Age-specific PSA reference ranges in Chinese men without prostate cancer

Age-specific percentile-based prostate-specific antigen cutoff values predict the risk of prostate cancer: A single hospital observation

Background

Testing for prostate-specific antigen (PSA) is often recommended for men with a potential risk of prostate cancer (PCa) before requiring advanced examination. However, the best PSA cutoff value remains controversial.

Object

We compared the predictive performance of age-specific percentile-based PSA thresholds with a conventional cutoff of >4 ng/mL for the risk of PCa.

Methods

We included men who received PSA measurements between 2003 and 2017 in a medical center in Taiwan. Logistic regression modeling was used to assess the association between age-specific percentile-based PSA thresholds and PCa risk in age subgroups. We further applied C-statistic and decision curve analysis to compare the predictive performance of age-specific percentile-based PSA with that of a conventional cutoff PSA.

Results

We identified 626 patients with PCa and 40 836 patients without PCa. The slope of PSA in patients >60-year-old was almost 3 times that of those <60-year-old (0.713 vs 0.259). The risk effect sizes of the 75th percentile PSA cutoff (<60-year-old: 2.19; 60-70-year-old: 4.36; >70-year-old: 5.84 ng/mL) were comparable to those observed based on the conventional cutoff in all age groups. However, the discrimination performance of the 75th percentile PSA cutoff was better than that of the conventional cutoff among patients aged <60-year-old (C-statistic, 0.783 vs. 0.729, p < 0.05). The 75th percentile cutoffs also correctly identified an additional 2 patients with PCa for every 100 patients with PSA screening at the threshold probability of 20%.

Conclusions

Our data support the use of the 75th percentile PSA cutoff to facilitate individualized risk assessment, particularly for patients aged <60-year-old.

Association Between Statin Exposure and Incidence and Prognosis of Prostate Cancer: A Meta-analysis Based on Observational Studies

It is widely thought that statins have huge therapeutic potential against prostate cancer (PCA). This study aimed to investigate the effect of statin exposure on PCA incidence and prognosis. PubMed, Web of Science, Embase, and Cochrane databases were searched for observational studies on the association between statin exposure and PCA from inception until July 2022. The primary endpoints were the incidence of PCA and the survival rate. A total of 21 studies were included in this meta-analysis. The pooled estimates showed that exposure to hydrophilic statins was not associated with the incidence of PCA (odds ratio [OR]=0.94, 95% CI=0.88-1.01, P =0.075), while the incidence of PCA was significantly decreased in populations exposed to lipophilic statins compared with the nonexposed group (OR=0.94, 95% CI=0.90-0.98, P =0.001), mainly in Western countries (OR=0.94, 95% CI=0.91-0.98, P =0.006). Subgroup analysis showed that simvastatin (OR=0.83, 95% CI=0.71-0.97, P =0.016) effectively reduced the incidence of PCA. The prognosis of PCA in patients exposed to both hydrophilic (hazard ratio [HR]=0.57, 95% CI=0.49-0.66, P <0.001) and lipophilic (HR=0.65, 95% CI=0.58-0.73, P <0.001) statins were better than in the nonexposed group, and this improvement was more significant in the East than in Western countries. This study demonstrates that statins can reduce the incidence of PCA and improve prognosis, and are affected by population region and statin properties (hydrophilic and lipophilic).

Ethnic differences in the age-related distribution of serum prostate-specific antigen values: A study in a Taiwanese male population

This study investigates age-specific prostate-specific antigen (PSA) distributions in Taiwanese men and recommends reference ranges for this population after comparison with other studies. From January 1999 to December 2016, a total of 213,986 Taiwanese men aged above 19 years old without history of prostate cancer, urinary tract infection, or prostate infection were recruited from the Taiwan MJ cohort, an ongoing prospective cohort of health examinations conducted by the MJ Health Screening Center in Taiwan. Participants were divided into seven age groups. Simple descriptive statistical analyses were carried out and quartiles and 95th percentiles were calculated for each group as reference ranges for serum PSA in screening for prostate cancer in Taiwanese men. Serum PSA concentration correlated with age (r = 0.274, p<0.001). The median serum PSA concentration (5th to 95th percentile) ranged from 0.7 ng/ml (0.3 to 1.8) for men 20-29 years old (n = 6,382) to 1.6 ng/ml (0.4 to 8.4) for men over 79 years old (n = 504). The age-specific PSA reference ranges are as follows: 20-29 years, 1.80 ng/ml; 30-39 years, 1.80 ng/ml; 40-49 years, 2.0 ng/ml; 50-59 years, 3.20 ng/ml; 60-69 years, 5.60 ng/ml; 70-79 years, 7.40 ng/ml; over 80 years, 8.40 ng/ml. Almost no change occurred in the median serum PSA value in men 50 years old or younger, while a gradual increase was observed in men over 50. Taiwanese men aged 60 years above showed higher 95th percentile serum PSA values compared to Caucasian men and men in other Asian countries but were closer to those of Asian American and African American men. Results indicate significantly different PSA levels correlating to different ethnicities, suggesting that Oesterling's age-specific PSA reference ranges might not be appropriate for Taiwanese men. Our results should be further studied to validate the age-specific PSA reference ranges for Taiwanese men presented in this study.

Age-Adjusted Reference Values for Prostate Specific Antigen - A Systematic Review and Meta-Analysis

OBJECTIVES

To systematically evaluates the evidence on ethnic differences in age-adjusted reference values of PSA.

MATERIALS AND METHODS

In concordance with the Preferred Reporting Items for Systematic Review and Meta-analysis statement, a review of English articles using Medline, Embase and Cochrane databases, from inception to December 2019 was conducted. Studies that reported the PSA upper reference value as 95th percentile of the cohort distribution, in healthy men aged 40 to 79, were included. Methodological quality was assessed with a modified version of the Agency for Healthcare Research and Quality checklist for cross-sectional studies.

RESULTS

Forty-three studies examining 325,514 participants were included in the analysis. These were published between 1993 and 2018. Majority were prospective observational studies and reported the reference values in ten-year age intervals. Only five reports directly compared ethnic differences in PSA values. Due to missing data, six studies were not considered in the quantitative synthesis. For the remainder (37/43), heterogeneity in PSA reference values was considerable (Higgin's index = 99.2%), with age and ethnicity being the sole identified significant contributors. Accordingly, the pooled upper limits for PSA reference values were 2.1, 3.2, 4.9 and 6.5 ng/ml for men in their 40 s, 50 s, 60 s, and 70 s, respectively.

