Mass screening of prostate cancer in a Chinese population:the relationship between pathological features of prostate cancer and serum prostate specific antigen

Aim:To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA).Methods:A total of 12 027 Chinese men in Changchun were screened for prostate cancer by means of the serum total prostate specific antigen (tPSA) test (by Elisa assay).Transrectal ultrasound-guided systematic six-sextant biopsies were performed on those whose serum tPSA value was >4.0 ng/mL and those who had obstructive symptoms (despite their tPSA value) and were subject to subse- quent pathological analysis with the aid of the statistic software SPSS 10.0 (SPSS.Inc.,Chicago.USA).Results:Of the 12 027 cases,158 (including 137 patients whose serum tPSA values were >4.0 ng/mL and 21 patients [serum tPSA <4. 0 ng/mL] who had obstructive symptoms) undertook prostate biopsy.Of the 158 biopsies,41 cases of prostatic carci- noma were found (25.9 %,41/158).The moderately differentiated carcinoma and poorly differentiated carcinoma ac- counted for 61% and 34 %,respectively.A significant linear positive correlation between the serum tPSA and the Gleason scores in the 41 cases of prostatic carcinoma (r=0.312,P<0.01) was established.A significant linear positive correlation between the serum tPSA value of the 41 prostatic carcinoma and the positive counts of carcinoma in sextant biopsies was established (r=0.406,P<0.01),indicating a significant linear relationship between serum tPSA and the size of tumor. Condusion:This study was the first to conduct mass screening for prostate cancer by testing for serum tPSA values and the first to investigate the pathological features of prostate cancer in a cohort of Chinese men.Our results reveal that the moderately differentiated carcinoma is the most common type of prostate cancer.This study also has shown that the serum tPSA value in prostate cancer is associated with the Gleason score and the size of tumor.

A nomogram based on age, prostate-specific antigen level, prostate volume and digital rectal examination for predicting risk of prostate cancer

Nomograms for predicting the risk of prostate cancer developed using other populations may introduce sizable bias when applied to a Chinese cohort. In the present study, we sought to develop a nomogram for predicting the probability of a positive initial prostate biopsy in a Chinese population. A total of 535 Chinese men who underwent a prostatic biopsy for the detection of prostate cancer in the past decade with complete biopsy data were included. Stepwise logistic regression was used to determine the independent predictors of a positive initial biopsy. Age, prostate-specific antigen （PSA）, prostate volume （PV）, digital rectal examination （DRE） status, % free PSA and transrectal ultrasound （TRUS） findings were included in the analysis. A nomogram model was developed that was based on these independent predictors to calculate the probability of a positive initial prostate biopsy. A receiver-operating characteristic curve was used to assess the accuracy of using the nomogram and PSA levels alone for predicting positive prostate biopsy. The rate for positive initial prostate biopsy was 41.7% （223/535）. The independent variables used to predict a positive initial prostate biopsy were age, PSA, PV and DRE status. The areas under the receiver-operating characteristic curve for a positive initial prostate biopsy for PSA alone and the nomogram were 79.7% and 84.8%, respectively. Our results indicate that the risk of a positive initial prostate biopsy can be predicted to a satisfactory level in a Chinese population using our nomogram. The nomogram can be used to identify and counsel patients who should consider a prostate biopsy, ultimately enhancing accuracy in diagnosing prostate cancer.

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

This study is to determine age-specific prostate-specific antigen （PSA） distributions in Chinese men without prostate cancer （PC） and to recommend reference ranges for this population after comparison with other studies. From September 2003 to December 2006, 9 374 adult men aged from 18 to 96 years agreed to participate in the study. After all cases of PC were excluded, 8 422 adult men participated in statistical analysis and were divided into five age groups. Simple descriptive statistical analyses were carried out and quartiles and 95th percentiles were calculated for each age group. The age-specific PSA reference ranges are as follows： 4049 years, 2.15 ng mLl; 50-59 years, 3.20 ng mLl; 60-9 years, 4.10 ng mL^-1; 70-79 years, 5.37 ng mL^-1. The results indicate that the ethnic differences in PSA levels are obvious. The currently adopted Oesterling＇s age-specific PSA reference ranges are not appropriate for Chinese men. The reference ranges of this study should be more suitable to Chinese men.

