Association of prostate cancer risk alleles with unfavourable pathological characteristics in potential candidates for active surveillance

Genetic associations of visfatin polymorphisms with clinicopathologic characteristics of prostate cancer in Taiwanese males

The most general cancer in men is prostate cancer (PCa), with its risk increasing due to age and obesity. Visfatin, a member of adipokines, is related to cancer progression and metastasis, but its relationship in PCa remains undetermined. In addition, no knowledge is available regarding relations between visfatin polymorphisms and clinicopathological characteristics in PCa. We sought to investigate the functions of four visfatin gene polymorphisms and clinicopathological characteristics on the hazard of developing PCa in 695 Taiwanese males with PCa. Carriers of the GA+AA heterozygote of SNP rs61330082 were at a markedly higher risk of biochemical recurrence than those with the GG genotype. Visfatin rs61330082 and rs11977021 were related with a high risk of perineural invasion, lymphovascular invasion, and biochemical recurrence in prostate-specific antigen (PSA) > 10 PCa patients. The Cancer Genome Atlas database noted that visfatin mRNA level did not prominently differ with pathological T/N stage and overall survival. This finding is the first to document a connection between visfatin polymorphisms and clinicopathological characteristics of PCa in Taiwanese males.

Impact of Family History and Germline Genetic Risk Single Nucleotide Polymorphisms on Long-Term Outcomes of Favorable-Risk Prostate Cancer

PURPOSE

Family history and germline genetic risk single nucleotide polymorphisms (SNPs) have been separately shown to stratify lifetime risk of prostate cancer. Here, we evaluate the combined prognostic value of family history of prostate and other related cancers and germline risk SNPs among patients with favorable-risk prostate cancer.

MATERIALS AND METHODS

A total of 1367 participants from the prospective Health Professionals Follow-up Study diagnosed with low- or favorable intermediate-risk prostate cancer from 1986 to 2017 underwent genome-wide SNP genotyping. Multivariable Cox regression was used to estimate the association between family history, specific germline risk variants, and a 269 SNP polygenic risk score with prostate cancer‒specific death.

RESULTS

Family history of prostate, breast, and/or pancreatic cancer was observed in 489 (36%) participants. With median follow-up from diagnosis of 14.9 years, participants with favorable-risk prostate cancer with a positive family history had a significantly higher risk of prostate cancer‒specific death (HR 1.95, 95% CI 1.15-3.32, P = .014) compared to those without any family history. The rs2735839 (19q13) risk allele was associated with prostate cancer‒specific death (HR 1.81 per risk allele, 95% CI 1.04-3.17, P = .037), whereas the polygenic risk score was not. Combined family history and rs2735839 risk allele were each associated with an additive risk of prostate cancer‒specific death (HR 1.78 per risk factor, 95% CI 1.25-2.53, P = .001).

CONCLUSIONS

Family history of prostate, breast, or pancreatic cancer and/or a 19q13 germline risk allele are associated with an elevated risk of prostate cancer‒specific death among favorable-risk patients. These findings have implications for how family history and germline genetic risk SNPs should be factored into clinical decision-making around favorable-risk prostate cancer.

The role of genetic testing in prostate cancer screening, diagnosis, and treatment

PURPOSE OF REVIEW

This review provides an overview of the current role of genetic testing in prostate cancer screening, diagnosis, and treatment.

RECENT FINDINGS

Recent studies have uncovered few but highly penetrant rare pathogenic mutations (RPMs), in genes, such as BRCA2, with strong prostate cancer risk and outcomes associations. Over 260 single nucleotide polymorphisms (SNPs) have also been identified, each associated with small incremental prostate cancer risk and when combined in a polygenic risk score (PRS), they provide strong prostate cancer risk prediction but do not seem to predict outcomes. Tumor tissue sequencing can also help identify actionable somatic mutations in many patients with advanced prostate cancer and inform on their risk of harboring a germline pathogenic mutation.

SUMMARY

RPM testing, PRS testing, and tumor sequencing all have current and/or potential future roles in personalized prostate cancer care.

