The impact of PLCO control arm contamination on perceived PSA screening efficacy

Prostate-Specific Antigen Screening and 15-Year Prostate Cancer Mortality: A Secondary Analysis of the CAP Randomized Clinical Trial

Importance

The Cluster Randomized Trial of PSA Testing for Prostate Cancer (CAP) reported no effect of prostate-specific antigen (PSA) screening on prostate cancer mortality at a median 10-year follow-up (primary outcome), but the long-term effects of PSA screening on prostate cancer mortality remain unclear.

Objective

To evaluate the effect of a single invitation for PSA screening on prostate cancer-specific mortality at a median 15-year follow-up compared with no invitation for screening.

Design, Setting, and Participants

This secondary analysis of the CAP randomized clinical trial included men aged 50 to 69 years identified at 573 primary care practices in England and Wales. Primary care practices were randomized between September 25, 2001, and August 24, 2007, and men were enrolled between January 8, 2002, and January 20, 2009. Follow-up was completed on March 31, 2021.

Intervention

Men received a single invitation for a PSA screening test with subsequent diagnostic tests if the PSA level was 3.0 ng/mL or higher. The control group received standard practice (no invitation).

Main Outcomes and Measures

The primary outcome was reported previously. Of 8 prespecified secondary outcomes, results of 4 were reported previously. The 4 remaining prespecified secondary outcomes at 15-year follow-up were prostate cancer-specific mortality, all-cause mortality, and prostate cancer stage and Gleason grade at diagnosis.

Results

Of 415 357 eligible men (mean [SD] age, 59.0 [5.6] years), 98% were included in these analyses. Overall, 12 013 and 12 958 men with a prostate cancer diagnosis were in the intervention and control groups, respectively (15-year cumulative risk, 7.08% [95% CI, 6.95%-7.21%] and 6.94% [95% CI, 6.82%-7.06%], respectively). At a median 15-year follow-up, 1199 men in the intervention group (0.69% [95% CI, 0.65%-0.73%]) and 1451 men in the control group (0.78% [95% CI, 0.73%-0.82%]) died of prostate cancer (rate ratio [RR], 0.92 [95% CI, 0.85-0.99]; P = .03). Compared with the control, the PSA screening intervention increased detection of low-grade (Gleason score [GS] ≤6: 2.2% vs 1.6%; P < .001) and localized (T1/T2: 3.6% vs 3.1%; P < .001) disease but not intermediate (GS of 7), high-grade (GS ≥8), locally advanced (T3), or distally advanced (T4/N1/M1) tumors. There were 45 084 all-cause deaths in the intervention group (23.2% [95% CI, 23.0%-23.4%]) and 50 336 deaths in the control group (23.3% [95% CI, 23.1%-23.5%]) (RR, 0.97 [95% CI, 0.94-1.01]; P = .11). Eight of the prostate cancer deaths in the intervention group (0.7%) and 7 deaths in the control group (0.5%) were related to a diagnostic biopsy or prostate cancer treatment.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, a single invitation for PSA screening compared with standard practice without routine screening reduced prostate cancer deaths at a median follow-up of 15 years. However, the absolute reduction in deaths was small.

Trial Registration

isrctn.org Identifier: ISRCTN92187251.

Mortality reduction and cumulative excess incidence (CEI) in the prostate-specific antigen (PSA) screening era

The extent to which PSA screening is related to prostate cancer mortality reduction in the United States (US) is controversial. US Surveillance, Epidemiology, and End Results Program (SEER) data from 1980 to 2016 were examined to assess the relationship between prostate cancer mortality and cumulative excess incidence (CEI) in the PSA screening era and to clarify the impact of race on this relationship. CEI was considered as a surrogate for the intensity of prostate cancer screening with PSA testing and subsequent biopsy as appropriate. Data from 163,982,733 person-years diagnosed with 544,058 prostate cancers (9 registries, 9% of US population) were examined. Strong inverse linear relationships were noted between CEI and prostate cancer mortality, and 317,356 prostate cancer deaths were avoided. Eight regions of the US demonstrated prostate cancer mortality reduction of 46.0-63.7%. On a per population basis, the lives of more black men than white men were saved in three of four registries with sufficient black populations for comparison. Factor(s) independent of CEI (potential effects of treatment advances) explained 14.6% of the mortality benefit (p-value = 0.3357) while there was a significant main effect of CEI (effect = -0.0064; CI: [-0.0088, -0.0040]; p-value < 0.0001). Therefore, there is a strong relationship between CEI and prostate cancer mortality reduction that was not related to factors independent of screening utilization. Minority populations have experienced large mortality reductions in the context of PSA mass utilization.

Benefits and harms of prostate specific antigen testing according to Australian guidelines

Guidelines for prostate specific antigen (PSA) testing in Australia recommend that men at average risk of prostate cancer who have been informed of the benefits and harms, and who decide to undergo regular testing, should be offered testing every 2 years from 50 to 69 years. This study aimed to estimate the benefits and harms of regular testing in this context. We constructed Policy1-Prostate, a discrete event microsimulation platform of the natural history of prostate cancer and prostate cancer survival, and PSA testing patterns and subsequent management in Australia. The model was calibrated to pre-PSA (before 1985) prostate cancer incidence and mortality and validated against incidence and mortality trends from 1985 to 2011 and international trials. The model predictions were concordant with trials and Australian observed incidence and mortality data from 1985 to 2011. Out of 1000 men who choose to test according to the guidelines, 36 [21-41] men will die from prostate cancer and 126 [119-133] men will be diagnosed with prostate cancer, compared with 50 [47-54] and 94 [90-98] men who do not test, respectively. During the 20 years of active PSA testing, 32.3% [25.6%-38.8%] of all PSA-test detected cancers are overdiagnosed cases that is, 30 [21-42] out of 94 [83-107] PSA-test detected cancers. Australian men choosing to test with PSA every two years from 50 to 69 will reduce their risk of ever dying from prostate cancer and incur a risk of overdiagnosis: for every man who avoids dying from prostate cancer, two will be overdiagnosed with prostate cancer between 50 and 69 years of age. Australian men, with health professionals, can use these results to inform decision-making about PSA testing.

Relationship Between Baseline Prostate-specific Antigen on Cancer Detection and Prostate Cancer Death: Long-term Follow-up from the European Randomized Study of Screening for Prostate Cancer

BACKGROUND

The European Association of Urology guidelines recommend a risk-based strategy for prostate cancer screening based on the first prostate-specific antigen (PSA) level and age.