CONCLUSION

Moderate quality evidence suggest that upper PSA reference limits increased with age and significant ethnic differences were present.

Integration of quantitative diffusion kurtosis imaging and prostate specific antigen in differential diagnostic of prostate cancer

This study aimed to evaluate the diagnostic performance of diffusion kurtosis imaging (DKI) and prostate-specific antigen (PSA) biomarkers in differentiating prostate cancer (PCa) and benign prostatic hyperplasia (BPH).A total of 43 cases of prostate diseases verified by pathology were enrolled in the present study. These cases were assigned to the BPH group (n = 20, 68.85±10.81 years old) and PCa group (n = 23, 74.13 ± 7.37 years old). All patients underwent routine prostate magnetic resonance imaging and DKI examinations, and the mean diffusivity (MD), mean kurtosis (MK), and fractional anisotropy (FA) values were calculated. Three serum indicators (PSA, free PSA [fPSA], and f/t PSA) were collected. We used univariate logistic regression to analyze the above quantitative parameters between the 2 groups, and the independent factors were further incorporated into the multivariate logistic regression model. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic efficacy of the single indicator and combined model.The difference in PSA, f/t PSA, MK, and FA between PCa and BPH was statistically significant (P < .05). The AUC for the combined model (f/t PSA, MK, and FA) of 0.972 (95% confidence interval [CI]: 0.928, 1.000) was higher than the AUC of 0.902 (95% CI: 0.801, 1.000) for f/t PSA, 0.833 (95% CI: 0.707, 0.958) for MK, and 0.807 (95% CI: 0.679, 0.934) for FA.The MK and FA values for DKI and f/t PSA effectively identify PCa and BPH, compared to the PSA indicators. Combining DKI and PSA derivatives can further improve the diagnosis efficiency and might help in the clinical setting.

Relationship between serum prostate-specific antigen and transrectal prostate sonographic findings in asymptomatic Ugandan males

Background

Prostate disorders are among the leading causes of morbidity and mortality in men above the age of 40 years globally. Serum prostate-specific antigen (PSA) levels may be used to screen men at risk of prostate cancer and determine choice of medical treatment in benign prostatic hyperplasia (BPH) and evaluation of patients with prostatitis, while prostate sonography determines prostate volume (PV) and detects nodules. BPH may exhibit distinct hypoechoic, isoechoic, or hyperechoic nodules in the transition zone, whereas hypoechoic nodules in the peripheral zone are diagnostic for prostate cancer in over 50% of cases. In this study, we aimed at determining the relationship between serum PSA levels and transrectal prostate sonographic findings among asymptomatic Ugandan males.

Methods

Ugandan males above 30 years of age or older without lower urinary tract symptoms were cross-sectionally enrolled into the study. Serum PSA determination and transrectal ultrasound were performed. Association between PSA levels and PV was assessed using Spearman’s correlation coefficients (ρ).

Results

A total of 277 men were studied. The median serum PSA level was 1 (95% CI: 1–2). Most (n = 217, 78.3%) participants had serum PSA levels ≤ 4 ng/ml. The median sonographic PV was 26 (95% CI: 26–29) mls. One hundred and fifty-five (56.0%) participants had PV between 25 and 50 mls. Both PSA levels and PV progressively increased with age from 0.9 ng/ml and 22 mls in the 30–39 year age group to 7 ng/ml and 38 mls in the 60–69 year age group, respectively. PSA levels weakly correlated with PV (ρ = 0.27) (p < 0.0001). One hundred and thirty (47%) participants had prostatic nodules. Of these, 100 (77%) had features of benign nodules and 23% had suspicious nodules for prostate cancer. The median (range) serum PSA level in those with nodules was 2.0 (0.1–16.0) ng/ml and for those without nodules was 1.1 (0.1–8.0) ng/ml (p < 0.0001).

Conclusions

Serum PSA has a weak direct correlation with PV and not a reliable marker for the prediction of presence or absence of prostatic nodules in asymptomatic adult males.

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.

Asian Race and Risk of Prostate Cancer: Results from the REDUCE Study

BACKGROUND

Global prostate cancer incidence rates are lower in Asian men than Caucasian men. Whether this is the result of less screening in Asian men remains to be determined. We examined whether Asian race was associated with prostate cancer diagnosis in the Reduction by Dutasteride of Cancer Events (REDUCE) study.

METHODS

REDUCE was a 4-year, multicenter, randomized trial of dutasteride versus placebo for prostate cancer prevention among men who underwent prostate-specific antigen (PSA)-independent biopsies at 2 and 4 years. Eligible men were ages 50 to 75 years, had PSA between 2.5 and 10 ng/mL, and a negative prestudy prostate biopsy. We tested the association between Asian and Caucasian race and prostate cancer diagnosis using logistic regression.

RESULTS

Of 8,122 men in REDUCE, 5,755 (71%) were Caucasian and 105 (1.8%) were Asian. Asians had lower body mass index (24.8 vs. 26.9 kg/m², P < 0.001), had smaller prostate volume (35.0 vs. 43.5 cc, P < 0.001), and were less likely to have abnormal digital rectal exams (P = 0.048), but were similar in baseline age, PSA, family history of prostate cancer, and smoking status compared with Caucasian men (all P ≥ 0.164). Asian men were equally likely to receive any on-study biopsy compared with Caucasian men (P = 0.634). After adjusting for potential confounders, Asian men were less likely to be diagnosed with prostate cancer during the 4-year study (OR = 0.49; 95% confidence interval, 0.28-0.88; P = 0.016), compared with Caucasian men.

CONCLUSIONS

In REDUCE, where all men underwent biopsies largely independent of PSA, Asian race was associated with lower prostate cancer diagnosis.

IMPACT

These findings suggest that lower prostate cancer risk in Asian men may be due to biological, genetic, and/or lifestyle factors.

Age-specific reference ranges of prostate-specific antigen in the elderly of Amirkola: A population-based study

Objective

To determine the age-specific reference ranges of prostate-specific antigen (PSA) in the older men in the city of Amirkola.

Methods

This cross-sectional study is a part of Amirkola Health and Ageing Project (AHAP) which has been conducted as a cohort study since 2011 in Amirkola, a city in northern Iran. The demographic information of all men aged 60 and older were collected through questionnaires and interviews and the PSA measurements were performed using ELISA and Diametra kit. The acquired data were analyzed afterwards.

