Incorporating Genetic Risk Into Prostate Cancer Care: Implications for Early Detection and Precision Oncology

The availability and cost of germline and somatic genetic testing have dramatically improved over the past two decades, enabling precision medicine approaches in oncology, with significant implications for prostate cancer (PCa) care. Roughly 12% of individuals with advanced disease are carriers of rare pathogenic germline variants that predispose to particularly aggressive and earlier-onset disease. Several of these variants are already established as clinically actionable by modern precision oncology therapeutics, while others may come to aid the selection of active surveillance, definitive local therapies, and systemic therapies. Concurrently, the number of common variants (ie, incorporated into polygenic risk scores) associated with PCa risk has continued to grow, but with several important considerations both at the intersection of race and ancestry and for early detection of aggressive disease. Family history has historically been used as a proxy for this inherited genetic risk of PCa, but recently emerging evidence examining this relation has shifted our understanding of how best to leverage this tool in PCa care. This review seeks to clarify and contextualize the existing and emerging precision oncology paradigms that use inherited genetic risk in PCa care, for both early detection and localized disease management.

GRADE concept 4: rating the certainty of evidence when study interventions or comparators differ from PICO targets

OBJECTIVES

This Grading of Recommendations Assessment, Development and Evaluation (GRADE) concept article offers systematic reviewers, guideline authors, and other users of evidence assistance in addressing randomized trial situations in which interventions or comparators differ from those in the target people, interventions, comparators, and outcomes. To clarify what GRADE considers under indirectness of interventions and comparators, we focus on a particular example: when comparator arm participants receive some or all aspects of the intervention management strategy (treatment switching).

STUDY DESIGN AND SETTING

An interdisciplinary panel of the GRADE working group members developed this concept article through an iterative review of examples in multiple teleconferences, small group sessions, and e-mail correspondence. After presentation at a GRADE working group meeting in November 2022, attendees approved the final concept paper, which we support with examples from systematic reviews and individual trials.

RESULTS

In the presence of safeguards against risk of bias, trials provide unbiased estimates of the effect of an intervention on the people as enrolled, the interventions as implemented, the comparators as implemented, and the outcomes as measured. Within the GRADE framework, differences in the people, interventions, comparators, and outcomes elements between the review or guideline recommendation targets and the trials as implemented constitute issues of indirectness. The intervention or comparator group management strategy as implemented, when it differs from the target comparator, constitutes one potential source of indirectness: Indirectness of interventions and comparators-comparator group receipt of the intervention constitutes a specific subcategory of said indirectness. The proportion of comparator arm participants that received the intervention and the apparent magnitude of effect bear on whether one should rate down, and if one does, to what extent.

CONCLUSION

Treatment switching and other differences between review or guideline recommendation target interventions and comparators vs. interventions and comparators as implemented in otherwise relevant trials are best considered issues of indirectness.

Mortality impact, risks, and benefits of general population screening for ovarian cancer: the UKCTOCS randomised controlled trial

Background

Ovarian and tubal cancers are lethal gynaecological cancers, with over 50% of the patients diagnosed at advanced stage.

Trial design

Randomised controlled trial involving 27 primary care trusts adjacent to 13 trial centres based at NHS Trusts in England, Wales and Northern Ireland.

Methods

Postmenopausal average-risk women, aged 50-74, with intact ovaries and no previous ovarian or current non-ovarian cancer.

Interventions

One of two annual screening strategies: (1) multimodal screening (MMS) using a longitudinal CA125 algorithm with repeat CA125 testing and transvaginal scan (TVS) as second line test (2) ultrasound screening (USS) using TVS alone with repeat scan to confirm any abnormality. The control (C) group had no screening. Follow-up was through linkage to national registries, postal follow-up questionnaires and direct communication with trial centres and participants.

Objective

To assess comprehensively risks and benefits of ovarian cancer screening in the general population.

Outcome

Primary outcome was death due to ovarian or tubal cancer as assigned by an independent outcomes review committee. Secondary outcomes included incidence and stage at diagnosis of ovarian and tubal cancer, compliance, performance characteristics, harms and cost-effectiveness of the two screening strategies and a bioresource for future research.

Randomisation

The trial management system confirmed eligibility and randomly allocated participants using computer-generated random numbers to MMS, USS and C groups in a 1:1:2 ratio.

Blinding

Investigators and participants were unblinded and outcomes review committee was masked to randomisation group.

Analyses

Primary analyses were by intention to screen, comparing separately MMS and USS with C using the Versatile test.

Results

1,243,282 women were invited and 205,090 attended for recruitment between April 2001 and September 2005.

Randomised

202,638 women: 50,640 MMS, 50,639 USS and 101,359 C group.

Numbers analysed for primary outcome

202,562 (>99.9%): 50,625 (>99.9%) MMS, 50,623 (>99.9%) USS, and 101,314 (>99.9%) C group.

Outcome

Women in MMS and USS groups underwent 345,570 and 327,775 annual screens between randomisation and 31 December 2011. At median follow-up of 16.3 (IQR 15.1-17.3) years, 2055 women developed ovarian or tubal cancer: 522 (1.0% of 50,625) MMS, 517 (1.0% of 50,623) USS, and 1016 (1.0% of 101314) in C group. Compared to the C group, in the MMS group, the incidence of Stage I/II disease was 39.2% (95% CI 16.1 to 66.9) higher and stage III/IV 10.2% (95% CI -21.3 to 2.4) lower. There was no difference in stage in the USS group. 1206 women died of the disease: 296 (0.6%) MMS, 291 (0.6%) USS, and 619 (0.6%) C group. There was no significant reduction in ovarian and tubal cancer deaths in either MMS (p = 0.580) or USS (p = 0.360) groups compared to the C group. Overall compliance with annual screening episode was 80.8% (345,570/420,047) in the MMS and 78.0% (327,775/420,047) in the USS group. For ovarian and tubal cancers diagnosed within one year of the last test in a screening episode, in the MMS group, the sensitivity, specificity and positive predictive values were 83.8% (95% CI 78.7 to 88.1), 99.8% (95% CI 99.8 to 99.9), and 28.8% (95% CI 25.5 to 32.2) and in the USS group, 72.2% (95% CI 65.9 to 78.0), 99.5% (95% CI 99.5 to 99.5), and 9.1% (95% CI 7.8 to 10.5) respectively. The final within-trial cost-effectiveness analysis was not undertaken as there was no mortality reduction. A bioresource (UKCTOCS Longitudinal Women's Cohort) of longitudinal outcome data and over 0.5 million serum samples including serial annual samples in women in the MMS group was established and to date has been used in many new studies, mainly focused on early detection of cancer.