OBJECTIVE

To analyze the impact of the first PSA level on prostate cancer (PCa) detection and PCa-specific mortality (PCSM) in a population-based screening trial (repeat screening every 2-4 yr).

DESIGN, SETTING, AND PARTICIPANTS

We evaluated 25589 men aged 55-59 yr, 16898 men aged 60-64 yr, and 12936 men aged 65-69 yr who attended at least one screening visit in the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial (screening arm: repeat PSA testing every 2-4 yr and biopsy in cases with elevated PSA; control arm: no active screening offered) during 16-yr follow-up (FU).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We assessed the actuarial probability for any PCa and for clinically significant (cs)PCa (Gleason ≥7). Cox proportional-hazards regression was performed to assess whether the association between baseline PSA and PCSM was comparable for all age groups. A Lorenz curve was computed to assess the association between baseline PSA and PCSM for men aged 60-61 yr.

RESULTS AND LIMITATIONS

The overall actuarial probability at 16 yr ranged from 12% to 16% for any PCa and from 3.7% to 5.7% for csPCa across the age groups. The actuarial probability of csPCa at 16 yr ranged from 1.2-1.5% for men with PSA <1.0 ng/ml to 13.3-13.8% for men with PSA ≥3.0 ng/ml. The association between baseline PSA and PCSM differed marginally among the three age groups. A Lorenz curve for men aged 60-61 yr showed that 92% of lethal PCa cases occurred among those with PSA above the median (1.21 ng/ml). In addition, for men initially screened at age 60-61 yr with baseline PSA <2 ng/ml, further continuation of screening is unlikely to be beneficial after the age of 68-70 yr if PSA is still <2 ng/ml. No case of PCSM emerged in the subsequent 8 yr (up to age 76-78 yr). A limitation is that these results may not be generalizable to an opportunistic screening setting or to contemporary clinical practice.

CONCLUSIONS

In all age groups, baseline PSA can guide decisions on the repeat screening interval. Baseline PSA of <1.0 ng/ml for men aged 55-69 yr is a strong indicator to delay or stop further screening.

PATIENT SUMMARY

In prostate cancer screening, the patient's baseline PSA (prostate-specific antigen) level can be used to guide decisions on when to repeat screening. The PSA test when used according to current knowledge is valuable in helping to reduce the burden of prostate cancer.

The Patient Journey from Randomization to Detection of Prostate Cancer and Death: Results from ERSPC Rotterdam

Background

The ERSPC study has demonstrated that prostate-specific antigen (PSA)-based screening results in a relative increase in diagnosis of (low-risk) prostate cancer (PCa) and a reduction in metastatic disease and PCa mortality.

Objective

To evaluate the burden of PCa among men randomized to active screening compared to those in the control arm in ERSPC Rotterdam.

Design setting and participants

We analyzed data for participants in the Dutch section of the ERSPC, including 21 169 men randomized to the screening arm and 21 136 randomized to the control arm. Men in the screening arm were invited for PSA-based screening every 4 yr, and transrectal ultrasound-guided prostate biopsy was recommended for those with PSA ≥3.0 ng/ml.

Outcome measurements and statistical analysis

We analyzed detailed follow-up and mortality data up to January 1, 2019, to a maximum of 21 yr, using multistate models.

Results and limitations

At 21 yr, 3046 men (14%) had been diagnosed with nonmetastatic PCa and 161 (0.76%) with metastatic PCa in the screening arm. In the control arm, 1698 men (8.0%) had been diagnosed with nonmetastatic PCa and 346 (1.6%) with metastatic PCa. In comparison to the control arm, men in the screening arm were diagnosed with PCa almost 1 yr earlier and if diagnosed with nonmetastatic PCa lived on average for almost 1 yr longer without disease progression. Among those who experienced biochemical recurrence (18-19% after nonmetastatic PCa), progression to metastatic disease or death was quicker in the control arm: men in the screening arm lived for 7.17 yr without progression, while the progression-free interval was only 1.59 yr for men in the control arm over a 10-yr time period. Among those who experienced metastatic disease, men in both study arms lived for 5 yr over a 10-yr time period.

Conclusions

PCa diagnosis was earlier after study entry for men in the PSA-based screening arm. However, disease progression was not as fast in the screening arm as in the control arm: once men in the control arm experienced biochemical recurrence, progression to metastatic disease or death was 5.6 yr faster than in the screening arm. Our results confirm the ability of early disease detection to reduce suffering and death from PCa at the cost of earlier (and more frequent) treatment-induced reductions in quality of life.

Patient summary

Our study shows that early detection of prostate cancer can reduce suffering and death from this disease. However, screening based on measurement of prostate-specific antigen (PSA) can also result in an earlier treatment-induced reduction in quality of life.

Encounter-based randomization did not result in contamination in a shared decision-making trial: a secondary analysis

OBJECTIVES

To estimate the level of contamination in an encounter-randomized trial evaluating a shared decision-making (SDM) tool.

STUDY DESIGN AND SETTING

We assessed contamination at three levels: (1) tool contamination (whether the tool was physically present in the usual care encounter), (2) functional contamination (whether components of the SDM tool were recreated in the usual care encounters without directly accessing the tool), and (3) learned contamination (whether clinicians "got better at SDM" in the usual care encounters as assessed by the OPTION-12 score). For functional and learned contamination, the interaction with the number of exposures to the tool was assessed.

RESULTS

We recorded and analyzed 830 of 922 randomized encounters. Of the 411 recorded encounters randomized to usual care, the SDM tool was used in nine (2.2%) encounters. Clinicians discussed at least one patient-important issue in 377 usual care encounters (92%) and the risk of stroke in 214 encounters (52%). We found no significant interaction between number of times the SDM tool was used and subsequent functional or learned contamination.

CONCLUSION

Despite randomly assigning clinicians to use an SDM tool in some and not other encounters, we found no evidence of contamination in usual care encounters.

How Did CNBSS Influence Guidelines for So Long and What Can That Teach Us?

The biased randomization and other quality concerns about the Canadian National Breast Screening Studies (CNBSS) were documented and criticized for decades, even by several individuals very close to the research. CNBSS were the outlier studies among several RCTs of the era and yet were given equal weighting and occasionally higher importance than the remainder of the canon of mammography RCTs. These studies have had an ongoing influence on subsequent evidence review, guideline formation, and, ultimately, patient access to screening. This article explores possible reasons for the ongoing inclusion of CNBSS in the body of mammography screening evidence, discusses the lack of expertise in critical healthcare guideline processes, and, ultimately, suggests several actions and reforms.

