Definition of Outcome-Based Prostate-Specific Antigen (PSA) Thresholds for Advanced Prostate Cancer Risk Prediction.
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ABSTRACT:
SUBMITTER: Ferraro S
PROVIDER: S-EPMC8305281 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:PURPOSE:To examine whether age-related reference ranges for "normal" prostate-specific antigen (PSA) change (determined in men without prostate cancer) can be used to identify men at high risk of having prostate cancer. METHODS:Subjects were men aged 50-69 years with PSA < 10 ng/mL from the UK-based Prostate Testing for cancer and Treatment (ProtecT) study. Men with prostate cancer were categorized as high or low risk of progression (Low risk: Gleason score ≤ 6 and stage T1-T2a; High risk: Gleason score 7-10 or stage T2C). Men without prostate cancer were those with no histological confirmation of prostate cancer. Previously developed longitudinal reference ranges for normal age-related PSA change were used to calculate an age-specific PSA threshold. We compared the ability of our age-specific PSA threshold to discriminate between high- and no/low-risk prostate cancer with that of two existing thresholds: (i) threshold of PSA = 3 ng/ml for all ages; (ii) National Institute of Clinical Excellence (NICE) guidelines dependent on age-group thresholds (age 50-59: PSA = 3 ng/mL; age 60-70: PSA = 4 ng/mL; age ≥ 70: PSA = 5 ng/mL). RESULTS:We included 823 men with high-risk prostate cancer and 80,721 men with no/low-risk prostate cancer. A threshold of PSA = 3 ng/ml for all ages identified more high-risk prostate cancers, recommending biopsy in 9.8% of men, of which 10.3% (n = 823) had high-risk prostate cancer. Using the NICE guidelines as the threshold for biopsy, 6.9% men were recommended for biopsy, of which 11.9% (n = 668) had high-risk prostate cancer. Using the new age-specific threshold for biopsy, 2.3% men were recommended for biopsy, of which 15.2% (n = 290) had high-risk prostate cancer. The age-specific threshold identified fewer high-risk prostate cancers, but fewer men received unnecessary biopsy. CONCLUSION:There is no benefit to using reference ranges for "normal" PSA that change with age nor the age-specific thresholds suggested by the NICE guidelines. While the age-varying thresholds are more discriminatory, too many high-risk cancers are missed.
| S-EPMC5834577 | biostudies-literature
Project description:The prostate-specific antigen (PSA) assays currently employed for the detection of prostate cancer (PCa) lack the specificity needed to differentiate PCa from benign prostatic hyperplasia and have high false positive rates. The PSA calibrants used to create calibration curves in these assays are typically purified from seminal plasma and contain many molecular forms (intact PSA and cleaved subforms). The purpose of this study was to determine if the composition of the PSA molecular forms found in these PSA standards contribute to the lack of PSA test reliability. To this end, seminal plasma purified PSA standards from different commercial sources were investigated by western blot (WB) and in multiple research grade PSA ELISAs. The WB results revealed that all of the PSA standards contained different mass concentrations of intact and cleaved molecular forms. Increased mass concentrations of intact PSA yielded higher immunoassay absorbance values, even between lots from the same manufacturer. Standardization of seminal plasma derived PSA calibrant molecular form mass concentrations and purification methods will assist in closing the gaps in PCa testing measurements that require the use of PSA values, such as the % free PSA and Prostate Health Index by increasing the accuracy of the calibration curves.
