What is the effect of MRI with targeted biopsies on the rate of patients discontinuing active surveillance? A reflection of the use of MRI in the PRIAS study.

BACKGROUND: The reduction of overtreatment by active surveillance (AS) is limited in patients with low-risk prostate cancer (PCa) due to high rates of patients switching to radical treatment. MRI improves biopsy accuracy and could therewith affect inclusion in or continuation of AS. We aim to assess the effect of MRI with target biopsies on the total rate of patients discontinuing AS, and in particular discontinuation due to Grade Group (GG) reclassification. METHODS: Three subpopulations included in the prospective PRIAS study with GG 1 were studied. Group A consists of patients diagnosed before 2009 without MRI before or during AS. Group B consists of patients diagnosed without MRI, but all patients underwent MRI within 6 months after diagnosis. Group C consists of patients who underwent MRI before diagnosis and during follow-up. We used cumulative incidence curves to estimate the rates of discontinuation. RESULTS: In Group A (n = 500), the cumulative probability of discontinuing AS at 2 years is 27.5%; GG reclassification solely accounted for 6.9% of the discontinuation. In Group B (n = 351) these numbers are 30.9 and 22.8%, and for Group C (n = 435) 24.2 and 13.4%. The three groups were not randomized, however, baseline characteristics are highly comparable. CONCLUSIONS: Performing an MRI before starting AS reduces the cumulative probability of discontinuing AS at 2 years. Performing an MRI after already being on AS increases the cumulative probability of discontinuing AS in comparison to not performing an MRI, especially because of an increase in GG reclassification. These results suggest that the use of MRI could lead to more patients being considered unsuitable for AS. Considering the excellent long-term cancer-specific survival of AS before the MRI era, the increased diagnostic accuracy of MRI could potentially lead to more overtreatment if definitions and treatment options of significant PCa are not adapted.

Adaptation and external validation of the European randomised study of screening for prostate cancer risk calculator for the Chinese population.

BACKGROUND: To adapt the well-performing European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculator to the Chinese setting and perform an external validation. METHODS: The original ERSPC risk calculator 3 (RC3) for prostate cancer (PCa) and high-grade PCa (HGPCa) was applied to a development cohort of 3006 previously unscreened Hong Kong Chinese men with initial transrectal biopsies performed from 1997 to 2015, age 50-80 years, PSA 0.4-50 ng ml-1 and prostate volume 10-150 ml. A simple adaptation to RC3 was performed and externally validated in a cohort of 2214 Chinese men from another Hong Kong hospital. The performance of the models were presented in calibration plots, area under curve (AUC) of receiver operating characteristics (ROCs) and decision curve analyses. RESULTS: PCa and HGPCa was diagnosed in 16.7% (503/3006) and 7.8% (234/3006) men in the development cohort, and 20.2% (447/2204) and 9.7% (214/2204) men in the validation cohort, respectively. The AUCs using the original RC3 model in the development cohort were 0.75 and 0.84 for PCa and HGPCa, respectively, but the calibration plots showed considerable overestimation. In the external validation of the recalibrated RC3 model, excellent calibration was observed, and discrimination was good with AUCs of 0.76 and 0.85 for PCa and HGPCa, respectively. Decision curve analyses in the validation cohort showed net clinical benefit of the recalibrated RC3 model over PSA. CONCLUSIONS: A recalibrated ERSPC risk calculator for the Chinese population was developed, and it showed excellent discrimination, calibration and net clinical benefit in an external validation cohort.

Prostate Specific Antigen as a Tumor Marker in Prostate Cancer: Biochemical and Clinical Aspects.

In this chapter the use of prostate specific antigen (PSA) as a tumor marker for prostate cancer is discussed. The chapter provides an overview of biological and clinical aspects of PSA. The main drawback of total PSA (tPSA) is its lack of specificity for prostate cancer which leads to unnecessary biopsies. Moreover, PSA-testing poses a risk of overdiagnosis and subsequent overtreatment. Many PSA-based markers have been developed to improve the performance characteristics of tPSA. As well as different molecular subforms of tPSA, such as proPSA (pPSA) and free PSA (fPSA), and PSA derived kinetics as PSA-velocity (PSAV) and PSA-doubling time (PSADT). The prostate health index (phi), PSA-density (PSAD) and the contribution of non PSA-based markers such as the urinary transcripts of PCA3 and TMPRSS-ERG fusion are also discussed. To enable further risk stratification tumor markers are often combined with clinical data (e.g. outcome of DRE) in so-called nomograms. Currently the role of magnetic resonance imaging (MRI) in the detection and staging of prostate cancer is being explored.