Assessment of factors associated with PSA level in prostate cancer cases and controls from three geographical regions

It is being debated whether prostate-specific antigen (PSA)-based screening effectively reduces prostate cancer mortality. Some of the uncertainty could be related to deficiencies in the age-based PSA cut-off thresholds used in screening. Current study considered 2779 men with prostate cancer and 1606 men without a cancer diagnosis, recruited for various studies in New Zealand, US, and Taiwan. Association of PSA with demographic, lifestyle, clinical characteristics (for cases), and the aldo–keto reductase 1C3 (AKR1C3) rs12529 genetic polymorphisms were analysed using multiple linear regression and univariate modelling. Pooled multivariable analysis of cases showed that PSA was significantly associated with demographic, lifestyle, and clinical data with an interaction between ethnicity and age further modifying the association. Pooled multivariable analysis of controls data also showed that demographic and lifestyle are significantly associated with PSA level. Independent case and control analyses indicated that factors associated with PSA were specific for each cohort. Univariate analyses showed a significant age and PSA correlation among all cases and controls except for the US-European cases while genetic stratification in cases showed variability of correlation. Data suggests that unique PSA cut-off thresholds factorized with demographics, lifestyle and genetics may be more appropriate for prostate cancer screening.

A 25-year perspective on evaluation and understanding of biomarkers in urologic cancers

The past 25 years have witnessed an explosion of investigative attempts to identify clinically useful biomarkers which can have meaningful impacts for patients with urologic cancers. However, in spite of the enormous amount of research aiming to identify markers with the hope of impacting patient care, only a handful have proven to have true clinical utility. Improvements in targeted imaging, pan-omics evaluation, and genetic sequencing at the tissue and single-cell levels have yielded many potential targets for continued biomarker investigation. This article, as one in this series for the 25th Anniversary Issue of Urologic Oncology: Seminars and Original Investigations, serves to give a perspective on our progress and failures over the past quarter-century in our highest volume urologic cancers: prostate, bladder, and kidney cancers.

Differences in Prostate Cancer Incidence and Mortality in Lower Saxony (Germany) and Groningen Province (Netherlands): Potential Impact of Prostate-Specific Antigen Testing

Background

Prostate cancer (PCa) is the most frequent cancer among men in Europe. Differences in PCa incidence around the world can be partly explained by variations in recommendations for prostate-specific antigen (PSA), particularly for early detection. For example, the PSA testing policy is more conservative in the Netherlands than in Germany. To better understand the relationship between PSA testing recommendations and PCa incidence, stage distribution, and mortality, we compared these variables over time between Lower Saxony in northwestern Germany and the neighboring province of Groningen in the Netherlands.

Methods

Population data, tumor stage- and age group-specific PCa incidence (ICD-10 C61) and mortality rates for Lower Saxony and Groningen were obtained from the Lower Saxony Epidemiological Cancer Registry, the Netherlands Comprehensive Cancer Organization, and Statistics Netherlands for 2003–2012. Incidence and mortality rates per 100,000 person-years were age-standardized (ASR, old European standard). Trends in age-standardized incidence rates (ASIR) and mortality rates (ASMR) for specific age groups were assessed using joinpoint regression.

Results

The mean annual PCa ASIR between 2003 and 2012 was on average 19.9% higher in Lower Saxony than in Groningen (120.5 vs. 100.5 per 100,000), while the mean annual ASMR was on average 24.3% lower in Lower Saxony than in Groningen (21.5 vs. 28.4 per 100,000). Between 2003 and 2012, the average annual percentage change (AAPC) in PCa incidence rates did not change significantly in either Lower Saxony (−1.8%, 95% CI −3.5, 0.0) or Groningen (0.2%, 95% CI −5.0, 5.7). In contrast, the AAPC in mortality rate decreased significantly during the same time period in Lower Saxony (−2.5%, 95% CI −3.0, −2.0) but not in Groningen (0.1%, 95% CI −2.4, 2.6).

Conclusions

Higher PCa incidence and lower PCa-related mortality was detected in Lower Saxony than in Groningen. Although recommendations on PSA testing may play a role, the assessed data could not offer obvious explanations to the observed differences. Therefore, further investigations including data on the actual use of PSA testing, other influences (e.g., dietary and ethnic factors), and better data quality are needed to explain differences between the regions.

Number of screening rounds attended and incidence of high-risk prostate cancer in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC)

BACKGROUND

The European Randomized Study of Screening for Prostate Cancer has shown a 20% reduction in prostate cancer (PC) mortality by prostate-specific antigen-based screening. In addition, screening has been shown to reduce the risk of advanced PC. The objective of the current study was to analyze the impact of screening participation on the incidence of PC by risk group.

METHODS

The participants in the screening arm of the Finnish trial (31,867 men) were classified according to screening attendance in a time-dependent fashion. Initially, all men in the screening arm were regarded as nonattenders until the first screening attendance; they then remained in the once-screened group until the second screen and similarly for the possible third round. The control arm formed the reference group. Follow-up started at randomization and ended at the time of diagnosis of PC, emigration, or the end of 2015. PC cases were divided into risk groups according to European Association of Urology definitions.

RESULTS

The incidence of low-risk PC increased with the number of screens, whereas no clear relation with participation was noted in the intermediate-risk and high-risk cases. For patients with advanced PC, attending screening at least twice was associated with a lower risk.

CONCLUSIONS

Screening reduces the risk of advanced PC after only 2 screening cycles. A single screen demonstrated no benefit in terms of PC incidence. Repeated screening is necessary to achieve screening advantages.

Personalized strategies in population screening for prostate cancer

This review discusses evidence for population-based screening with contemporary screening tools. In Europe, prostate-specific antigen (PSA)-based screening led to a relative reduction of prostate cancer (PCa) mortality, but also to a substantial amount of overdiagnosis and unnecessarily biopsies. Risk stratification based on a single variable (a clinical variable or based on the presence of a lesion on prostate imaging) or based on multivariable approaches can aid in reducing unnecessary prostate biopsies and overdiagnosis by selecting men who can benefit from further clinical assessment. Multivariable approaches include clinical variables, and biomarkers, often combined in risk calculators or nomograms. These risk calculators can also incorporate the result of MRI imaging. In general, as compared to a purely PSA based approach, the combination of relevant prebiopsy information results in superior selection of men at higher risk of harboring clinically significant prostate cancer. Currently, it is not possible to draw any conclusions on the superiority of these multivariable risk-based approaches since head-to-head comparisons are virtually lacking. Recently initiated large population-based screening studies in Finland, Germany and Sweden, incorporating various multivariable risk stratification approaches will hopefully give more insight in whether the harm-benefit ratio can be improved, that is, maintain (or improving) the ability to reduce metastatic disease and prostate cancer mortality while reducing harm caused by unnecessary testing and overdiagnosis including related overtreatment.