| S-EPMC4766849 | biostudies-other
Project description:Prostate-specific antigen (PSA or kallikrein-related peptidase-3, KLK3) exerts chymotrypsin-like proteolytic activity. The main biological function of PSA is the liquefaction of the clot formed after ejaculation by cleavage of semenogelins I and II in seminal fluid. PSA also cleaves several other substrates, which may explain its putative functions in prostate cancer and its antiangiogenic activity. We compared the proteolytic efficiency of PSA towards several protein and peptide substrates and studied the effect of peptides stimulating the activity of PSA with these substrates. An endothelial cell tube formation model was used to analyze the effect of PSA-degraded protein fragments on angiogenesis. We showed that PSA degrades semenogelins I and II much more efficiently than other previously identified protein substrates, e.g., fibronectin, galectin-3 and IGFBP-3. We identified nidogen-1 as a new substrate for PSA. Peptides B2 and C4 that stimulate the activity of PSA towards small peptide substrates also enhanced the proteolytic activity of PSA towards protein substrates. Nidogen-1, galectin-3 or their fragments produced by PSA did not have any effect on endothelial cell tube formation. Although PSA cleaves several other protein substrates, in addition to semenogelins, the physiological importance of this activity remains speculative. The PSA levels in prostate are very high, but several other highly active proteases, such as hK2 and trypsin, are also expressed in the prostate and may cleave protein substrates that are weakly cleaved by PSA.
| S-EPMC4169579 | biostudies-literature
Project description:Prostate specific antigen (PSA/KLK3) is known to be the chief executor of the fragmentation of semenogelins, dissolution of semen coagulum, thereby releasing sperm for active motility. Recent research has found that semenogelins also play significant roles in sperm fertility by affecting hyaluronidase activity, capacitation and motility, thereby making PSA important for sperm fertility beyond simple semen liquefaction. PSA level in semen has been shown to correlate with sperm motility, suggesting that PSA level/activity can affect fertility. However, no study investigating the genetic variations in the KLK3/PSA gene in male fertility has been undertaken. We analyzed the complete coding region of the KLK3 gene in ethnically matched 875 infertile and 290 fertile men to find if genetic variations in KLK3 correlate with infertility. Interestingly, this study identified 28 substitutions, of which 8 were novel (not available in public databases). Statistical comparison of the genotype frequencies showed that five SNPs, rs266881 (OR = 2.92, P < 0.0001), rs174776 (OR = 1.91, P < 0.0001), rs266875 (OR = 1.44, P = 0.016), rs35192866 (OR = 4.48, P = 0.025) and rs1810020 (OR = 2.08, P = 0.034) correlated with an increased risk of infertility. On the other hand, c.206 + 235 T > C, was more freuqent in the control group, showing protective association. Our findings suggest that polymorphisms in the KLK3 gene correlate with infertility risk.
| S-EPMC5593825 | biostudies-literature
Project description:ObjectiveTo investigate the efficacy and safety of prostate-specific antigen (PSA) testing to screen for prostate cancer.DesignSystematic review and meta-analysis.Data sourcesElectronic search of Cochrane Central Register of Controlled Trials, Web of Science, Embase, Scopus, OpenGrey, LILACS, and Medline, and search of scientific meeting abstracts and trial registers to April 2018.Eligibility criteria for selecting studiesRandomised controlled trials comparing PSA screening with usual care in men without a diagnosis of prostate cancer.Data extractionAt least two reviewers screened studies, extracted data, and assessed the quality of eligible studies. A parallel guideline committee (BMJ Rapid Recommendation) provided input on the design and interpretation of the systematic review, including selection of outcomes important to patients. We used a random effects model to obtain pooled incidence rate ratios (IRR) and, when feasible, conducted subgroup analyses (defined a priori) based on age, frequency of screening, family history, ethnicity, and socioeconomic level, as well as a sensitivity analysis based on the risk of bias. The quality of the evidence was assessed with the GRADE approach.ResultsFive randomised controlled trials, enrolling 721?718 men, were included. Studies varied with respect to screening frequency and intervals, PSA thresholds for biopsy, and risk of bias. When considering the whole body of evidence, screening probably has no effect on all-cause mortality (IRR 0.99, 95% CI 0.98 to 1.01; moderate certainty) and may have no effect on prostate-specific mortality (IRR 0.96, 0.85 to 1.08; low certainty). Sensitivity analysis of studies at lower risk of bias (n=1) also demonstrates that screening seems to have no effect on all-cause mortality (IRR 1.0, 0.98 to 1.02; moderate certainty) but may have a small effect on prostate-specific mortality (IRR 0.79, 0.69 to 0.91; moderate certainty). This corresponds to one less death from prostate cancer per 1000 men screened over 10 years. Direct comparative data on biopsy and treatment related complications from the included trials were limited. Using modelling, we estimated that for every 1000 men screened, approximately 1, 3, and 25 more men would be hospitalised for sepsis, require pads for urinary incontinence, and report erectile dysfunction, respectively.ConclusionsAt best, screening for prostate cancer leads to a small reduction in disease-specific mortality over 10 years but has does not affect overall mortality. Clinicians and patients considering PSA based screening need to weigh these benefits against the potential short and long term harms of screening, including complications from biopsies and subsequent treatment, as well as the risk of overdiagnosis and overtreatment.Systematic review registrationPROSPERO registration number CRD42016042347.
