Dual-labeled chemiluminescence enzyme immunoassay for simultaneous measurement of total prostate specific antigen (TPSA) and free prostate specific antigen (FPSA).

The specificity for early diagnostic of prostate-specific antigen (PSA) is low because the current technology mostly allows the detection of only one biomarker at one time. In this work, a dual-labeled chemiluminescence enzyme immunoassay (CLEIA) for simultaneous measurement of total PSA (TPSA) and free PSA (FPSA) was proposed. Anti-PSA McAb (Mab1) was immobilized on a microplate as the solid phase, horseradish peroxidase (HRP)-labeled anti-TPSA monoclonal antibody (McAb2) and alkaline phosphatase (ALP)-labeled anti-FPSA McAb3 were used as detection antibodies. Two chemiluminescence reactions of HRP with luminol and ALP with 4-methoxy-4-(3-phosphate-phenyl)-spiro-(1,2-dioxetane-3,2'-adamantane) (AMPPD) were used as the signal detecting system. Based on a sandwich model, the amount of FPSA and TPSA could be determined simultaneously. The effects of several physico-chemical parameters were studied and optimized. Cross-reactivities of six common tumor markers in serum were studied. The proposed method presented the sensitivity of 0.03 ng ml-1 and 0.05 ng ml-1 for FPSA and TPSA respectively, with low cross-reactivities. Compared with the results from commercial chemiluminescent kits there was good correlation, indicating that this established method could be used to simultaneously to measure the concentrations of FPSA and TPSA in one serum sample and also could greatly facilitate the early diagnosis for PCa in clinical practice.

Predictive value of different prostate-specific antigen-based markers in men with baseline total prostate-specific antigen <2.0 ng/mL.

OBJECTIVES: To investigate the predictive value of various molecular forms of prostate-specific antigen in men with baseline prostate-specific antigen <2.0 ng/mL. METHODS: The case cohort comprised 150 men with a baseline prostate-specific antigen level <2.0 ng/mL, and who developed prostate cancer within 10 years. The control cohort was 300 baseline prostate-specific antigen- and age-adjusted men who did not develop prostate cancer. Serum prostate-specific antigen, free prostate-specific antigen, and [-2] proenzyme prostate-specific antigen were measured at baseline and last screening visit. The predictive impact of baseline prostate-specific antigen- and [-2] proenzyme prostate-specific antigen-related indices on developing prostate cancer was investigated. The predictive impact of those indices at last screening visit and velocities from baseline to final screening on tumor aggressiveness were also investigated. RESULTS: The baseline free to total prostate-specific antigen ratio was a significant predictor of prostate cancer development. The odds ratio was 6.08 in the lowest quintile baseline free to total prostate-specific antigen ratio subgroup. No serum indices at diagnosis were associated with tumor aggressiveness. The Prostate Health Index velocity and [-2] proenzyme prostate-specific antigen/free prostate-specific antigen velocity significantly increased in patients with higher risk D'Amico risk groups and higher Gleason scores. CONCLUSIONS: Free to total prostate-specific antigen ratio in men with low baseline prostate-specific antigen levels seems to predict the risk of developing prostate cancer, and it could be useful for a more effective individualized screening system. Longitudinal changes in [-2] proenzyme prostate-specific antigen-related indices seem to correlate with tumor aggressiveness, and they could be used as prognostic tool before treatment and during active surveillance.

Age and total and free prostate-specific antigen levels for predicting prostate volume in patients with benign prostatic hyperplasia.