Prostate-specific antigen half-life： a new predictor of progression- free survival and overall survival in Chinese prostate cancer patients

We investigated the potential value of prostate-specific antigen half-life （PSAHL） and decreasing velocity （PSAVd） to predict progression-free survival （PFS） and overall survival （OS） in Chinese patients with prostate cancer. A total of 153 patients treated with hormonal therapy were included in the study. Of these, 78 patients progressed to hormone- refractory prostate cancer （HRPC） and 24 patients died by the end of follow-up. PSAHL was defined as the time during which prostate-specific antigen （PSA） concentration became half of the initial value during the first hormonal therapy. PSAVd reflected the decreasing velocity of PSA during the first hormonal therapy. PFS was defined as the interval from the beginning of hormonal therapy to HRPC. Cox proportional hazards regression analysis was used to evaluate whether PSAHL and PSAVd were significantly associated with PFS and OS. The median PSAHL and PSAVd were 0.50 months and 33.8 ng mL^-1 per month. The median PFS and OS were 22.7 months （95% confidence interval [CI], 22.0-29.6 months） and 43.5 months （95% CI, 37.9-48.4 months）, respectively. On univariate and multivariate analysis, long PSAHL （〉 0.5 months）, metastatic disease, high biopsy Gleason scores （〉 8） and high nadir PSA （〉 0.4 ng mL^-1） were all found to be significantly associated with short PFS. Long PSAHL, high nadir PSA and short PSA doubling time （PSADT 〈 2.0 months） were significantly associated with short OS. There were no significant relationships between PSAVd and either PFS or OS. Thus, PSAHL is a promising new independent predictor of survival. Patients with long PSAHL were identified as those at high risk for a relatively short PFS and OS.

Radioiodine therapy for castration-resistant prostate cancer following prostate-specific membrane antigen promoter-mediated transfer of the human sodium iodide symporter

Radioiodine therapy, the most effective form of systemic radiotherapy available, is currently useful only for thyroid cancer because of the thyroid-specific expression of the human sodium iodide symporter （hNIS）. Here, we explore the efficacy of a novel form of gene therapy using prostate-specific membrane antigen （PSMA） promoter-mediated hNIS gene transfer followed by radioiodine administration for the treatment of castration-resistant prostate cancer （CRPC）. The androgen-dependent C33 LNCaP cell line and the androgen-independent C81 LNCaP cell line were transfected by adenovirus. PSMA promoter-hNIS （Ad.PSMApro-hNIS） or adenovirus.cytomegalovirus-hNIS containing the cytomegalovirus promoter （Ad.CMM-hNIS） or a control virus. The iodide uptake was measured in vitro. The in vivo iodide uptake by C81 cell xenografts in nude mice injected with an adenovirus carrying the hNIS gene linked to PSMA and the corresponding tumor volume fluctuation were assessed. Iodide accumulation was shown in different LNCaP cell lines after Ad.PSMApro-hNIS and Ad.CMV-hNIS infection, but not in different LNCaP cell lines after adenovirus.cytomegalovirus （Ad.CMV） infection. At each time point, higher iodide uptake was shown in the C81 cells infected with Ad.PSMApro-hNIS than in the C33 cells （P 〈 0.05）. An in vivo animal model showed a significant difference in 1311 radioiodine uptake in the tumors infected with Ad.PSMApro-hNIS, Ad.CMV-hNIS and control virus （P 〈 0.05） and a maximum reduction of tumor volume in mice infected with Ad.PSMApro-hNIS. These results show prostate-specific expression of the hNIS gene delivered by the PSMA promoter and effective radioiodine therapy of CRPC by the PSMA promoter-driven hNIS transfection.