| S-EPMC6283370 | biostudies-literature
Project description:Objectives• To develop a '2010 Partin Nomogram' with total prostate-specific antigen (tPSA) as a continuous biomarker, in light of the fact that the current 2007 Partin Tables restrict the application of tPSA as a non-continuous biomarker by creating 'groups' for risk stratification with tPSA levels (ng/mL) of 0-2.5, 2.6-4.0, 4.1-6.0, 6.1-10.0 and >10.0. • To use a 'predictiveness curve' to calculate the percentile risk of a patient among the cohort.Patients and methods• In all, 5730 and 1646 patients were treated with radical prostatectomy (without neoadjuvant therapy) between 2000 and 2005 at the Johns Hopkins Hospital (JHH) and University Clinic Hamburg-Eppendorf (UCHE), respectively. • Multinomial logistic regression analysis was performed to create a model for predicting the risk of the four non-ordered pathological stages, i.e. organ-confined disease (OC), extraprostatic extension (EPE), and seminal vesicle (SV+) and lymph node (LN+) involvement. • Patient-specific risk was modelled as a function of the B-spline basis of tPSA (with knots at the first, second and third quartiles), clinical stage (T1c, T2a, and T2b/T2c) and biopsy Gleason score (5-6, 3 + 4 = 7, 4 + 3 = 7, 8-10).Results• The '2010 Partin Nomogram' calculates patient-specific absolute risk for all four pathological outcomes (OC, EPE, SV+, LN+) given a patient's preoperative clinical stage, tPSA and biopsy Gleason score. • While having similar performance in terms of calibration and discriminatory power, this new model provides a more accurate prediction of patients' pathological stage than the 2007 Partin Tables model. • The use of 'predictiveness curves' has also made it possible to obtain the percentile risk of a patient among the cohort and to gauge the impact of risk thresholds for making decisions regarding radical prostatectomy.Conclusion• The '2010 Partin Nomogram' using tPSA as a continuous biomarker together with the corresponding 'predictiveness curve' will help clinicians and patients to make improved treatment decisions.
| S-EPMC3082635 | biostudies-literature
Project description:ObjectiveTo validate six previously identified markers among men at increased risk of prostate cancer (African-American men and those with a family history of prostate cancer) enrolled in the Prostate Cancer Risk Assessment Program (PRAP), a prostate cancer screening study.Patients and methodsEligibility criteria for PRAP include age 35-69 years with a family history of prostate cancer, African-American ethnicity regardless of family history, and known BRCA gene mutations. The genome-wide association study markers assessed included rs2736098 (5p15.33), rs10993994 (10q11), rs10788160 (10q26), rs11067228 (12q24), rs4430796 (17q12) and rs17632542 (19q13.33). Genotyping methods included either the Taqman(®) single nucleotide polymorphism (SNP) genotyping assay (Applied Biosystems, Foster City, CA, USA) or pyrosequencing. Linear regression models were used to evaluate the association between individual markers and log-transformed baseline PSA levels, while adjusting for potential confounders.ResultsA total of 707 participants (37% Caucasian, 63% African-American) with clinical and genotype data were included in the analysis. Rs10788160 (10q26) was strongly associated with PSA levels among Caucasian participants in the high-risk group (P < 0.01), with a 33.2% increase in PSA level with each A-allele carried. Furthermore, rs10993994 (10q11) was found to be associated with PSA level (P = 0.03) in Caucasian men in the high-risk group, with a 15% increase in PSA level with each T-allele carried. A PSA adjustment model based on allele carrier status at rs10788160 and rs10993994 was proposed, specific to high-risk Caucasian men.ConclusionsGenetic variation at 10q may be particularly important in personalizing the interpretation of PSA level for Caucasian men in the high-risk group. Such information may have clinical relevance in shared decision-making and individualized prostate cancer screening strategies for Caucasian men in the high-risk group, although further study is warranted.