Harms

Both screening tests (venepuncture and TVS) were associated with minor complications with low (8.6/100,000 screens MMS; 18.6/100,000 screens USS) complication rates. Screening itself did not cause anxiety unless more intense repeat testing was required following abnormal screens. In the MMS group, for each screen-detected ovarian or tubal cancer, an additional 2.3 (489 false positives; 212 cancers) women in the MMS group had unnecessary false-positive (benign adnexal pathology or normal adnexa) surgery. Overall, 14 (489/345,572 annual screens) underwent unnecessary surgery per 10,000 screens. In the USS group, for each screen-detected ovarian or tubal cancer, an additional 10 (1630 false positives; 164 cancers) underwent unnecessary false-positive surgery. Overall, 50 (1630/327,775 annual screens) women underwent unnecessary surgery per 10,000 screens.

Conclusions

Population screening for ovarian and tubal cancer for average-risk women using these strategies should not be undertaken. Decreased incidence of Stage III/IV cancers during multimodal screening did not translate to mortality reduction. Researchers should be cautious about using early stage as a surrogate outcome in screening trials. Meanwhile the bioresource provides a unique opportunity to evaluate early cancer detection tests.

Funding

Long-term follow-up UKCTOCS (2015-2020) - National Institute for Health and Care Research (NIHR HTA grant 16/46/01), Cancer Research UK, and The Eve Appeal. UKCTOCS (2001-2014) - Medical Research Council (MRC) (G9901012/G0801228), Cancer Research UK (C1479/A2884), and the UK Department of Health, with additional support from The Eve Appeal. Researchers at UCL were supported by the NIHR UCL Hospitals Biomedical Research Centre and by MRC Clinical Trials Unit at UCL core funding (MR_UU_12023).

Serum PSA-based early detection of prostate cancer in Europe and globally: past, present and future

In the pre-PSA-detection era, a large proportion of men were diagnosed with metastatic prostate cancer and died of the disease; after the introduction of the serum PSA test, randomized controlled prostate cancer screening trials in the USA and Europe were conducted to assess the effect of PSA screening on prostate cancer mortality. Contradictory outcomes of the trials and the accompanying overdiagnosis resulted in recommendations against prostate cancer screening by organizations such as the United States Preventive Services Task Force. These recommendations were followed by a decline in PSA testing and a rise in late-stage diagnosis and prostate cancer mortality. Re-evaluation of the randomized trials, which accounted for contamination, showed that PSA-based screening does indeed reduce prostate cancer mortality; however, the debate about whether to screen or not to screen continues because of the considerable overdiagnosis that occurs using PSA-based screening. Meanwhile, awareness among the population of prostate cancer as a potentially lethal disease stimulates opportunistic screening practices that further increase overdiagnosis without the benefit of mortality reduction. However, in the past decade, new screening tools have been developed that make the classic PSA-only-based screening an outdated strategy. With improved use of PSA, in combination with age, prostate volume and with the application of prostate cancer risk calculators, a risk-adapted strategy enables improved stratification of men with prostate cancer and avoidance of unnecessary diagnostic procedures. This combination used with advanced detection techniques (such as MRI and targeted biopsy), can reduce overdiagnosis. Moreover, new biomarkers are becoming available and will enable further improvements in risk stratification.

Real-world data in elderly men from Yokosuka City 15 years after introducing prostate-specific antigen-based population screening

Mass screening based on prostate-specific antigen (PSA) reduces mortality in prostate cancer. However, the effectiveness of this screening in the elderly has not been demonstrated. In the city of Yokosuka, Japan, PSA screening has been conducted since 2001 and the present study examined the real-world status of PSA-based population screening in the elderly. It retrospectively evaluated 1,117 prostate cancer patients >75 years of age. The patients were divided into two groups: The screened group comprising patients diagnosed by PSA-based population screening or workplace screening and PSA follow-up patients at urology clinics; and the non-screened group comprising patients detected by other methods. Overall survival (OS), cancer-specific survival (CSS) and factors contributing to shorter CSS between the groups were compared. In patients >75 years of age, the screened group had significantly longer OS (171 vs. 154 months; P=0.019) and CSS (median not reached; P=0.020) but screening was not an independent factor associated with prolonged OS or CSS on multivariate analysis. The factors contributing to shorten CSS in the elderly were ≥T3 (odds ratio: 3.301 [1.704-6.369], P<0.001), M1 (odds ratio: 4.856 [2.809-8.393], P<0.001) and Gleason score ≥8 (odds ratio: 4.691 [2.479-8.876], P<0.001). In those with metastasis, PSA screening was not associated with prolonged OS or CSS. Real-world data 15 years after introducing PSA-based population screening was not an independent factor for both OS and CSS in multivariate analyses for patients >75 years of age.

Contamination: How much can an individually randomized trial tolerate?

