Comparative effectiveness of alternative prostate-specific antigen--based prostate cancer screening strategies: model estimates of potential benefits and harms.
ABSTRACT: The U.S. Preventive Services Task Force recently concluded that the harms of existing prostate-specific antigen (PSA) screening strategies outweigh the benefits.To evaluate comparative effectiveness of alternative PSA screening strategies.Microsimulation model of prostate cancer incidence and mortality quantifying harms and lives saved for alternative PSA screening strategies.National and trial data on PSA growth, screening and biopsy patterns, incidence, treatment distributions, treatment efficacy, and mortality.A contemporary cohort of U.S. men.Lifetime.Societal.35 screening strategies that vary by start and stop ages, screening intervals, and thresholds for biopsy referral.PSA tests, false-positive test results, cancer detected, overdiagnoses, prostate cancer deaths, lives saved, and months of life saved.Without screening, the risk for prostate cancer death is 2.86%. A reference strategy that screens men aged 50 to 74 years annually with a PSA threshold for biopsy referral of 4 µg/L reduces the risk for prostate cancer death to 2.15%, with risk for overdiagnosis of 3.3%. A strategy that uses higher PSA thresholds for biopsy referral in older men achieves a similar risk for prostate cancer death (2.23%) but reduces the risk for overdiagnosis to 2.3%. A strategy that screens biennially with longer screening intervals for men with low PSA levels achieves similar risks for prostate cancer death (2.27%) and overdiagnosis (2.4%), but reduces total tests by 59% and false-positive results by 50%.Varying incidence inputs or reducing the survival improvement due to screening did not change conclusions.The model is a simplification of the natural history of prostate cancer, and improvement in survival due to screening is uncertain.Compared with standard screening, PSA screening strategies that use higher thresholds for biopsy referral for older men and that screen men with low PSA levels less frequently can reduce harms while preserving lives.National Cancer Institute and Centers for Disease Control and Prevention.
Project description:New biomarkers for early detection of cancer must pass through several phases of development. Early phases provide information on diagnostic properties but not on population benefits and harms. Prostate cancer antigen 3 (PCA3) is a promising prostate cancer biomarker still in early development. We use simulation modeling to project the impact of adding PCA3 to prostate-specific antigen (PSA) screening on prostate cancer detection and mortality in the United States.We used data from a recent study of PCA3 in men referred for prostate biopsy to extend an existing simulation model of PSA growth, disease progression, and survival. We specified several PSA-PCA3 strategies designed to improve specificity and reduce overdiagnosis. Using these strategies to screen a cohort of men biennially between ages 50 and 74, we projected true- and false-positive tests, overdiagnoses, and lives saved relative to a PSA-based strategy with a cutoff of 4.0 ng/mL for biopsy referral.We identified several PSA-PCA3 strategies that substantially reduced false-positive tests and overdiagnoses while preserving the majority of lives saved. PCA3>35 for biopsy referral in men with PSA between 4.0 and 10.0 ng/mL retained 85% of lives saved while approximately halving false positives and reducing overdiagnoses by 25%.Adding PCA3 to PSA screening can significantly reduce adverse screening outcomes. Strategies can be identified that preserve most of the lives saved relative to PSA-based screening.Simulation modeling provides advance projections of population outcomes of new screening biomarkers and may help guide early detection research.
Project description:The Memorial Sloan Kettering Cancer Center (MSKCC) recommendations on prostate cancer screening were developed in response to three limitations of previous screening guidelines: insufficient evidence base, failure to link screening with treatment, and lack of risk stratification. The objective of the recommendations is to provide a schema for prostate cancer screening that maximizes the benefits, in terms of reduction in prostate cancer-specific mortality, and minimizes the harms, in terms of overdiagnosis and overtreatment. We recommend the following schema for men choosing to be screened following informed decision-making: starting at age 45, prostate-specific antigen (PSA) without digital rectal examination. If PSA???3?ng/mL: consider prostate biopsy; if PSA???1 but?<?3?ng/mL: return for PSA testing every 2-4 years; if PSA?<?1?ng/mL: return for PSA testing at 6-10 years. PSA testing should end at age 60 for men with PSA???1?ng/ mL; at 70, unless a man is very healthy and has a higher than average PSA; at 75 for all men. The decision to biopsy a man with a PSA?>?3?ng/mL should be based on a variety of factors including repeat blood draw for confirmatory testing of the PSA level, digital rectal examination results, and workup for benign disease. Additional reflex tests in blood such as a free-to-total PSA ratio, the Prostate Health Index, or 4Kscore, or urinary testing of PCA3, can also be informative in some patients. The best evidence suggests that more restricted indication for prostate biopsy and a more focused approach to pursue screening in men at highest risk of lethal cancer would retain most of the mortality benefits of aggressive screening schema, while importantly reducing harms from overdetection and overtreatment.
