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Journal of Clinical Oncology : Official... Oct 2016
Topics: Humans; Male; Mass Screening; Prostate-Specific Antigen; Prostatic Neoplasms; Research
PubMed: 27432925
DOI: 10.1200/JCO.2016.67.8938 -
Detection of two biological markers of intercourse: prostate-specific antigen and Y-chromosomal DNA.Contraception Dec 2013Although biological markers of women's exposure to semen from vaginal intercourse have been developed as surrogates for risk of infection or probability of pregnancy,...
BACKGROUND
Although biological markers of women's exposure to semen from vaginal intercourse have been developed as surrogates for risk of infection or probability of pregnancy, data on their persistence time and clearance are limited.
STUDY DESIGN
During 2006-2008, 52 couples were enrolled for three 14-day cycles of abstinence from vaginal sex during which women were exposed in the clinic to a specific quantity (10, 100 or 1000 μL) of their partner's semen. Vaginal swabs were collected before and at 1, 6, 12, 24, 48, 72 and 144 h after exposure for testing for prostate-specific antigen (PSA) and Y-chromosome DNA (Yc DNA).
RESULTS
Immediately after exposure to 1000 μL of semen, the predicted sensitivity of being PSA positive was 0.96; this decreased to 0.65, 0.44, 0.21 and 0.07 at 6, 12, 24 and 48 h, respectively. Corresponding predicted sensitivity of being Yc DNA positive was 0.72 immediately postexposure; this increased to 0.76 at 1 h postexposure and then decreased to 0.60 (at 6 h), 0.63 (at 12 h), 0.49 (at 24 h), 0.21 (at 48 h), 0.17 (at 72 h) and 0.12 (at 144 h).
CONCLUSIONS
Overall findings suggest that PSA may be more consistent as a marker of very recent exposure and that Yc DNA is more likely to be detected in the vagina after 12 h postexposure compared to PSA.
Topics: Adult; Biomarkers; Chromosomes, Human, Y; Coitus; DNA; Female; Humans; Male; Prostate-Specific Antigen; Semen; Vagina; Vaginal Smears
PubMed: 24028752
DOI: 10.1016/j.contraception.2013.08.003 -
Tumour Biology : the Journal of the... Sep 2018Prostate cancer presents itself in a heterogeneous way with both aggressive and indolent forms. Despite the controversy surrounding its use, prostate-specific antigen... (Review)
Review
Prostate cancer presents itself in a heterogeneous way with both aggressive and indolent forms. Despite the controversy surrounding its use, prostate-specific antigen screening ultimately leads to a greater number of diagnosed patients. One of the biggest challenges in clinical practice is to select the right patients for biopsy and, among diagnosed patients, to differentiate tumors with an indolent course from those with an unfavorable prognosis, in order to determine the best therapeutic decision for each case, avoiding unnecessary interventions. Currently, several types of biomarkers are available for clinical use in patients with prostate cancer, which include blood-based (prostate-specific antigen, Prostate Health Index®, 4K score®); urine sample-based (PCA3, SelectMDx®, ExoDx Prostate IntelliScore®); and biopsy, transurethral resection, or radical prostatectomy tissue-based (ConfirmMDx®, Oncotype®, Prolaris®, Decipher®). The aim of this review is to provide an overview of the current state of evidence and to highlight recent advances in the evaluation and diagnosis of prostate cancer, with emphasis on biomarkers related to diagnosis and to prognostic evaluation of localized prostate cancer.
Topics: Biomarkers, Tumor; Humans; Male; Prognosis; Prostate; Prostate-Specific Antigen; Prostatic Neoplasms
PubMed: 30204063
DOI: 10.1177/1010428318799255 -
JAMA Network Open Nov 2019
Topics: Biopsy; Chemoprevention; Diabetes Mellitus; Humans; Hypoglycemic Agents; Male; Prostate-Specific Antigen; Prostatic Neoplasms
PubMed: 31693117
DOI: 10.1001/jamanetworkopen.2019.14644 -
Journal of Clinical Oncology : Official... May 2011For patients who elect to have prostate cancer screening, the optimal time to discontinue screening is unknown. Our objective was to describe rates and predictors of...
PURPOSE
For patients who elect to have prostate cancer screening, the optimal time to discontinue screening is unknown. Our objective was to describe rates and predictors of prostate-specific antigen (PSA) screening among older men in the United States.
METHODS
Data were extracted from the population-based 2000 and 2005 National Health Interview Survey (NHIS). PSA screening was defined as a PSA test as part of a routine exam within the past year. Demographic, socioeconomic, and functional characteristics were collected, and a validated 5-year estimated life expectancy was calculated. Age-specific rates of PSA screening were determined, and sampling weight-adjusted multivariate regressions were fitted to determine predictors of screening among men age 70 years or older.