Cost-effectiveness of prostate cancer screening: a simulation study based on ERSPC data.

BACKGROUND: The results of the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial showed a statistically significant 29% prostate cancer mortality reduction for the men screened in the intervention arm and a 23% negative impact on the life-years gained because of quality of life. However, alternative prostate-specific antigen (PSA) screening strategies for the population may exist, optimizing the effects on mortality reduction, quality of life, overdiagnosis, and costs. METHODS: Based on data of the ERSPC trial, we predicted the numbers of prostate cancers diagnosed, prostate cancer deaths averted, life-years and quality-adjusted life-years (QALY) gained, and cost-effectiveness of 68 screening strategies starting at age 55 years, with a PSA threshold of 3, using microsimulation modeling. The screening strategies varied by age to stop screening and screening interval (one to 14 years or once in a lifetime screens), and therefore number of tests. RESULTS: Screening at short intervals of three years or less was more cost-effective than using longer intervals. Screening at ages 55 to 59 years with two-year intervals had an incremental cost-effectiveness ratio of $73000 per QALY gained and was considered optimal. With this strategy, lifetime prostate cancer mortality reduction was predicted as 13%, and 33% of the screen-detected cancers were overdiagnosed. When better quality of life for the post-treatment period could be achieved, an older age of 65 to 72 years for ending screening was obtained. CONCLUSION: Prostate cancer screening can be cost-effective when it is limited to two or three screens between ages 55 to 59 years. Screening above age 63 years is less cost-effective because of loss of QALYs because of overdiagnosis.

Patients' and urologists' preferences for prostate cancer treatment: a discrete choice experiment.

BACKGROUND: Patients' preferences are important for shared decision making. Therefore, we investigated patients' and urologists' preferences for treatment alternatives for early prostate cancer (PC). METHODS: A discrete choice experiment was conducted among 150 patients who were waiting for their biopsy results, and 150 urologists. Regression analysis was used to determine patients' and urologists' stated preferences using scenarios based on PC treatment modality (radiotherapy, surgery, and active surveillance (AS)), and risks of urinary incontinence and erectile dysfunction. RESULTS: The response rate was 110 out of 150 (73%) for patients and 50 out of 150 (33%) for urologists. Risk of urinary incontinence was an important determinant of both patients' and urologists' stated preferences for PC treatment (P<0.05). Treatment modality also influenced patients' stated preferences (P<0.05), whereas the risk of erectile dysfunction due to radiotherapy was mainly important to urologists (P<0.05). Both patients and urologists preferred AS to radical treatment, with the exception of patients with anxious/depressed feelings who preferred radical treatment to AS. CONCLUSION: Although patients and urologists generally may prefer similar treatments for PC, they showed different trade-offs between various specific treatment aspects. This implies that urologists need to be aware of potential differences compared with the patient's perspective on treatment decisions in shared decision making on PC treatment.

Treatment of local-regional prostate cancer detected by PSA screening: benefits and harms according to prognostic factors.

BACKGROUND: Men with screen-detected prostate cancer can choose to undergo immediate curative treatment or enter into an expectant management programme. We quantified how the benefits and harms of immediate treatment vary according to the prognostic factors of clinical T-stage, Gleason score, and patient age. METHODS: A microsimulation model based on European Randomized Study of Screening for Prostate Cancer data was used to predict the benefits and harms of immediate treatment versus delayed treatment of local-regional prostate cancer in men aged 55-74 years. Benefits included life-years gained and reduced probability of death from prostate cancer. Harms included lead time and probability of overdiagnosis. RESULTS: The ratio of mean lead time to mean life-years gained ranged from 1.8 to 31.2, and the additional number of treatments required per prostate cancer death prevented ranged from 0.3 to 11.6 across the different prognostic groups. Both harm-benefit ratios were lowest, most favourable, for men aged 55-59 years and diagnosed with moderate-risk prostate cancer. Ratios were high for men aged 70-74 years regardless of clinical T-stage and Gleason score. CONCLUSION: Men aged 55-59 years with moderate-risk prostate cancer are predicted to derive greatest benefit from immediate curative treatment. Immediate treatment is least favourable for men aged 70-74 years with either low-risk or high-risk prostate cancer.