OBJECTIVES: To investigate the predictive values of free prostate-specific antigen (fPSA), total PSA (tPSA) and age on the prostate volume. METHODS: The data of 2148 patients with lower urinary tract symptoms were analyzed retrospectively. The patients who had transrectal ultrasonography guided 10 core biopsies owing to the findings obtained on digital rectal examination and presence of high PSA levels (PSA = 2.5-10 ng/dl), and proven to have BPH histopathologically were included in the study. Age, tPSA, fPSA and the prostate volumes (PV) of the patients were noted. RESULTS: One thousand patients that fulfilled the inclusion criteria were included in the study. The PV of the patients were significantly correlated with age, tPSA and fPSA (p < 0.001 and r = 0.307, p < 0.001 and r = 0.382, p < 0.001 and r = 0.296, respectively). On linear regression model, fPSA was found as a stronger predictive for PV (AUC = 0.75, p < 0.001) when compared to age (AUC = 0.64, p < 0.001), and tPSA (AUC = 0.69, p = 0.013). CONCLUSIONS: Although tPSA is an important prognostic factor for predicting PV, the predictive value of fPSA is higher. PV can easily be predicted by using age, and serum tPSA and fPSA levels.

Predictive role of free prostate-specific antigen in a prospective active surveillance program (PRIAS).

PURPOSE: To evaluate the utility of percentage of free serum PSA (%fPSA) as a predictor of adverse rebiopsy findings, treatment change and radical prostatectomy (RP) findings in a prospective active surveillance (AS) trial. METHODS: Patients enrolled in the global PRIAS study with baseline %fPSA available were included. Putative baseline predictors (e.g. PSA, %fPSA) of adverse rebiopsy findings were explored using logistic regression analysis. Association of variables with treatment change and RP findings over time were evaluated with Cox regression analysis. Active treatment-free survival was assessed with a Kaplan-Meier method. RESULTS: Of 3701 patients recruited to PRIAS, 939 had %fPSA measured at study entry. Four hundred and thirty-eight of them had %fPSA available after 1 year. Median follow-up was 17.2 months. First rebiopsy results were available for 595 patients and of those, 144 (24.2 %) had adverse findings. A total of 283 (30.1 %) patients discontinued surveillance, of those 181 (64.0 %) due to protocol-based reasons. Although median %fPSA values were significantly lower in patients who changed treatment, according to the multivariate regression analysis, initial %fPSA value was not predictive for treatment change or adverse rebiopsy findings. However, the probability of discontinuing AS was significantly lower in patients with "favourable" initial %fPSA characteristics and %fPSA during follow-up (initial %fPSA ≥15 and positive %fPSA velocity) compared to those with "adverse" %fPSA characteristics (initial %fPSA <15 and negative %fPSA velocity). CONCLUSIONS: Diagnostic %fPSA provides no additional prognostic value when compared to other predictors already in use in AS protocols. However, %fPSA velocity during surveillance may aid in predicting the probability for future treatment change.

Prostate cancer with elevated free prostate-specific antigen density: A case report.

BACKGROUND: Prostate cancer is the second most common cancer among men worldwide, and prostate-specific antigen (PSA) is often used in clinical practice to screen for prostate cancer. Normal total PSA (tPSA) level initially excludes prostate cancer. Here, we report a case of prostate cancer with elevated free PSA density (fPSAD). CASE SUMMARY: A patient diagnosed with benign prostatic hyperplasia underwent prostatectomy, and the postoperative pathological results showed acinar adenocarcinoma of the prostate. The patient is currently undergoing endocrine chemotherapy. CONCLUSION: We provide a clinical reference for diagnosis and treatment of patients with normal tPSA but elevated fPSAD.

Technetium-99m-methylene diphosphonate single photon emission computed tomography/computed tomography combined with prostate-specific antigen/free prostate-specific antigen ratio for bone metastasis of prostate cancer.

