Pathological outcomes associated with the 17q prostate cancer risk variants

Cumulative evidence for relationships between multiple variants of HNF1B and the risk of prostate and endometrial cancers

Background

To provide a synopsis of the current understanding of the association between variants of HNF1B and cancer susceptibility, we conducted a comprehensive research synopsis and meta-analysis to evaluate associations between HNF1B variants and prostate and endometrial cancers.

Results

Eighteen studies totaling 34,937 patients and 55,969 controls were eligible for this meta-analysis. Four variants showed a significant association with the risk of individual cancer. Strong significant associations were found between rs4430796 A and the risk of both prostate cancer (OR = 1.247, p = 2.21 × 10^− 77) and endometrial cancer (OR = 1.217, p = 8.98 × 10^− 16); the AA, AG genotypes also showed strong significant associations with the risk of prostate cancer (OR1 = 1.517, p = 4.46 × 10^− 22; OR2 = 1.180, p = 0.002). There was a strong significant association between rs7501939 G and the risk of prostate cancer (OR = 1.201, p = 9.31 × 10^− 31). Strong significant association was found between rs11649743 G (OR = 1.138, p = 1.08 × 10^− 12), rs3760511 C (OR = 1.214, p = 1.57 × 10^− 19) and the prostate cancer risk;the GG, AG genotypes of rs11649743 also showed strong significant associations with the risk of prostate cancer (OR1 = 1.496, p = 3.32 × 10^− 6; OR2 = 1.276, p = 7.82 × 10^− 6). All the cumulative epidemiological evidence of associations was graded as strong.

Conclusions

Our study summarizes the evidence and helps to reveal that common variants of HNF1B are associated with risk of prostate and endometrial cancer.

Association between single nucleotide polymorphisms on chromosome 17q and the risk of prostate cancer in a Chinese population

In European populations, 7 single nucleotide polymorphisms (SNPs) on chromosome 17q, 3 SNPs on 17q12, and 4 SNPs on 17q24.3 were recently identified to be closely related to the risk of prostate cancer by a genome-wide association study. In Japanese populations, the correlation between 2 SNPs on 17q and the risk of prostate cancer and tumor aggressiveness was also confirmed by a large-scale experiment. However, whether 17q is associated with prostate cancer and its clinical manifestations in Chinese populations is still unknown. Therefore, we conducted a case-control study in a northern Chinese population and tested 2 SNPs, rs4430796 and rs1859962, on 17q in 124 prostate cancer patients and 111 controls using polymerase chain reaction-high resolution melting curve (PCR-HRM) combined with sequencing. We analyzed the association of the 2 SNPs with the risk of prostate cancer as well as patients' lifestyles, onset ages, Gleason scores, PSA levels, and pathologic stages. We found a significant difference in the G allele of SNP rs1859962 (P = 0.035, OR = 1.51, 95% CI = 1.03-2.21) but not in the rs4430796 genotype frequency or allele frequency distribution between prostate cancer patients and the controls (P > 0.05). Neither of the SNPs was significantly associated with the onset age, Gleason score, PSA level, pathologic stage, or other clinical indicators of patients with prostate cancer (P > 0.05). Our results show that polymorphism of the G allele of SNP rs1859962 is associated with the risk of prostate cancer in a Chinese population.

[Prostate cancer: promising biomarkers related to aggressive disease]

BACKGROUND

Although a rapidly growing number of candidate biological markers of prognosis and/or response to specific treatments in prostate cancer, none have to date showed ability to completely prognosticate prostate cancer on evidence based urology.

OBJECTIVE

To review the pertinent literature on the issue.

ACQUISITION OF EVIDENCE

A comprehensive review of the current literature was done focusing on promising biomarkers related to aggressive prostate cancer.

SUMMARY OF EVIDENCE

Combined with the heterogeneous nature of the disease, mixed case series are the most common study design, impeding robust results and the development of an effective therapeutic strategy. Improvement in prostate cancer patient survival requires not only the identification of new therapeutic target based on detailed understanding of the biological mechanisms involved in metastatic dissemination and tumor growth but strong clinical studies as well.

CONCLUSION

Better study design involving potential markers and including well-classified and staged patients with robust methodology and adequate outcomes (mainly survival) are necessary to the field evolution.

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

OBJECTIVE

• To assess whether the carrier status of 35 risk alleles for prostate cancer (CaP) is associated with having unfavourable pathological features in the radical prostatectomy specimen in men with clinically low risk CaP who fulfil commonly accepted criteria as candidates for active surveillance.

PATIENTS AND METHODS

• We studied men of European ancestry with CaP who fulfilled the commonly accepted clinical criteria for active surveillance (T1c, prostate-specific antigen <10 ng/mL, biopsy Gleason ≤6, three or fewer positive cores, ≤50% tumour involvement/core) but instead underwent early radical prostatectomy. • We genotyped these men for 35 CaP risk alleles. We defined 'unfavourable' pathological characteristics to be Gleason ≥7 and/or ≥ pT2b in their radical prostatectomy specimen.