A natural history model for planning prostate cancer testing: Calibration and validation using Swedish registry data

Recent prostate cancer screening trials have given conflicting results and it is unclear how to reduce prostate cancer mortality while minimising overdiagnosis and overtreatment. Prostate cancer testing is a partially observable process, and planning for testing requires either extrapolation from randomised controlled trials or, more flexibly, modelling of the cancer natural history. An existing US prostate cancer natural history model (Gulati et al, Biostatistics 2010;11:707-719) did not model for differences in survival between Gleason 6 and 7 cancers and predicted too few Gleason 7 cancers for contemporary Sweden. We re-implemented and re-calibrated the US model to Sweden. We extended the model to more finely describe the disease states, their time to biopsy-detectable cancer and prostate cancer survival. We first calibrated the model to the incidence rate ratio observed in the European Randomised Study of Screening for Prostate Cancer (ERSPC) together with age-specific cancer staging observed in the Stockholm PSA (prostate-specific antigen) and Biopsy Register; we then calibrated age-specific survival by disease states under contemporary testing and treatment using the Swedish National Prostate Cancer Register. After calibration, we were able to closely match observed prostate cancer incidence trends in Sweden. Assuming that patients detected at an earlier stage by screening receive a commensurate survival improvement, we find that the calibrated model replicates the observed mortality reduction in a simulation of ERSPC. Using the resulting model, we predicted incidence and mortality following the introduction of regular testing. Compared with a model of the current testing pattern, organised 8 yearly testing for men aged 55–69 years was predicted to reduce prostate cancer incidence by 14% and increase prostate cancer mortality by 2%. The model is open source and suitable for planning for effective prostate cancer screening into the future.

A blueprint for cancer screening and early detection: Advancing screening's contribution to cancer control

From the mid-20th century, accumulating evidence has supported the introduction of screening for cancers of the cervix, breast, colon and rectum, prostate (via shared decisions), and lung. The opportunity to detect and treat precursor lesions and invasive disease at a more favorable stage has contributed substantially to reduced incidence, morbidity, and mortality. However, as new discoveries portend advancements in technology and risk-based screening, we fail to fulfill the greatest potential of the existing technology, in terms of both full access among the target population and the delivery of state-of-the art care at each crucial step in the cascade of events that characterize successful cancer screening. There also is insufficient commitment to invest in the development of new technologies, incentivize the development of new ideas, and rapidly evaluate promising new technology. In this report, the authors summarize the status of cancer screening and propose a blueprint for the nation to further advance the contribution of screening to cancer control.

Cancer screening in the United States, 2018: A review of current American Cancer Society guidelines and current issues in cancer screening

Each year, the American Cancer Society publishes a summary of its guidelines for early cancer detection, data and trends in cancer screening rates from the National Health Interview Survey, and select issues related to cancer screening. In this 2018 update, we also summarize the new American Cancer Society colorectal cancer screening guideline and include a clarification in the language of the 2013 lung cancer screening guideline. CA Cancer J Clin 2018;68:297-316. © 2018 American Cancer Society.

Prostate cancer screening: what can we learn from randomised trials?

In this article, the principle of randomised trials are first described and then prostate cancer screening trials published to date are evaluated based on these principles. A summary of the randomised prostate cancer screening is provided. The conclusion that can be made from the results of the screening trials, as well as limitations of the evidence and open questions are outlined in the end.

Prostate Cancer: Update on Early Detection and New Biomarkers

Screening and early treatment of prostate cancer (PCa) has recently come under scrutiny due to the rates of overdiagnosis of low risk cancer. Randomized trials, including ERSPC and PLCO, have informed our understanding of the survival benefit provided by systematic PCa screening with serum prostate-specific antigen (PSA). To reduce the number of patients diagnosed with indolent disease, new adjuvant risk stratification tests have become available.

Heterogeneous impacts: adverse childhood experiences and cancer screening

BACKGROUND

Adverse childhood experiences (ACEs) have been associated with higher odds of cancer in adulthood. One potential explanation for this association is the impact of ACEs on cancer screening. To address this shortcoming, this study examined how ACEs were associated with current compliance and ever use of prostate, breast, cervical, and colorectal cancer screening.

METHODS

Data from the 2014 Kansas Behavioral Risk Factor Surveillance System were used (n = 11,794). Logistic regressions were used to calculate odds of cancer screening behaviors from each of nine different ACE items and a count of ACEs.

RESULTS

Individual ACE items were associated with lower odds of compliance with PSA screening, clinical breast exam, and pap test guidelines. Certain ACEs were associated with increased odds of compliance with colorectal cancer screening guidelines among women and lower odds of compliance among men. ACEs were associated with ever screening for PSA and ever use of colonoscopy or sigmoidoscopy among men and women. Physical abuse was most consistently associated with cancer screening, across outcomes.

CONCLUSIONS

Most significant associations showed that specific ACEs were associated with lower odds of cancer screening. Therefore, efforts should be made to promote screening among those with histories of ACEs.

Screening for prostate cancer: are organized screening programs necessary?

Already in 1991 when the prostate-specific antigen (PSA) test was proposed as a diagnostic test, screening for prostate cancer (PCa) was considered controversial due to the considerable risk of detecting latent PCa. Randomised controlled trials were initiated to assess the potential of PSA-based screening in reducing disease-specific mortality. Harms and benefit were closely monitored and both were confirmed. A reduction in mortality was seen and at the same time the initial fear of unnecessary testing and over diagnosis became reality. This triggered professional organizations to adapt their guidelines and to focus on shared decision making (SDM) and selective screening for those men considered at high risk. Unfortunately implementation of guidelines into daily clinical practice is bothersome. As a result many men are being (re)tested while not being at risk and the potential benefit being unclear. This raises the question on whether PSA screening should be organized in controlled programs. While the PSA test will remain the mainstay of PCa early detection many other additional tests (biomarkers/imaging) are currently being tested in large population-based initiatives as a first step to organized programs in selective groups of men.

