Mass Screening For Prostate Cancer Research Articles

Cost-effectiveness analysis of PSA-based mass screening: Evidence from a randomised controlled trial combined with register data.

In contrast to earlier studies which have used modelling to perform cost-effectiveness analysis, this study links data from a randomised controlled trial with register data from nationwide registries to reveal new evidence on costs, effectiveness, and cost-effectiveness of organised mass prostate-cancer screening based on prostate-specific antigen (PSA) testing. Cost-effectiveness analyses were conducted with individual-level data on health-care costs from comprehensive registers and register data on real-world effectiveness from the two arms of the Finnish Randomised Study of Screening for Prostate Cancer (FinRSPC), following 80,149 men from 1996 through 2015. The study examines cost-effectiveness in terms of overall mortality and, in addition, in terms of diagnosed men's mortality from prostate cancer and mortality with but not from prostate cancer. Neither arm of the FinRSPC was clearly more cost-effective in analysis in terms of overall mortality. Organised screening in the FinRSPC could be considered cost-effective in terms of deaths from prostate cancer: averting just over one death per 1000 men screened. However, even with an estimated incremental cost-effectiveness ratio of below 20,000€ per death avoided, this result should not be considered in isolation. This is because mass screening in this trial also resulted in increases in death with, but not from, prostate cancer: with over five additional deaths per 1000 men screened. Analysis of real-world data from the FinRSPC reveals new evidence of the comparative effectiveness of PSA-based screening after 20 years of follow-up, suggesting the possibility of higher mortality, as well as higher healthcare costs, for screening-arm men who have been diagnosed with prostate cancer but who do not die from it. These findings should be corroborated or contradicted by similar analyses using data from other trials, in order to reveal if more diagnosed men have also died in the screening arms of other trials of mass screening for prostate cancer.

Cellular Refractive Index Comparison of Various Prostate Cancer and Noncancerous Cell Lines via Photonic-Crystal Biosensor.

The current clinical standard for mass screening of prostate cancer are prostate-specific antigen (PSA) biomarker assays. Unfortunately, the low specificity of PSA's bioassays to prostate cancer leads to high false-positive rates, as such there is an urgent need for the development of a more specific detection system independent of PSA levels. In our previous research, we have successfully demonstrated, with the use of our Photonic-Crystal based biosensor in a Total-Internal-Reflection (PC-TIR) configuration, detection of prostate cancer (PC-3) cells against benign prostate hyperplasia (BPH-1) cells. The PC-TIR biosensor achieved detection of individual prostate cancer cells utilizing cellular refractive index (RI) as the only contrast parameter. To further study this methodology in vitro, we report a comprehensive study of the cellular RI's of various prostate cancer and noncancerous cell lines (i.e. RWPE-1, BPH-1, PC-3, DU-145, and LNCaP) via reflectance spectroscopy and single-cell RI imaging utilizing the PC-TIR biosensor. Our study shows promising clinical potential in utilizing the PC-TIR biosensor system for the detection of prostate cancer against noncancerous prostate epithelial cells.

Label-free in vitro prostate cancer cell detection via photonic-crystal biosensor.

Prostate-specific antigen (PSA) biomarker assays are the current clinical method for mass screening of prostate cancer. However, high false-positive rates are often reported due to PSA's low specificity, leading to an urgent need for the development of a more specific detection system independent of PSA levels. In our previous research, we demonstrated the feasibility of using cellular refractive indices (RI) as a unique contrast parameter to accomplish label-free detection of prostate cancer cells via variance testing, but were unable to determine if a specific cell was cancerous or noncancerous. In this paper, we report the use of our Photonic-Crystal biosensor in a Total-Internal-Reflection (PC-TIR) configuration to construct a label-free imaging system, which allows for the detection of individual prostate cancer cells utilizing cellular RI as the only contrast parameter. Noncancerous prostate (BPH-1) cells and prostate cancer (PC-3) cells were mixed at varied ratios and measured concurrently. Additionally, we isolated and induced PC-3 cells to undergo epithelial-mesenchymal transition (EMT) by exposing these cells to soluble factors such as TGF-01. The biophysical characteristics of the cellular RI were quantified extensively in comparison to non-induced PC-3 cells as well as BPH-1 cells. EMT is a crucial mechanism for the invasion and metastasis of epithelial tumors characterized by the loss of cell-cell adhesion and increased cell mobility. Our study shows promising clinical potential in utilizing the PC-TIR biosensor imaging system to not only detect prostate cancer cells, but also evaluate prostate cancer progression.