Cluster randomization results in an increase in sample size compared to individual randomization, referred to as an efficiency loss. This efficiency loss is typically presented under an assumption of no contamination in the individually randomized trial. An alternative comparator is the sample size needed under individual randomization to detect the attenuated treatment effect due to contamination. A general framework is provided for determining the extent of contamination that can be tolerated in an individually randomized trial before a cluster randomized design yields a larger sample size. Results are presented for a variety of cluster trial designs including parallel arm, stepped-wedge and cluster crossover trials. Results reinforce what is expected: individually randomized trials can tolerate a surprisingly large amount of contamination before they become less efficient than cluster designs. We determine the point at which the contamination means an individual randomized design to detect an attenuated effect requires a larger sample size than cluster randomization under a nonattenuated effect. This critical rate is a simple function of the design effect for clustering and the design effect for multiple periods as well as design effects for stratification or repeated measures under individual randomization. These findings are important for pragmatic comparisons between a novel treatment and usual care as any bias due to contamination will only attenuate the true treatment effect. This is a bias that operates in a predictable direction. Yet, cluster randomized designs with post-randomization recruitment without blinding, are at high risk of bias due to the differential recruitment across treatment arms. This sort of bias operates in an unpredictable direction. Thus, with knowledge that cluster randomized trials are generally at a greater risk of biases that can operate in a nonpredictable direction, results presented here suggest that even in situations where there is a risk of contamination, individual randomization might still be the design of choice.

A multistate survival model of the natural history of cancer using data from screened and unscreened population

One of the main aims of models using cancer screening data is to determine the time between the onset of preclinical screen-detectable cancer and the onset of the clinical state of the cancer. This time is called the sojourn time. One problem in using screening data is that an individual can be observed in preclinical phase or clinically diagnosed but not both. Multistate survival models provide a method of modeling the natural history of cancer. The natural history model allows for the calculation of the sojourn time. We developed a continuous-time Markov model and the corresponding likelihood function. The model allows for the use of interval-censored, left-truncated and right-censored data. The model uses data of clinically diagnosed cancers from both screened and nonscreened individuals. Parameters of age-varying hazards and age-varying misclassification are estimated simultaneously. The mean sojourn time is calculated from a micro-simulation using model parameters. The model is applied to data from a prostate screening trial. The simulation study showed that the model parameters could be estimated accurately.

Prostate-specific antigen testing and opportunistic prostate cancer screening: a cohort study in England, 1998-2017

Background

Prostate cancer is a leading cause of cancer- related death. Interpreting the results from trials of screening with prostate-specific antigen (PSA) is complex in terms of defining optimal prostate cancer screening policy.

Aim

To assess the rates of, and factors associated with, the uptake of PSA testing and opportunistic screening (that is, a PSA test in the absence of any symptoms) in England between 1998 and 2017, and to estimate the likely rates of pre-randomisation screening and contamination (that is, unscheduled screening in the ‘control’ arm) of the UK-based Cluster Randomised Trial of PSA Testing for Prostate Cancer (CAP).

Design and setting

Open cohort study of men in England aged 40–75 years at cohort entry (1998–2017), undertaken using the QResearch database.

Method

Eligible men were followed for up to 19 years. Rates of PSA testing and opportunistic PSA screening were calculated; Cox regression was used to estimate associations.

Results

The cohort comprised 2 808 477 men, of whom 631 426 had a total of 1 720 855 PSA tests. The authors identified that 410 724 men had opportunistic PSA screening. Cumulative proportions of uptake of opportunistic screening in the cohort were 9.96% at 5 years’, 22.71% at 10 years’, and 44.13% at 19 years’ follow-up. The potential rate of contamination in the CAP control arm was estimated at 24.50%.

Conclusion

A substantial number of men in England opt in to opportunistic prostate cancer screening, despite uncertainty regarding its efficacy and harms. The rate of opportunistic prostate cancer screening in the population is likely to have contaminated the CAP trial, making it difficult to interpret the results.

Screening for Prostate Cancer

This article gives an overview of the current state of the evidence for prostate cancer early detection with prostate-specific antigen (PSA) and summarizes current recommendations from guideline groups. The article reviews the global public health burden and risk factors for prostate cancer with clinical implications as screening tools. Screening studies, novel biomarkers, and MRI are discussed. The article outlines 7 key practice points for primary care physicians and provides a simple schema for facilitating shared decision-making conversations.

Examining the relationship between diabetes and prostate cancer through changes in screening guidelines

PURPOSE

Previous studies have found that men with diabetes are at reduced risk of prostate cancer compared to men without diabetes. The lower risk could be due to biologic differences and/or a diagnosis bias from use of the prostate-specific antigen (PSA) test as a screening and diagnostic tool. We sought to further examine the relationship between diabetes and incidence of prostate cancer and examine the potential impact of changes in PSA screening guidelines in 2008 and 2012.

METHODS

We used 2004-2015 Surveillance, Epidemiology and End Results (SEER)-Medicare data and limited the study population to men aged 67-74 with at least 2 years of continuous enrollment. Using the 5% Medicare sample as the denominator and prostate cancer cases as the numerator, we calculated age-adjusted rate ratios (RR) in 2006-2011 and 2012-2015 by diabetes status, overall and by tumor grade. We used multivariable logistic regression to compare tumor characteristics by diabetes status.

RESULTS

Men with diabetes had lower incidence rates of prostate cancer compared to men without diabetes in 2006-2011 [RR = 0.89 95% confidence interval (CI) 0.87-0.91] and 2012-2015 (RR = 0.92 95% CI 0.89-0.95) but the slight attenuation toward the null in 2012-2015 was primarily due to the change in RRs for low-grade tumors.

CONCLUSION

We found differences in the risk and characteristics of prostate cancer by diabetes status and that some risks have changed over time as guidelines have changed. With lower PSA use in the more recent time-period, rates of low-grade tumors have become more similar by diabetes status.

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.