A 24-year prospective study of dietary α-linolenic acid and lethal prostate cancer

Several meta-analyses have attempted to determine the relationships between intake of α-linolenic acid (ALA) and prostate cancer, but results were inconclusive. 47,885 men aged 40-75 years without prior cancer in the Health Professionals Follow-Up Study were prospectively followed from 1986 to 2010. Intake of ALA was determined from validated food frequency questionnaires every 4 years. We used multivariate Cox proportional hazards models to estimate hazard ratios (HR) with 95% confidence intervals (CIs) for lethal prostate cancer (distant metastasis or prostate cancer death). 386 lethal prostate cancers were diagnosed in the pre-PSA era (before February, 1994) and 403 cancers in the PSA era. Intake of ALA was associated with increased risk of lethal prostate cancer in the pre-PSA era (comparing top to bottom quintile of intake, multivariate-adjusted HR = 1.78; 95% CI = 1.22-2.06; p_trend  = 0.003), but not in the PSA era (HR = 0.81; 95% CI = 0.56-1.17; p_trend  = 0.53), and the difference in associations was statistically significant (p for interaction = 0.02). Mayonnaise, a primary food source of ALA intake in our cohort, was likewise only significantly associated with lethal prostate cancer in the pre-PSA era. Among many other fatty acids that are correlated with ALA due to shared food sources, none was associated with lethal prostate cancer in the pre-PSA era. In conclusion, higher intake of ALA was associated with an increased risk of lethal prostate cancer in the pre-PSA era, but not in the PSA era. Potential reasons for the differential associations warrant further investigation.

The efficacy of prostate-specific antigen screening: Impact of key components in the ERSPC and PLCO trials

BACKGROUND

The European Randomized Study of Screening for Prostate Cancer (ERSPC) demonstrated that prostate-specific antigen (PSA) screening significantly reduced prostate cancer mortality (rate ratio, 0.79; 95% confidence interval, 0.69-0.91). The US Prostate, Lung, Colorectal, and Ovarian (PLCO) trial indicated no such reduction but had a wide 95% CI (rate ratio for prostate cancer mortality, 1.09; 95% CI, 0.87-1.36). Standard meta-analyses are unable to account for key differences between the trials that can impact the estimated effects of screening and the trials' point estimates.

METHODS

The authors calibrated 2 microsimulation models to individual-level incidence and mortality data from 238,936 men participating in the ERSPC and PLCO trials. A cure parameter for the underlying efficacy of screening was estimated by the models separately for each trial. The authors changed step-by-step major known differences in trial settings, including enrollment and attendance patterns, screening intervals, PSA thresholds, biopsy receipt, control arm contamination, and primary treatment, to reflect a more ideal protocol situation and differences between the trials.

RESULTS

Using the cure parameter estimated for the ERSPC, the models projected 19% to 21% and 6% to 8%, respectively, prostate cancer mortality reductions in the ERSPC and PLCO settings. Using this cure parameter, the models projected a reduction of 37% to 43% under annual screening with 100% attendance and biopsy compliance and no contamination. The cure parameter estimated for the PLCO trial was 0.

CONCLUSIONS

The observed cancer mortality reduction in screening trials appears to be highly sensitive to trial protocol and practice settings. Accounting for these differences, the efficacy of PSA screening in the PLCO setting is not necessarily inconsistent with ERSPC results. Cancer 2018;124:1197-206. © 2017 American Cancer Society.

Impact of a Prostate Specific Antigen Screening Decision Aid on Clinic Function

INTRODUCTION

Decision aids (DAs) around prostate cancer screening can increase knowledge and shared decision making (SDM), but remain underutilized due to cost and time constraints that disrupt clinic flow. We examined the impact of a simple prostate specific antigen (PSA) screening DA distribution strategy on clinic flow as well as SDM in a diverse urban primary care clinic.

METHODS

Men ages 50-75 viewed the DA while waiting for physicians. Participants and physicians completed questionnaires evaluating the SDM process. Focus groups were conducted with clinic staff and physicians to evaluate the impact on clinic operations.

RESULTS

Fifty percent of men discussed PSA screening and 85% reported the DA made decision making easier. Participants reported an average of 12.9 min reading the DA. Participants reported high decision satisfaction and low decisional conflict. Physicians reported an average of 5.2 minutes discussing PSA screening. Clinic staff reported increased enthusiasm for the process after adjustments were made in response to concerns including time, and lack of both knowledge about the DA subject matter and involvement in the process. Physician-reported barriers included ambivalence about PSA screening.

CONCLUSIONS

A PSA DA, requiring few resources, can be implemented with broad involvement of clinic staff and minimal disruption to clinic flow in an urban primary care clinic, and may facilitate SDM.

Reconciling the Effects of Screening on Prostate Cancer Mortality in the ERSPC and PLCO Trials

BACKGROUND

The ERSPC (European Randomized Study of Screening for Prostate Cancer) found that screening reduced prostate cancer mortality, but the PLCO (Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial) found no reduction.

OBJECTIVE

To evaluate whether effects of screening on prostate cancer mortality relative to no screening differed between the ERSPC and PLCO.

DESIGN

Cox regression of prostate cancer death in each trial group, adjusted for age and trial. Extended analyses accounted for increased incidence due to screening and diagnostic work-up in each group via mean lead times (MLTs), which were estimated empirically and using analytic or microsimulation models.

SETTING

Randomized controlled trials in Europe and the United States.

PARTICIPANTS

Men aged 55 to 69 (ERSPC) or 55 to 74 (PLCO) years at randomization.

INTERVENTION

Prostate cancer screening.

MEASUREMENTS

Prostate cancer incidence and survival from randomization; prostate cancer incidence in the United States before screening began.

RESULTS

Estimated MLTs were similar in the ERSPC and PLCO intervention groups but were longer in the PLCO control group than the ERSPC control group. Extended analyses found no evidence that effects of screening differed between trials (P = 0.37 to 0.47 [range across MLT estimation approaches]) but strong evidence that benefit increased with MLT (P = 0.0027 to 0.0032). Screening was estimated to confer a 7% to 9% reduction in the risk for prostate cancer death per year of MLT. This translated into estimates of 25% to 31% and 27% to 32% lower risk for prostate cancer death with screening as performed in the ERSPC and PLCO intervention groups, respectively, compared with no screening.

LIMITATION

The MLT is a simple metric of screening and diagnostic work-up.

CONCLUSION

After differences in implementation and settings are accounted for, the ERSPC and PLCO provide compatible evidence that screening reduces prostate cancer mortality.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Prostate cancer screening in Brazil: should it be done or not?