Serum prostate-specific antigen as a predictor of prostate volume and lower urinary tract symptoms in acommunity-based cohort： a large-scale Korean screening study

The aim of this study is to assess the ability of serum prostate-specific antigen （PSA） to predict prostate volume （PV） and lower urinary tract symptoms （LUTS） represented by the international prostate symptom score （IPSS）. From January 2001 to December 2011, data were collected from men who first enrolled in the Korean Prostate Health Council Screening Program. Patients with a serum PSA level of 10 ng ml^-1 or age 〈40 years were excluded. Accordingly, a total of 34 857 men were included in our study, and serum PSA, PV and the IPSS were estimated in all patients. Linear and age-adjusted multivariate logistic analyses were used to assess the potential association between PSA and PV or IPSS. The predictive value of PSA for estimating PV and IPSS was assessed based on the receiver operating characteristics-derived area under the curve （AUC）. The mean PV was 29.9 ml, mean PSA level was 1.49 ng ml^-1 and mean IPSS was 15.4. A significant relationship was shown between PSA and PV, and the IPSS and PSA were also significantly correlated after adjusting by age. The AUCs of PSA for predicting PV ~20 ml, 〉25 ml and 〉35 ml were 0.722, 0.728 and 0.779, respectively. The AUCs of PSA for predicting IPSS 〉 7, 〉 13 and 〉 19 were 0. 548, 0.536 and 0. 537, respectively. Serum PSA was a strong predictor of PV in a community-based cohort in a large-scale screening study. Although PSA was also significantly correlated with IPSS, predictive values of PSA for IPSS above the cutoff levels were not excellent. Further investigations are required to elucidate the exact interactions between PSA and LUTS and between PSA and PV in prospective controlled studies. Such studies may suggest how PSA can be used to clinically predict PV and the IPSS.

Small ubiquitin-like modifier protein-specific protease 1 and prostate cancer

Small ubiquitin-like modifier protein （SUMO） modification is a highly dynamic process, catalyzed by SUMO- specific activating （El）, conjugating （E2） and ligating （E3） enzymes, and reversed by a family of SUMO-specific proteases （SENPs）. There are six members of the human SENP family, and each SENP has different cellular locations and substrate specificities. However, the precise roles of SENPs in cellular processes have not been elucidated to date. This brief review will focus on recent advances pertaining to the identified targets of SENP 1 and its potential role in prostate cancer.

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 m1-1 in 2000, and gradually decreased to approximately 1.30 ng ml-I in 2006. That of participants excluding prostate cancer patients was 1.46 ng m1-1 in 2000, and there was no remarkable change during the study period. The 95t＂ 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 m1-1, 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.

Body mass index and serum lipid profile influence serum prostate-specific antigen in Chinese men younger than 50 years of age

This study is to assess the potential factors that could affect the serum prostate-specific antigen （PSA） level in healthy younger men. We evaluated the associations of age, body mass index （BMI） and serum lipid profile with serum PSA level in 6774 Chinese men （aged 20-49 years） who received a routine health examination. Eligible men were classified into 10-year age groups, BMI was categorized as underweight （〈18.5）, normal （18.5-22.9）, overweight （23.0-24.9）, obese （25.0-29,9） and very obese （〉30） according to the redefined World Health Organization （WHO） criteria for the Asia-Pacific region. PSA levels were compared among groups as well, In multiple linear regression analysis, PSA was positively correlated with age （P〈0.0001）. Negative correlations existed between PSA and BMI （P〈0.0001） and triglyceride level （P=0.01）. No relationship could be found between PSA and serum cholesterol （P=0.711） or high-density lipoprotein （HDL; P =0.665）. In addition, we found that serum PSA levels increased with age and decreased with BMI. Our study demonstrates that age, BMI and triglyceride levels influence the PSA level in men 〈50 years of age.

Construction of Smac gene-containing and human prostate specific antigen promoter-regulated vector and its expression

To construct an eukaryotic expression vector containing Smac gene and study the expression efficiency and specificity of prostate specific antigen（PSA） enhancer/promoter in a possible targeted gene therapy scheme for prostate cancer. Methods： PSA enhancer （PSAE） and promoter （PSAP） sequences were amplified using PCR method. CMV and T7 promoters were deleted from pcDNA3.1-Smac and replaced by the two specific fragments to generate pPSAE-PSAP-Smac. After transfection into different cell lines, the status of cells was observed. And then, we determined the relative concentration of Smac mRNA in RT-PCR. Results： The recombinant plasmid of pPSAE-PSAP-Smac was successfully constructed. And only the prostate cancer cell line PC-3 was suppressed after transfection with pPSAE-PSAP-Smac. However, other nonprostate lines were not. Moreover, the concentration of Smac mRNA regulated by PSA promoter and enhancer was higher in comparison to the CMV promoter-driven control vectors. Conclusion： An expression vector containing the Smac gene （based on elements of the PSA gene regulatory sequences） has been developed and shown to function in prostate cancer cell lines which provides a solid platform for launching clinical studies.