Germline Testing for Prostate Cancer Prognosis: Implications for Active Surveillance

Available evidence supports routine implementation of germline genetic testing for many aspects of prostate cancer (PCa) decision making. The purpose of obtaining genetic testing for newly diagnosed men would be focused on identifying mutations that predispose to aggressive PCa. Based on an evidence-based review, the authors review germline rare pathogenic mutations in several genes that are significantly associated with aggressiveness, metastases, and mortality. Then recent studies of these germline mutations in predicting tumor grade reclassification among patients undergoing active surveillance are discussed. Single nucleotide polymorphisms-based polygenic risk scores in differentiating PCa aggressiveness and prognosis are reviewed.

Genetic polymorphism and carbonic anhydrase 9 expression can predict nodal metastatic prostate cancer risk in patients with prostate-specific antigen levels ≤10 ng/ml at initial biopsy

OBJECTIVES

Active surveillance is a common management method for low-risk prostate cancer (CaP). However, devising a method to prevent disease progression is crucial. Carbon anhydrase 9 (CA9) plays a vital role in cell adhesion and intercellular communication correlated to tumor metastasis. Our study explored the impact of CA9 genetic polymorphism on the clinicopathological features and prognosis of CaP.

MATERIALS AND METHODS

In total, 579 patients with CaP who underwent robot-assisted radical prostatectomy were enrolled, 270 of whom had an initial prostate-specific antigen (PSA) level ≤10 ng/ml and 309 had initial one >10 ng/ml. Three single-nucleotide polymorphisms of CA9 gene were examined using real-time polymerase chain reaction assay.

RESULTS

After adjusting the confounding factors, participants carrying at least one G allele at CA9 rs3829078 had a 2.241-fold change in PSA compared with the wild-type carrier (AA), leading to an initial PSA level of ≤10 ng/ml. Furthermore, patients with CaP with an initial PSA level ≤10 ng/ml who carried at least one G allele at CA9 rs3829078 had a 4.532-fold and 3.484-fold risk of lymph node metastasis and lymphovascular invasion, respectively. Moreover, The Cancer Genome Atlas database showed that the CA9 mRNA expression significantly increased N1 disease risk and worsened overall survival trends.

CONCLUSION

The rs3829078 polymorphic genotype of CA9 can predict the risk of lymph node metastasis of CaP with an initial PSA level ≤10 ng/ml. This is the first study to report a correlation between CA9 gene polymorphisms/CA9 mRNA expression and early detection of CaP.

Genetic associations of T cell cancer immune response with tumor aggressiveness in localized prostate cancer patients and disease reclassification in an active surveillance cohort

Determining prostate cancer (PCa) aggressiveness and reclassification are critical events during the treatment of localized disease and for patients undergoing active surveillance (AS). Since T cells play major roles in cancer surveillance and elimination, we aimed to identify genetic biomarkers related to T cell cancer immune response which are predictive of aggressiveness and reclassification risks in localized PCa. The genotypes of 3,586 single nucleotide polymorphisms (SNPs) from T cell cancer immune response pathways were analyzed in 1762 patients with localized disease and 393 who elected AS. The aggressiveness of PCa was defined according to pathological Gleason score (GS) and D'Amico criteria. PCa reclassification was defined according to changes in GS or tumor characteristics during subsequent surveillance biopsies. Functional characterization and analysis of immune phenotypes were also performed. In the localized PCa cohort, seven SNPs were significantly associated with the risk of aggressive disease. In the AS cohort, another eight SNPs were identified as predictors for aggressiveness and reclassification. Rs1687016 of PSMB8 was the most significant predictor of reclassification. Cumulative analysis showed that a genetic score based on the identified SNPs could significantly predict risk of D'Amico high risk disease (P-trend = 2.4E-09), GS4 + 3 disease (P-trend = 1.3E-04), biochemical recurrence (P-trend = 0.01) and reclassification (P-trend = 0.01). In addition, the rs34309 variant was associated with functional somatic mutations in the PI3K/PTEN/AKT/MTOR pathway and tumor lymphocyte infiltration. Our study provides plausible evidence that genetic variations in T cell cancer immune response can influence risks of aggressiveness and reclassification in localized PCa, which may lead to additional biological insight into these outcomes. Abbreviations: PCa, prostate cancer; AS, active surveillance; GS, Gleason score; PSA, prostate specific antigen; TCGA, The Cancer Genome Atlas; SNP, single nucleotide polymorphisms; UFG, unfavorable genotype.