Merging new-age biomarkers and nanodiagnostics for precision prostate cancer management

The accurate identification and stratified treatment of clinically significant early-stage prostate cancer have been ongoing concerns since the outcomes of large international prostate cancer screening trials were reported. The controversy surrounding clinical and cost benefits of prostate cancer screening has highlighted the lack of strategies for discriminating high-risk disease (that requires early treatment) from low-risk disease (that could be managed using watchful waiting or active surveillance). Advances in molecular subtyping and multiomics nanotechnology-based prostate cancer risk delineation can enable refinement of prostate cancer molecular taxonomy into clinically meaningful and treatable subtypes. Furthermore, the presence of intertumoural and intratumoural heterogeneity in prostate cancer warrants the development of novel nanodiagnostic technologies to identify clinically significant prostate cancer in a rapid, cost-effective and accurate manner. Circulating and urinary next-generation prostate cancer biomarkers for disease molecular subtyping and the newest complementary nanodiagnostic platforms for enhanced biomarker detection are promising tools for precision prostate cancer management. However, challenges in merging both aspects and clinical translation still need to be overcome.

Association of Baseline Prostate-Specific Antigen Level With Long-term Diagnosis of Clinically Significant Prostate Cancer Among Patients Aged 55 to 60 Years: A Secondary Analysis of a Cohort in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial

IMPORTANCE

The use of prostate-specific antigen (PSA) screening for prostate cancer is controversial because of the risk of overdiagnosis and overtreatment of indolent cancers. Optimal screening strategies are highly sought.

OBJECTIVE

To estimate the long-term risk of any prostate cancer and clinically significant prostate cancer based on baseline PSA levels among men aged 55 to 60 years.

DESIGN, SETTING, AND PARTICIPANTS

This secondary analysis of a cohort in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial uses actuarial analysis to analyze the association of baseline PSA levels with long-term risk of any prostate cancer and of clinically significant prostate cancer among men aged 55 to 60 years enrolled in the screening group of the trial between 1993 and 2001.

EXPOSURE

Single PSA measurement at study entry.

MAIN OUTCOMES AND MEASURES

Long-term risk of any prostate cancer and clinically significant prostate cancer diagnoses.

RESULTS

There were 10 968 men aged 55 to 60 years (median [interquartile range] age, 57 [55-58] years) at study enrollment in the screening group of the PLCO Cancer Screening Trial who had long-term follow-up. Actuarial 13-year incidences of clinically significant prostate cancer diagnosis among participants with a baseline PSA of 0.49 ng/mL or less was 0.4% (95% CI, 0%-0.8%); 0.50-0.99 ng/mL, 1.5% (95% CI, 1.1%-1.9%); 1.00-1.99 ng/mL, 5.4% (95% CI, 4.4%-6.4%); 2.00-2.99 ng/mL, 10.6% (95% CI, 8.3%-12.9%); 3.00-3.99 ng/mL, 15.3% (95% CI, 11.4%-19.2%); and 4.00 ng/mL and greater, 29.5% (95% CI, 24.2%-34.8%) (all pairwise log-rank P ≤ .004). Only 15 prostate cancer-specific deaths occurred during 13 years of follow-up, and 9 (60.0%) were among men with a baseline PSA level of 2.00 ng/mL or higher.

CONCLUSIONS AND RELEVANCE

In this secondary analysis of a cohort from the PLCO Cancer Screening Trial, baseline PSA levels among men aged 55 to 60 years were associated with long-term risk of clinically significant prostate cancer. These findings suggest that repeated screening can be less frequent among men aged 55 to 60 years with a low baseline PSA level (ie, <2.00 ng/mL) and possibly discontinued among those with baseline PSA levels of less than 1.00 ng/mL.

Metastatic prostate cancer at diagnosis and through progression in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

BACKGROUND

The Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial assessed the effect of screening with prostate-specific antigen and a digital rectal examination on prostate cancer mortality. Another endpoint of interest was the burden of total metastatic disease.

METHODS

All men in PLCO were assessed for metastatic prostate cancer at diagnosis; men with clinical stage I/II disease were assessed for metastatic progression. The rate of total metastatic disease was defined as metastases found either at diagnosis or through progression divided by person-years (PYs) of follow-up for all men in the trial. Metastatic progression rates were computed among men with clinical stage I/II prostate cancer. Survival among men with metastases at diagnosis was compared with survival among men with metastatic progression.

RESULTS

Among 38,340 men in the intervention arm and 38,343 men in the control arm in PLCO, there were 4974 and 4699 prostate cancer cases, respectively. The rates of total metastatic disease were 4.72 and 4.83 per 10,000 PYs in the intervention and control arms, respectively (rate ratio, 0.98; 95% CI, 0.81-1.18). The rates of metastatic progression among men with clinical stage I/II prostate cancer were 43.7 and 50.5 per 10,000 PYs in the intervention and control arms, respectively (P = .30). Prostate cancer-specific 5- and 10-year survival rates were significantly worse for men with metastatic progression (24% and 19%, respectively) than men with metastases at diagnosis (40% and 26%, respectively).

CONCLUSIONS

Rates of total metastatic disease and metastatic progression were similar across arms in PLCO. Survival was worse for men with metastatic progression in comparison with those with metastatic disease at diagnosis.