RESULTS
The PSA screening rate was 24.0% in men age 50 to 54 years, and it increased steadily with age until a peak of 45.5% among age 70 to 74 years. Screening rates then gradually declined by age, and 24.6% of men age 85 years or older reported being screened. Among men age 70 years or older, screening rates varied by estimated 5-year life expectancy: rates were 47.3% in men with high life expectancies (≤ 15% probability of 5-year mortality), 39.2% in men with intermediate life expectancies (16% to 48% probability), and 30.7% in men with low life expectancies (> 48% probability; P < .001). In multivariate analysis, estimated life expectancy and age remained independently associated with PSA screening (P < .001 for each).
CONCLUSION
Rates of PSA screening in the United States are associated with age and estimated life expectancy, but excessive PSA screening in elderly men with limited life expectancies remains a significant problem. The merits and limitations of PSA should be discussed with all patients considering prostate cancer screening.
Topics: Age Factors; Aged; Early Detection of Cancer; Humans; Life Expectancy; Male; Middle Aged; Population Surveillance; Prostate-Specific Antigen; Prostatic Neoplasms; United States
PubMed: 21444863
DOI: 10.1200/JCO.2010.31.9004 -
Annals of Laboratory Medicine Jul 2019Measurement of serum prostate specific antigen (PSA) concentrations remains one of the leading methods for diagnosing prostate cancer. We developed and evaluated an...
BACKGROUND
Measurement of serum prostate specific antigen (PSA) concentrations remains one of the leading methods for diagnosing prostate cancer. We developed and evaluated an immunoglobulin Y (IgY)-based ELISA to measure total PSA (tPSA) concentrations in human serum that could be used as an alternative to commercially available diagnostic assays that rely on mouse monoclonal IgG.
METHODS
A sandwich ELISA based on an anti-PSA IgY antibody was developed. We evaluated the ability of the anti-PSA IgY antibody to detect free and complexed PSA at the same molar ratio. The assay was optimized, and its analytical performance was verified by calculating limit of background (LoB), limit of detection (LoD), and limit of quantification (LoQ). We performed correlation and regression analyses between tPSA concentrations measured by our ELISA and those from commercial assays: Cobas 6000 (Roche Diagnostics, Warszawa, Poland) and PSA total ELISA (IBL International, Hamburg, Germany).
RESULTS
LoB, LoD, and LoQ, were 0.061, 0.083, and 0.100 ng/mL, respectively, and linearity range was 0.100-3.375 ng/mL. tPSA concentrations from our IgY-based ELISA strongly correlated with those from the commercial assays.
CONCLUSIONS
Our IgY-based ELISA is an efficient equivalent to the above commercial assays. The use of IgY as the detecting agent could reduce the risk of false positive results, as well as decrease the overall cost of analysis.
Topics: Aged; Antibodies; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulins; Limit of Detection; Male; Middle Aged; Prostate-Specific Antigen; Prostatic Neoplasms; Regression Analysis
PubMed: 30809983
DOI: 10.3343/alm.2019.39.4.373 -
Journal of Biomedical Optics Oct 2013Assays for blood levels of prostate-specific antigen (PSA), performed in prostate cancer detection, measure mostly inactive/complexed PSA and do not provide information...
Assays for blood levels of prostate-specific antigen (PSA), performed in prostate cancer detection, measure mostly inactive/complexed PSA and do not provide information regarding enzymatically active PSA, which is biologically more relevant. Thus, we designed and synthesized an enzymatically cleavable peptide sequence labeled with near-infrared (NIR) fluorophores (ex/em 740/770 nm) and coupled it to a pharmacokinetic modifier designed to improve its plasma kinetics. In its native state, the agent, PSA750 FAST™ (PSA750), is optically quenched (>95%) and only becomes fluorescent upon cleavage by active PSA, yielding a significant increase in signal. This activation is highly selective for PSA relative to a large panel of disease-relevant enzymes. Active PSA was detected in tumor frozen sections using PSA750 and this activity was abolished in the presence of the inhibitor, alpha-1 anti-chymotrypsin. In vivo imaging of tumor-bearing mice using fluorescence molecular tomography demonstrated a significantly higher fluorescent signal in PSA+ LNCaP tumors as compared to PSA- prostate cancer 3 tumors (13.0±3.7 versus 2.8±0.8 pmol, p=0.023). Ex vivo imaging of tumor sections confirms PSA750-derived NIR signal localization in nonvascular tissue. This is the first report that demonstrates the feasibility and effectiveness of noninvasive, real time, fluorescence molecular imaging of PSA enzymatic activity in prostate cancer.