Blinded and uniform causes of death verification in cancer screening: a major influence on the outcome of a prostate cancer screening trial?

BACKGROUND: To assess the agreement between the causes of death assigned by a blinded and uniform review panel of the Rotterdam section of the European Randomised Study of Screening for Prostate Cancer and the official vital statistics and to explore the possible effect of the use of either of these two sources on the outcome of the screening trial. METHODS: A total of 670 deaths amongst men with prostate cancer, reviewed by the causes of death committee (CODC) up to 31st December 2006 were included in this study. The kappa statistics with confidence intervals (CI), sensitivity and specificity of the official statistics were determined, with the CODC considered the gold standard. The rate ratio (RR) and 95% confidence intervals (95% CI) for prostate cancer mortality, official statistics relative to CODC, were calculated following the Mantel-Haenszel procedure. RESULTS: The overall concordance and the kappa between official statistics and the CODC were 90.6% and 0.76 (0.71-0.82), remaining comparable when only the CODC category definitely prostate cancer was applied, with the sensitivity of official statistics increasing from 88.3% to 91.3% and specificity hardly changing (91.3% and 90.5%). High specificity and lower sensitivity is observed in the screening arm, whilst the opposite was seen in the control arm in men aged 55-69 and 70-74 years at entry. Considerable lower false positive rate was seen for both age groups in the screening arm (3.9% and 4.7%) compared to the control arm (8.4% and 14.3%). A statistically significant excess of prostate cancer death was observed for the official statistics in the age group 70-74 years, 1.53 (1.07-2.19), whilst it was not significant for men aged 55-69 at entry, 1.06 (0.83-1.36). CONCLUSION: In the Rotterdam ERSPC section, official statistics tended to overreport prostate cancer as an underlying cause of death, particularly in the age group 70-plus in the control arm, which would overestimate the true effect in favour of screening.

Detection rates of cancer, high grade PIN and atypical lesions suspicious for cancer in the European Randomized Study of Screening for Prostate Cancer.

THE AIM OF THE STUDY: This article presents the incidence of prostate cancer, isolated high grade prostatic intraepithelial neoplasia (PIN) and atypical lesions suspicious for prostate cancer (LSPC) during subsequent screening rounds in the centres of five of the countries participating in the European Randomized Study of Screening for Prostate Cancer (ERSPC). The incidence and predictive value of high grade PIN and LSPC for prostate cancer in subsequent biopsy following these diagnoses were evaluated. PATIENTS AND METHODS: Study group consisted of 56,653 screened men in the ERSPC centres of Finland, Italy, Netherlands, Sweden and Switzerland, who underwent 3-7 screening rounds at 2-4 year interval. Data for prostate cancer were obtained from the ERSPC central database. Data for high grade PIN and LSPC were gathered from each ERSPC centre. Detection rates of subsequent prostate cancer in the first re-biopsy after these diagnoses were determined. RESULTS: The average cancer detection rate was 3.5%, 3.2% and 3.5% for the completed rounds 1, 2 and 3, respectively, in all five centres. Incidence of high grade PIN increased from 1.5% in the first round to 5.0% in the third round, varying among centres in the first round between 0.8% and 7.6%. The cancer detection rate in the first re-biopsy after the diagnosis of high grade PIN was 12.9%. Incidence of LSPC was 2.4%, 2.7%, 2.2% and 2.6% in the first, second, third and fourth round, respectively. The cancer detection rate at the first re-biopsy after the diagnosis of LSPC was in average 33.8%. CONCLUSIONS: Cancer detection rate was stable during the three screening rounds. The wide variation in frequency in particular of high grade PIN among the ERSPC centres suggests a considerable inter-observer variation. The average comparatively low detection rate of isolated high grade PIN in the first screening round may be screening-related, while its consistent increase during three screening rounds could be the consequence of a.o. previous screening and ageing of the population. The observed low risk of prostate cancer after isolated high grade PIN in this screening setting is in line with the current recommendation to abstain from early repeat biopsies after this diagnosis. The association of LSPC with high incidence of prostate cancer in re-biopsies confirms the need for early repeat biopsies and follow-up of these men. The low percentage of LSPC (<3% of biopsies) throughout all rounds is reassuring as it limits the biopsy burden in a screening setting.

Change of tumour characteristics and treatment over time in both arms of the European Randomized study of Screening for Prostate Cancer.