Screening for prostate cancer: History, evidence, controversies and future perspectives toward individualized screening

Differences in the incidence and mortality rate of prostate cancer between the USA and Japan have been decreasing over time, and were only twofold in 2017. Therefore, countermeasures against prostate cancer could be very important not only in Western countries, but also in developed Asian countries. Screening for prostate cancer in the general population using transrectal ultrasonography, digital rectal examination and/or prostate acid phosphatase began in Japan in the early 1980s, and screening with prostate-specific antigen and digital rectal examination has been widespread in the USA since the late 1980s. Large- and mid-scale randomized controlled trials on screening for prostate cancer began around 1990 in the USA, Canada and Europe. However, most of these studies failed as randomized controlled trials because of high contamination in the control arm, low compliance in the screening arm or insufficient screening setting about screening frequency and/or biopsy indication. The best available level 1 evidence is data from the European Randomized Study of Screening for Prostate Cancer and the Göteborg screening study. However, several non-urological organizations and lay media around the world have mischaracterized the efficacy of prostate-specific antigen screening. To avoid long-term confusion about screening for prostate cancer, leading professional urological organizations, including the Japanese Urological Association, are moving toward the establishment of an optimal screening system that minimizes the drawbacks of overdetection, overtreatment and loss of quality of life due to treatment, and maximizes reductions in the risk of death as a result of prostate cancer and the development of metastatic prostate cancer.

Overall mortality in men and women in the randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Objective

To assess the secondary outcome of overall mortality in the randomized Prostate, Lung, Colorectal, and Ovarian cancer screening trial.

Methods

In the Prostate, Lung, Colorectal, and Ovarian trial, subjects were randomized to usual care or intervention. In the intervention arm, men and women received annual chest radiographs and two sigmoidoscopy exams. Men also received annual prostate-specific antigen tests and digital rectal exams, and women also received annual CA125 tests and trans-vaginal ultrasounds. Poisson regression and Cox proportional hazards models were used to assess differences across trial arms in overall mortality and overall mortality excluding deaths from trial cancers (OMEX). Due to slight age imbalances in later trial years, age-adjusted rate ratios and hazard ratios were computed.

Results

There were 76,678 men and 78,209 women randomized, with median follow-up of 17 years. In men there was a significant reduction in both overall mortality (age-adjusted rate ratio = 0.966; 95% CI: 0.943–0.989; p = 0.004) and OMEX (age-adjusted rate ratio = 0.970, 95% CI: 0.946–0.995; p = 0.02) in the intervention versus usual care arm. In women, no reduction was seen in either overall mortality (age-adjusted rate ratio = 1.002) or OMEX (age-adjusted rate ratio = 1.006). In both sexes combined, there was a significant reduction in overall mortality (age-adjusted rate ratio = 0.980; 95% CI: 0.963–0.999; p = 0.036) but not OMEX (age-adjusted rate ratio = 0.985; 95% CI: 0.965–1.004; p = 0.13). Results were similar using age-adjusted hazard ratios.

Conclusion

In the Prostate, Lung, Colorectal, and Ovarian trial, there was a small but significant reduction in overall mortality in men, and in both sexes combined, and a small but significant reduction in overall mortality excluding trial cancer deaths in men.

Extended follow-up for prostate cancer incidence and mortality among participants in the Prostate, Lung, Colorectal and Ovarian randomized cancer screening trial

OBJECTIVE

To examine prostate cancer (PCa) incidence and mortality by arm in the randomized Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial.

PATIENTS AND METHODS

Patients aged 55-74 years at 10 screening centres were randomized between 1993 and 2001 to an intervention or usual care arm. Patients in the intervention arm received six annual prostate-specific antigen (PSA) tests and four annual digital rectal examinations. The patients were followed for PCa incidence and for mortality via active follow-up processes and by linkage to state cancer registries and the National Death Index. For cancers identified through active follow-up, trial abstractors recorded the mode of diagnosis (screen-detected, symptomatic, other).

RESULTS

A total of 38 340 patients were randomized to the intervention arm and 38 343 to a usual care arm. The median follow-up for mortality was 16.9 (intervention) and 16.7 years (usual care). There were 333 (intervention) and 352 (usual care) PCa cancer deaths, giving rates (per 10 000 person-years) of 5.5 and 5.9, respectively, and a rate ratio (RR) of 0.93 (95% confidence interval [CI] 0.81-1.08; P = 0.38). The RR for overall PCa incidence was 1.05 (95% CI 1.01-1.09). The RRs by Gleason category were 1.17 (95% CI 1.11-1.23) for Gleason 2-6, 1.00 (95% CI 0.93-1.07) for Gleason 7 and 0.89 (95% CI 0.80-0.99) for Gleason 8-10 disease. By mode of detection, during the trial's screening phase, 13% of intervention arm vs 27% of usual care arm cases were symptomatic; post-screening, these percentages were 18% in each arm.

CONCLUSION

After almost 17 years of median follow-up, there was no significant reduction in PCa mortality in the intervention compared with the usual care arm. There was a significant increase in Gleason 2-6 disease and a significant reduction in Gleason 8-10 disease in the intervention compared with the usual care arm.

New Evidence for the Benefit of Prostate-specific Antigen Screening: Data From 400,887 Kaiser Permanente Patients

OBJECTIVE

To investigate whether prostate cancer screening with prostate-specific antigen (PSA) is beneficial in reducing prostate cancer mortality, and to determine optimal screening intervals and age groups to be screened.

METHODS

This is a retrospective cohort study of 400,887 men under age 80, with no history of prostate cancer, who had PSA testing at Kaiser Permanente Northern California in the 5 calendar years 1998-2002, and were followed up for 12-16 years. Subjects were stratified into 6 groups based on the screening interval, and into 7 groups based on age. Prostate cancer mortality rates for each of the 42 subgroups were calculated and compared.

RESULTS

The data show that yearly PSA screening is beneficial, reducing prostate cancer deaths by 64% for men aged 55-75 years (95% confidence interval 50-78%, P <.001), and all-cause mortality by 24% (95% confidence interval 15%-34%, P <.001). This is the first study to evaluate various screening intervals and age groups, showing that yearly screening is the interval of choice. No benefit was found for screening at any interval for men under age 55.

CONCLUSION

Yearly PSA screening is highly effective in reducing both prostate cancer mortality and all-cause mortality in men with prostate cancer, and when combined with active surveillance to prevent overtreatment, lends support for PSA screening for men in good health aged 55-75.