Prévalence et diversité de la prise en charge des patients atteints de cancer de la prostate classés à faible risque selon la classification de d’Amico ou le score de CAPRA : étude française multicentrique

Currently, the French High Authority for Health does not recommend mass screening for prostate cancer (PCa), due to the risk of over-treatment, notably of low risk patients. Our study is intended to reflect the therapeutic attitudes for the management of patients classified as low risk of progression in French clinical centers. For all positive prostate biopsies performed during 2012 and 2013 in five French departments of urology, clinicopathological characteristics required to calculate the d'Amico risk group and the Cancer of the Prostate Risk Assessment (CAPRA) score were filled. Information on the first treatment of "low risk" patients was collected. A total of 1035 patients were included, with a median age at diagnosis of 66 years old. According to d'Amico and CAPRA classifications, 30.4% and 35.0% of patients were at low, 34.5% and 33.2% at intermediate, 35.1% and 31.8% at high risk. The diagnosis severity increased with age (P<0.0001). The main treatment for low risk patients was radical prostatectomy (41.6% and 42.0% for d'Amico and CAPRA, respectively), but active surveillance was the most frequent treatment if diagnosed after 75 years old. The management of low risk patients varied significantly between centers (P<0.0001), according to the therapeutic platforms available within the hospital. In absence of strong progression predictor, the management of low risk PCa remains based on center habits and local therapeutic platforms. New predictive markers, such as multiparametric MRI or molecular tests, are needed to guide rational management of low risk PCa. 4.

Fostering informed decisions: A randomized controlled trial assessing the impact of a decision aid among men registered to undergo mass screening for prostate cancer

ObjectiveScreening asymptomatic men for prostate cancer is controversial and informed decision making is recommended. Within two prostate cancer screening programs, we evaluated the impact of a print-based decision aid (DA) on decision-making outcomes. MethodsMen (N=543) were 54.9 (SD=8.1) years old and 61% were African-American. The 2(booklet type: DA vs. usual care (UC))×2(delivery mode: Home vs. Clinic) randomized controlled trial assessed decisional and screening outcomes at baseline, 2-months, and 13-months. ResultsIntention-to-treat linear regression analyses using generalized estimating equations revealed that DA participants reported improved knowledge relative to UC (B=.41, p<.05). For decisional conflict, per-protocol analyses revealed a group by time interaction (B=−.69, p<.05), indicating that DA participants were less likely to report decisional conflict at 2-months compared to UC participants (OR=.49, 95% CI: .26–.91, p<.05). ConclusionThis is the first randomized trial to evaluate a DA in the context of free mass screening, a challenging setting in which to make an informed decision. The DA was highly utilized by participants, improved knowledge and reduced decisional conflict. Practice implicationsThese results are valuable in understanding ways to improve the decisions of men who seek screening and can be easily implemented within many settings.

Consommation du dosage de l’antigène spécifique de la prostate (PSA) en France chez les hommes sans cancer de la prostate déclaré (2008-2010)

This study evaluated the rate of prostate-specific antigen (PSA) dosage in men age 40 or older, affiliated to the general social security system in France between 2008 and 2010: 10.9 million men, excluding those with known prostate cancer. In 2010, 30.7% of this male population had at least one dosage of PSA, i.e. 12.3% of those between 40 and 54, 47.7% of those between 55 and 74, and 47.6% of those 75years old or older. Percentages of men who had at least one dosage in the three-year period were 26.2 %, 77.3 % and 75.6% for the same age brackets, respectively. Overall, 13% of men age 40 or older, and in particular 21% of men 75years old or older had more than three PSA dosages during the three-year time period. Eighty-eight percent of PSA dosages performed in 2010 were prescribed by a general practitioner and 3.2% by an urologist. Conflicting with French and internationally published recommendations regarding PSA dosage, the present results demonstrate a shift toward chaotic mass screening of prostate cancer particularly in men aged 75 or older.