Results

A number of 837 elderly men with a mean age of 69.99±7.72 years participated in this study. The serum PSA level (95th percentile) was determined to be 0.9 (0–4.89) ng/mL in the age group of 60–64 years, 1.1 (0–4.88) ng/mL in the age group of 65–69 years, 0.93 (0–9.01) ng/mL in the age group of 70–74 years, 1.3 (0–7.95) ng/mL in the age group of 75–79 years, 1.9 (0–11.98 ng/mL) in the age group of 80–84 years, and 1.45 (0–33.17) ng/mL in the 85 and older group. The serum PSA level was significantly correlated with age (p=0.000).

Conclusion

This study indicated that there is a direct correlation between the age and serum PSA levels. The use of age-specific reference range could guide clinicians on the incidence of prostate cancer in this population and perhaps reduce the number of unnecessary tests in this population group.

Establishment of reference intervals for serum [-2]proPSA (p2PSA), %p2PSA and prostate health index in healthy men

Background

Prostate cancer (PCa) is the second most common cancer among men worldwide. Recent research has identified [-2]proPSA (p2PSA), %p2PSA and prostate health index (phi) as new biomarkers for the early diagnosis and grading of PCa. However, few studies have used these parameters in a healthy population. In this study, we aimed to establish reference intervals (RIs) for p2PSA, %p2PSA and phi in healthy men based on age stratification.

Methods

Between April 2016 and March 2018, healthy subjects were recruited. Healthy men were then stratified into four age groups: <40 years, 40-49 years, 50-59 years and ≥60 years. Total PSA (tPSA), free PSA (fPSA), %fPSA, p2PSA, %p2PSA and phi were measured and RIs were established for p2PSA, %p2PSA and phi.

Results

In total, 732 healthy men were used for analysis. The RIs of phi were 9.77-48.44 for <40 years of age, 9.85-65.28 for 40-49 years of age, 9.98-39.72 for 50-59 years of age and 8.16-40.76 for ≥60 years of age. The reference values at the age of 40-49 years were generally higher than those at ≥60 years of age.

Conclusions

Age-specific RIs for p2PSA, %p2PSA and phi were established in this study. This first set of established RIs will be invaluable for physicians to make precise medical decisions and carry out appropriate medical interventions.

Improving the detection rate of prostate cancer in the gray zone of PI-RADS v2 and serum tPSA by using prostate-specific antigen-age volume

To improve the detection of prostate cancer (PCa) by combining the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) and prostate-specific antigen-age volume (PSA-AV), especially among those in gray zone with PI-RADS v2 score 3 or serum total prostate-specific antigen (tPSA) 4 to 10 ng/mL.The 357 patients were enrolled in this study. The PI-RADS v2 scoring system was used to represent characteristics on multiparametric magnetic resonance imaging (mpMRI). PI-RADS v2 score 3 or tPSA 4 to 10 ng/mL were defined as the gray zone in detecting PCa. The formula equates to the patient age multiplied by the prostate volume, which is divided by the tPSA level. Univariate and multivariate analyses were done to ascertain significant predictors of prostate cancer.In all, 174 (48.7%) were benign prostatic hyperplasia, 183 (51.3%) had PCa. The results showed that PI-RADS v2, tPSA, and PSA-AV were significant independent predictors of prostate cancer. PI-RADS v2 score ≥4 could detect PCa with rate of 82.1%. Serum tPSA ≥10 ng/mL could detect PCa with rate of 66.2%, PSA density (PSAD) ≥0.15 ng/mL/cc with rate of 62.8%, and PSA-AV ≤250 with rate of 83.5%. Combining with PSA-AV ≤250, patients those with tPSA 4 to 10 ng/mL could improve the detection from 36.0% up to 81%, those with PI-RADS v2 score 3 from 28.6% up to 60.0%.PI-RADS v2 and PSA-AV are faithful variables for detecting PCa. And for patients, those in gray zones of PI-RADS v2 and tPSA, PSA-AV can improve detection rate of PCa.

Optimizing prostate cancer accumulating model: combined PI-RADS v2 with prostate specific antigen and its derivative data

BACKGROUND

To establish a new accumulating model to enhance the accuracy of prostate cancer (PCa) diagnosis by incorporating prostate-specific antigen (PSA) and its derivative data into the Prostate Imaging-Reporting and Data System version 2 (PI-RADS v2).

METHODS

A total of 357 patients who underwent prostate biopsy between January 2014 and December 2017 were included in this study. All patients had 3.0 T multiparametric magnetic resonance imaging (MRI) and complete laboratory examinations. PI-RADS v2 was used to assess the imaging. PSA, PSA density (PSAD), the free/total PSA ratio (f/t PSA) and the Gleason score (GS) were classified into four-tiered levels, and optimal weights were pursued on these managed levels to build a PCa accumulating model. A receiver operating characteristic curve was generated.

RESULTS

In all, 174 patients (48.7%) had benign prostatic hyperplasia, and 183 (51.3%) had PCa, among whom 149 (81.4%, 149/183) had clinically significant PCa. The established model 6 (PI-RADS v2 + level of PSAD + level of f/t PSA+ level of PSA) had a sensitivity and specificity of 81.4 and 84.5%, respectively, at the cut-off point of 11 in PCa diagnosis. Correspondingly, at the 12 cut-off point, the sensitivity and specificity were 87.7 and 83.0%, respectively, in diagnosing clinically significant PCa. The score of the new accumulating system was significantly different among the defined GS groups (p < 0.001). The mean values and 95% confidence intervals for GS 1-4 groups were 10.20 (9.63-10.40), 12.03 (11.19-12.87), 14.12 (13.60-14.64) and 15.44 (15.09-15.79).

CONCLUSIONS

A new PCa accumulating model may be useful in improving the accuracy of the primary diagnosis of PCa and helpful in the clinical decision to perform a biopsy when MRI results are negative.