BACKGROUND: Prostate cancer (PC) is one of the most common malignant tumors in men, and bone metastasis is one of its common complications, which seriously affects the quality of life and prognosis of patients. AIM: To investigate the diagnostic value of technetium-99m-methylene diphosphonate (99mTc-MDP) single photon emission computed tomography (SPECT)/CT imaging combined with the serum prostate-specific antigen (PSA)/free PSA ratio for PC bone metastasis (PCBM). METHODS: One hundred patients with PC who visited the Hospital of Chengdu University of Traditional Chinese Medicine from January 2020 to January 2022 were recruited as the experimental (Exp) group, while 30 patients with benign prostatic lesions (BPLs) were recruited as the control (Ctrl) group. All patients underwent 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA testing. The SPECT/CT imaging results and serum PSA/fPSA ratios of patients were analyzed to evaluate their diagnostic values for PCBM. RESULTS: The difference in general information of the patients was not obvious, showing comparability. The two methods showed no visible differences in negative predictive value and sensitivity for patients with PCBM, but had great differences in positive predictive value and specificity (P < 0.05). The PSA/fPSA ratio of patients with PC in the Exp group was lower than those with BPLs, and patients with PCBM had a much lower PSA/fPSA ratio than those without PC (P < 0.05). The results confirmed that the combined use of 99mTc-MDP SPECT/CT imaging and serum PSA/fPSA ratio achieved a detection rate of 95% for PCBM. CONCLUSION: The combination of 99mTc-MDP SPECT/CT and PSA/fPSA ratio is accurate and reliable for the diagnosis of PCBM, which provides an important reference for clinical practice.

Phage Display's Prospects for Early Diagnosis of Prostate Cancer.

Prostate cancer (PC) is the second most diagnosed cancer among men. It was observed that early diagnosis of disease is highly beneficial for the survival of cancer patients. Therefore, the extension and increasing quality of life of PC patients can be achieved by broadening the cancer screening programs that are aimed at the identification of cancer manifestation in patients at earlier stages, before they demonstrate well-understood signs of the disease. Therefore, there is an urgent need for standard, sensitive, robust, and commonly available screening and diagnosis tools for the identification of early signs of cancer pathologies. In this respect, the "Holy Grail" of cancer researchers and bioengineers for decades has been molecular sensing probes that would allow for the diagnosis, prognosis, and monitoring of cancer diseases via their interaction with cell-secreted and cell-associated PC biomarkers, e.g., PSA and PSMA, respectively. At present, most PSA tests are performed at centralized laboratories using high-throughput total PSA immune analyzers, which are suitable for dedicated laboratories and are not readily available for broad health screenings. Therefore, the current trend in the detection of PC is the development of portable biosensors for mobile laboratories and individual use. Phage display, since its conception by George Smith in 1985, has emerged as a premier tool in molecular biology with widespread application. This review describes the role of the molecular evolution and phage display paradigm in revolutionizing the methods for the early diagnosis and monitoring of PC.

Comparative effectiveness review: prostate cancer antigen 3 testing for the diagnosis and management of prostate cancer.

PURPOSE: We compared the effectiveness of PCA3 (prostate cancer antigen 3) and select comparators for improving initial or repeat biopsy decision making in men at risk for prostate cancer, or treatment choices in men with prostate cancer. MATERIALS AND METHODS: MEDLINE®, EMBASE®, Cochrane Database and gray literature were searched from January 1990 through May 2012. Included studies were matched, and measured PCA3 and comparator(s) within a cohort. No matched analyses were possible. Differences in independent performance estimates between PCA3 and comparators were computed within studies. Studies were assessed for quality using QUADAS (Quality Assessment of Diagnostic Accuracy Studies) and for strength of evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria. RESULTS: Among 1,556 publications identified, 34 observational studies were analyzed (24 addressed diagnostic accuracy and 13 addressed treatment decisions). Most studies were conducted in opportunistic cohorts of men referred for procedures and were not designed to answer key questions. Two study biases (partial verification and sampling) were addressed by analyses, allowing some conclusions to be drawn. PCA3 was more discriminatory than total prostate specific antigen increases (eg at an observed 50% specificity, summary sensitivities were 77% and 57%, respectively). Analyses indicated that this finding holds for initial and repeat biopsies, and that the markers were independent predictors. For all other biopsy decision making comparisons and associated health outcomes, strength of evidence was insufficient. For treatment decision making, strength of evidence was insufficient for all outcomes and comparators. CONCLUSIONS: PCA3 had a higher diagnostic accuracy than total prostate specific antigen increases, but strength of evidence was low (limited confidence in effect estimates). Strength of evidence was insufficient to conclude that PCA3 testing leads to improved health outcomes. For all other outcomes and comparators, strength of evidence was insufficient.