RESULTS

• In all, 263 men (median age 60 [46-72] years) fulfilled our selection criteria for active surveillance, and 58 of 263 (22.1%) were found to have 'unfavourable' pathological characteristics. • The frequencies of three CaP risk alleles (rs1447295 [8q24], P= 0.004; rs1571801 [9q33.2], P= 0.03; rs11228565 [11q13], P= 0.02) were significantly higher in men with 'unfavourable' pathological characteristics. • Two other risk alleles were proportionately more frequent (rs10934853 [3q21], P= 0.06; rs1859962 [17q24], P= 0.07) but did not achieve nominal statistical significance. • Carriers of any one of the significantly over-represented risk alleles had twice the likelihood of unfavourable tumour features (P= 0.03), and carriers of any two had a sevenfold increased likelihood (P= 0.001). • Receiver-operator curve analysis demonstrated an area under the curve of 0.66, suggesting that the number of single nucleotide polymorphisms carried provided discrimination between men with 'favourable' and 'unfavourable' tumour features in their prostatectomy specimen.

CONCLUSION

• In potential candidates for active surveillance, certain CaP risk alleles are more prevalent in patients with 'unfavourable' pathological characteristics in their radical prostatectomy specimen.

Prostate cancer risk alleles significantly improve disease detection and are associated with aggressive features in patients with a "normal" prostate specific antigen and digital rectal examination

BACKGROUND

Several reports suggest that a combination of risk alleles may be associated with prostate cancer (CaP) risk and tumor features. However, their ability to detect CaP and tumor characteristics in patients with a "normal" PSA (<4 ng/ml) and non-suspicious digital rectal examination (DRE) remains to be determined.

METHODS

We examined 203 men of European ancestry with clinical stage T1c CaP diagnosed at a "normal" PSA and 611 healthy volunteer controls. The genotypes for 17 different risk alleles were compared between CaP cases and controls. Additional analyses were used to compare the pathologic features between carriers and non-carriers (defined using best-fit genetic model) of these variants.

RESULTS

All risk alleles were present at an increased frequency in cases with "normal" PSA values and DRE compared to controls. Amongst CaP patients, carriers of an increasing number of genetic risk factors (i.e., alleles and positive family history) were at a significantly increased risk of CaP (P-trend <0.001). Specifically, men with >10 genetic risk factors had an 11.2-fold risk (95% CI 4.3-29.2) of having the disease compared to men with ≤5 variants. There also was a higher frequency of many the variants amongst men with adverse pathologic features.

CONCLUSIONS

A substantial proportion of biopsy-detectable CaP occurs in men with "normal" PSA levels and negative DRE. In this population, CaP risk alleles and family history are significantly associated with CaP risk and may help predict aggressive disease. Future studies are warranted to determine the utility of incorporating these variants into CaP screening programs.

Number of prostate cancer risk alleles may identify possibly 'insignificant' disease

OBJECTIVE

To determine whether the cumulative effects of five prostate cancer risk alleles (three single-nucleotide polymorphisms [SNPs] on chromosome 8Q24 and two SNPs on chromosome 17a) could help to identify possibly 'insignificant' disease.

MATERIALS AND METHODS

We genotyped 629 men of European ancestry who underwent radical prostatectomy at our institution between 2002 and 2007. Possibly 'insignificant' CaP was defined using the Ohori criteria (organ-confined, tumour volume <0.5 mL, Gleason pattern ≤4). Statistical analysis was used to compare patients with 'insignificant' and all other 'significant' cancer based upon genotype. Carrier status for the 5 SNPs were compared between patients with 'insignificant' disease and a separate population of 801 controls without CaP.

RESULTS

Overall, 38 (6.0%) patients with CaP met the Ohori criteria for 'insignificant' disease. Men with 'significant' cancer had a greater frequency of any of the five risk alleles than either patients with 'insignificant' disease or controls. None of the individual alleles genotyped on chromosomes 8 or 17 distinguished between 'significant' and 'insignificant' CaP. However, carriers of two or more risk alleles were more likely to have 'significant' disease.

CONCLUSIONS

Although no single risk allele distinguished 'insignificant' CaP, 'insignificant' disease was nearly three times as likely among carriers of ≤ one risk allele. Future studies are needed to further elucidate the cumulative relationship between CaP risk alleles and CaP aggressiveness.

Inherited variants in the chemokine CCL2 gene and prostate cancer aggressiveness in a Caucasian cohort

PURPOSE

Though C-C chemokine ligand 2 (CCL2) has been shown to play a pivotal role in prostate cancer tumorigenesis and invasion, the role of inherited variation in the CCL2 gene in prostate cancer progression and metastases remains unanswered. This study is aimed to determine the influence of CCL2 germline variants on prostate cancer aggressiveness.

EXPERIMENTAL DESIGN

We performed an association study between six single nucleotide polymorphisms (SNP) in the CCL2 gene and prostate cancer clinicopathologic variables in a large hospital-based Caucasian patient cohort (N = 4,073).