The reference intervals for CA125, CA15-3, CA19-9, CA72-4, AFP, CEA, NSE and CYFRA21-1

Tumor markers are noninvasive diagnostic tools for cancer. Their abnormal expression often occurs earlier than clinical symptoms or other detection signals. Appropriate reference intervals (RIs) of tumor markers are important for health evaluation, cancer diagnosis, therapy monitoring and prognosis assessment. In this study, we aimed to establish the RIs of cancer antigen 125 (CA125), CA15-3, CA19-9, CA72-4, alpha fetoprotein (AFP), carcino-embryonic antigen (CEA), neuron-specific enolase (NSE) and cytokeratin 19 fragment antigen 21-1 (CYFRA21-1) in apparently healthy Henan population. A total of 1705 apparently healthy participants (21-89 years) were recruited from five representative geographical regions in Henan province. Nonparametric 95th percentile intervals were used to define the RIs of CA125, CA15-3, CA19-9, CA72-4, AFP, CEA, NSE and CYFRA21-1. The test results of CA125, CA15-3, CA19-9, CA72-4, AFP, CEA, NSE and CYFRA21-1 can traceable to reference measurement procedures. The age- and gender-specific RIs of the tumor markers were established. We established age- and gender-specific RIs for CA125, CA15-3, CA19-9, CA72-4, AFP, CEA, NSE and CYFRA21-1. The newly established RIs should be more suitable for Henan population. It will be valuable for clinicians to make a medical diagnosis, therapeutic management decision and other physiological assessment.

Age-Specific Reference Ranges of Prostate-Specific Antigen among Saudi Men as a Representation of the Arab Population

OBJECTIVE

To describe the reference ranges of serum prostate-specific antigen (PSA) in Saudi men. Materials/Subjects and Methods: Saudi males, aged 30 and above, were invited to participate in the study. Blood samples were taken from each subject to determine serum levels of PSA. Blood sugar levels, lipid profile, and anthropometric measurements were also obtained.

RESULTS

Our cohort consisted of 7,814 men; their mean PSA level was 1.24 ng/mL. The majority (90.5%) had PSA values between 0 and 2.5 ng/mL. The median PSA and the 95th percentile increased steadily with age. There was a sharp increase in the 95th percentile, from 3.8 ng/mL in men between 60 and 70 years old to 6.9 ng/mL in men over 71 years old. The 95th percentiles of PSA serum levels were lower in Saudi men than in the general population.

CONCLUSIONS

PSA serum levels in Saudi men are lower than in other communities. Creating age-specific reference ranges could improve the sensitivity of the PSA tests by allowing the detection of treatable tumors in younger men if the threshold of 4.0 ng/mL is lowered. Furthermore, unnecessary biopsies among older men may be avoided if the threshold is increased.

Dual-timing PSA as a biomarker for patients with salvage intensity modulated radiation therapy for biochemical failure after radical prostatectomy

We investigated the outcomes and the associated clinical-pathological factors in patients with prostate cancer (PCa) undergoing salvage intensity modulated radiation therapy (IMRT) for post-radical-prostatectomy (RP) biochemical failure. We report clinical outcomes of post-RP salvage IMRT, and describe chronic toxicity in these patients.Fifty patients with PCa underwent post-RP salvage IMRT. The median dose of IMRT was 70 Gy to the prostatic and seminal vesicle bed. Clinical-pathological and toxicity information were collected. The prostate cancer-specific survival (PCSS), disease-free survival (DFS), and biochemical-failure-free survival (BFFS) were calculated. Prognostic factors were analyzed for their association with disease control.The median follow-up time was 74 months. The 5-year PCSS, DFS, and BFFS after salvage IMRT were 95%, 88%, and 60%, respectively. Two patients (4%) experienced late gastrointestinal toxicity ≥ grade 3, and 5 patients (10%) had late genitourinary toxicity ≥ grade 3. On multivariate analysis, post-RP prostate-specific antigen (PSA) nadir ≤0.1 ng/ml (P=0.018) and PSA ≤0.5 ng/ml at salvage IMRT (P=0.016) were independent factors predicting better BFFS. Patients with both post-RP PSA nadir ≤0.1 ng/ml and PSA ≤0.5 ng/ml at salvage IMRT had a 5-year BFFS of 83% as compared with 43% in other patients (P=0.001).In conclusion, with hormonal therapy in most PCa patients, the addition of salvage IMRT for post-RP biochemical failure can achieve a good outcome with low toxicity. Patients with a post-RP PSA nadir ≤0.1 ng/ml and PSA ≤0.5 ng/ml at salvage IMRT could benefit the most from salvage IMRT.

A novel classification of prostate specific antigen (PSA) biosensors based on transducing elements

During the last few decades, there has been a tremendous rise in the number of research studies dedicated towards the development of diagnostic tools based on bio-sensing technology for the early detection of various diseases like cardiovascular diseases (CVD), many types of cancer, diabetes mellitus (DM) and many infectious diseases. Many breakthroughs have been developed in the areas of improving specificity, selectivity and repeatability of the biosensor devices. Innovations in the interdisciplinary areas like biotechnology, genetics, organic electronics and nanotechnology also had a great positive impact on the growth of bio-sensing technology. As a product of these improvements, fast and consistent sensing policies have been productively created for precise and ultrasensitive biomarker-based disease diagnostics. Prostate-specific antigen (PSA) is widely considered as an important biomarker used for diagnosing prostate cancer. There have been many publications based on various biosensors used for PSA detection, but a limited review was available for the classification of these biosensors used for the detection of PSA. This review highlights the various biosensors used for PSA detection and proposes a novel classification for PSA biosensors based on the transducer type used. We also highlight the advantages, disadvantages and limitations of each technique used for PSA biosensing which will make this article a complete reference tool for the future researches in PSA biosensing.

The age-specific reference intervals for tPSA, fPSA, and %fPSA in healthy Han ethnic male

INTRODUCTION

Prostate cancer (PC) is one of the most common malignancies in male, and has become the fastest growing malignancy in recent years. Prostate specific antigen (PSA) is widely used as a tumor marker to screen for PC. Many studies have been performed to define the reference intervals (RIs) for total circulating PSA (tPSA). The results were different among different nations and races, even in the same race. Few researches have been performed on the RIs of free PSA (fPSA) and the ratio of free to total PSA (%fPSA). In this study, we aimed to simultaneously determine the age-specific RIs for tPSA, fPSA, and %fPSA in the healthy Han ethnic male.

METHODS

A total of 1862 apparently healthy male aged from 21 to 94 years were included in our study. Nonparametric 95th percentile intervals were used to define the RIs.

RESULTS

The reference limits in different age groups (21-50, 51-60, 61-70, 71-80, and ≥81 years) were 2.07, 3.59, 4.93, 6.83, and 7.73 ng/mL for tPSA, and 0.60, 0.76, 0.83, 1.30, and 2.41 ng/mL for fPSA. The RIs of %fPSA were ≥0.16 for 21-50 years and ≥0.13 for male over 50 years old.