Topics: Analysis of Variance; Animals; Cell Line, Tumor; Female; Fluorescent Dyes; Histocytochemistry; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Fluorescence; Molecular Imaging; Oligopeptides; Prostate-Specific Antigen; Prostatic Neoplasms; Tomography, Optical
PubMed: 23933968
DOI: 10.1117/1.JBO.18.10.101319 -
Journal of the National Cancer Institute Sep 2013
Topics: Biomarkers, Tumor; Humans; Male; Prostate-Specific Antigen; Prostatic Neoplasms
PubMed: 23943863
DOI: 10.1093/jnci/djt218 -
Archives of Pathology & Laboratory... Oct 2014Prostate-specific antigen (PSA) is a 34-kDa glycoprotein with chymotrypsin-like enzyme activity that circulates both in free forms and complexed to various enzyme... (Comparative Study)
Comparative Study
Serum concentrations of prostate-specific antigen measured using immune extraction, trypsin digestion, and tandem mass spectrometry quantification of LSEPAELTDAVK peptide.
CONTEXT
Prostate-specific antigen (PSA) is a 34-kDa glycoprotein with chymotrypsin-like enzyme activity that circulates both in free forms and complexed to various enzyme inhibitors including antichymotrypsin and α2-macroglobulin. Prostate-specific antigen bound to α2-macroglobulin is not detected by commercial PSA immunoassays.
OBJECTIVE
To develop a mass spectrometry assay that detects the same forms of PSA as the immunoassays, which could serve as a reference for harmonizing PSA immunoassays.
DESIGN
Prostate-specific antigen was immune extracted from serum, trypsin was digested, and the LSEPAELTDAVK peptide was quantitated on an API 5000 spectrometer. Calibrators were made by adding 10% free and 90% antichymotrypsin-bound PSA to female sera. The assay was standardized to the World Health Organization 96/670 reference standard. Validation of clinical utility and comparisons with 2 immunoassays (Roche cobas and Beckman Access) were performed using frozen sera aliquots from 100 men undergoing prostate biopsy (50 negative, 50 with cancer) and 5 serial samples collected over time from 5 men with advanced prostate cancer.
RESULTS
The antibody extraction efficiency was greater than 99%. The assay has an analytic range from 1.2 to 76 ng/mL, with precision ranging from 8.6% at 1.5 ng/mL to 5.4% at 27 ng/mL. The mass spectrometry assay correlated well with 2 immunoassays. All 3 assays showed statistically equivalent separation of prostate cancer from benign disease using receiver operating characteristic curve analysis.
CONCLUSIONS
This mass spectrometry assay can reliably measure PSA concentrations in human serum and could serve as a reference standard for harmonizing PSA immunoassays.
Topics: Analytic Sample Preparation Methods; Antibodies, Monoclonal; Calibration; Humans; Indicators and Reagents; Male; Peptide Fragments; Prostate-Specific Antigen; Prostatic Neoplasms; Proteolysis; ROC Curve; Reproducibility of Results; Tandem Mass Spectrometry; Trypsin
PubMed: 25268201
DOI: 10.5858/arpa.2013-0462-OA -
The Western Journal of Medicine Mar 1995Prostate cancer is a serious health care problem in the United States. Whether or not to screen for it has become a timely issue. Although a large number of men have... (Comparative Study)
Comparative Study Review
Prostate cancer is a serious health care problem in the United States. Whether or not to screen for it has become a timely issue. Although a large number of men have clinically important, asymptomatic, undetected prostate cancer, an even larger number have clinically unimportant cancer. To justify screening programs, not only must we avoid detecting biologically unimportant cancers, we must also detect and effectively treat that subset of tumors that, if undiagnosed, would progress, produce symptoms, and reduce life expectancy. Serum prostate-specific antigen (PSA) assay, or its variations such as PSA density, PSA velocity, and age-specific reference ranges, and the digital rectal examination are the best tests for detecting clinically important, asymptomatic, curable tumors. Recent data suggest that using serum PSA levels does not result in an overdetection of unimportant tumors. Highly effective, curative treatment of localized prostate cancer is available. These factors promote optimism that screening for prostate cancer will ultimately prove beneficial. Nonetheless, men should be informed regarding the benefits and possible risks before being screened for prostate cancer.
Topics: Humans; Male; Prostate-Specific Antigen; Prostatic Neoplasms
PubMed: 7536993
DOI: No ID Found