Role of Prostate Specific Antigen (PSA) in Pathogenesis of Prostate Cancer

Prostate cancer (PCa) is most common diagnosed cancer in men and it is second most common cause of male cancer death. Many factors have been implicated in the pathogenesis of PCa. Although many papers have discussed the prostate specific antigen (PSA) as biomarker of PCa, very few have addressed its rule in the carcinogenesis, metastasis and invasion of PCa. In this article we will review the pathological role of PSA, as a potential target in the therapeutics of PCa.

Relationship between insulin resistance, obesity and serum prostate-specific antigen levels in healthy men

The purpose of this study was to determine the relationship between insulin resistance, obesity and serum prostate-specific antigen （PSA） levels in healthy men with serum PSA level below 4 ng mL-1. The men included in the study cohort were 11 827 healthy male employees of the Korea Hydro and Nuclear Power Co., LTD who had undergone medical checkups including fasting glucose, fasting insulin and serum PSA between January 2003 and December 2008. Insulin resistance was calculated by homeostasis model assessment （HOMA [fasting glucose × fasting insulin]/22.5） and quantitative insulin sensitivity check index （QUICK/; 1/[log （fasting insulin） ＋ log （fasting glucose）]）. Age-adjusted body mass index （BMI） was significantly increased according to increasing quartile of insulin resistance as determined by HOMA and QUICKI, respectively, in analysis of variance （ANOVA） test and Duncan＇s multiple comparison test （P 〈 0.001）, but age-adjusted serum PSA concentration was significantly decreased according to increasing quartile of insulin resistance as determined by HOMA and QUICK/（P 〈 0.001）. Age, BMI, insulin resistance by HOMA or QUICK/were significantly independent variables to serum PSA level in a multivariate linear regression analysis （P 〈 0.001）. Insulin resistance was a significant independent variable to serum PSA level along with BMI. Insulin resistance and BMI were negatively correlated with serum PSA level in healthy men. Insulin resistance was positively correlated with BMI.

Prostate-specific antigen kallikrein and the heart

Currently,there is growing interest regarding prostatespecific antigen(PSA) and the cardiovascular system.Increased PSA serum levels have been reported after prolonged cardiopulmonary resuscitation,cardiac surgery,extracorporeal cardiopulmonary bypass,acute myocardial infarction(AMI) and coronary artery stenting.The possible role of PSA in cardiac events has been questioned due to the finding of PSA decrease during AMI and by the correlation of variation in PSA levels with coronary lesions and occurrence of major adverse cardiac events.Complexed PSA forms and uncomplexed PSA forms are observed in the bloodstream but the increasing formation of irreversible bound PSA seems to be a crucial finding during AMI.Large studies need to be carried out to confirm these preliminary results and to elucidate unclear aspects.These findings present many potential directions for future research including the role of uncomplexed forms of PSA,the possible distribution of PSA in the heart,the relative expression levels in heart disease states,the mode of expression regulation and other potential specific substrates.The journey of PSA investigation could be longer than initially expected.

A population study of fasting time and serum prostate-specific antigen （PSA） level

Prostate cancer is one of the most common cancers in men. Traditional screening and diagnostic methods include digital rectal examinations （DREs）, biopsies and serum prostate-specific antigen （PSA） tests, with the latter being the more popular. PSA is a biomarker for prostate cancer; however, it is highly sensitive to external factors as well as other prostate diseases. As such, the reliability of of the serum PSA level as a sole screening and diagnostic tool for prostate cancer is controversial. Recently, it has been shown that fasting extremes can affect concentrations of serum chemistry analytes, thus raising the question of whether or not fasting has an effect on the highly sensitive PSA biomarker. Patients testing for serum PSA levels are often concomitantly submitting to other tests that require fasting, subjecting certain patients to a fasting PSA level while others not. The objective of this study was to investigate whether this discrepancy in fasting state translates into an effect on serum PSA levels. Serum PSA levels and fasting time records for 157 276 men who underwent testing at Calgary Laboratory Services （CLS; Calgary, Alberta, Canada） between 01 January 2010 and 31 March 2013 were accessed. Linear regression models of mean PSA levels and fasting times revealed a statistically important relationship at certain fasting times. Applying a dynamic mathematical model to explore the clinical effect of fasting suggests minimal impact on serum PSA result interpretation. Thus, patients can be tested for serum PSA levels regardless of their fasting state.