Practice Patterns of Korean Urologists for Screening and Managing Prostate Cancer according to PSA Level

PurposeThere are still debates on the benefit of mass screening for prostate cancer (PCA) by prostate specific antigen (PSA) testing, and on systemized surveillance protocols according to PSA level. Furthermore, there is a paucity of literature on current practice patterns according to PSA level in the Korean urologic field. Here, we report the results of a nationwide, multicenter, retrospective chart-review study.Materials and MethodsOverall 2122 Korean men (>40 years old, PSA >2.5 ng/mL) were included in our study (from 122 centers, in 2008). The primary endpoint was to analyze the rate of prostate biopsy according to PSA level. Secondary aims were to analyze the detection rate of PCA, the clinical features of patients, and the status of surveillance for PCA according to PSA level.ResultsThe rate of prostate biopsy was 7.1%, 26.3%, 54.2%, and 64.3% according to PSA levels of 2.5-3.0, 3.0-4.0, 4.0-10.0, and >10.0 ng/mL, respectively, and the PCA detection rate was 16.0%, 22.2%, 20.2%, and 59.6%, respectively. At a PSA level >4.0 ng/mL, we found a lower incidence of prostate biopsy in local clinics than in general hospitals (21.6% vs. 66.2%, respectively). A significant proportion (16.6%) of patients exhibited high Gleason scores (≥8) even in the group with low PSA values (2.5-4.0 ng/mL).ConclusionWe believe that the results from this nationwide study might provide an important database for the establishment of practical guidelines for the screening and management of PCA in Korean populations.

Mass Screening of Prostate Cancer and its Impact on Inhabitants in Akita Prefecture, Japan

In 2001, the Akita Medical Association started a prostate cancer (PC) mass screening project for >or= 50-year-old male inhabitants in individual municipalities of Akita Prefecture, utilizing serum prostate-specific antigen. The number of examinees increased from 4321 in 2001 to 29,936 in 2006, while the annual rate of examinees per target inhabitants remained at 11.6 to 16.8% and the fraction of repeat examinees increased up to 77% in 2006. A total of 944 PCs were screened with a stage B tumor incidence of 84.1% (range: 82.2 to 86.6%). The annual PC detection rate was 0.95 to 1.11% for the first 4 years, but then declined to 0.54% in 2006 mainly due to the increase of repeat examinees. PSA mass screening is effective for the detection of early stage PC, but a further promotion is needed to mobilize the sleeping inhabitants. Indeed, the number of new PC patients in 17 major hospitals in Akita Prefecture rapidly increased after the mass screening started (3.2-fold), suggesting an enlightenment effect of the screening project on both the inhabitants and general physicians.

Characteristics of prostate cancers found in specimens removed by radical cystoprostatectomy for bladder cancer and their relationship with serum prostate‐specific antigen level

Prostate cancer mass screening using serum prostate-specific antigen (PSA) has been conducted widely in the world. However, little is known about the true prevalence of prostate cancer in the 'normal' PSA range (4.0 ng/mL or less). The aim of the present study was to elucidate the clinicopathological features of prostate cancer occurring in men with a wide range of PSA levels. The study comprised 349 male patients who underwent radical cystoprostatectomy for bladder cancer. Patients who had had treatment for known prostate cancer were excluded. Tissue specimens were reviewed microscopically. Ninety-one patients (26.1%) were found to have prostate cancer, and 68 (74.7%) of these 91 cancers were considered to be clinically significant. Both increasing patient age and PSA level were significantly correlated with an increased incidence of both all and significant prostate cancers. Sixty-five (21.9%) among 297 patients with PSA < 4.0 ng/mL had prostate cancer, and 45 (69.2%) of the 65 cancers were significant cancers. Eighteen patients had prostate cancers 0.5 mL or more in volume. Among the 18 patients, the PSA level was 4 ng/mL or more in 11, and 3 ng/mL or more in 15. Our study shows that prostate cancer is a common finding in radical cystoprostatectomy specimens excised because of bladder cancers, and a significant proportion of these cancers are clinically significant. PSA still appears to be a useful screening tool for detecting prostate cancers with significant volume.