Systematic identification of functionally relevant risk alleles to stratify aggressive versus indolent prostate cancer

Novel approaches for classification, including molecular features, are needed to direct therapy for men with low-grade prostate cancer (PCa), especially men on active surveillance. Risk alleles identified from genome-wide association studies (GWAS) could improve prognostication. Those risk alleles that coincided with genes and somatic copy number aberrations associated with progression of PCa were selected as the most relevant for prognostication.

In a systematic literature review, a total of 698 studies were collated. Fifty-three unique SNPs residing in 29 genomic regions, including 8q24, 10q11 and 19q13, were associated with PCa progression. Functional studies implicated 21 of these single nucleotide polymorphisms (SNPs) as modulating the expression of genes in the androgen receptor pathway and several other oncogenes. In particular, 8q24, encompassing MYC, harbours a high density of SNPs conferring unfavourable pathological characteristics in low-grade PCa, while a copy number gain of MYC in low-grade PCa was associated with prostate-specific antigen recurrence after radical prostatectomy.

By combining GWAS data with gene expression and structural rearrangements, risk alleles were identified that could provide a new basis for developing a prognostication tool to guide therapy for men with early prostate cancer.

Associations Between iCOGS Single Nucleotide Polymorphisms and Upgrading in Both Surgical and Active Surveillance Cohorts of Men with Prostate Cancer

BACKGROUND

Associations have been documented recently between some of the 23 single nucleotide polymorphisms newly discovered with the Collaborative Oncological Gene-environment Study iCOGS array that indicate prostate cancer (PCa) risk and aspects of disease aggressiveness. The utility of these iCOGS SNPs remains to be determined in active surveillance (AS).

OBJECTIVE

To determine associations between iCOGS SNPs and upgrading among men who underwent surgical treatment and AS for low-risk PCa.

DESIGN, SETTING, AND PARTICIPANTS

The genotypes of the 23 iCOGS SNPs were determined for all white subjects with biopsy Gleason score (GS) 6 including 950 men who underwent definitive treatment with surgery and 209 men who elected AS. The clinical and pathologic characteristics were documented for all subjects.

OUTCOME MEASURES AND STATISTICAL ANALYSIS

Men who underwent surgery were grouped according to their pathologic GS (upgraded was defined as GS ≥7; nonupgraded remained GS 6). Men who were enrolled in AS were also grouped according to their GS on subsequent surveillance biopsies. Statistical analyses were performed comparing the genotypes between the upgraded and nonupgraded groups.

RESULTS AND LIMITATIONS

Overall, 31% and 34% of men were upgraded in the surgery and AS cohorts, respectively. Three iCOGS SNPs were significantly associated with the risk of upgrading in the surgical cohort. After correction for multiple testing, only rs11568818 on chromosome 11q22 remained significantly associated with upgrading. Assessment of this allele in the AS cohort reveals that it was present at noteworthy higher frequencies in men with high-grade disease on surveillance biopsies compared with nonupgraded men (p=0.003). This study was primarily limited by the homogeneous patient population.

CONCLUSIONS

This is the first report of a SNP on chromosome 11q22 associated with higher grade disease in a surgical cohort that is also validated for eventual upgrading in a prospective AS cohort.

PATIENT SUMMARY

We examined the relationship between a group of genetic markers and prostate cancer (PCa) aggressiveness in a group of patients who underwent surgery for PCa and a group of patients who were enrolled in active surveillance. We found that these genetic markers helped predict which patients had more aggressive disease in both groups.