Early diagnosis of prostate cancer using free/total prostate specific antigen ratio: a population based screening data

Aim: To evaluate the use of free/total prostate specific antigen ratio (fPSA/tPSA ratio) in improving the early diagnosis of prostate cancer. Methods: The fPSA/tPSA ratio in the serum was analyzed in 187 men with tPSA ranging between 4.0 and 20.0 μg/L. All of them underwent ultrasound guided sextant prostatic biopsy. The results were calculated by SPSS 10.0 software. Results: (1) When the tPSA was within the ranges of 4.0 - 10.0 and 10.0 -20.0 μg/L, the prostate cancer detection rate was 18.1 % and 22.5 %, respectively; (2) The area under the curve (AUC) was bigger in fPSA/tPSA than in tPSA (P<0.05) in all the men; (3) When the cut off value of fPSA/tPSA ratio was set at 0.25 and the tPSA at 4.0 - 10.0 μg/L and 10.0 - 20.0 μg/L, the diagnostic sensitivity of tPSA was 90.5 % and 87.5 %, respectively. Thus at the tPSA ranges of 4.0 - 10.0 and 10.0 - 20.0 μg/L, 26.7 % and 11.3 % of biopsies could be avoided, respectively. Conclusion: The use of fPSA/tPSA ratio can improve the prostate cancer detection rate and reduce unnecessary biopsies when tPSA is within the range of 4.0 - 20.0 μg/L.

Contemporary outcomes in the detection of prostate cancer using transrectal ultrasound-guided 12-core biopsy in Singaporean men with elevated prostate specific antigen and/or abnormal digital rectal examination

Objective:Despite being the third commonest cancer in Singaporean men,there is a dearth of basic data on the detection rate of prostate cancer and post-procedure complication rates locally using systematic 12-core biopsy.Our objective is to evaluate prostate cancer detection rates using 12-core prostate biopsy based on serum prostate specific antigen(PSA)levels and digital rectal examination(DRE)findings in Singaporean men presenting to a single tertiary centre.The secondary objective is to evaluate the complication rates of transrectal prostate biopsies.Methods:We retrospectively examined 804 men who underwent first transrectal-ultrasound(TRUS)guided 12-core prostate biopsies from January 2012 to April 2014.Prostate biopsies were performed on men presenting to a tertiary institution when their PSA levels were
4.0 ng/mL and/or when they had suspicious DRE findings.Results:Overall prostate cancer detection rate was 35.1%.Regardless of DRE findings,patients were divided into four subgroups based on their serum PSA levels:0e3.99 ng/mL,4.00 e9.99 ng/mL,10.00e19.99 ng/mL and
20.00 ng/mL and their detection rates were 9.5%,20.9%,38.4% and 72.3%,respectively.The detection rate of cancer based on suspicious DRE findings alone was 59.2% compared to 36.5% based on serum PSA cut-off of 4.0 ng/mL alone.The post-biopsy admission rate for sepsis was 1.5%.Conclusion:In conclusion,using contemporary 12-core biopsy methods,the local prostate cancer detection rate based on serum PSA and DRE findings has increased over the past decade presumably due to multiple genetic and environmental factors.Post-biopsy sepsis remains an important complication worldwide.