OBJECTIVE: To evaluate a change in tumour characteristics and applied treatments over time in the control arm of all centres of the European Randomized study of Screening for Prostate Cancer (ERSPC) and to compare this with similar data of the screening arm. METHODS: Between 1993 and 2003, 182,160 men, aged 50-74 years, were randomised to the screening arm (N=82,816) and the control arm (N=99,184). Men in the screening arm were offered Prostate Specific Antigen (PSA) testing every 4 years whilst men in the control arm received usual care. Tumour characteristics and treatment were evaluated in all men diagnosed with prostate cancer up to December 2006 or the third screening round. Data on the control arm were divided into 3 periods: 1994-1998, 1999-2002 and 2003-2006. RESULTS: Tumour characteristics were more favourable over time in both the control and the screening arm, with especially increasing proportions of T1C tumours with 29% in 1994-1998 versus 50% in 2003-2006 and 48% at the initial screening round versus 75% at the third screening round, respectively. Tumour characteristics observed in the last period of the control arm were comparable to tumour characteristics in the initial screening round. In the control arm, treatment changed over time with surgery as the most common treatment in the entire observed period, but almost doubling of expectant management and the combination of hormone therapy and radiotherapy over time. In the initial screening round, surgery was the most common treatment (42%), changing over time to expectant management as the most frequently applied treatment in the third screening round (33%). CONCLUSION: Tumour characteristics in the control arm became more favourable over time and show similarity with prostate cancer cases detected at the initial screening round. The most prominent change in treatment over time was an increase of application of expectant management in both arms of the ERSPC. These observations reflect an increasing rate of opportunistic testing over time in men randomised to the control arm.

Feasibility study of screening for bladder cancer with urinary molecular markers (the BLU-P project).

INTRODUCTION: The prognosis of bladder cancer (BC) depends mainly on its histology, grade, and stage. Patients with superficial BC (70% of the urothelial carcinomas) have a relatively good prognosis, but patients diagnosed with invasive, high grade BC, and those who progress to invasive BC, have a poor prognosis and will not survive their disease in many cases due to their metastases, despite the currently available treatment options. Early detection can only be beneficial regarding mortality if the high risk cancers are recognized and treated at a localized stage. MATERIALS AND METHODS: Previous pilot studies on early detection consisted of home-based repeated hematuria testing and, in case of hematuria, a urologic evaluation with cytology and cystoscopy was carried out. This design resulted in too many cystoscopies. The recently initiated [Bladder Cancer Urine Marker Project (BLU-P) study www.blu-project.org] assesses the feasibility of a population-based screening for BC and at the same time evaluates a screening algorithm using next to hematuria testing, sensitive specific urine markers for BC (NMP22, FGFR3, MA analyses and MLPa) in an attempt to circumvent the high number of cystoscopies. RESULTS: So far 1,611 men are included and 23.5% tested positive for hematuria (11.6% had one or more true positive test results). The additional molecular-based screening tests before referring to cystoscopy resulted in a decrease of the number of cystoscopies from 378 to 66 (82.5%). In those men referred for cystoscopy, so far only 1 BC case was detected. CONCLUSIONS: Further research is needed to evaluate whether this extremely low detection rate is caused by, e.g., a healthy screenee bias or that the additional selection step using the molecular urine tests is too strict and diagnoses are missed.

A four-kallikrein panel for the prediction of repeat prostate biopsy: data from the European Randomized Study of Prostate Cancer screening in Rotterdam, Netherlands.

BACKGROUND: Most men with elevated levels of prostate-specific antigen (PSA) do not have prostate cancer, leading to a large number of unnecessary biopsies. A statistical model based on a panel of four kallikreins has been shown to predict the outcome of a first prostate biopsy. In this study, we apply the model to an independent data set of men with previous negative biopsy but persistently elevated PSA. METHODS: The study cohort consisted of 925 men with a previous negative prostate biopsy and elevated PSA (>or=3 ng ml(-1)), with 110 prostate cancers detected (12%). A previously published statistical model was applied, with recalibration to reflect the lower positive biopsy rates on rebiopsy. RESULTS: The full-kallikrein panel had higher discriminative accuracy than PSA and DRE alone, with area under the curve (AUC) improving from 0.58 (95% confidence interval (CI): 0.52, 0.64) to 0.68 (95% CI: 0.62, 0.74), P<0.001, and high-grade cancer (Gleason >or=7) at biopsy with AUC improving from 0.76 (95% CI: 0.64, 0.89) to 0.87 (95% CI: 0.81, 0.94), P=0.003). Application of the panel to 1000 men with persistently elevated PSA after initial negative biopsy, at a 15% risk threshold would reduce the number of biopsies by 712; would miss (or delay) the diagnosis of 53 cancers, of which only 3 would be Gleason 7 and the rest Gleason 6 or less. CONCLUSIONS: Our data constitute an external validation of a previously published model. The four-kallikrein panel predicts the result of repeat prostate biopsy in men with elevated PSA while dramatically decreasing unnecessary biopsies.

