Active surveillance for prostate cancer

It is worth distinguishing between the two strategies of expectant management for prostate cancer. Watchful waiting entails administering non-curative androgen deprivation therapy to patients on development of symptomatic progression, whereas active surveillance entails delivering curative treatment on signs of disease progression. The objectives of the two management strategies and the patients enrolled in either are different: (i) to review the role of active surveillance as a management strategy for patients with low-risk prostate cancer; and (ii) review the benefits and pitfalls of active surveillance. We carried out a systematic review of active surveillance for prostate cancer in the literature using the National Center for Biotechnology Information's electronic database, PubMed. We carried out a search in English using the terms: active surveillance, prostate cancer, watchful waiting and conservative management. Selected studies were required to have a comprehensive description of the demographic and disease characteristics of the patients at the time of diagnosis, inclusion criteria for surveillance, and a protocol for the patients' follow up. Review articles were included, but not multiple papers from the same datasets. Active surveillance appears to reduce overtreatment in patients with low-risk prostate cancer without compromising cancer-specific survival at 10 years. Therefore, active surveillance is an option for select patients who want to avoid the side-effects inherent to the different types of immediate treatment. However, inclusion criteria for active surveillance and the most appropriate method of monitoring patients on active surveillance have not yet been standardized.

Prevention and early detection of prostate cancer

Prostate cancer is a common malignancy in men and the worldwide burden of this disease is rising. Lifestyle modifications such as smoking cessation, exercise, and weight control offer opportunities to reduce the risk of developing prostate cancer. Early detection of prostate cancer by prostate-specific antigen (PSA) screening is controversial, but changes in the PSA threshold, frequency of screening, and the use of other biomarkers have the potential to minimise the overdiagnosis associated with PSA screening. Several new biomarkers for individuals with raised PSA concentrations or those diagnosed with prostate cancer are likely to identify individuals who can be spared aggressive treatment. Several pharmacological agents such as 5α-reductase inhibitors and aspirin could prevent development of prostate cancer. In this Review, we discuss the present evidence and research questions regarding prevention, early detection of prostate cancer, and management of men either at high risk of prostate cancer or diagnosed with low-grade prostate cancer.

Implementation of PSA-based active surveillance in prostate cancer

Prostate cancer screening had led to the diagnosis of a large proportion of localized and low-risk disease. Many of these cancer cases are believed to be indolent and would not be clinically perceived in the absence of screening. In addition to that, the wide use of active treatment has exposed these patients to treatment-related quality-of-life impact. In this setting active surveillance as a way of deferring active treatment and reserving such treatment to cases of disease progression only has gained interest. PSA has been widely used to identify patients eligible for active surveillance and also for disease monitoring. The goal of this review was to describe the place of PSA in the monitoring of patients under active surveillance based on the existing studies and to discuss the importance of PSA in light of other existing or emerging tools to monitor prostate cancer in active surveillance.

Reducing prostate cancer racial disparity: evidence for aggressive early prostate cancer PSA testing of African American men

BACKGROUND

There is continuing controversy about prostate cancer testing and the recent American Urological Association guidelines. We hypothesize that the reduction and elimination of racial survival disparity among African American men (AAM; high-risk group) compared with European American men (EAM; intermediate-risk group) during the PSA testing era compared with the pre-PSA era strongly supports the use of PSA testing in AAM.

METHODS

We used Surveillance, Epidemiology, and End Results (SEER) data to investigate relative survival disparities between AAM and EAM. To evaluate pre-PSA testing era, we selected malignant first primary prostate cancer in AAM and EAM, all stages, diagnosed during 1973-1994. To evaluate relative survival disparities in the current PSA testing era, we selected malignant first primary local, regional, and distant stage prostate cancers diagnosed during 1998-2005 to calculate 5-year relative survival rates.