Screening for Prostate Cancer: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

In the United States, the lifetime risk of being diagnosed with prostate cancer is approximately 13%, and the lifetime risk of dying of prostate cancer is 2.5%. The median age of death from prostate cancer is 80 years. Many men with prostate cancer never experience symptoms and, without screening, would never know they have the disease. African American men and men with a family history of prostate cancer have an increased risk of prostate cancer compared with other men.

OBJECTIVE

To update the 2012 US Preventive Services Task Force (USPSTF) recommendation on prostate-specific antigen (PSA)-based screening for prostate cancer.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on the benefits and harms of PSA-based screening for prostate cancer and subsequent treatment of screen-detected prostate cancer. The USPSTF also commissioned a review of existing decision analysis models and the overdiagnosis rate of PSA-based screening. The reviews also examined the benefits and harms of PSA-based screening in patient subpopulations at higher risk of prostate cancer, including older men, African American men, and men with a family history of prostate cancer.

FINDINGS

Adequate evidence from randomized clinical trials shows that PSA-based screening programs in men aged 55 to 69 years may prevent approximately 1.3 deaths from prostate cancer over approximately 13 years per 1000 men screened. Screening programs may also prevent approximately 3 cases of metastatic prostate cancer per 1000 men screened. Potential harms of screening include frequent false-positive results and psychological harms. Harms of prostate cancer treatment include erectile dysfunction, urinary incontinence, and bowel symptoms. About 1 in 5 men who undergo radical prostatectomy develop long-term urinary incontinence, and 2 in 3 men will experience long-term erectile dysfunction. Adequate evidence shows that the harms of screening in men older than 70 years are at least moderate and greater than in younger men because of increased risk of false-positive results, diagnostic harms from biopsies, and harms from treatment. The USPSTF concludes with moderate certainty that the net benefit of PSA-based screening for prostate cancer in men aged 55 to 69 years is small for some men. How each man weighs specific benefits and harms will determine whether the overall net benefit is small. The USPSTF concludes with moderate certainty that the potential benefits of PSA-based screening for prostate cancer in men 70 years and older do not outweigh the expected harms.

CONCLUSIONS AND RECOMMENDATION

For men aged 55 to 69 years, the decision to undergo periodic PSA-based screening for prostate cancer should be an individual one and should include discussion of the potential benefits and harms of screening with their clinician. Screening offers a small potential benefit of reducing the chance of death from prostate cancer in some men. However, many men will experience potential harms of screening, including false-positive results that require additional testing and possible prostate biopsy; overdiagnosis and overtreatment; and treatment complications, such as incontinence and erectile dysfunction. In determining whether this service is appropriate in individual cases, patients and clinicians should consider the balance of benefits and harms on the basis of family history, race/ethnicity, comorbid medical conditions, patient values about the benefits and harms of screening and treatment-specific outcomes, and other health needs. Clinicians should not screen men who do not express a preference for screening. (C recommendation) The USPSTF recommends against PSA-based screening for prostate cancer in men 70 years and older. (D recommendation).

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 Screening

During the prostate-specific antigen-based prostate cancer (PCa) screening era there has been a 53% decrease in the US PCa mortality rate. Concerns about overdiagnosis and overtreatment combined with misinterpretation of clinical trial data led to a recommendation against PCa screening, resulting in a subsequent reversion to more high-risk disease at diagnosis. Re-evaluation of trial data and increasing acceptance of active surveillance led to a new draft recommendation for shared decision making for men aged 55 to 69 years old. Further consideration is needed for more intensive screening in men with high-risk factors. PCa screening significantly reduces PCa morbidity and mortality.

Prostate cancer screening-when to start and how to screen?

Prostate-specific antigen (PSA) screening reduces prostate cancer (PCa) mortality; however such screening may lead to harm in terms of overdiagnosis and overtreatment. Therefore, upfront shared decision making involving a discussion about pros and cons between a physician and a patient is crucial. Total PSA remains the most commonly used screening tool and is a strong predictor of future life-threatening PCa. Currently there is no strong consensus on the age at which to start PSA screening. Most guidelines recommend PSA screening to start no later than at age 55 and involve well-informed men in good health and a life expectancy of at least 10–15 years. Some suggest to start screening in early midlife for men with familial predisposition and men of African-American descent. Others suggest starting conversations at age 45 for all men. Re-screening intervals can be risk-stratified as guided by the man’s age, general health and PSA-value; longer intervals for those at lower risk and shorter intervals for those at higher risk. Overdiagnosis and unnecessary biopsies can be reduced using reflex tests. Magnetic resonance imaging in the pre-diagnostic setting holds promise in pilot studies and large-scale prospective studies are ongoing.

Comparative effectiveness of prostate cancer screening between the ages of 55 and 69 years followed by active surveillance

BACKGROUND

Because of the recent grade C draft recommendation by the US Preventive Services Task Force (USPSTF) for prostate cancer screening between the ages of 55 and 69 years, there is a need to determine whether this could be cost-effective in a US population setting.

METHODS

This study used a microsimulation model of screening and active surveillance (AS), based on data from the European Randomized Study of Screening for Prostate Cancer and the Surveillance, Epidemiology, and End Results Program, for the natural history of prostate cancer and Johns Hopkins AS cohort data to inform the probabilities of referral to treatment during AS. A cohort of 10 million men, based on US life tables, was simulated. The lifetime costs and effects of screening between the ages of 55 and 69 years with different screening frequencies and AS protocols were projected, and their cost-effectiveness was determined.

RESULTS

Quadrennial screening between the ages of 55 and 69 years (55, 59, 63, and 67 years) with AS for men with low-risk cancers (ie, those with a Gleason score of 6 or lower) and yearly biopsies or triennial biopsies resulted in an incremental cost per quality-adjusted life-year (QALY) of $51,918 or $69,380, respectively. Most policies in which screening was followed by immediate treatment were dominated. In most sensitivity analyses, this study found a policy with which the cost per QALY remained below $100,000.