Mass Screening for Prostate Cancer in Korea: A Population Based Study

We investigated the detection rate of prostate cancer in Korean men through a population based mass screening test. In June 2007 serum prostate specific antigen was examined in 3,943 residents in the Gangneung (1,429), Daegu (1,396) and Jeonju (1,118) areas who were 55 years or older with prostate specific antigen 3.0 ng/ml or greater considered the criterion for 12-site transrectal biopsy recommendation. The serum prostate specific antigen distribution and the cancer detection rate were analyzed according to participant regions and age groups. Mean +/- SD serum prostate specific antigen in the entire cohort was 2.4 +/- 8.6 ng/ml. It significantly increased with increasing age, that is 1.2, 2.2, 3.4 and 4.7 ng/ml in the groups 55 to 64, 65 to 74, 75 to 84 and 85 years or older, respectively (p <0.0001). However, no regional differences were noted among Gangneung, Daegu and Jeonju (2.2, 2.7 and 2.3 ng/ml, respectively, p = 0.290). Biopsy candidates represented 7.3% (48 men), 17.7% (395), 25.5% (240) and 32.7% (36) of the 55 to 64, 65 to 74, 75 to 84 and 85 years or older groups, respectively, or 18.2% of the entire cohort of 719. Of biopsy candidates 268 (37.3%) had undergone biopsy, of whom cancer was detected in 76 (28.4%) for a cancer detection rate and estimated cancer detection rate of 1.93% and 5.17%, respectively. The age adjusted estimated cancer detection rate (55 years or older) was 3.36%. Cancer detection increased significantly with increasing prostate specific antigen, that is 12.3% at 3.0 to 4.0 ng/ml, 27.3% at 4.1 to 10.0 and 64.1% at greater than 10.0. The Gleason score was 2-6 in 41 men (53.9%), 7 in 14 (18.4%) and 8-10 in 21 (27.6%). The estimated cancer detection rate in Korean men 55 years or older was 3.36%. The significance of the high rate in this population should be determined through repeat screening and further surveillance in the future.

Mass screening-based case-control study of diet and prostate cancer in Changchun, China

To investigate possible correlation factors for prostate cancer by a population-based case-control study in China. We carried out a mass screening of prostate cancer in Changchun, China, using a prostate-specific antigen assisted by Japan International Cooperation Agency. From June 1998 to December 2000, 3 940 men over 50 years old were screened. Of these, 29 men were diagnosed with prostate cancer. We selected 28 cases and matched them with controls of low prostate-specific antigen value (< 4.1 ng/mL) by 1:10 according to age and place of employment. A case-control study of diet and prostate cancer was then carried out. After adjustment for education, body mass index (BMI), smoking, alcohol consumption, marriage and diet, intake of soybean product was discovered to be inversely related to prostate cancer. Men who consumed soybean product more than twice per week on different days had a multivariate odds ratio (OR) of 0.38 (95% confidence interval [CI], 0.13-1.12). In addition, men who consumed soybean products more than once per day had a multivariate OR of 0.29 (95% CI, 0.11-0.79) compared with men who consumed soybean products less than once per week. The P for trend was 0.02, which showed significant difference. There was no significant difference in P trend for any dairy food. Even when we matched the cases and controls by other criteria, we found that soybean food was the only preventive factor associated with prostate cancer. Our study suggests that consumption of soybeans, one of the most popular foods in Asia, would decrease the risk of prostate cancer.

The Accuracy of Diagnosis in the Mass Screening for Prostate Cancer

The Accuracy of Diagnosis in the Mass Screening for Prostate Cancer

Ten year trend in prostate cancer screening with high prostate‐specific antigen exposure rate in Japan

The tendency of the results and quality control of prostate cancer screening serially performed for 10 years in an area of Japan were evaluated. A total of 39 213 men over 55 years of age have participated in the mass screening of prostate cancer in the Otokuni District, since 1995. Men whose prostate-specific antigen (PSA) levels were more than 4.1 ng/mL were indicated for the second screening. In the second screening, prostate-specific antigen density (PSAD) was calculated in men whose PSA levels ranged from 4.1 to 10.0 ng/mL. Secondary screening was indicated in a total of 2428 subjects, of whom 1633 underwent it. Prostate cancer was diagnosed in 267 men. As a result of the evaluation of the indication of prostate biopsy according to the PSAD in 894 who underwent secondary screening for the first time, the procedure was judged to be unnecessary in 269 (35%) of 765 cases. Of these 269 subjects, 23 (8.5%) were found to have cancer. Clinically localized prostate cancer increased by 17%, and locally advanced and metastatic cancers decreased by 12% in the second compared with the first five years of the ten-year period. The exposure rate of PSA screening in the Otokuni District was 65% with the application for the rate of screenees whose PSA level was 4.1 ng/mL or above. The Japanese basic health screening system allows the determination of high-PSA exposure areas. Serial prostate cancer screening showed a tendency of stage migration in the screened cancer patients. The use of PSAD in secondary screening substantially reduces the necessity of prostate biopsy; however, the encouragement of PSA-positive individuals to periodically receive prostate cancer screening is essential to maintain the quality of the screening system.

