might increment the accuracy of detection, diagnosis, prognostication and prediction of response to therapy

– They are usually expensive and there are no cost-effectiveness studies that may anticipate the real clinicalimpact in the long term

– As a rule, test results convey a relative risk information, that has to be interpreted based on the clinical andpathological context

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• Future perspectives– The use of so-called “liquid biopsies” as source of nucleic

acids, exosomes or CTCs for molecular analyses willprobably expand in the near future

– These samples might provide a better assessment of tumor heterogeneity, as well as less invasive and, potentially, more specific disease monitoring

– Larger confirmatory and validation studies are required to fully support its use in clinical practice, but the sooner westart, the sooner we will know the answer to our doubts!

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• My proposal for the clinical cases– Clinical case #1: raising serum PSA but negative biopsies

• Prostate Health Index: **

• PCA3: **

• MiPS: **

• ConfirmMDx: *** (high negative predictive value)

• Prostarix: *

– Clinical case #2: low-risk PCa: intervention vs. active surveillance

• Prostate Health Index: **

• PCA3: *

• Prolaris: *** (in combination with CAPRA – risk of mortality)

Biomarkers in Prostate CancerCurrent clinical implications and

future perspectives

Rui HenriqueServiço de Anatomia Patológica e Centro de Investigação

Instituto Português de Oncologia do Porto Francisco Gentil, E.P.E.

&Departamento de Patologia e Imunologia Molecular

Instituto de Ciências Biomédicas Abel Salazar

Universidade do Porto