The use of PSA in the screening, detection and prognosis of prostate cancer (PCa) has revolutionized the diagnosis and treatment of this disorder with an increase in detection rates and PCa organ-confined. Despite these benefits and ease of implementation, tracking PCa remains a matter of great controversy. We conducted a literature review and demographic and epidemiological data in Brazil feeling to assess the current state of screening and whether there is justification for population programs. the differences are valued between developed and underdeveloped countries as the incidence, mortality, screening and access to health. an analysis of the advantages and disadvantages of screening is made as well as a critical analysis of existing studies on screening and some recommendations on a rational screening.

Economic Analysis of Prostate-Specific Antigen Screening and Selective Treatment Strategies

IMPORTANCE

Prostate-specific antigen (PSA) screening for prostate cancer is controversial. Experts have suggested more personalized or more conservative strategies to improve benefit-risk tradeoffs, but the value of these strategies-particularly when combined with increased conservative management for low-risk cases-is uncertain.

OBJECTIVES

To evaluate the potential cost-effectiveness of plausible PSA screening strategies and to assess the value added by increased use of conservative management among low-risk, screen-detected cases.

DESIGN, SETTING, AND PARTICIPANTS

A microsimulation model of prostate cancer incidence and mortality was created. A simulated contemporary cohort of US men beginning at 40 years of age underwent 18 strategies for PSA screening. Treatment strategies included (1) contemporary treatment practices based on age and cancer stage and grade observed in the Surveillance, Epidemiology, and End Results program in 2010 or (2) selective treatment practices whereby cases with a Gleason score lower than 7 and clinical T2a stage cancer or lower are treated only after clinical progression, and all other cases undergo contemporary treatment practices. National and trial data on PSA growth, screening and biopsy patterns, incidence of prostate cancer, treatment distributions, treatment efficacy, mortality, health-related quality of life, and direct medical expenditure were analyzed. Data were collected from March 18, 2009, to August 15, 2014, and analyzed from November 20, 2012, to December 11, 2015.

INTERVENTIONS

Eighteen screening strategies that vary by start and stop age, screening interval, and criteria for biopsy referral and contemporary or selective treatment practices.

MAIN OUTCOMES AND MEASURES

Life-years (LYs), quality-adjusted life-years (QALYs), direct medical expenditure, and cost per LY and QALY gained.

RESULTS

All 18 screening strategies were associated with increased LYs (range, 0.03-0.06) and costs ($263-$1371) compared with no screening, with the cost ranging from $7335 to $21 649 per LY. With contemporary treatment, only strategies with biopsy referral for PSA levels higher than 10.0 ng/mL or age-dependent thresholds were associated with increased QALYs (0.002-0.004), and only quadrennial screening of patients aged 55 to 69 years was potentially cost-effective in terms of cost per QALY (incremental cost-effectiveness ratio, $92 446). With selective treatment, all strategies were associated with increased QALYs (0.002-0.004), and several strategies were potentially cost-effective in terms of cost per QALY (incremental cost-effectiveness ratio, $70 831-$136 332).

CONCLUSIONS AND RELEVANCE

For PSA screening to be cost-effective, it needs to be used conservatively and ideally in combination with a conservative management approach for low-risk disease.

Screening Men at Increased Risk for Prostate Cancer Diagnosis: Model Estimates of Benefits and Harms

BACKGROUND

Guidelines for PSA screening in subgroups with increased risk of prostate cancer diagnosis due to race or genotype are underdeveloped. Our goal was to investigate types of increased prostate cancer risk and implications for targeted screening.

METHODS

We investigated computer simulation of subgroups with average and hypothetical increased risk(s) of onset of latent disease, progression, and/or cancer-specific death. For each subgroup, we predicted lifetime probabilities of overdiagnosis and life saved under more and less intensive PSA screening strategies. An application estimated risks of onset among BRCA1/2 mutation carriers in the Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls (IMPACT) study using maximum likelihood.

RESULTS

Our simulations implied PSA screening can save more lives among subgroups with increased risk than with average risk, but more intensive screening did not always improve harm-benefit trade-offs. IMPACT data were consistent with increased risks of onset among BRCA1 and BRCA2 mutation carriers [HR = 1.05; 95% confidence interval (CI), 0.63-1.59 and HR = 1.81; 95% CI, 1.14-2.78, respectively]. Our analysis suggests screening BRCA2 mutation carriers earlier and more frequently than the average-risk population, but a lower PSA threshold for biopsy is unlikely to improve outcomes.

CONCLUSIONS

Effective screening in men with increased prostate cancer risk depends on the manner in which the risk is increased. More intensive screening is not always optimal.

IMPACT

Guidelines for screening men at increased prostate cancer risk should consider the mechanism inducing the increased risk. Although the benefit of screening may be greater in men with increased risks, more intensive screening is not always appropriate. Cancer Epidemiol Biomarkers Prev; 26(2); 222-7. ©2016 AACR.

Estimate of Opportunistic Prostate Specific Antigen Testing in the Finnish Randomized Study of Screening for Prostate Cancer

PURPOSE

Screening for prostate cancer remains controversial, although ERSPC (European Randomized Study of Screening for Prostate Cancer) showed a 21% relative reduction in prostate cancer mortality. The Finnish Randomized Study of Screening for Prostate Cancer, which is the largest component of ERSPC, demonstrated a statistically nonsignificant 16% mortality benefit in a separate analysis. The purpose of this study was to estimate the degree of contamination in the control arm of the Finnish trial.

MATERIALS AND METHODS

Altogether 48,295 and 31,872 men were randomized to the control and screening arms, respectively. The screening period was 1996 to 2007. The extent of prostate specific antigen testing was analyzed retrospectively using laboratory databases. The incidence of T1c prostate cancer (impalpable prostate cancer detected by elevated prostate specific antigen) was determined from the national Finnish Cancer Registry.

RESULTS

Approximately 1.4% of men had undergone prostate specific antigen testing 1 to 3 years before randomization. By the first 4, 8 and 12 years of followup 18.1%, 47.7% and 62.7% of men in the control arm had undergone prostate specific antigen testing at least once and in the screening arm the proportions were 69.8%, 81.1% and 85.2%, respectively. The cumulative incidence of T1c prostate cancer was 6.1% in the screening arm and 4.5% in the control arm (RR 1.21, 95% CI 1.13-1.30).