Project description:To investigate the efficacy and safety of prostate-specific antigen (PSA) testing to screen for prostate cancer.Systematic review and meta-analysis.Electronic search of Cochrane Central Register of Controlled Trials, Web of Science, Embase, Scopus, OpenGrey, LILACS, and Medline, and search of scientific meeting abstracts and trial registers to April 2018.Randomised controlled trials comparing PSA screening with usual care in men without a diagnosis of prostate cancer.At least two reviewers screened studies, extracted data, and assessed the quality of eligible studies. A parallel guideline committee (BMJ Rapid Recommendation) provided input on the design and interpretation of the systematic review, including selection of outcomes important to patients. We used a random effects model to obtain pooled incidence rate ratios (IRR) and, when feasible, conducted subgroup analyses (defined a priori) based on age, frequency of screening, family history, ethnicity, and socioeconomic level, as well as a sensitivity analysis based on the risk of bias. The quality of the evidence was assessed with the GRADE approach.Five randomised controlled trials, enrolling 721?718 men, were included. Studies varied with respect to screening frequency and intervals, PSA thresholds for biopsy, and risk of bias. When considering the whole body of evidence, screening probably has no effect on all-cause mortality (IRR 0.99, 95% CI 0.98 to 1.01; moderate certainty) and may have no effect on prostate-specific mortality (IRR 0.96, 0.85 to 1.08; low certainty). Sensitivity analysis of studies at lower risk of bias (n=1) also demonstrates that screening seems to have no effect on all-cause mortality (IRR 1.0, 0.98 to 1.02; moderate certainty) but may have a small effect on prostate-specific mortality (IRR 0.79, 0.69 to 0.91; moderate certainty). This corresponds to one less death from prostate cancer per 1000 men screened over 10 years. Direct comparative data on biopsy and treatment related complications from the included trials were limited. Using modelling, we estimated that for every 1000 men screened, approximately 1, 3, and 25 more men would be hospitalised for sepsis, require pads for urinary incontinence, and report erectile dysfunction, respectively.At best, screening for prostate cancer leads to a small reduction in disease-specific mortality over 10 years but has does not affect overall mortality. Clinicians and patients considering PSA based screening need to weigh these benefits against the potential short and long term harms of screening, including complications from biopsies and subsequent treatment, as well as the risk of overdiagnosis and overtreatment.PROSPERO registration number CRD42016042347.
Project description:To examine the use of the Prostate Health Index (PHI) as a continuous variable in multivariable risk assessment for aggressive prostate cancer in a large multicentre US study.The study population included 728 men, with prostate-specific antigen (PSA) levels of 2-10 ng/mL and a negative digital rectal examination, enrolled in a prospective, multi-site early detection trial. The primary endpoint was aggressive prostate cancer, defined as biopsy Gleason score ?7. First, we evaluated whether the addition of PHI improves the performance of currently available risk calculators (the Prostate Cancer Prevention Trial [PCPT] and European Randomised Study of Screening for Prostate Cancer [ERSPC] risk calculators). We also designed and internally validated a new PHI-based multivariable predictive model, and created a nomogram.Of 728 men undergoing biopsy, 118 (16.2%) had aggressive prostate cancer. The PHI predicted the risk of aggressive prostate cancer across the spectrum of values. Adding PHI significantly improved the predictive accuracy of the PCPT and ERSPC risk calculators for aggressive disease. A new model was created using age, previous biopsy, prostate volume, PSA and PHI, with an area under the curve of 0.746. The bootstrap-corrected model showed good calibration with observed risk for aggressive prostate cancer and had net benefit on decision-curve analysis.Using PHI as part of multivariable risk assessment leads to a significant improvement in the detection of aggressive prostate cancer, potentially reducing harms from unnecessary prostate biopsy and overdiagnosis.