Value of serum free prostate-specific antigen density in the diagnosis of prostate cancer.

PURPOSE: To investigate the value of serum free prostate-specific antigen density (fPSAD) in the diagnosis of prostate cancer (PCa). METHODS: The data of 558 patients who underwent transrectal ultrasound-guided prostate biopsy were retrospectively analyzed. According to the pathological results, the patients were divided into a PCa group and a benign prostatic hyperplasia (BPH) group. Receiver operating characteristic curves were plotted, based on which the sensitivity, specificity, Youden index, concordance, and kappa values of free prostate-specific antigen (fPSA), the free-to-total f/tPSA, prostate-specific antigen density (PSAD), the free-to-total (f/t)/PSAD ratio, and fPSAD were compared. The patients were divided into three groups by PSA levels (PSA < 4 ng/mL, PSA = 4-10 ng/mL, and PSA > 10 ng/mL), into three groups by age (age < 60 year, age = 60-80y, and age > 80 years), and into two groups by prostate volume (PV) (PV ≤ 80 mL and PV > 80 mL) to compare the sensitivity, specificity, and concordance of indicators. RESULTS: tPSA, PSAD, (f/t)/PSAD, and fPSAD had high accuracy in predicting PCa with AUC values of 0.820, 0.900, 0.846, and 0.867. fPSAD showed lower diagnostic sensitivity but significantly higher specificity and concordance for PCa than tPSA, f/tPSA, (f/t)/PSAD, or PSAD. Thus, fPSAD had the highest accuracy in the diagnosis of PCa. In the groups with different PSA, age, and PV stratification, the concordance of fPSAD was significantly higher (88.61%, 90.74%, and 90.38%) than that of other indicators. CONCLUSION: With the optimal cutoff value of 0.062, fPSAD has a higher diagnostic value for PCa than tPSA, f/tPSA, (f/t)/PSAD, and PSAD, and can well predict the risk of PCa, significantly improve the clinical diagnostic rate of PCa, and reduce unnecessary biopsy.

SERS-based biosensor for detection of f-PSA%: Implications for the diagnosis of prostate cancer.

In diagnosing prostate cancer and distinguishing it from other prostate diseases, the ratio of the concentration of free prostate-specific antigen (f-PSA) to total prostate-specific antigen (t-PSA), i.e., (f-PSA%) is more accurate than the concentration of t-PSA alone. Immunoassay based on surface-enhanced Raman scattering (SERS) frequency shift has been proven to be particularly suitable for detecting large biomolecules with high reproducibility. Along similar lines, the present study developed a SERS-based biosensor that simultaneously detects t-PSA and f-PSA. The 4-mercaptobenzoic acid (MBA) on the immunocapture substrate is coupled to the t-PSA antibody through the carboxyl group, and the combination of t-PSA induces the Raman frequency shifts of MBA. The immunocolloidal gold attached with f-PSA antibodies selectively capture the f-PSA that immobilized on the MBA-modified SERS substrates, allowing for f-PSA quantification according to the SERS intensities of the 5, 5'-Dithiobis (succinimidyl-2-nitrobenzoate) (DSNB) probe. The results show that f-PSA and t-PSA have good linear response in the concentration scale of 0.1-20 ng/mL, and 1-200 ng/mL, respectively. The biosensor combines Raman frequency shifts and intensities, which greatly simplifies traditional procedures for f-PSA% detection. All the results demonstrated the great potential of the proposed biosensor in highly reproducible and accurate diagnosis of prostate cancers.

A novel screening strategy for clinically significant prostate cancer in elderly men over 75 years of age.