Sensitization of radio-resistant prostate cancer cells with a unique cytolethal distending toxin

Cytolethal distending toxin (CDT) produced by Campylobacter jejuni is a genotoxin that induces cell-cycle arrest and apoptosis in mammalian cells. Recent studies have demonstrated that prostate cancer (PCa) cells can acquire radio-resistance when DOC-2/DAB2 interactive protein (DAB2IP) is downregulated. In this study, we showed that CDT could induce cell death in DAB2IP-deficient PCa cells. A combination of CDT and radiotherapy significantly elicited cell death in DAB2IP-deficient PCa cells by inhibiting the repair of ionizing radiation (IR)-induced DNA double-strand break (DSB) during G2/M arrest, which is triggered by ataxia telangiectasia mutated (ATM)-dependent DNA damage checkpoint responses. We also found that CDT administration significantly increased the efficacy of radiotherapy in a xenograft mouse model. These results indicate that CDT can be a potent therapeutic agent for radio-resistant PCa.

Clinical implications of family history of prostate cancer and genetic risk single nucleotide polymorphism (SNP) profiles in an active surveillance cohort

OBJECTIVES

To explore the potential prognostic role of family history (FH) of prostate cancer and prostate cancer risk single nucleotide polymorphisms (SNPs) in patients undergoing active surveillance (AS) for prostate cancer. This is the first study to date, which has investigated the potential prognostic role of SNP profiles in an AS cohort

PATIENTS AND METHODS

FH data were collected from patients in the Royal Marsden Hospital AS study. In all, 39 prostate cancer-risk SNPs identified from published genome wide association studies (GWAS) were genotyped using the Sequenom Platform and TaqMan™ assays from available DNA. The cumulative genetic-risk scores for each patient were then calculated using the weighted effect estimated from previous GWAS (log-additive model). FH status and the genetic-risk scores were assessed against adverse outcomes in AS, time to treatment and adverse histology on repeat biopsy, using univariable and multivariable Cox regression models to address time to treatment; and binary logistic regression to address biopsy upgrade.

RESULTS

Of 471 patients, 55 (13.6%) had adverse histology on repeat biopsies and 145 (30.8%) had deferred treatment. On univariate analysis, there was no significant relationship between FH of prostate cancer in any degree of relation, and adverse histology or time to treatment. For risk score analyses, 386 patients' DNA was studied; and there was also no relationship found between the calculated genetic risk scores and adverse histology or time to treatment (P = 0.573 and P = 0.965, respectively). The retrospective study design and the few events were the main limitation of the study.

CONCLUSIONS

There is currently insufficient data to support the use of FH status or prostate cancer SNP profile risk scores as prognostic factors in AS and these should not be used to influence management decisions. As more genetic variants are discovered this may change and should be reassessed in multicentre AS cohorts.

Improving risk stratification in patients with prostate cancer managed by active surveillance: a nomogram predicting the risk of biopsy progression

OBJECTIVE

To develop a clinical tool that integrates different risk factors and provides individual predictions of the risk of biopsy progression in patients with prostate cancer managed by active surveillance.

MATERIALS AND METHODS

Our analysis included 205 patients on active surveillance, each of whom had had at least two surveillance biopsies. We used the Cox proportional hazard regression model to analyse the association between different risk factors and progression-free survival over successive biopsies. This multivariate model was then used to develop a nomogram. Discrimination and calibration of the nomogram were internally validated using 200 bootstrap resamplings.

RESULTS

The median follow-up of patients free of progression was 4.6 years. A total of 58 (28%) patients experienced progression. Factors significantly associated with progression were: overall number of positive cores in the diagnostic and first surveillance biopsies, race and prostate-specific antigen density. The bootstrapping concordance index of the nomogram including these variables was 81%. The nomogram tended to underestimate the probability of progression but it identified fairly accurately the distinct groups of patients at low, intermediate and high risk of progression.

CONCLUSIONS

In the development cohort, the nomogram was able to separate patients with respect to their risk of biopsy progression. Since accurate risk stratification is essential to optimize patient care, this tool, if external validation confirms its performance, may prove useful for both the counselling and management of patients with low-volume, Gleason 6 prostate cancer.