Overdetection, overtreatment and costs in prostate-specific antigen screening for prostate cancer.

BACKGROUND: Prostate cancer screening with prostate-specific antigen (PSA) has shown to reduce prostate cancer mortality in the European Randomised study of Screening for Prostate Cancer (ERSPC) trial. Overdetection and overtreatment are substantial unfavourable side effects with consequent healthcare costs. In this study the effects of introducing widespread PSA screening is evaluated. METHODS: The MISCAN model was used to simulate prostate cancer growth and detection in a simulated cohort of 100,000 men (European standard population) over 25 years. PSA screening from age 55 to 70 or 75, with 1, 2 and 4-year-intervals is simulated. Number of diagnoses, PSA tests, biopsies, treatments, deaths and corresponding costs for 100,000 men and for United Kingdom and United States are compared. RESULTS: Without screening 2378 men per 100,000 were predicted to be diagnosed with prostate cancer compared with 4956 men after screening at 4-year intervals. By introducing screening, the costs would increase with 100% to 60,695,000 euro. Overdetection is related to 39% of total costs (23,669,000 euro). Screening until age 75 is relatively most expensive because of the costs of overtreatment. CONCLUSION: Introduction of PSA screening will increase total healthcare costs for prostate cancer substantially, of which the actual screening costs will be a small part.

The interobserver variability of digital rectal examination in a large randomized trial for the screening of prostate cancer.

BACKGROUND: To analyze to what extent the percentage of suspicious digital rectal examination (DRE) findings vary between examiners and to what extent the percentage of prostate cancers (PCs) detected in men with these suspicious findings varies between examiners. METHODS: In the first screening round of the European Randomized study of Screening for PC (ERSPC) Rotterdam, 7,280 men underwent a PSA-determination and DRE of whom 2,102 underwent prostate biopsy (biopsy indication PSA > or = 4.0 ng/ml and/or suspicious DRE and/or TRUS). Descriptive statistics of DRE-outcome per PSA-range were used to determine the observer variability of six examiners. Because this analysis did not correct properly for other predictors of a suspicious DRE (PSA-level, biopsy indication, TRUS-outcome, prostate volume and age), a logistic regression analysis controlling for these explanatory variables was performed as well. RESULTS: In 2,102 men biopsied, 443 PCs were detected (PPV = 21%). For all PSA levels the percentage suspicious DRE varied between examiners from 4% to 28% and percentage PC detected in men with a suspicious DRE varied from 18% to 36%. Logistic regression analysis showed that three of six examiners considered DRE significantly more often abnormal than others (ORs 3.48, 2.80, 2.47, P < 0.001). For all examiners the odds to have PC was statistically significantly higher in case of a suspicious DRE (ORs 2.21-5.96, P < 0.05). This increased chance to find PC was not significantly observer-dependent. CONCLUSIONS: Three of six examiners considered DRE significantly more often suspicious than the others. However, under equal circumstances a suspicious DRE executed by each examiner increased the chance of the presence of PC similarly.

Prediction of indolent prostate cancer: validation and updating of a prognostic nomogram.