RESULTS

Age-adjusted 5-year relative survival of prostate cancer diagnosed during 1973-1994 in the national SEER data revealed significantly shorter survival for AAM compared with EAM (P < 0.0001). The SEER-based survival analysis from 1995 to 2005 indicated no statistical difference in relative survival rates between AAM and EAM by year of diagnosis of local, regional, or distant stage prostate cancer.

CONCLUSION

We conclude that the elimination of prostate cancer racial disparity of local, regional, and metastatic prostate cancer relative survival in the current PSA testing era compared with pre-PSA era as an endpoint to test PSA efficacy as a marker for prostate cancer diagnosis is evidence for aggressive testing of AAM.

IMPACT

Evidence for screening AAM.

Pathology consultation on prostate-specific antigen testing

OBJECTIVES

To provide clarity on the pros and cons of using prostate-specific antigen (PSA) as a screening tool for prostate cancer.

METHODS

Case scenarios and a literature review of recently published clinical trial data are presented to provide evidence of the controversy.

RESULTS

PSA is a sensitive biomarker for detecting diseases of the prostate, but it is limited in its ability to distinguish cancerous from noncancerous conditions or aggressive from indolent cancers and has resulted in a considerable amount of overdiagnosis and overtreatment.

CONCLUSIONS

The analytical methodology for total PSA testing is both reliable and cost-effective, but patients should be encouraged to talk to their providers to understand the benefits and harms associated with this testing.

Implications of the new AUA guidelines on prostate cancer detection in the U.S

In 2012, the U.S. Preventive Services Task Force (USPSTF) issued a blanket "D" recommendation against all prostate-specific antigen (PSA)-based early detection efforts for prostate cancer, reflecting critical misinterpretations of the major evidence regarding benefits and harms of such testing. Against the backdrop of the ensuing controversy, in 2013 the American Urological Association (AUA) published a new, methodologically rigorous guideline. This guideline recommended that men aged 55-69 be offered biennial screening in the setting of shared decision-making, that men under 40 or over 69 years of age should not be screened routinely, and that evidence was insufficient to recommend screening for men aged 40-54 years. While it has received criticism with regard to the age-based recommendations, the AUA guideline reflects a far better and more balanced presentation of the available evidence than the USPSTF statement. However, because the USPSTF is far more influential than the AUA among primary care providers, the ultimate impact of the new AUA guideline on practice patterns may be limited. Optimizing early detection practices should involve consensus-building incorporating both primary care and specialist input, with the goals of minimizing overtreatment of low-risk disease while continuing to reduce prostate cancer mortality rates through early detection and aggressive management of high-risk disease.

Evolution and immediate future of US screening guidelines

Although observational studies and simulation models have shed some interesting light on many of the uncertainties surrounding prostate cancer screening, well-done clinical trials provide the best evidence on screening among the extremes of age, the most appropriate interval to screen, and the best complement of tests to use. Enthusiasm for screening is temporized by the acknowledgment that overdetection leads to frequent overtreatment despite evidence supporting the safety of active surveillance in many men with low-risk disease.

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.

Prostate cancer incidence and mortality in the Spanish section of the European Randomized Study of Screening for Prostate Cancer (ERSPC)

BACKGROUND

To present the long-term results of a prostate cancer (PC) screening trial conducted in a Mediterranean setting.

METHODS

A total of 4276 men aged 45-70 years were randomized to screening arm (PSA test performed) and control arm (no tests). Transrectal ultrasonography-guided sextant prostate biopsy was conducted when PSA > or = 3 ng ml(-1). Date and cause of death were retrieved from death certificates. PC incidence, and disease-specific and overall mortality curves were plotted and comparison between arms was made. Analysis of causes of death was also performed.