RESULTS

Genetic variation at CCL2 is associated with markers of disease aggressiveness. Three SNPs, each in strong linkage disequilibrium, are associated with a higher (>7) biopsy Gleason score: CCL2 -1811 A/G, -2835 A/C, and +3726 T/C (P = 0.01, 0.03, and 0.04, respectively). The CCL2 -1811 G allele is additionally associated with advanced pathologic stages in patients who underwent radical prostatectomy (P = 0.04). In haplotype analysis, we found that the frequency of a common haplotype, H5, was higher among patients with D'Amico good risk features (P(permutation) = 0.04).

CONCLUSIONS

These results support the influence of CCL2 variants on prostate cancer development and progression.

Binding of pro-prion to filamin A: by design or an unfortunate blunder

Over the last decades, cancer research has focused on tumor suppressor genes and oncogenes. Genes in other cellular pathways has received less attention. Between 0.5% to 1% of the mammalian genome encodes for proteins that are tethered on the cell membrane via a glycosylphosphatidylinositol (GPI)-anchor. The GPI modification pathway is complex and not completely understood. Prion (PrP), a GPI-anchored protein, is infamous for being the only normal protein that when misfolded can cause and transmit a deadly disease. Though widely expressed and highly conserved, little is known about the functions of PrP. Pancreatic cancer and melanoma cell lines express PrP. However, in these cell lines the PrP exists as a pro-PrP as defined by retaining its GPI anchor peptide signal sequence (GPI-PSS). Unexpectedly, the GPI-PSS of PrP has a filamin A (FLNA) binding motif and binds FLNA. FLNA is a cytolinker protein, and an integrator of cell mechanics and signaling. Binding of pro-PrP to FLNA disrupts the normal FLNA functions. Although normal pancreatic ductal cells lack PrP, about 40% of patients with pancreatic ductal cell adenocarcinoma express PrP in their cancers. These patients have significantly shorter survival time compared with patients whose cancers lack PrP. Pro-PrP is also detected in melanoma in situ but is undetectable in normal melanocyte, and invasive melanoma expresses more pro-PrP. In this review, we will discuss the underlying mechanisms by which binding of pro-PrP to FLNA disrupts normal cellular physiology and contributes to tumorigenesis, and the potential mechanisms that cause the accumulation of pro-PrP in cancer cells.

Genetic prostate cancer risk assessment: common variants in 9 genomic regions are associated with cumulative risk

PURPOSE

Five genetic variants along chromosomes 8q24 and 17q have a cumulative association with prostate cancer risk. Our research group previously reported an association between these variants and clinicopathological characteristics. More recently 4 additional prostate cancer susceptibility variants were identified on chromosomes 2p15, 10q11, 11q13 and Xp11. We performed cumulative risk assessment incorporating all 9 genetic variants and determined the relationship of the new variants to clinicopathological tumor features.

MATERIALS AND METHODS

The genotype of 9 variants was determined in 687 men of European ancestry who underwent radical prostatectomy from 2002 to 2008 and in 777 healthy volunteer controls. We compared the incidence of these variants in prostate cancer cases and controls, and assessed their cumulative risk. We also determined the relationship of carrier status for the 4 new variants and clinicopathological tumor features.

RESULTS

Prostate cancer cases had an increased incidence of all 9 risk variants compared to controls. A cumulative model including the 9 single nucleotide polymorphisms provided greater prostate cancer risk stratification than a model restricted to the original 5 single nucleotide polymorphisms described. Specifically men with 6 or more variants were at greater than 6-fold increased risk for prostate cancer. Although 2p15 and 11q13 carriers were more likely to have aggressive features, other clinicopathological features were similar in carriers and noncarriers.

CONCLUSIONS

Genetic variants located in 9 regions have a cumulative association with prostate cancer risk. Identification of an increasing number of single nucleotide polymorphisms may provide greater understanding of their combined relationship with CaP risk and disease aggressiveness.

Does diabetes mellitus modify the association between 17q12 risk variant and prostate cancer aggressiveness?

OBJECTIVE

To examine further the relationship between diabetes mellitus (DM), genotype and prostate cancer aggressiveness. Specifically, we sought to evaluate for effect modification between DM, a newly discovered prostate cancer susceptibility locus on chromosome 17q12 (single nucleotide polymorphism rs4430796) and prostate cancer features.

PATIENTS AND METHODS

In 593 genotyped men treated with radical prostatectomy (RP), we examined RP features stratified by DM and rs4430796 carrier status.

RESULTS

Despite a significantly higher body mass index among patients with DM, individual pathological features were similar between men with and without DM. Using a dominant model, 17q12 carriers were less likely to have DM and more likely to have a RP Gleason score of >or=7. However, the presence or absence of DM did not modify the relationship between 17q12 susceptibility alleles and pathological features.

CONCLUSION

Among 17q12 risk allele carriers, there was no significant relationship between DM and adverse tumour features. However, there were relatively few men with DM (7%) in our RP cohort, particularly compared with its 21% prevalence in the USA population aged >60 years. It is unclear whether this reflects selection bias, genetic protection from prostate cancer among patients with DM, or both. Despite these limitations, the present data suggest that DM alone does not appear to modify any association between 17q12 risk alleles with prostate cancer features.