PURPOSE: Screening with serum prostate specific antigen testing leads to the detection of many prostate cancers early in their natural history. Statistical models have been proposed to predict indolent cancer. We validated and updated model predictions for a screening setting. MATERIALS AND METHODS: We selected 247 patients with clinical stage T1C or T2A from the European Randomized Study on Screening for Prostate Cancer who were treated with radical prostatectomy. We validated a nomogram that had previously been developed in a clinical setting. Predictive characteristics were serum prostate specific antigen, ultrasound prostate volume, clinical stage, prostate biopsy Gleason grade, and total length of cancer and noncancer tissue in biopsy cores. Indolent cancer was defined as pathologically organ confined cancer 0.5 cc or less in volume without poorly differentiated elements. Logistic regression was used to update the previous model and examine the contribution of other potential predictors. RESULTS: Overall 121 of 247 patients (49%) had indolent cancer, while the average predicted probability was around 20% (p <0.001). Effects of individual variables were similar to those found before and discriminative ability was adequate (AUC 0.76). An updated model was constructed, which merely recalibrated the nomogram and did not apply additional predictors. CONCLUSIONS: Prostate cancers identified in a screening setting have a substantially higher likelihood of being indolent than those predicted by a previously proposed nomogram. However, an updated model can support patients and clinicians when the various treatment options for prostate cancer are considered.

The value of different screening tests in predicting prostate biopsy outcome in screening for prostate cancer data from a multicenter study (ERSPC).

BACKGROUND: Although serum PSA testing is widely used as a screening test for prostate cancer (PC), it is known that it is not specific for PC. The study described here focuses on the value of screening tests next to PSA in identifying men with an elevated risk of having PC and the differences between three centers of the European Randomised study of Screening for Prostate Cancer (ERSPC). METHODS: The study population consists of 2,483 men with a PSA > or =4.0 ng/ml, all biopsied. We assessed data on age, serum PSA level at initial and repeat screening, prostate volume, number of positive DRE and TRUS findings, number of previous negative biopsies, and PPV of the three centers and overall. Using logistic regression analysis, predictors for biopsy outcome at repeat screening in men with a PSA value > or =4.0 ng/ml were determined on the complete dataset and per center. RESULTS: In 2,483 men biopsied, 665 cancers were detected (PPV = 26.8%). Data show that all predictors except prostate volume loose their predictive value in men previously biopsied. In men not previously biopsied, the predictive value of DRE and TRUS vary considerably among the three centers. CONCLUSIONS: Looking at the differences in the predictive value of screening tests in three "comparable" centers, generasibility is not as straightforward as it seems. Using a nomogram for predictive purposes developed elsewhere will require a thorough knowledge of the patient population of which it is derived, and one should interpret its results with a critical mind.

Circulating free insulin-like growth factor (IGF)-I, total IGF-I, and IGF binding protein-3 levels do not predict the future risk to develop prostate cancer: results of a case-control study involving 201 patients within a population-based screening with a 4-year interval.

Recent studies have reported that serum IGF-I levels in the highest quartile of the normal range and IGF binding protein-3 (IGFBP-3) in the lowest quartile of the normal range are associated with an increased risk of future prostate cancer and/or presence of prostate cancer. It has also been suggested that the measurement of circulating total IGF-I concentrations might be a useful tool for the early detection of prostate cancer in men with moderately increased prostate-specific antigen (PSA) levels. To determine whether circulating free IGF-I, total IGF-I, and IGFBP-3 levels can predict future prostate cancer risk, we prospectively studied prostate cancer characteristics in a cohort of men during two rounds (mean interval, 4 yr) of a population-based screening study for prostate cancer. Two hundred one prostate cancer cases were detected at the second-round screening (aged 55-70 yr), and all these subjects were enrolled in the case group for the present study. Prostate cancer had been confirmed by biopsy in all cases. These 201 subjects were matched with the 201 nonprostate cancer cases by age, serum PSA range at the first-round screening (PSA < 2 ng/ml, n = 67; PSA = 2-3 ng/ml, n = 67; and PSA = 3-4 ng/ml, n = 67), and residence area. At baseline, total IGF-I, free IGF-I, and IGFBP-3 levels and prostate volume of cases with prostate cancer were not different from those of healthy controls. PSA velocity was significantly different between cases and controls (P < 0.001).Stepwise forward logistic regression analysis showed that only PSA levels at baseline and PSA at round 2 after 4 yr are good predictors of prostate cancer, whereas total IGF-I, free IGF-I, and IGFBP-3 did not predict the development of prostate cancer. Only one of the 201 subjects with prostate cancer had metastases. Within the subjects with prostate cancer, there were no differences of IGF-I parameters with different tumor node metastasis categories and/or Gleason scores. Our study suggests that the measurement of serum IGF-I and/or IGFBP-3 concentrations in addition to PSA does not improve the identification of men at high risk to develop early stages of prostate cancer. In addition, our results indicate that the endocrine IGF-I system is not directly involved in the growth of the early stages of prostate cancer.