CONCLUSIONS

A large proportion of men in the control arm had undergone a prostate specific antigen test during the 15-year followup. Contamination is likely to dilute differences in prostate cancer mortality between the arms in the Finnish screening trial.

Design-corrected variation by centre in mortality reduction in the ERSPC randomised prostate cancer screening trial

Objectives To calculate design-corrected estimates of the effect of screening on prostate cancer mortality by centre in the European Randomised Study of Screening for Prostate Cancer (ERSPC). Setting The ERSPC has shown a 21% reduction in prostate cancer mortality in men invited to screening with follow-up truncated at 13 years. Centres either used pre-consent randomisation (effectiveness design) or post-consent randomisation (efficacy design). Methods In six centres (three effectiveness design, three efficacy design) with follow-up until the end of 2010, or maximum 13 years, the effect of screening was estimated as both effectiveness (mortality reduction in the target population) and efficacy (reduction in those actually screened). Results The overall crude prostate cancer mortality risk ratio in the intervention arm vs control arm for the six centres was 0.79 ranging from a 14% increase to a 38% reduction. The risk ratio was 0.85 in centres with effectiveness design and 0.73 in those with efficacy design. After correcting for design, overall efficacy was 27%, 24% in pre-consent and 29% in post-consent centres, ranging between a 12% increase and a 52% reduction. Conclusion The estimated overall effect of screening in attenders (efficacy) was a 27% reduction in prostate cancer mortality at 13 years' follow-up. The variation in efficacy between centres was greater than the range in risk ratio without correction for design. The centre-specific variation in the mortality reduction could not be accounted for by the randomisation method.

Long-term prostate-specific antigen contamination in the Spanish arm of the European Randomized Study of Screening for Prostate Cancer (ERSPC)

OBJECTIVES

Recently, the European Randomized Study of Screening for Prostate Cancer achieved a reduction in prostate cancer mortality by measuring serum prostate-specific antigen (PSA) levels. These results were not reproduced in the Spanish arm of European Randomized Study of Screening for Prostate Cancer. PSA contamination (opportunistic measurements outside the study) could decrease the study's contrasting power if performed in the control arm. We have calculated the long-term rate of PSA contamination and its effect on performing prostate biopsy and detecting cancer.

MATERIAL AND METHODS

A total of 4,276 men were randomised (2,415 to the screening arm, 1,861 to the control arm) in the Spanish section of the European Randomized Study of Screening for Prostate Cancer. PSA measurements were not scheduled in the control arm. Sextant prostate biopsy was indicated if PSA levels were ≥3 ng/mL. All PSA readings performed outside the study were labelled as "PSA contamination". We calculated the rates of PSA contamination, biopsy implementation and cancer detection.

RESULTS

The median age and follow-up time were 57 and 15.1 years, respectively. A total of 2,511 men underwent at least one PSA reading outside the study. PSA contamination at 5, 10 and 15 years was 22.0%, 47.1% and 66.3% in the screening arm, respectively, and 20.8%, 43.2% and 58.6% in the control arm, respectively (P<.0001). The biopsy rate at 5, 10 and 15 years was 19.3%, 22.6% and 24.1% (screening), respectively, and 1.0%, 3.6% and 7.1% (control), respectively (P<.0001). The PC detection rate was 6.7% (screening) and 4.3% (control; P=.0006).

CONCLUSIONS

Although the cumulative PSA contamination was pronounced in the 2 study arms, the rate of prostate biopsies was low in the control arm. We therefore believe that the effect of PSA contamination on the study's statistical power should be limited.

A System Dynamics Model of Serum Prostate-Specific Antigen Screening for Prostate Cancer

Since 2012, US guidelines have recommended against prostate-specific antigen (PSA) screening for prostate cancer. However, evidence of screening benefit from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening trial and the European Randomized Study of Screening for Prostate Cancer has been inconsistent, due partly to differences in noncompliance and contamination. Using system dynamics modeling, we replicated the PLCO trial and extrapolated follow-up to 20 years. We then simulated 3 scenarios correcting for contamination in the PLCO control arm using Surveillance, Epidemiology, and End Results (SEER) incidence and survival data collected prior to the PSA screening era (scenario 1), SEER data collected during the PLCO trial period (1993-2001) (scenario 2), and data from the European trial's control arm (1991-2005) (scenario 3). In all scenarios, noncompliance was corrected using incidence and survival rates for men with screen-detected cancer in the PLCO screening arm. Scenarios 1 and 3 showed a benefit of PSA screening, with relative risks of 0.62 (95% confidence interval: 0.53, 0.72) and 0.70 (95% confidence interval: 0.59, 0.83) for cancer-specific mortality after 20 years, respectively. In scenario 2, however, there was no benefit of screening. This simulation showed that after correcting for noncompliance and contamination, there is potential benefit of PSA screening in reducing prostate cancer mortality. It also demonstrates the utility of system dynamics modeling for synthesizing epidemiologic evidence to inform public policy.

Who and when should we screen for prostate cancer? Interviews with key opinion leaders

Prostate cancer screening using prostate-specific antigen (PSA) is highly controversial. In this Q & A, Guest Editors for BMC Medicine's 'Spotlight on Prostate Cancer' article collection, Sigrid Carlsson and Andrew Vickers, invite some of the world's key opinion leaders to discuss who, and when, to screen for prostate cancer. In response to the points of view from the invited experts, the Guest Editors summarize the experts' views and give their own personal opinions on PSA screening.

Diagnostic associations of gene expression signatures in prostate cancer tissue

PURPOSE OF REVIEW

Over the past several years, multiple biomarkers designed to improve prostate cancer risk stratification have become commercially available, while others are still being developed. In this review, we focus on the evidence supporting recently reported biomarkers, with a focus on gene expression signatures.

RECENT FINDINGS

Many recently developed biomarkers are able to improve upon traditional risk assessment at nearly all stages of disease. Prominent examples are reviewed in this article. ConfirmMDx uses gene methylation patterns to improve detection of clinically significant cancer following negative biopsy. Both the Prolaris and Oncotype DX Genomic Prostate Score tests can improve risk stratification following biopsy, especially among men who are eligible for active surveillance. Prolaris and the Decipher genomic classifier have been associated with risk of adverse outcome following prostatectomy, while Oncotype DX is being studied in this setting. Finally, recent reports of the association of androgen receptor-V7 in circulating tumor cells with resistance to enzalutamide and abiraterone raise the possibility of extending the use of genetic biomarkers to advanced disease.