RESULTS

Median age at randomization was 57.0 years. Median follow-up time was 15.2 years. A total of 241 men were diagnosed with PC, 161 (6.7%) in the screening arm and 80 (4.3%) in the control arm (P<0.01). Eventually, 554 men (13%) died. No difference in all-cause mortality was found between arms (P=0.34). Only 10 men (10/4276, 0.23%) died from PC, no differences between arms (P=0.67). Overall, the main causes of death were malignancy (54.2%), cardiovascular (17.9%) and respiratory (9.2%) diseases. Main cancer causes of death were lung and bronchus cancer (37.2%), colorectum (15.0%) and stomach (9.0%) cancer. PC only accounted for 3.0% of all malignant causes of death (ranked 10th).

CONCLUSIONS

Our study failed to demonstrate benefits of PC screening in terms of all-cause and PC-specific mortality after a median follow-up of 15 years. The limited sample size and the low long-term PC mortality observed in our setting were probably the most important factors to explain these results.

Is prostate cancer screening cost-effective? A microsimulation model of prostate-specific antigen-based screening for British Columbia, Canada

Prostate-specific antigen (PSA) screening for prostate cancer may reduce mortality, but it incurs considerable risk of over diagnosis and potential harm to quality of life. Our objective was to evaluate the cost-effectiveness of PSA screening, with and without adjustment for quality of life, for the British Columbia (BC) population. We adapted an existing natural history model using BC incidence, treatment, cost and mortality patterns. The modeled mortality benefit of screening derives from a stage-shift mechanism, assuming mortality reduction consistent with the European Study of Randomized Screening for Prostate Cancer. The model projected outcomes for 40-year-old men under 14 combinations of screening ages and frequencies. Cost and utility estimates were explored with deterministic sensitivity analysis. The incremental cost-effectiveness of regular screening ranged from $36,300/LYG, for screening every four years from ages 55 to 69 years, to $588,300/LYG, for screening every two years from ages 40 to 74 years. The marginal benefits of increasing screening frequency to 2 years or starting screening at age 40 years were small and came at significant cost. After utility adjustment, all screening strategies resulted in a loss of quality-adjusted life years (QALYs); however, this result was very sensitive to utility estimates. Plausible outcomes under a range of screening strategies inform discussion of prostate cancer screening policy in BC and similar jurisdictions. Screening may be cost-effective, but the sensitivity of results to utility values suggests individual preferences for quality versus quantity of life should be a key consideration.

Response to the U.S. Preventative Services Task Force decision on prostate cancer screening

The population-level data demonstrate that the inception of prostate-specific antigen (PSA) screening has lowered mortality for prostate cancer over the past 2 decades. However, more recent evidence from randomized trials has presented conflicting results regarding the benefit of PSA screening for prostate cancer mortality. Using available data, the U.S. Preventative Services Task Force recently recommended against PSA screening for prostate cancer. However, prostate cancer continues to kill over 30,000 men annually, and as such, completely abandoning screening for this disease is a disservice to many patients. Rather, the emphasis should be on utilizing evidence-based medicine to reduce overdiagnosis and overtreatment through less frequent screening for low-risk individuals or those unlikely to benefit from screening, halting further screening when appropriate, and utilizing observational strategies in patients unlikely to suffer clinically significant effects of prostate cancer over their anticipated life expectancy.

Risk-based prostate cancer screening: who and how?

The purpose of this review is to identify clinical risk factors for prostate cancer and to assess the utility and limitations of our current tools for prostate cancer screening. Prostate-specific antigen is the single most important factor for identifying men at increased risk of prostate cancer but is best assessed in the context of other clinical factors; increasing age, race, and family history are well-established risk factors for the diagnosis of prostate cancer. In addition to clinical risk calculators, novel tools such as multiparametric imaging, serum or urinary biomarkers, and genetic profiling show promise in improving prostate cancer diagnosis and characterization. Optimal use of existing and future tools will help alleviate the problems of overdiagnosis and overtreatment of low-risk prostate cancer without reversing the substantial mortality declines that have been achieved in the screening era.