A standard modality for prostate cancer detection in men 75 years and older has not been established. A simple screening method for elderly patients is needed to avoid unnecessary biopsies and to effectively diagnose prostate cancer. A retrospective study was conducted on elderly patients who had prostate biopsy at Kanazawa University Hospital (Kanazawa, Japan) between 2000 and 2017. Of the 2251 patients who underwent prostate biopsy, 254 had clinically significant prostate cancer (CSPC) with a Gleason score (GS) of≥7 and 273 had a GS of <7 or no malignancy. In this study, patients aged 75 years or older were classified as elderly patients. GS ≥ 7 was characterized by a prostate-specific antigen (PSA) of the maximum area under the curve of 12 ng ml-1 with a sensitivity of 76.2% and a specificity of 73.2%. For PSA levels between 4 ng ml-1 and 12 ng ml-1, based on the maximum area under the curve, patients with three or four of the following factors may present a GS of ≥ 7: percent free PSA >24, PSA density≥ 0.24 ng ml-2, positive findings on digital rectal examination, and transrectal with 90.0% sensitivity and 67.4% specificity. In this study, we found that raising the PSA cutoff to 12 ng ml-1 for CSPC in elderly individuals can significantly reduce unnecessary prostate biopsies. Furthermore, CSPC could be efficiently discovered by combining the four supplementary markers in patients with a PSA level of 4-12 ng ml-1. By performing this screening for elderly men over 75 years of age, unnecessary biopsies may be reduced and CSPC may be detected efficiently.

The Value of Prostate-Specific Antigen-Related Indexes and Imaging Screening in the Diagnosis of Prostate Cancer.

OBJECTIVE: The aim of this study was to explore the value of the prostate-specific antigen (PSA) levels, the ratio of free PSA to total PSA (fPSA/TPSA), the PSA density (PSAD), digital rectal examination (DRE), transrectal prostate ultrasound (TRUS), and multiparameter MRI (MP-MRI) in the differential diagnosis of benign prostatic hyperplasia (BPH) and prostate cancer (PCa). METHODS: From February 2016 to September 2019, data from 620 patients who underwent systematic transrectal ultrasound-guided prostate biopsy (STURS-PB) in our hospital were retrospectively collected, including the PSA levels, the fPSA/TPSA ratio, the PSAD, DRE, TRUS, MP-MRI, prostate volume, and other clinical data. RESULTS: Among the 620 patients, 249 patients were in the PCa group, and 371 patients in the BPH group. The positive puncture rate was 40.16%. The positive predictive values of DRE, TRUS, mpMRI, and TPSA levels for PCa were 39.91%, 39.38%, 64.14%, and 41.57%, respectively; the sensitivity of these parameters was 37.35%, 51.41%, 74.69%, and 57.43%, respectively; and the specificity of these parameters was 62.26%, 46.90%, 71.97%, and 45.82%, respectively. When the TPSA concentration was in the range of 4-20 ng/mL, the positive puncture rate of STURS-PB was 23.18%, with a high rate of misdiagnosis. When the TPSA concentration was in the range of 4-20 ng/mL, the fPSA/TPSA ratio was 0.15, the PSAD was 0.16, the comprehensive evaluation of PCa was optimal (the sensitivity of these parameters was 88.85% and 84.09%, respectively; the specificity was 80.17% and 67.29%, respectively; the positive predictive value was 57.41% and 51.39%, respectively). When the TPSA concentration >4 ng/mL, the fPSA/TPSA ratio ≤0.15 and the PSAD ≥0.16, the sensitivity, specificity, and correctness index of the PCa and BPH diagnosis were 80.54%, 82.75%, and 67.07%, respectively. CONCLUSION: When using DRE, TRUS, and MP-MRI to screen for PCa, MP-MRI has a relatively high sensitivity and specificity. Using these three thresholds (TPSA >4 ng/mL combined with an fPSA/TPSA ratio ≤0.15 and a PSAD ≥0.16) is significantly better than using TPSA levels alone for the differential diagnosis of PCa and BPH.

A pilot study on percent free prostate specific antigen as an additional tool in prostate cancer screening.