SUMMARY

With the development of multiple genetic expression panels in prostate cancer, careful study and validation of these tests and integration into clinical practice will be critical to realizing the potential of these tools.

Impact of Early Diagnosis of Prostate Cancer on Survival Outcomes

CONTEXT

The relationship between early detection of prostate cancer (PCa) and disease-specific mortality is still the subject of much debate.

OBJECTIVE

This review describes developments in PCa mortality rates and disease-stage shift on a population level. The main findings from the randomised screening trials are also discussed. Finally, we consider the expected consequences for the individual man interested in screening.

EVIDENCE ACQUISITION

The PubMed database was searched for trials of screening for PCa from inception through October 11, 2014. Supplementary information was collected by cross-referencing the reference lists.

EVIDENCE SYNTHESIS

Since the introduction of prostate-specific antigen testing, PCa incidence has risen, and a stage shift towards more favourable disease at diagnosis has been observed. PCa mortality rates are gradually decreasing. Although screening trials show conflicting results, the largest randomised trial of screening for PCa shows a 21% decrease in PCa-specific mortality. After correction for noncompliance and contamination, a risk reduction in PCa-specific mortality of up to 49% has been reported. The main side effect of screening is that some studies have estimated that approximately 50% of detected cases may represent overdiagnosis, which may be reduced by stopping screening in older men and using an individual risk-based approach.

CONCLUSIONS

To maximise the benefits while minimising the risk of overdiagnosis, future screening should follow an individual risk-based approach.

PATIENT SUMMARY

On a population level, the introduction of screening for prostate cancer (PCa) is associated with more men diagnosed but with more favourable disease. The largest screening study confirmed the reduction in death due to PCa. Individual risk estimation is important to best balance the benefits and potential harms of early detection.

Prostate-specific antigen-based prostate cancer screening: Past and future

Prostate-specific antigen-based prostate cancer screening remains a controversial topic. Up to now, there is worldwide consensus on the statement that the harms of population-based screening, mainly as a result of overdiagnosis (the detection of clinically insignificant tumors that would have never caused any symptoms), outweigh the benefits. However, worldwide opportunistic screening takes place on a wide scale. The European Randomized Study of Screening for Prostate Cancer showed a reduction in prostate cancer mortality through prostate-specific antigen based-screening. These population-based data need to be individualized in order to avoid screening in those who cannot benefit and start screening in those who will. For now, lacking a more optimal screening approach, screening should only be started after the process of shared decision-making. The focus of future research is the reduction of unnecessary testing and overdiagnosis by further research to better biomarkers and the value of the multiparametric magnetic resonance imaging, potentially combined in already existing prostate-specific antigen-based multivariate risk prediction models.

A primer on clinical trial design

A well-designed and executed clinical trial is the gold standard of evidence-based medicine. It is important for readers to understand the rationale for the study design, identify common pitfalls, and scrutinize limitations. Herein, we present a brief overview of types of designs used for clinical trials and discuss the use of appropriate end points, the selection of study participants, randomization, sample size calculation, blinding, and analysis of data. Finally, we emphasize the importance of accurate and transparent reporting. Our goal is to provide a primer for practicing urologists to enhance their understanding of the clinical trial literature.

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.

Expected population impacts of discontinued prostate-specific antigen screening

BACKGROUND

Prostate-specific antigen (PSA) screening for prostate cancer has high risks of overdiagnosis, particularly among older men, and reports from screening trials indicate that it saves few lives after 11 to 13 years of follow-up. New clinical guidelines recommend against PSA screening for all men or for men aged >70 years, but, to the authors' knowledge, the expected population effects of these guidelines have not been studied to date.

METHODS

Two models of prostate cancer natural history and diagnosis were previously developed using reconstructed PSA screening patterns and prostate cancer incidence in the United States. Assuming a survival benefit of PSA screening consistent with the screening trials, the authors used the models to predict incidence and mortality rates for the period from 2013 through 2025 under continued PSA screening and under discontinued PSA screening for all men or for men aged >70 years.

RESULTS

The models predicted that continuation of recent screening rates will overdiagnose 710,000 to 1,120,000 men (range between models) but will avoid 36,000 to 57,000 cancer deaths over the period 2013 through 2025. Discontinued screening for all men eliminated 100% of overdiagnoses but failed to prevent 100% of avoidable cancer deaths. Continued screening for men aged <70 years eliminated 64% to 66% of overdiagnoses but failed to prevent 36% to 39% of avoidable cancer deaths.

CONCLUSIONS

Discontinuing PSA screening for all men may generate many avoidable cancer deaths. Continuing PSA screening for men aged <70 years could prevent greater than one-half of these avoidable cancer deaths while dramatically reducing overdiagnoses compared with continued PSA screening for all ages.

Design and preliminary recruitment results of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP)

BACKGROUND

Screening for prostate cancer continues to generate controversy because of concerns about over-diagnosis and unnecessary treatment. We describe the rationale, design and recruitment of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP) trial, a UK-wide cluster randomised controlled trial investigating the effectiveness and cost-effectiveness of prostate-specific antigen (PSA) testing.

METHODS

Seven hundred and eighty-five general practitioner (GP) practices in England and Wales were randomised to a population-based PSA testing or standard care and then approached for consent to participate. In the intervention arm, men aged 50-69 years were invited to undergo PSA testing, and those diagnosed with localised prostate cancer were invited into a treatment trial. Control arm practices undertook standard UK management. All men were flagged with the Health and Social Care Information Centre for deaths and cancer registrations. The primary outcome is prostate cancer mortality at a median 10-year-follow-up.

RESULTS

Among randomised practices, 271 (68%) in the intervention arm (198,114 men) and 302 (78%) in the control arm (221,929 men) consented to participate, meeting pre-specified power requirements. There was little evidence of differences between trial arms in measured baseline characteristics of the consenting GP practices (or men within those practices).

CONCLUSIONS

The CAP trial successfully met its recruitment targets and will make an important contribution to international understanding of PSA-based prostate cancer screening.

What do the screening trials really tell us and where do we go from here?

Publication of apparently conflicting results from 2 large trials of prostate cancer screening has intensified the debate about prostate-specific antigen (PSA) testing and has led to a recommendation against screening from the US Preventive Services Task Force. This article reviews the trials and discusses the limitations of their empirical results in informing public health policy. In particular, the authors explain why harm-benefit trade-offs based on empirical results may not accurately reflect the trade-offs expected under long-term population screening. This information should be useful to clinicians in understanding the implications of these studies regarding the value of PSA screening.