CONCLUSIONS

We established age-specific RIs for tPSA, fPSA and %fPSA. The newly established RIs should be more suitable for Chinese Han ethnic male. It will be valuable for physicians to make exact medical decision and appropriate medical intervention.

Age-specific Serum Prostate Specific Antigen Ranges Among Apparently Healthy Nigerian Men Without Clinical Evidence of Prostate Cancer

INTRODUCTION

Serum prostate specific antigen (PSA) levels increase with age and varies among different races and communities. The study was aimed at defining the age-specific reference ranges of serum PSA in our environment.

METHODS

We evaluated the relationship between age and serum PSA levels and the age-specific reference ranges of serum PSA among civil servants in Lagos, who underwent routine medical checkups. Criteria for inclusion were men who have no lower urinary tract symptoms, normal digital rectal examination and serum PSA ≤ 20 ng/ml. SPSS Statistic 21 was used for data evaluation and the mean, median, 95(th) percentile PSA levels were estimated. Pearson's correlation was used to examine the relationship, and P < 0.05 was considered significant.

RESULTS

4032 men met the criteria for inclusion in the evaluation. The mean age was 51.6 (range 40-70) years, and there was a strong correlation between serum PSA levels and age (r = 0.097, P < 0.001). PSA ranges of 0-2.5, >2.5-4.0, >4.0-10, and >10 ng/ml were found in 3218 (80%), 481 (12%), 284 (7%), and 52 (1%) men, respectively. The mean, median and the 95(th) percentile PSA for the overall group were 1.84, 1.33, and 5.2 ng/ml respectively. However the 95(th) percentile PSA levels for men aged 40-49, 50-59, and 60-70 years were 4.78, 5.47, and 8.93 ng/ml respectively.

CONCLUSION

The age-specific PSA levels among Nigerian men for each age group is higher than what was described for men in the Western world. These reference ranges of serum PSA should be considered for men aged ≥40 years in our environment.

Prostate-specific antigen-based population screening for prostate cancer: current status in Japan and future perspective in Asia

In Western countries, clinical trials on prostate cancer screening demonstrated a limited benefit for patient survival. In the Asia-Pacific region, including Japan, the rate of prostate-specific antigen (PSA) testing remains very low compared with Western countries, and the benefits of population-based screening remain unclear. This review describes the current status of population screening and diagnosis for prostate cancer in Japan and discusses the efficacy of population screening for the Asian population. Since the 1990s, screening systems have been administered by each municipal government in Japan, and decreases in the prostate cancer mortality rate are expected in some regions where the exposure rate to PSA screening has increased markedly. A population-based screening cohort revealed that the proportion of metastatic disease in cancer detected by screening gradually decreased according to the increased exposure rate, and a decreasing trend in the proportion of cancer with high serum PSA levels after population screening was started. The prognosis of the prostate cancer detected by population screening was demonstrated to be more favorable than those diagnosed outside of the population screening. Recent results in screening cohorts demonstrated the efficacy of PSA. These recent evidences regarding population-based screening in Japan may contribute to establishing the optimal prostate cancer screening system in Asian individuals.

The use of a gas chromatography-sensor system combined with advanced statistical methods, towards the diagnosis of urological malignancies

Prostate cancer is one of the most common cancers. Serum prostate-specific antigen (PSA) is used to aid the selection of men undergoing biopsies. Its use remains controversial. We propose a GC-sensor algorithm system for classifying urine samples from patients with urological symptoms. This pilot study includes 155 men presenting to urology clinics, 58 were diagnosed with prostate cancer, 24 with bladder cancer and 73 with haematuria and or poor stream, without cancer. Principal component analysis (PCA) was applied to assess the discrimination achieved, while linear discriminant analysis (LDA) and support vector machine (SVM) were used as statistical models for sample classification. Leave-one-out cross-validation (LOOCV), repeated 10-fold cross-validation (10FoldCV), repeated double cross-validation (DoubleCV) and Monte Carlo permutations were applied to assess performance. Significant separation was found between prostate cancer and control samples, bladder cancer and controls and between bladder and prostate cancer samples. For prostate cancer diagnosis, the GC/SVM system classified samples with 95% sensitivity and 96% specificity after LOOCV. For bladder cancer diagnosis, the SVM reported 96% sensitivity and 100% specificity after LOOCV, while the DoubleCV reported 87% sensitivity and 99% specificity, with SVM showing 78% and 98% sensitivity between prostate and bladder cancer samples. Evaluation of the results of the Monte Carlo permutation of class labels obtained chance-like accuracy values around 50% suggesting the observed results for bladder cancer and prostate cancer detection are not due to over fitting. The results of the pilot study presented here indicate that the GC system is able to successfully identify patterns that allow classification of urine samples from patients with urological cancers. An accurate diagnosis based on urine samples would reduce the number of negative prostate biopsies performed, and the frequency of surveillance cystoscopy for bladder cancer patients. Larger cohort studies are planned to investigate the potential of this system. Future work may lead to non-invasive breath analyses for diagnosing urological conditions.

Decreasing trend in prostate cancer with high serum prostate-specific antigen levels detected at first prostate-specific antigen-based population screening in Japan

To clarify the recent trends in prostate-specific antigen (PSA) distribution in men in Japan, we analyzed the PSA distributions of men undergoing PSA-based population screening. We summarized the annual individual data of PSA-based population screening in Kanazawa, Japan, from 2000 to 2011, and analyzed baseline serum PSA values of the participants at the first population screening. Serum PSA distributions were estimated in all participants and those excluding prostate cancer patients according to age. From 2000 to 2011, 19 620 men participated aged 54–69 years old in this screening program. Mean baseline serum PSA level of all participants at the first screening was 2.64 ng ml⁻¹ in 2000, and gradually decreased to approximately 1.30 ng ml⁻¹ in 2006. That of participants excluding prostate cancer patients was 1.46 ng ml⁻¹ in 2000, and there was no remarkable change during the study period. The 95^th percentiles in the participants excluding prostate cancer patients detected at the first population screening of men aged 54–59, 60–64, and 65–69 years old were 2.90, 3.60, and 4.50 ng ml⁻¹, respectively. After the commencement of population screening, the proportion of prostate cancer patients with high serum PSA levels decreased. However, there were no changes in serum PSA levels in men without prostate cancer. Age-specific PSA reference level of men without prostate cancer in Japan was similar to that in China and Korea.