A cross sectional pilot study was carried out to look into the usefulness of percent free prostate specific antigen (fPSA) in the diagnosis of prostatic cancer in HUSM patients. All patients who attended surgical clinic and admitted to surgical wards with signs and symptoms of prostate problems during the study period were taken as the study subjects. Total prostate specific antigen (tPSA) was estimated by immunoassay technique and those values of 4 ng/mL or more were proceeded for estimation of fPSA. Using the cut-off value of less than 25% fPSA for diagnosing patients with prostate cancer, our study showed that majority of the prostate cancer patients have a ratio of fPSA:tPSA more than 25% and a significantly higher level of total prostate specific antigen (P<0.005) when compared with patients with benign prostatic hyperplasia (BPH). Unexpectedly, the fPSA values were high in patients diagnosed as prostate cancer compared to BPH. Ratio of percent fPSA to tPSA was found not to be sensitive and specific, in diagnosing prostate cancer at the cut-off value of 25%. In conclusion, total PSA is a more useful biochemical test for diagnosing prostate cancer in our patients.

Prostate-specific antigen reduction after empiric antibiotic treatment does not rule out biopsy in patients with lower urinary tract symptoms: prospective, controlled, single-center study.

BACKGROUND: To evaluate men, with lower urinary tract symptoms and newly elevated serum prostate specific antigen (PSA) to determine whether a three-week course of ciprofloxacin antibiotics lowers serum PSA levels and affects recommendations for prostate biopsy. METHODS: A prospective, controlled, single-center prospective trial of 177 men with a newly elevated PSA and lower urinary tract symptoms was conducted. Patients were randomized to three weeks of ciprofloxacin or observation. After three weeks, patients PSA levels and derivatives were repeated. At the end of 3 weeks, all patients underwent TRUS guided systematic 12-core prostate biopsies regardless of the final PSA value. RESULTS: Of 177 men who completed the study, 88 were in the treatment and 89 in the observation group. 46.5% of treatment and %18 of control groups patients PSA levels had decreased after 3 weeks and a significant PSA reduction was observed in the treatment group compare to control group (p: 0.035) but no significant prostate cancer detection rates were observed between the groups (p: 0.418). Also, in the treatment group prostate cancer detection rate was significantly higher in patients whom PSA levels were decreased (p: 0.011). CONCLUSION: This study has shown that, use empirical antibiotic treatment decreased the PSA levels but did not have any effect on prostate cancer detection. In addition, prostate cancer detection rates were found to be higher in patients with reduced PSA levels after treatment. Therefore, it may not be safe to rule out biopsies in patients who achieve a satisfactory PSA response to antibiotics.

Evaluation of prostatic cancer prevalence in patients with prostatic-specific antigen between 4 and 10 and normal digital rectal examination.

BACKGROUND: Prostate cancer is one of the most common male cancers. The prevalence of prostate cancer is different due to genetic and environmental factors. Diagnosis of prostate cancer is by biopsy due to prostate-specific antigen (PSA) and Digital Rectal Examination (DRE). Controversy about decision making for prostate biopsy in PSA between 4 and 10 and normal DRE, is one of the problems in this time. In this study we evaluated the prevalence of prostate cancer in males with PSA between 4 and 10 and normal DRE. We also evaluated the PSA density and percent of free PSA in patients with prostate cancer. MATERIALS AND METHODS: A total of 121 males with PSA between 4 and 10 and normal DRE, were evaluated. Then, transrectal ultrasonography (TRUS) andprostate biopsy from 12 points of peripheral zone, was done. These data were analyzed by Chi-square, t-test and ANOVA and Roc curve. RESULTS: In this study, the prevalence of prostate cancer in PSA between 4 and 10 and normal DRE, was evaluated, 29.8%. With use of Roc curve, PSA density cutoff point was calculated 0.12 and percent of free PSA cutoff point, was calculated, 18%. CONCLUSION: In males with PSA between 4 and 10 and normal DRE, PSA density smaller than 0.12-0.15, and percent of free PSA greater than 18%, the prevalence of prostate cancer is very few and we can safely ignore the TRUS and prostate biopsy in these males and eliminate its costs and side effects.

Prostate health index and prostate cancer gene 3 score but not percent-free Prostate Specific Antigen have a predictive role in differentiating histological prostatitis from PCa and other nonneoplastic lesions (BPH and HG-PIN) at repeat biopsy.