Project description:BACKGROUND:Prostate cancer screening incurs a high risk of overdiagnosis and overtreatment. An organized and age-targeted screening strategy may reduce the associated harms while retaining or enhancing the benefits. METHODS:Using a micro-simulation analysis (MISCAN) model, we assessed the harms, benefits, and cost-effectiveness of 230 prostate-specific antigen (PSA) screening strategies in a Dutch population. Screening strategies were varied by screening start age (50, 51, 52, 53, 54, and 55), stop age (51-69), and intervals (1, 2, 3, 4, 8, and single test). Costs and effects of each screening strategy were compared with a no-screening scenario. RESULTS:The most optimum strategy would be screening with 3-year intervals at ages 55-64 resulting in an incremental cost-effectiveness ratio (ICER) of €19 733 per QALY. This strategy predicted a 27% prostate cancer mortality reduction and 28 life years gained (LYG) per 1000 men; 36% of screen-detected men were overdiagnosed. Sensitivity analyses did not substantially alter the optimal screening strategy. CONCLUSIONS:PSA screening beyond age 64 is not cost-effective and associated with a higher risk of overdiagnosis. Similarly, starting screening before age 55 is not a favored strategy based on our cost-effectiveness analysis.
Project description:BACKGROUND:Prostate-specific antigen (PSA) based screening for early detection of prostate cancer is common although it is associated with both benefits and potential harms (e.g., the risk of overdiagnosis). Evidence-based health information could help individuals make informed decisions about whether to undergo PSA testing or not. This evaluation aimed to determine whether the written health information materials available in Germany provide appropriate information for informed decision-making on PSA based screening. METHODS:A list of criteria was developed and used to systematically assess the quality of information on the benefits and harms of prostate cancer screening included in written health information materials. Fourteen information materials identified by information requests and online searches were evaluated independently by two of three reviewers. Consensus was achieved with a third reviewer. RESULTS:Of the 14 information materials evaluated, 10 (71%) list the ability to reduce the absolute risk of death from prostate cancer as a benefit of PSA testing, 9 (64%) point out the risks of follow-up diagnostics, 13 (93%) describe the risks of the available prostate cancer treatments, and all 14 specify the risk of overdiagnosis. The minority provide numerical data on benefits and risks. Partially mismatched framing was identified in four cases: two information materials report only the relative frequencies of benefits, and two report only the absolute frequencies of harms. Half of the materials encouraged participation using downplaying or frightening language. CONCLUSIONS:The majority of health information materials in Germany describe the benefits and harms of PSA based screening, including overdiagnosis, but often lack adequate balance, neutrality and numbers.
Project description:An American Society of Clinical Oncology (ASCO) provisional clinical opinion (PCO) offers timely clinical direction to the ASCO membership after publication or presentation of potentially practice-changing data from major studies. This PCO addresses the role of prostate-specific antigen (PSA) testing in the screening of men for prostate cancer.Prostate cancer is the second leading cause of cancer deaths among men in the United States. The rationale for screening men for prostate cancer is the potential to reduce the risk of death through early detection.Evidence from a 2011 Agency for Healthcare Research and Quality systematic review primarily informs this PCO on the benefits and harms of PSA-based screening. An update search was conducted to March 16, 2012, for additional evidence related to the topic.In one randomized trial, PSA testing in men who would not otherwise have been screened resulted in reduced death rates from prostate cancer, but it is uncertain whether the size of the effect was worth the harms associated with screening and subsequent unnecessary treatment. Although there are limitations to the existing data, there is evidence to suggest that men with longer life expectancy may benefit from PSA testing. Adverse events associated with prostate biopsy are low for the majority of men; however, several population-based studies have shown increasing rates of infectious complications after prostate biopsy, which is a concern.