Age-Specific Cutoff Value for the Application of Percent Free Prostate-Specific Antigen (PSA) in Chinese Men with Serum PSA Levels of 4.0-10.0 ng/ml

OBJECTIVE

The influence of age on the performance of percent free prostate-specific antigen (%fPSA) in diagnosing prostate cancer (PCa) in East Asians is controversial. We tested the diagnostic performance of %fPSA in a multi-center biopsy cohort in China and identified the proper age-specific cutoff values to avoid unnecessary biopsies.

METHODS

Consecutive patients with a prostate-specific antigen (PSA) level of 4.0-10.0 ng/ml or 10.1-20.0 ng/ml who underwent transrectal ultrasound-guided or transperineal prostate biopsy were enrolled from 22 Chinese medical centers from Jan 1, 2010 to Dec 31, 2013. The diagnostic accuracy of PSA and %fPSA was determined using the area under the receiver operating characteristic (ROC) curve (AUC). Age-specific cutoff values were calculated using ROC curve analysis.

RESULTS

The median %fPSA was much lower in younger patients compared with older patients with a PSA level of 4.0-10.0 ng/ml or 10.1-20.0 ng/ml. The AUC of %fPSA was higher than PSA only in older patients. In patients aged 50 to 59 years, %fPSA failed to improve the diagnosis compared with PSA in these two PSA ranges. Age-specific cutoff values were 24%, 27% and 32% for patients aged 60-69, 70-79 and ≥80 years, respectively, to reduce unnecessary biopsies in men with PSA levels of 4.0-10.0 ng/ml to detect 90% of all PCa.

CONCLUSIONS

The effectiveness of %fPSA is correlated with age in the Chinese population. Age-specific cutoff values would help avoid unnecessary biopsies in the Chinese population.

Percent free prostate-specific antigen for prostate cancer diagnosis in Chinese men with a PSA of 4.0-10.0 ng/mL: Results from the Chinese Prostate Cancer Consortium

Objective

To test the diagnostic performance of percent free prostate-specific antigen (%fPSA) in predicting any prostate cancer (PCa) and high-grade prostate cancer (HGPCa) in a retrospective multi-center biopsy cohort with a PSA level of 4.0-10.0 ng/mL in China.

Methods

Consecutive patients with a PSA of 4.0-10.0 ng/mL who underwent transrectal ultrasound-guided biopsy were enrolled at 16 Chinese medical centers from January 1st, 2010 to December 31st, 2013. Total and free serum PSA determinations were performed using three types of electro-chemiluminescence immunoassays recalibrated to the World Health Organization (WHO) standard. The diagnostic accuracy of PSA, %fPSA, and %fPSA in combination with PSA (%fPSA + PSA) was determined using the area under the receiver operating characteristic (ROC) curve (AUC).

Results

A total of 2310 consecutive men with PSA levels between 4.0 and 10.0 ng/mL were included, and the detection rate of PCa was 25.1%. The AUC of %fPSA and %fPSA + PSA in predicting any PCa was superior to PSA alone in men aged ≥60 years (0.623 vs. 0.534, p < 0.0001) but not in men aged 40-59 years (0.517 vs. 0.518, p = 0.939). Similar result was yield in predicting HGPCa.

Conclusion

In a clinical setting of Chinese men with 4.0-10.0 ng/mL PSA undergoing initial prostate biopsy, adding %fPSA to PSA can moderately improve the diagnostic accuracy for any PCa and HGPCa compared with PSA alone in patients ≥60 but not in patients aged 40-59 years.

Prostate cancer in Asia: A collaborative report

The incidence of prostate cancer (PCa) within Asian population used to be much lower than in the Western population; however, in recent years the incidence and mortality rate of PCa in some Asian countries have grown rapidly. This collaborative report summarized the latest epidemiology information, risk factors, and racial differences in PCa diagnosis, current status and new trends in surgery management and novel agents for castration-resistant prostate cancer. We believe such information would be helpful in clinical decision making for urologists and oncologists, health-care ministries and medical researchers.

A hospital based study on reference range of serum prostate specific antigen levels

BACKGROUND & OBJECTIVES

Serum prostate specific antigen (PSA) levels are known to vary with race and ethnicity, environmental factors, lifestyle, metabolic and physiologic changes and advancing age. This study was designed to determine age specific serum PSA level in healthy Indian men and its comparison with that reported in different populations of the world.

METHODS

A total of 1300 adult men who attended Executive Health Check-up programme in a tertiary care hospital in Haryana, India, were included in the study. Forty seven men were excluded from the analysis because of urological conditions affecting PSA values. Overall, 1253 men were analyzed for age specific PSA values.

RESULTS

The age specific reference range of serum PSA values was 0.71 ng/ml in those younger than 40 yr; 0.85 ng/ml in 40-49 yr; 1.13 ng/ml in 50-59 yr group; 1.45 ng/ml in 60-69 yr group; 1.84 ng/ml in 70-79 yr group and 2.35 ng/ml in men older than 80 yr.

INTERPRETATION & CONCLUSIONS

Our study provided the age-specific reference range of serum PSA in healthy men in India. The data suggested that the PSA levels were associated with increasing age.

Age-specific reference range of prostate-specific antigen and prostate cancer detection in population-based screening cohort in Japan: verification of Japanese Urological Association Guideline for prostate cancer

OBJECTIVES

To investigate the age-specific reference range of prostate-specific antigen and clinical characteristics of screening-detected cancer in prostate-specific antigen-based screening, and to verify the age-specific prostate-specific antigen cut-offs in the Japanese Urological Association Guidelines.

METHODS

Prostate-specific antigen distributions were estimated in a total of 69,028 screening tests according to the age of the participants in population screening from 2000 to 2013. The age-specific reference range of prostate-specific antigen for detection of cancer was investigated by analyzing the receiver operating characteristic curves. Furthermore, the clinicopathological features of screening-detected cancer with serum prostate-specific antigen levels below the age-specific prostate-specific antigen cut-off in the Japanese Urological Association Guidelines were also investigated.

RESULTS

Of all 69,028 screens, 2053 prostate biopsies (2.97%) were carried out and 549 cases of cancer (0.79%) were diagnosed. The 95th percentiles in all participants aged 54-59, 60-64, 65-69 and 70-75 years old were 2.90, 3.60, 4.10, and 4.70 ng/mL, respectively. The optimal prostate-specific antigen cut-offs for cancer detection determined from the receiver operating characteristic curves were 2.3 and 2.6 for the age ranges 54-69 and 70-75 years, respectively. These values were lower than the age-specific cut-offs in the Japanese Urological Association Guidelines. Of all 137 patients with prostate-specific antigen levels below the age-specific cut-offs in the Japanese Urological Association Guidelines, 80 (58.4%) had unfavorable clinicopathological features as active surveillance criteria.