OBJECTIVE: To determine if prostate health index (PHI), prostate cancer antigen gene 3 (PCA3) score, and percentage of free prostate-specific antigen (%fPSA) may be used to differentiate asymptomatic acute and chronic prostatitis from prostate cancer (PCa), benign prostatic hyperplasia (BPH), and high-grade prostate intraepithelial neoplasia (HG-PIN) in patients with elevated PSA levels and negative findings on digital rectal examination at repeat biopsy (re-Bx). PATIENTS AND METHODS: In this prospective study, 252 patients were enrolled, undergoing PHI, PCA3 score, and %fPSA assessments before re-Bx. We used 3 multivariate logistic regression models to test the PHI, PCA3 score, and %fPSA as risk factors for prostatitis vs. PCa, vs. BPH, and vs. HG-PIN. All the analyses were performed for the whole patient cohort and for the "gray zone" of PSA (4-10ng/ml) cohort (171 individuals). RESULTS: Of the 252 patients, 43 (17.1%) had diagnosis of PCa. The median PHI was significantly different between men with a negative biopsy and those with a positive biopsy (34.9 vs. 48.1, P<0.001), as for the PCA3 score (24 vs. 54, P<0.001) and %fPSA (11.8% vs. 15.8%, P = 0.012). The net benefit of using PCA3 and PHI to differentiate prostatitis and PCa was moderate, although it extended to a good range of threshold probabilities (40%-100%), whereas that from using %fPSA was negligible: this pattern was reported for the whole population as for the "gray zone" PSA cohort. CONCLUSION: In front of a good diagnostic performance of all the 3 biomarkers in distinguishing negative biopsy vs. positive biopsy, the clinical benefit of using the PCA3 score and PHI to estimate prostatitis vs. PCa was comparable. PHI was the only determinant for prostatitis vs. BPH, whereas no biomarkers could differentiate prostate inflammation from HG-PIN.

Comparison of prostate cancer gene 3 score, prostate health index and percentage free prostate-specific antigen for differentiating histological inflammation from prostate cancer and other non-neoplastic alterations of the prostate at initial biopsy.

AIM: To determine if prostate cancer gene 3 (PCA3) score, Prostate Health Index (PHI), and percent free prostate-specific antigen (%fPSA) may be used to differentiate prostatitis from prostate cancer (PCa), benign prostatic hyperplasia (BPH) and high-grade prostate intraepithelial neoplasia (HG-PIN) in patients with elevated PSA and negative digital rectal examination (DRE). PATIENTS AND METHODS: in the present prospective study, 274 patients, undergoing PCA3 score, PHI and %fPSA assessments before initial biopsy, were enrolled. Three multivariate logistic regression models were used to test PCA3 score, PHI and %fPSA as risk factors for prostatitis vs. PCa, vs. BPH, and vs. HG-PIN. All the analyses were performed for the whole patient cohort and for the 'gray zone' of PSA (4-10 ng/ml) cohort (188 individuals). RESULTS: The determinants for prostatitis vs. PCa were PCA3 score, PHI and %fPSA (Odds Ratio [OR]=0.97, 0.96 and 0.94, respectively). Unit increase of PHI was the only risk factor for prostatitis vs. BPH (OR=1.06), and unit increase of PCA3 score for HG-PIN vs. prostatitis (OR=0.98). In the 'gray zone' PSA cohort, the determinants for prostatitis vs. PCa were PCA3 score, PHI and %fPSA (OR=0.96, 0.94 and 0.92, respectively), PCA3 score and PHI for prostatitis vs. BPH (OR=0.96 and 1.08, respectively), and PCA3 score for prostatitis vs. HG-PIN (OR=0.97). CONCLUSION: The clinical benefit of using PCA3 score and PHI to estimate prostatitis vs. PCa was comparable; even %fPSA had good diagnostic performance, being a faster and cheaper marker. PHI was the only determinant for prostatitis vs. BPH, while PCA3 score for prostatitis vs. HG-PIN.