| S-EPMC3830710 | biostudies-literature
Project description:Galectin-3 is a multivalent carbohydrate-binding protein involved in cell adhesion, cell cycle control, immunomodulation, and cancer progression, including prostate cancer. Galectin-3 function is regulated by proteolytic cleavage that destroys galectin-3 multivalency while preserving carbohydrate-binding activity. In human semen, galectin-3 is present in seminal plasma and is also associated with prostasomes, exosome-like vesicles secreted by the prostate. In the current study, we characterized the proteolytic activity that cleaves galectin-3 in human seminal plasma.An in vitro assay was developed to investigate galectin-3 cleavage in seminal plasma. The effect of protease inhibitors, divalent ion chelators, and Zn(2+) on the cleavage activity was determined. Proteases enriched from seminal plasma were tested for their ability to cleave galectin-3. Affinity purification and microsequence analysis were used to identify the cleavage site in galectin-3.Galectin-3 was identified in human seminal plasma in an intact and truncated form. Gelatinases enriched from seminal plasma did not cleave galectin-3. Inhibitor studies indicated that the galectin-3 cleavage activity in seminal plasma is a Zn(2+) sensitive, serine protease. Prostate specific antigen (PSA) was demonstrated to cleave galectin-3 between tyrosine¹??-glycine¹?? and produce a functionally active, monovalent lectin.PSA is a chymotrypsin-like serine protease secreted by the prostatic epithelium and normally functions in liquefaction of semen following ejaculation. Furthermore, PSA is implicated in the promotion of localized prostate tumors and bone metastases by its roles in immunomodulation, invasion, and apoptosis. Our results indicate that PSA regulates galectin-3 in human semen and may regulate galectin-3 function during prostate cancer progression.
| S-EPMC3606048 | biostudies-literature
Project description:External beam radiation therapy is a widespread treatment for prostate cancer. The ensuing patient follow-up is based on the evolution of the prostate-specific antigen (PSA). Serum levels of PSA decay due to the radiation-induced death of tumour cells and cancer recurrence usually manifest as a rising PSA. The current definition of biochemical relapse requires that PSA reaches nadir and starts increasing, which delays the use of further treatments. Also, these methods do not account for the post-radiation tumour dynamics that may contain early information on cancer recurrence. Here, we develop three mechanistic models of post-radiation PSA evolution. Our models render superior fits of PSA data in a patient cohort and provide a biological justification for the most common empirical formulation of PSA dynamics. We also found three model-based prognostic variables: the proliferation rate of the survival fraction, the ratio of radiation-induced cell death rate to the survival proliferation rate, and the time to PSA nadir since treatment termination. We argue that these markers may enable the early identification of biochemical relapse, which would permit physicians to subsequently adapt patient monitoring to optimize the detection and treatment of cancer recurrence.
| S-EPMC6731509 | biostudies-literature
Project description:Abstract Recent studies show decreasing prostate-specific antigen utilization and increasing incidence of metastatic prostate cancer in the United States after national recommendations against screening in 2012. Yet, whether the increasing incidence of metastatic prostate cancer is consistent in magnitude with the expected impact of decreased screening is unknown. We compared observed incidence of metastatic prostate cancer from the Surveillance, Epidemiology, and End Results program and published effects of continued historical screening and discontinued screening starting in 2013 projected by 2 models of disease natural history, screening, and diagnosis. The observed rate of new metastatic prostate cancer cases in 2017 was 44%-60% of the projected increase under discontinued screening relative to continued screening. Thus, the observed increase in incident metastatic prostate cancer is consistent with the expected impact of reduced screening. Although this comparison does not establish a causal relationship, it highlights the plausible role of decreased screening in the observed trend.
| S-EPMC7791607 | biostudies-literature