CONCLUSIONS

Prostate-specific antigen-based prostate cancer screening in the United States between the ages of 55 and 69 years, as recommended by the USPSTF, may be cost-effective at a $100,000 threshold but only with a quadrennial screening frequency and with AS offered to all low-risk men. Cancer 2018;124:507-13. © 2017 American Cancer Society.

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.

Metastatic prostate cancer incidence in Australia after amendment to prostate-specific antigen screening guidelines

BACKGROUND

To compare the incidence of newly diagnosed metastatic prostate cancer at an Australian facility pre- and post-publication of the United States Preventive Services Task Force (USPSTF) guidelines and subsequent amendment of the Royal Australian College of General Practitioners Preventive Activities in General Practice guidelines.

METHODS

A retrospective analysis was undertaken by patients with newly diagnosed prostate cancer following transrectal ultrasound-guided biopsy between 2009 and 2014. Patients were divided into two even groups based on whether they had undergone their transrectal ultrasound biopsy pre- (2009-2011) or post- (2013-2014) publication of USPSTF guidelines. Metastatic disease was determined by computed tomography chest, abdomen, pelvis as well as nuclear medicine bone scan. A comparison in the incidence of newly diagnosed metastatic prostate cancer was made.

RESULTS

A total of 130 patients were allocated into each group. In the pre-USPSTF group, 23 out of 130 patients had newly diagnosed metastatic prostatic cancer (17.7%). In the post-USPSTF group, 41 out of 130 (31.5%) had newly diagnosed metastatic prostate cancer (P < 0.05). The mean and median prostate-specific antigen was 15.9 and 9.4 (pre-guideline group) and 33.0 and 9.8 (post-guideline group), respectively (P = 0.02). The post-guidelines group had a higher incidence of low-grade disease (Gleason <7), a decreased incidence of intermediate grade disease (Gleason 7) and a relatively unchanged incidence in high-risk disease (Gleason >7).

CONCLUSION

The incidence of newly diagnosed metastatic prostate cancer nearly doubled in patients referred to our Urology Department post-release of the USPSTF guidelines.

Vasectomy and Risk of Prostate Cancer in a Screening Trial

Background: Vasectomy has been implicated as a risk factor for prostate cancer in multiple epidemiologic studies over the past 25 years. Whether this relationship is causal remains unclear. This study examines the association between vasectomy and prostate cancer in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, which randomized men to usual care or annual prostate cancer screening.Methods: We performed a retrospective analysis of 13-year screening and outcomes data from the PLCO trial. Multivariable Cox proportional hazards regression stratified by study arm and age at vasectomy was performed.Results: There was an increased risk of prostate cancer in men who had undergone a vasectomy and were randomized to the usual care arm of the study (adjusted HR, 1.11; 95% confidence interval, 1.03-1.20; P = 0.008). There was no association between vasectomy and diagnosis of prostate cancer in men randomized to the prostate cancer screening arm. Only men undergoing vasectomy at an older age in the usual care arm of the study, but not the prostate cancer screening arm, were at increased risk of being diagnosed with prostate cancer.Conclusions: Vasectomy was not associated with prostate cancer risk among men who were screened for prostate cancer as part of a clinical trial, but was associated with prostate cancer detection in men receiving usual care.Impact: The positive association between vasectomy and prostate cancer is likely related to increased detection of prostate cancer based on patterns of care rather than a biological effect of vasectomy on prostate cancer development. Cancer Epidemiol Biomarkers Prev; 26(11); 1653-9. ©2017 AACR.

Extended mortality results for prostate cancer screening in the PLCO trial with median follow-up of 15 years

BACKGROUND

Two large-scale prostate cancer screening trials using prostate-specific antigen (PSA) have given conflicting results in terms of the efficacy of such screening. One of those trials, the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, previously reported outcomes with 13 years of follow-up. This study presents updated findings from the PLCO trial.

METHODS

The PLCO trial randomized subjects from 1993 to 2001 to an intervention or control arm. Intervention-arm men received annual PSA tests for 6 years and digital rectal examinations for 4 years. This study used a linkage with the National Death Index to extend mortality follow-up to a maximum of 19 years after randomization.

RESULTS

Men were randomized to the intervention arm (n = 38,340) or the control arm (n = 38,343). The median follow-up time was 14.8 years (25th/75th, 12.7/16.5 years) in the intervention arm and 14.7 years (25th/75th, 12.6/16.4 years) in the control arm. There were 255 deaths from prostate cancer in the intervention arm and 244 deaths from prostate cancer in the control arm; this meant a rate ratio (RR) of 1.04 (95% confidence interval [CI], 0.87-1.24). The RR for all-cause mortality was 0.977 (95% CI, 0.950-1.004). It was estimated that 86% of the men in the control arm and 99% of the men in the intervention arm received any PSA testing during the trial, and the estimated yearly screening-phase PSA testing rates were 46% and 84%, respectively.

CONCLUSIONS

Extended follow-up of the PLCO trial over a median of 15 years continues to indicate no reduction in prostate cancer mortality for the intervention arm versus the control arm. Because of the high rate of control-arm PSA testing, this finding can be viewed as showing no benefit of organized screening versus opportunistic screening. Cancer 2017;123:592-599. © 2016 American Cancer Society.

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.