Dépistage du cancer de la prostate : les arguments « contre »

The mass screening for prostate cancer is often a subject of passionate debates since the availability of prostate-specific antigen testing, twenty years ago. The supporters of the mass screening emphasize on the fact that early detection of a tumour offers a better quality and less invasive treatment. In reality, this reasoning relies on some long-term studies on certain groups of subjects in spite of the fact that comparison with control groups has never been done. To examine the relationship between the mass screening and the decrease of population mortality (principal criteria for judgment), it is necessary to have recourse to randomized studies. At present, there are two such studies whose results will be available within three or four years. In the meantime, there is no answer to the question of the place for mass screening. Meanwhile, analysis of different parameters that would support the use of mass screening for prostate cancer to reduce the number of deaths has shown that the probability that it would is very low. Considering these conditions as well as the recommendations by the authorities, the mass screening has not yet found its place. The early detection requested by a patient accompanied by the discussion about its advantages and inconveniences are for now the right way between negligence and excessive management.

Willingness to pay for mass screening for prostate cancer: A contingent valuation survey

We recently reported on the willingness to pay (WTP) for prostate cancer screening with prostate specific antigen (PSA) using the contingent valuation method (CVM). This study, a continuation of the work outlined in the previous report, comprises a more precise and detailed survey. In an Internet questionnaire survey, 400 men aged 50-59 in Japan were randomly split into two groups: the ill-informed group (n = 207), which was provided with information about the detection rate, and the well-informed group (n = 193), which was given additional information about false positive/negative results, latent cancer, and the yet-to-be-demonstrated mortality-reducing effect of the test. The mean WTP was yen1670 ($15.2). Giving sufficient information would not decrease WTP for PSA screening. Men place a high value on 'peace of mind' through the ascertaining of no sign of cancer at the present rather than on the future-oriented life-saving effects that may be gained through such screening.

Prostate Biopsy Patterns in the CaPSURE Database: Evolution With Time and Impact on Outcome After Prostatectomy

Significant variability exists in the urological community regarding the number of cores that should be taken during prostate biopsy. Using CaPSURE we determined trends in prostate biopsy patterns during the last decade and assessed whether changes in biopsy number have had an impact on outcomes after radical prostatectomy. In CaPSURE between 1995 and 2004 we identified 6,450 men with newly diagnosed prostate cancer who underwent biopsy with 6 cores or greater. The number of cores removed, number of cores positive for cancer and percent of cores containing cancer were analyzed by year of diagnosis. For 1,757 men who underwent radical prostatectomy these variables were entered into Cox proportional hazards models controlling for preoperative prostate specific antigen, biopsy Gleason sum and clinical stage to predict recurrence-free survival. The mean number of removed cores increased from 6.9 in 1995 to 10.2 in 2004 (p <0.0001). The mean number of positive cores remained unchanged from 2.9 in 1995 to 3.2 in 2004 (p = 0.40). The percent of positive cores decreased from 42.6% in 1995 to 32.1% in 2004 (p <0.0001). The number and percent of positive cores were associated with recurrence-free survival after radical prostatectomy throughout the study period (each p <0.001). The percent of positive cores is an independent predictor of disease recurrence after radical prostatectomy. The total number of tissue cores sampled increased during the last decade, thereby driving down the mean percent of positive cores from 42.6% to 32.1%. The trend toward an increasing number of removed cores may have contributed indirectly to improved outcomes after radical prostatectomy in the last decade.

Impact of improvement in specificity of primary screening test on total cost of prostate cancer mass screening

Improvement in the specificity of primary screening tests, without significant cost elevation of the assay, provides cost savings in prostate cancer screening programs by reducing unnecessary secondary screening procedures. The purpose of this study was to evaluate the economic impact of improvement in the specificity of primary screening tests and to estimate the socially acceptable cost elevation for improved specificity. A decision-analytic model was designed to evaluate the total costs of prostate cancer mass screening according to the changes in the specificity and the cost of the primary screening test. All assumed factors were tested by three-way sensitivity analyses incorporating cost and specificity. The base case analysis showed that a 1% improvement in the specificity of the primary screening test provides a $1.19 cost reduction per participant. Sensitivity analyses showed that an acceptable cost elevation for a 1% improvement in the specificity ranged from 0.68 to 2.90 $/% with respect to changes in several factors in the screening program. The specificity and cost of the primary screening test has a significant economical impact on prostate cancer mass screening. For each screening program, it should be taken into consideration whether the cost of the new test deserves the specificity.