Magnetic-particle-based, ultrasensitive chemiluminescence enzyme immunoassay for free prostate-specific antigen.

We report a magnetic-particle (MMP)-based chemiluminescence enzyme immunoassay (CLEIA) for free prostate-specific antigen (f-PSA) in human serum. In this method, the f-PSA is sandwiched between the anti-PSA antibody coated MMPs and alkaline phosphatase (ALP)-labeled anti-f-PSA antibody. The signal produced by the emitted photons from the chemiluminescent substrate (4-methoxy-4-(3-phosphatephenyl)-spiro-(1,2-dioxetane-3,2'-adamantane)) is directly proportional to the amount of f-PSA in a sample. The present MMP-based assay can detect f-PSA in the range of 0.1-30 ng mL(-1) with the detection limit of 0.1 ng mL(-1). The linear detection range could match the concentration range within the "diagnostic gray zone" of serum f-PSA levels (4-10 ng mL(-1)). The detection limit was sufficient for measuring clinically relevant f-PSA levels (>4 ng mL(-1)). Furthermore, the method was highly selective; it was unaffected by cross-reaction with human glandular kallikrein-2, a kallikrein-like serine protease that is 80% similar to f-PSA. The proposed method was finally applied to determine f-PSA in 40 samples of human sera. Results obtained using the method showed high correlation with those obtained using a commercially available microplate CLEIA kit (correlation coefficient, 0.9821). This strategy shows great potential application in the fabrication of diagnostic kits for determining f-PSA in serum.

Actualización en cáncer de próstata: generalidades y diagnóstico / Update in prostate cancer: overview and diagnosis

Resumen: El cáncer de próstata es una enfermedad clínicamente caracterizada por un periodode latencia largo y un crecimiento tumoral lento. En la actualidad, es un problema de granimportancia para la salud pública, pues es el segundo cáncer más frecuentemente diagnosticadoy corresponde a la sexta causa de muerte por cáncer en hombres en el mundo. Se caracteriza poruna gran heterogeneidad clínica y molecular. Su diagnóstico se basa en el uso de tres pruebasfundamentales: el examen del tacto rectal y la medición de los niveles séricos del antígenoespecífico de próstata (AEP), los cuales se usan frecuentemente en el tamizaje, y la biopsiaprostática, mediante la cual se confirma el diagnóstico de cáncer de próstata. Actualmente, el AEPse ha constituido en la principal herramienta tamiz para el cáncer de próstata; no obstante, existeuna gran controversia en torno a su uso. Por ello, están siendo ampliamente estudiados nuevosbiomarcadores, a fin de disponer de pruebas diagnósticas más sensibles y específicas. Dado queel AEP es una prueba ampliamente utilizada internacionalmente y que han surgido biomarcadoresadicionales para el diagnóstico temprano del cáncer de próstata, es de fundamental importanciaque el personal de la salud en general y el personal de laboratorio en particular puedan contarcon información con respecto al uso de éstas y su relación con otras herramientas diagnósticas,además de otros aspectos generales del cáncer de próstata.

Abstract: Prostate cancer is a disease clinically characterized by a long latency period and slow tumorgrowth rate. Prostate cancer is currently a major public health problem because it is the second mostcommonly diagnosed cancer, and the sixth major cause of cancer-related death in men in the world.It is characterized by clinical and molecular heterogeneity. Diagnosis is based on the use of threebasic tests: digital rectal examination, measurement of prostate-specific antigen (PSA) serum levels,frequently used in screening, and prostate biopsy, which confirms the diagnosis of prostate cancer.Nowadays, PSA has become the main testing way for prostate cancer screening, although there ismuch controversy about its use. Therefore, new biomarkers are being widely researched, in order toprovide more sensitive and more specific diagnostic tests. Provided that PSA is a globally used test,and additional tests for early diagnosis of prostate cancer have aroused, is it essential that healthpersonnel, and particularly laboratory personnel, are granted with information about their use, andtheir relationship with further diagnostic techniques, besides other general aspects of prostate cancer.