The effect of the USPSTF PSA screening recommendation on prostate cancer incidence patterns in the USA

Guidelines regarding recommendations for PSA screening for early detection of prostate cancer are conflicting. In 2012, the United States Preventive Services Task Force (USPSTF) assigned a grade of D (recommending against screening) for men aged ≥75 years in 2008 and for men of all ages in 2012. Understanding temporal trends in rates of screening before and after the 2012 recommendation in terms of usage patterns in PSA screening, changes in prostate cancer incidence and biopsy patterns, and how the recommendation has influenced physician's and men's attitudes about PSA screening and subsequent ordering of other screening tests is essential within the scope of prostate cancer screening policy. Since the 2012 recommendation, rates of PSA screening decreased by 3-10% in all age groups and across most geographical regions of the USA. Rates of prostate biopsy and prostate cancer incidence have declined in unison, with a shift towards tumours being of higher grade and stage upon detection. Despite the recommendation, some physicians report ongoing willingness to screen appropriately selected men, and many men report intending to continue to ask for the PSA test from their physician. In the coming years, we expect to have an improved understanding of whether these decreased rates of screening will affect prostate cancer metastasis and mortality.

What explains the differences between centres in the European screening trial? A simulation study

BACKGROUND

The European Randomised study of Screening for Prostate Cancer (ERSPC) is a multicentre, randomised screening trial on men aged 55-69 years at baseline without known prostate cancer (PrCa) at randomisation to an intervention arm invited to screening or to a control arm. The ERSPC has shown a significant 21% reduction in PrCa mortality at 13 years of follow-up. The effect of screening appears to vary across centres, for which several explanations are possible. We set to assess if the apparent differences in PrCa mortality reduction between the centres can be explained by differences in screening protocols.

METHODS

We examined the centre differences by developing a simulation model and estimated how alternative screening protocols would have affected PrCa mortality.

RESULTS

Our results showed outcomes similar to those observed, when the results by centres were reproduced by simulating the screening regimens with PSA threshold of 3 versus 4ng/ml, or screening interval of two versus four years. The findings suggest that the differences are only marginally attributable to the different screening protocols.

CONCLUSION

The small screening impact in Finland was not explained by the differences in the screening protocols. A possible reason for it was the contamination of and the unexpectedly low PrCa mortality in the Finnish control arm.

[Current aspects of prostate cancer screening]

Screening programs for prostate cancer based on the determination of serum prostate specific antigen has led to overdiagnosis, and consequently overtreatment. A percentage of men diagnosed with prostate cancer have a tumour that will not progress, or do so slowly (overdiagnosis or pseudo-disease). This overdiagnosis rate ranges from 17-50%. Mass screening is defined as the systematic examination of asymptomatic men. Early detection or opportunistic screening involves the pursuit of individual cases being initiated by the doctor or the patient. In the case of a patient who requests a prostate specific antigen from their general practitioner, a number of issues on overdiagnosis, over-treatment and possible damage from the biopsy, should be explained to him. With data from randomised studies on prostate specific antigen and prostate cancer screening, population screening is not recommended by any urological society.

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.

Prostate cancer

Much progress has been made in research for prostate cancer in the past decade. There is now greater understanding for the genetic basis of familial prostate cancer with identification of rare but high-risk mutations (eg, BRCA2, HOXB13) and low-risk but common alleles (77 identified so far by genome-wide association studies) that could lead to targeted screening of patients at risk. This is especially important because screening for prostate cancer based on prostate-specific antigen remains controversial due to the high rate of overdiagnosis and unnecessary prostate biopsies, despite evidence that it reduces mortality. Classification of prostate cancer into distinct molecular subtypes, including mutually exclusive ETS-gene-fusion-positive and SPINK1-overexpressing, CHD1-loss cancers, could allow stratification of patients for different management strategies. Presently, men with localised disease can have very different prognoses and treatment options, ranging from observation alone through to radical surgery, with few good-quality randomised trials to inform on the best approach for an individual patient. The survival of patients with metastatic prostate cancer progressing on androgen-deprivation therapy (castration-resistant prostate cancer) has improved substantially. In addition to docetaxel, which has been used for more than a decade, in the past 4 years five new drugs have shown efficacy with improvements in overall survival leading to licensing for the treatment of metastatic castration-resistant prostate cancer. Because of this rapid change in the therapeutic landscape, no robust data exist to inform on the selection of patients for a specific treatment for castration-resistant prostate cancer or the best sequence of administration. Moreover, the high cost of the newer drugs limits their widespread use in several countries. Data from continuing clinical and translational research are urgently needed to improve, and, crucially, to personalise management.

Screening Coverage Needed to Reduce Mortality from Prostate Cancer: A Living Systematic Review

INTRODUCTION

Screening for prostate cancer remains controversial because of conflicting results from the two major trials: The Prostate, Lung, Colorectal and Ovarian Cancer (PLCO) screening trial and the European Randomized Study of Screening for Prostate Cancer (ERSPC).

OBJECTIVE

Meta-analyze and meta-regress the available PSA screening trials.

METHODS

We performed a living systematic review and meta-regression of the reduction in prostate cancer mortality as a function of the duration of screening provided in each trial. We searched PubMed, Web of Science, the Cochrane Registry, and references lists from previous meta-analyses to identify randomized trials of PSA screening. We followed PRISMA guidelines and qualified strength of evidence with a GRADE Profile.

RESULTS

We found 6 trials, but excluded one that also screened with trans-rectal ultrasound. We considered each ERSPC center as a separate trial. When pooling together all 11 trials we found no significant benefit from screening; however, the heterogeneity was 28.2% (95% CI: 0% to 65%). Heterogeneity was explained by variations in the duration of serial screening (I2 0%; 95% CI: 0% to 52%). When we analyzed the subgroup of trials that added more than 3 years of screening (range 3.2 to 3.8) we found a significant benefit for screening with risk ratio 0.78 (95% CI 0.65-0.94; I2 = 0%; 95% CI: 0% to 69%) and a number needed to invite for screening of 1000. We downgraded the quality of evidence to moderate due to our retrospective identification of subgroups and limited data on control group screening.

CONCLUSIONS

Adequate duration of screening reduces mortality from prostate cancer. The benefit, while small, compares favorably with screening for other cancers. Our projections are limited by the moderate quality of evidence.