CONCLUSIONS

The age-specific reference range of prostate-specific antigen might be lower than that recommended in the Japanese Urological Association Guidelines. An individualized and natural history-adjusted screening system should be established for screening participants with low prostate-specific antigen level.

Nano-Based PSA Biosensors: An Early Detection Technique of Prostate Cancer

Prostate-specific antigen or PSA is a protein biomarker which is produced by the cells of prostate gland. The normal level of PSA in blood is often elevated in men with prostate cancer. In India, prostate cancer is one among the five, mostly cited cancer in men and it is getting increased by 1% every year. The screening test used for prostate cancer is the Prostate Specific Antigen test. The first PSA assay was determined in 1979. Most of the current techniques used for PSA detection are utilizing large analyzers, there by increased time and cost. Increased PSA levels can also because of prostatitis (inflammation of the prostate gland) or due to many other reasons. A proper technique to differential diagnose this disease is also an issue. The benchmark for the PSA level cannot be determined accurately. For this, various types of biosensors are used. This review journal is is trying to analyze variouus Nano-Biosensors used for early detection of PSA from blood in an early stage itself.

Reference Ranges of Age-Related Prostate-Specific Antigen in Men without Cancer from Beijing Area

BACKGROUND

To determine the normal ranges of serum age-related prostate-specific antigen (PSA) level in men from Beijing area without cancer.

METHODS

In this cross sectional study, form April 2010 to October 2011, 1611 healthy men undergoing a routine health check-up in our hospital and all men received three examinations including serum PSA test, digital rectal ex-amination and transrectal ultrasound. Men with any two abnormal results of the three examinations were undergone a prostate biopsy. Men with any two normal results of the three examinations or with negative biopsy were defined as men without cancer. Men with a prior history of prostate cancer/surgery or with urinary tract infection/obstruction were excluded. 1572 men without cancer were recruited into the study finally and were stratified into 10-year age groups: 40 to 49, 50 to 59, 60 to 69, 70 to 79, and older than 80.

RESULTS

The median PSA value (95th percentile range) was 0.506(1.565), 1.04(2.920), 1.16(4.113), 1.34(5.561)and 2.975 (7.285) for each age group respectively, and the 25th percentile to 75 percentile was 0.343 to 0.923, 0.663 to 1.580, 0.693 to 2.203, 0.789 to 2.368 and 1.188 to 4.295 respectively. The serum PSA value is directly correlated with age (r=0.314, P＜0.001).

CONCLUSIONS

Use the age-related range for PSA increases the sensitivity in younger men and decreases the biopsy rate in older patients.

The number of tPSA tests continues to rise and variation in testing practices persists: a survey of laboratory services in Ireland 2008-2010

BACKGROUND

Ireland had the highest incidence of prostate cancer in Europe in 2008, due to widespread prostate specific antigen (PSA) testing.

AIMS

To investigate practices and costs of PSA testing in Ireland, 2008-2010.

METHODS

Postal laboratory questionnaire. Results were compared with 2006 and 2007 surveys.

RESULTS

Response rate was 95 % (42/44). In 2010, 37 laboratories measured total PSA (tPSA); 10 measured free PSA (fPSA). Eight assays were used and cut-offs to define 'normal' tPSA varied widely. There was a 9.9 % annual increase in the number of tPSA tests and a -31 % annual decrease in the number of fPSA, 2006-2010. A 100-fold difference in tPSA workload was observed across laboratories. In 2010, the estimated cost of PSA testing was <euro>3,649,984 (95 % CI <euro>2,532,745-<euro>4,767,222).

CONCLUSIONS

Health service costs of PSA testing are significant. The number of tPSA tests continues to rise; fPSA use fell by almost one-third. Inter-laboratory variation in testing practices persists. These have potentially important clinical consequences for men and need to be addressed.

Age-specific prostate specific antigen cutoffs for guiding biopsy decision in Chinese population

Background

Age-specific prostate specific antigen (PSA) cutoffs for prostate biopsy have been widely used in the USA and European countries. However, the application of age-specific PSA remains poorly understood in China.

Methods

Between 2003 and 2012, 1,848 men over the age of 40, underwent prostate biopsy for prostate cancer (PCa) at Huashan Hospital, Shanghai, China. Clinical information and blood samples were collected prior to biopsy for each patient. Men were divided into three age groups (≤60, 61 to 80, and >80) for analyses. Digital rectal examination (DRE), transrectal ultrasound (prostate volume and nodule), total PSA (tPSA), and free PSA (fPSA) were also included in the analyses. Logistic regression was used to build the multi-variate model.

Results

Serum tPSA levels were age-dependent (P = 0.008), while %fPSA (P = 0.051) and PSAD (P = 0.284) were age-independent. At a specificity of 80%, the sensitivities for predicting PCa were 83%, 71% and 68% with tPSA cutoff values of 19.0 ng/mL (age≤60),21.0 ng/mL (age 61–80), and 23.0 ng/mL (age≥81). Also, sensitivities at the same tPSA levels were able to reach relatively high levels (70%–88%) for predicting high-grade PCa. Area (AUC) under the receive operating curves (ROCs) of tPSA, %fPSA, PSAD and multi-variate model were different in age groups. When predicting PCa, the AUC of tPSA, %fPSA, PSAD and multi-variate model were 0.90, 0.57, 0.93 and 0.87 respectively in men ≤60 yr; 0.82, 0.70, 0.88 and 0.86 respectively in men 61–80 yr; 0.79, 0.78, 0.87 and 0.88 respectively in men>80 yr. When predicting Gleason Score ≥7 or 8 PCa, there were no significant differences between AUCs of each variable.

Conclusion

Age-specific PSA cutoff values for prostate biopsy should be considered in the Chinese population. Indications for prostate biopsies (tPSA, %fPSA and PSAD) should be considered based on age in the Chinese population.