Project description:BACKGROUND:Predictive models that take race into account like the Prostate Cancer Prevention Trial Risk Calculator 2.0 (PCPT RC) and the new Prostate Biopsy Collaborative Group (PBCG) RC have been developed to equitably mitigate the overdiagnosis of prostate specific antigen (PSA) screening. Few studies have compared the performance of both calculators across racial groups. METHODS:From 1485 prospectively recruited participants, 954 men were identified undergoing initial prostate biopsy for abnormal PSA or digital rectal examination in five Chicago hospitals between 2009 and 2014. Discrimination, calibration, and frequency of avoided biopsies were calculated to assess the performance of both risk calculators. RESULTS:Of 954 participants, 463 (48.5%) were Black, 355 (37.2%) were White, and 136 (14.2%) identified as Other. Biopsy results were as follows: 310 (32.5%) exhibited no cancer, 323 (33.9%) indolent prostate cancer, and 321 (33.6%) clinically significant prostate cancer (csPCa). Differences in area under the curve (AUC)s for the detection of csPCa between PCPT and PBCG were not statistically different across all racial groups. PBCG did not improve calibration plots in Blacks and Others, as it showed higher levels of overprediction at most risk thresholds. PCPT led to an increased number of avoidable biopsies in minorities compared to PBCG at the 30% threshold (68% vs. 28% of all patients) with roughly similar rates of missed csPCa (23% vs. 20%). CONCLUSION:Significant improvements were noticed in PBCG's calibrations and net benefits in Whites compared to PCPT. Since PBCG's improvements in Blacks are disputable and potentially biases a greater number of low risk Black and Other men towards unnecessary biopsies, PCPT may lead to better biopsy decisions in racial minority groups. Further comparisons of commonly used risk calculators across racial groups is warranted to minimize excessive biopsies and overdiagnosis in ethnic minorities.
Project description:BACKGROUND:Prostate-specific antigen (PSA) screening reduces prostate cancer deaths but leads to harm from overdiagnosis and overtreatment. OBJECTIVE:To determine the long-term risk of prostate cancer mortality using kallikrein blood markers measured at baseline in a large population of healthy men to identify men with low risk for prostate cancer death. DESIGN, SETTING, PARTICIPANTS:Study based on the Malmö Diet and Cancer cohort enrolling 11 506 unscreened men aged 45-73 yr during 1991-1996, providing cryopreserved blood at enrollment and followed without PSA screening to December 31, 2014. We measured four kallikrein markers in the blood of 1223 prostate cancer cases and 3028 controls. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS:Prostate cancer death (n=317) by PSA and a prespecified statistical model based on the levels of four kallikrein markers. RESULTS AND LIMITATIONS:Baseline PSA predicted prostate cancer death with a concordance index of 0.86. In men with elevated PSA (?2.0ng/ml), predictive accuracy was enhanced by the four-kallikrein panel compared with PSA (0.80 vs 0.73; improvement 0.07; 95% confidence interval 0.04, 0.10). Nearly half of men aged 60+ yr with elevated PSA had a four-kallikrein panel score of <7.5%, translating into 1.7% risk of prostate cancer death at 15 yr-a similar estimate to that of a man with a PSA of 1.6ng/ml. Men with a four-kallikrein panel score of ?7.5% had a 13% risk of prostate cancer death at 15 yr. CONCLUSIONS:A prespecified statistical model based on four kallikrein markers (commercially available as the 4Kscore) reclassified many men with modestly elevated PSA, to have a low long-term risk of prostate cancer death. Men with elevated PSA but low scores from the four-kallikrein panel can be monitored rather than being subject to biopsy. PATIENT SUMMARY:Men with elevated prostate-specific antigen (PSA) are often referred for prostate biopsy. However, men with elevated PSA but low scores from the four-kallikrein panel can be monitored rather than being subject to biopsy.
Project description:PURPOSE Finasteride has been shown to reduce the incidence of prostate cancer. Yet the use of finasteride remains low, likely because of the risk of adverse effects. We sought to determine whether prostate-specific antigen (PSA) levels could identify a high-risk subgroup for which the benefits of finasteride treatment outweigh the potential harms. PATIENTS AND METHODS Raw data from the Prostate Cancer Prevention Trial were used to model chemopreventive treatment strategies: treat all men, treat no men, or treat a high-risk subgroup based on PSA level. We weighted the benefits (reduction in cancer rate) and harms (treatment rate) of each strategy using numbers-needed-to-treat thresholds-the maximum number of men a clinician would treat with finasteride to prevent one cancer. Results Of 9,058 men, 1,957 were diagnosed with prostate cancer during the 7-year study. For the end point of all cancers, including both for-cause and end-of-study biopsies, the optimal strategy is to treat all or nearly all men. To reduce risk of cancers detected through routine care, treating men with PSA > 1.3 or > 2 ng/mL is optimal. For example, treating only men with PSA > 2 ng/mL reduced the treatment rate by 83% and resulted in a cancer rate only 1.1% higher than treating all men. CONCLUSION Clinicians wishing to reduce the risk of any biopsy-detectable prostate cancer should recommend finasteride to all men. Clinicians who believe that it is unnecessary to prevent all cancers, but that preventing those readily detectable by screening would be desirable, would be best off recommending finasteride only to a high-risk subgroup.