Prostate‐specific antigen assay using whole blood samples spotted on filter paper and its application to mass screening for prostate cancer

The disc assay system for prostate-specific antigen (PSA) is a novel technique using a small amount of whole blood on filter paper. The accuracy of this assay system and its feasibility for use in prostate cancer mass screening were evaluated. In the first arm of the study, to evaluate the accuracy of the disc assay system, PSA values were determined by both a disc assay system and a standard serum assay system using the same blood samples obtained from 420 outpatients. In the second arm of the study, the feasibility and reliability of the disc assay system were examined in prostate cancer mass screening. A total of 2475 men were screened by the disc assay (disc group) and 3348 men were screened by the standard serum assay (serum group) in the first step of mass screening. In the second step of the screening in the disc group, 101 men underwent PSA tests by a standard serum assay, then the first PSA values determined by the disc assay were compared with the second PSA values determined by the standard serum assay. In the second step of the screening in the serum group, 94 men underwent additional PSA tests by a serum assay, and then the first PSA values were compared with the second PSA values. Two men in each group were excluded from analysis because the true PSA values of the first step were not available (more than 50 ng/mL). The PSA values determined by the disc assay closely correlated with those obtained by the standard assay (r = 0.987) in 295 outpatients with PSA levels between 1.0 and 20 ng/mL. In the PSA mass screening, the PSA values determined in the first step closely correlated with those in the second step both in the disc group (r = 0.916) and in the serum group (r = 0.845). A significant dissociation of the two PSA values was observed in seven of 99 men in the disc group and in three of 92 men in the serum group. However, there was no statistical significance in the incidence of dissociation in the two PSA values between the disc group and the serum group. The disc assay system seems to be a sensitive and accurate assay system. The feasibility and reliability of the disc assay system were well demonstrated in the field during prostate cancer mass screening.

Le dépistage du cancer de la prostate : hétérogénéités des recommandations

At present, clinical practice guidelines for prostate cancer screening are controversial in France. The French National Agency for Health Care Quality does not recommend screening for prostate cancer. In contrast, since 2002 the French Urological Association has been supporting screening. However, both support selected screening for men with risk factors, despite there having been no assessment to date of whether the screening is justified. In 2002, Prostatic Specific Antigen prescriptions increased by 22% over one year and PSA was the first prescription for cancer markers. The history of the pros and cons for prostate cancer screening is summarized. Prostate cancer does not qualify under the World Health Organization's criteria for screening. At the present time, prostate cancer mass screening cannot be recommended. Pitfalls for Clinical Guidelines enforcement are discussed.

Relevance of the prostate-specific antigen (PSA) nanotest compared to the classical PSA test in the organized mass screening of prostate cancer

To assess the reliability of a new measurement of prostate-specific antigen (PSA) using a blotting-paper assay (nanotest) compared to the standard PSA immunoassay. The PSA level was measured in 205 men volunteers (median age 70 years, range 41-75) using a nanotest and a standard PSA immunoassay, collected at the same time; 30 microL of capillary blood placed on to a blotting paper were collected for the nanotest and sent by mail to the same laboratory for the two assays. The results were compared statistically using the Spearman test, the intraclass correlation coefficient and the Bland-Altman test. The nanotest threshold for an abnormal PSA level was 78 pg/mL, which corresponded to a standard PSA value of 3 ng/mL, with a sensitivity of 100%. There was a significant correlation (r = 0.98, Spearman test; P < 0.001) between the nanotest and the standard PSA assay. The intraclass correlation coefficient was 0.87. The Bland-Altman test showed a good agreement between the nanotest and the standard PSA assay, but there was an increasing proportional difference with increasing PSA value. There was a very high correlation between the nanotest and the standard PSA assay, especially for standard PSA levels of <5 ng/mL. Economic and clinical studies are indicated to confirm the utility of the nanotest in organized mass screening of prostate cancer.