The Distribution of PSA Age-Specific Profiles in Healthy Irish Men between 20 and 70

Background. Ireland is estimated to have the highest European incidence rate of prostate cancer (Pca) in 2006 which will increase by 275% by 2025. This study aimed to determine PSA cutoff values in different age groups of healthy male patients without Pca. Methods. 660 men in a pilot men's health programme, aged 18–67, had PSA assayed. Men were grouped into 8 age groups at 5-year intervals: 30–34, 35–39, 40–44, 45–49, 50–54, 55–59, 60–64, and 64–70. Results. Linear regression demonstrates a PSA velocity of 0.024 ng/ml/year. The 95% confidence interval demonstrates a near flat line of PSA values from age 20 to 50 and rises after. When transformed logarithmically, PSA correlates highly with expected values from the normal distribution (0.98). A fractional polynomial quantile regression model was used to predict median and 95th percentile for PSA as follows: 30–34 (0.73, 1.57), 35–39 (0.71, 1.65), 40–44 (0.73, 1.85), 45–49 (0.78, 2.17), 50–54 (0.88, 2.63), 55–59 (1.01, 3.25), 60–64 (1.20, 4.02), and 64–70 (1.43, 4.96). Conclusions. PSA levels are similar to other racial groups but not as high as US Caucasians until 65 years. These data define the predicted PSA for the Irish population and provide a reference for future screening programmes.

Characteristics of baseline PSA and PSA velocity in young men without prostate cancer: Racial differences

BACKGROUND

Baseline prostate specific antigen (PSA) and PSA velocity used to stratify subsequent prostate cancer risk in young men may not directly applicable to all populations. We sought to compare the baseline PSA and PSA velocity among ethnic groups.

PATIENTS AND METHODS

Chinese, African-American (AA), and Caucasian-American (CA) men aged ≤50 years old without prostate cancer were used to identify baseline PSA and PSA velocity. The differences of baseline PSA and PSA velocity between races were assessed. The important cutoffs of baseline PSA and PSA velocity were used to stratify patients among races.

RESULTS

Four thousand two hundred six Chinese, 997 AA, and 2,030 CA were included. The rates of baseline PSA of ≥1.0, ≥2.5, and ≥4.0 ng/ml was 24.4%, 4.2%, and 2.1% in Chinese, 30.7%, 5.2%, and 1.8% in AA, 29.7%, 5.3%, and 2.8% in CA, respectively. The rates of PSA velocity of ≥0.35, ≥0.75, and ≥1.0 ng/ml/year was 6.0%, 3.1%, and 2.6% in Chinese, 5.3%, 2.3%, and 1.7% in AA, 5.4%, 3.5%, and 3.3% in CA, respectively. Chinese had a lower baseline PSA and higher PSA velocity as compared to AA and CA. Baseline PSA and PSA velocity in AA had no statistical differences as compared to CA.

CONCLUSIONS

The distributions of baseline PSA and PSA velocity in young men among Chinese, AA, and CA races are different. These characteristics shall be taken into account when using these variables to stratify risk of prostate cancer in young men.

The value of prostate-specific antigen in Asia

One of the most important diagnostic tools used to detect prostate cancer is prostate-specific antigen (PSA), yet increased PSA alone does not reflect the presence of prostate cancer. Other pathological prostatic conditions such as prostatitis and benign prostatic hyperplasia (BPH) may also increase the level of PSA. However, unlike in other prostate diseases, PSA has a key role in the diagnosis and management of prostate cancer. The incidence of prostate cancer varies from country to country, with the highest incidence being found in the Western world and the lowest in Asian countries. Owing to the low incidence of prostate cancer, there could be different views regarding the use of PSA in Asian countries, especially for the early detection/screening of prostate cancer. The purpose of this article is to review the use and value of PSA in the diagnosis of prostate diseases (especially prostate cancer) in Asian countries/populations. A literature search was performed in 'MEDLINE' (PubMed) and Google Scholar using main keywords such as 'PSA', 'PSA usage', 'PSA sensitivity and specificity', 'Asia', and various countries in Asia. Articles that provide population/community-based PSA data, together with the characteristics, distribution, and indications for PSA testing in the respective countries, were selected. Eleven papers were finally selected for inclusion in this review. Five studies found that PSA, by its 95th percentile value, have an age-referenced tendency in Asian males, similarly to the West. The predictive values of PSA in detecting prostate cancer are also quite similar to those in Western countries. With the exponential growth of the aging population in the world, especially in Asia, the incidence of prostate cancer will follow this upward trend. Therefore, PSA testing for screening or diagnostic purposes would increase with time in Asia.

Quantitative assessment of AKAP12 promoter methylation in human prostate cancer using methylation-sensitive high-resolution melting: correlation with Gleason score

OBJECTIVES

To quantitatively investigate the A kinase anchoring protein 12 (AKAP12) gene promoter methylation and its association with clinicopathologic variables in human prostate cancer (PCa). The AKAP12 gene has shown reduced expression and marked hypermethylation in a variety of cancers.

METHODS

The percentage levels of DNA methylation were measured in 78 PCa, 22 benign prostatic hyperplasia, and 22 normal adjacent tissue samples using an AKAP12 methylation-sensitive high-resolution melting assay. AKAP12 gene expression was also examined in 4 human prostate carcinoma cell lines, PC-3, DU145, LNCaP, and 22RV1, using quantitative reverse transcriptase-polymerase chain reaction and methylation-sensitive high-resolution melting analysis and after DNA methyltransferase inhibition with 5-aza-2'-deoxycytidine.

RESULTS

Methylation (>1%) of the AKAP12 promoter region was present in 47 (60.2%) of the 78 PCa, 5 (22.7%) of the 22 benign prostatic hyperplasia, and 2 (9.1%) of the 22 adjacent normal tissue samples. AKAP12 methylation was significantly greater in the PCa than in the benign prostatic hyperplasia or adjacent tissue samples (P < .01). AKAP12 methylation was significantly greater in the PCa samples with higher Gleason scores (P = .03); however, no correlation was found with age, pT category, or serum prostate-specific antigen level. Reverse transcriptase-polymerase chain reaction demonstrated that PC-3 and DU-145 cells expressed AKAP12 RNA and LNCaP and 22RV1 did not. The AKAP12 locus was methylated in the LNCaP and 22RV1 cells. Treatment of LNCaP cells with 5-aza-2'-deoxycytidine markedly decreased the methylation levels and increased the expression of AKAP12.

CONCLUSIONS

The results of the present study have demonstrated that AKAP12 promoter methylation is a frequent event in human PCa. AKAP12 methylation represents a potential molecular biomarker for predicting the malignancy of PCa.