Prostate specific antigen bounce after intensity-modulated radiation therapy in an Asian population

Objective:Serum prostate specific antigen(PSA)is commonly used to evaluate treatment response after definitive radiation therapy(RT).However,PSA levels can temporarily rise without a clear reason,termed“PSA bounce”,and often engender great anxiety for both patients and physicians.The present study aimed to determine the prevalence and factors that predict“PSA bounce”after intensity-modulated radiation therapy(IMRT),and the relevance to biochemical failure and cancer recurrence in an Asian population.Methods:We retrospectively reviewed 206 patients who received IMRT for prostate cancer from 2004 to 2012 in the National Cancer Centre Singapore.These patients were followed up with regular PSA monitoring.We defined“PSA bounce”as a rise of 0.1 ng/mL,followed by two consecutive falls.Patients with biochemical failure(PSA nadir t 2 ng/mL)were further evaluated for cancer recurrence.Results:Sixty-one patients(29.6%)experienced“PSA bounce”,at a median time of 16 months and lasted for 12 months.Age remained the most consistent predictor of the incidence,duration and extent of“PSA bounce”.Other contributory factors included baseline PSA,Gleason score and PSA nadir.Hormonal therapy and prostate volume did not affect this phenomenon.Sixteen patients(7.8%)developed biochemical recurrence,at median time of 32 months,of which 11 were confirmed to have metastatic disease.The median follow-up time was 71 months.

Analysis of results related to the percent free prostate specific antigen among men without prostate diseases in Xi'an area

To measure the percent of free prostate specific antigen （fPSA） among men without prostate diseases in Xi＇an area, and to study the relationship of percent fPSA with age and pathological grade, clinical stage of prostate cancer （PCa） with percent fPSA, and to analyze the difference between the data in China and the.overseas data to determine appropriate reference range for Chinese male. Methods： A total of 713 participants were enrolled into the study, with PSA, fPSA in serum measured and the percent fPSA calculated. Out of 713 cases, 679 without prostate diseases were divided into 5 groups by age, and then the relationships of PSA, fPSA and percent fPSA with age were studied, respectively. The relationship of pathological grade and clinical stage with percent fPSA of the 34 participants with PCa was also studied. With the help of the related data of men without prostate disease, the appropriate reference range for Chinese male was established. Results： The increases in PSA or fPSA were correlated with age, while there was no significant correlation between age and percent fPSA. The percent fPSA was also correlated with pathological grade and clinical stage of PCa. The percent fPSA of men without prostate disease in Xi＇an area was significandy lower than that in the related overseas data. The reference range of percent fPSA for Chinese male was≥ 15%. Conclusion： Percent fPSA might be more useful than PSA in the detection of prostate cancer. As the percent fPSA is decreased, the pathological grade is decreased, and the clinical stage is increased, the malignant degree is increased. The reference range of ≥15% is more appropriate for Chinese male.

The neutrophil-to-lymphocyte ratio at the prostate-specific antigen nadir predicts the time to castration-resistant prostate cancer

Dear editor,With the spread of prostate-specific antigen(PSA)screening,an increasing number of early-stage prostate cancers have been diagnosed recently,although many patients are still diagnosed in the advanced stage[1].Although most prostate cancers with metastatic lesions respond to initial androgen ablation therapy,responders ultimately develop progressive disease due to hormone-refractory cancer.

The Performance of Abnormal Digital Rectal Examination for the Detection of Prostate Cancer at Stratified Prostate Specific Antigen Levels

Objective: Our aim was to determine the performance of abnormal digital rectal examination (DRE) in prostate cancer detection at different PSA levels. Methods: A total of 1612 patients having abnormal DRE and/or elevated PSA whom underwent TRUS guided prostate biopsies were included in the study. Any palpable induration or nodularity was accepted as abnormal DRE findings. Pathologic features of biopsy specimens were compared within groups according to DRE findings and serum PSA level groups of 2.5 - 4, 4 - 10 and >10 ng/ml. Results: Abnormal DRE was detected in 339 patients;of whom 48.7% were determined to have cancer. Cancer detection rates of patients having abnormal DRE were found to be 20%, 31.5% and 68% at PSA ranges 2.5-4, 4-10 and > 10 ng/ml, respectively. Significantly higher grade cancers were detected by abnormal DRE at each PSA group. The positive and negative predictive values of abnormal DRE according to groups of PSA 2.5 - 4, 4 - 10 and > 10 ng/ml were 20% and 84.1%, 31.5% and 80.6%, 68% and 66.6%, respectively. Conclusion: At each PSA group DRE resulted in detecting significantly more cancers with Gleason score > 7. Although predictive value of abnormal DRE diminishes with concomitantly decreasing PSA levels, significance of DRE in the diagnosis of prostate cancer cannot be ignored.