Update of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

The prostate portion of the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial began in the early 1990s to assess the ability of annual PSA and DRE to reduce prostate cancer specific mortality in men aged 55-74. Approximately 80,000 men have been randomized and followed for a minimum of 13 years. Thus far, annual screening in this study has not been associated with a reduction of prostate cancer specific mortality. The potential explanations for this finding are reviewed.

Biomarkers in prostate cancer surveillance and screening: past, present, and future

The use of biomarkers for prostate cancer (PCa) screening, detection, and prognostication have revolutionized the diagnosis and management of the disease. Current clinical practice has been driven largely by the utilization of prostate-specific antigen (PSA). The lack of specificity of PSA for PCa has led to both unnecessary biopsies and overdiagnosis of indolent cancers. The recent controversial recommendation by the United States Preventive Services Task Force against PCa screening has highlighted the need for novel clinically useful biomarkers. We review the literature on PCa biomarkers in serum, urine, and tissue. While these markers show promise, none seems poised to replace PSA, but rather may augment it. Further validation and consideration of how these novel markers improve clinical outcome is necessary. The discovery of new genetic markers shows promise in stratifying men with aggressive PCa.

Overdiagnosis of prostate cancer

This chapter addresses issues relevant to prostate cancer overdiagnosis. Factors promoting the overdiagnosis of prostate cancer are reviewed. First is the existence of a relatively large, silent reservoir of this disease, as can be seen by evaluating autopsy studies and histologic step-sectioning results of prostates removed for other causes. The second main factor responsible for prostate cancer overdiagnosis is fairly widespread prostate-specific antigen and digital rectal examination-based screening, which has been fairly widely practiced in the United States for the past 20 years among heterogeneous groups of men. This has resulted in the identification of many men from this reservoir who otherwise may never have been diagnosed with symptomatic prostate cancer and is substantially responsible for the current annual incidence to mortality ratio for prostate cancer of approximately 6 to 1. Finally, the relatively indolent natural history and limited cancer-specific mortality as reported in a variety of contemporary randomized screening and treatment trials is reviewed. We attempt to quantitate the proportion of newly diagnosed prostate cancers that are overdiagnosed using various trial results and models. We explore the impact of prostate cancer overdiagnosis in terms of patient anxiety and the potential for overtreatment, with its attendant morbidity. We explore strategies to minimize overdiagnosis by targeting screening and biopsy only to men at high risk for aggressive prostate cancer and by considering the use of agents such as 5-alpha reductase inhibitors. Future prospects to prevent overtreatment, including better biopsy and molecular characterization of newly diagnosed cancer and the role of active surveillance, are discussed.

PSA screening for prostate cancer: why so much controversy?

Since prostate cancer reaches the advanced and non curable stage in the absence of any specific symptom or sign, it seems reasonable to diagnose this cancer at an early and curable stage. Screening by prostate-specific antigen (PSA) has been the common technology used. The last follow-up of the first two prospective and randomized screening studies for prostate cancer, namely the Quebec and ERSPC (European Randomized Study of Screening for Prostate Cancer) clinical trials started in 1988 and 1991, respectively, have shown reductions of prostate cancer death of 62% (P<0.002) and 21% (P<0.001) (38% in the tenth and eleventh years of follow-up, P<0.003), respectively, while the PLCO (Prostate Lung Colorectal and Ovarian Cancer) screening trial reported no benefit. It has been estimated, however, that 85% of men in the planned 'non-screened' group of the US study have been screened. With such a serious flaw, the PLCO study does not have the statistical power to reach any valid conclusion. In the Quebec study, only 7.3% of men were screened in the control arm. The important benefit observed in the ERSPC study was achieved using a less than optimal 4-year PSA screening interval which misses a significant number of cancers while the Quebec study used the optimal 1-year interval. With proper information obtained from their physicians or otherwise using data collected only from the clinical trials having the required statistical power, men should be in a good position to decide about being or not being screened for prostate cancer.

Early detection of prostate cancer: AUA Guideline

PURPOSE

The guideline purpose is to provide the urologist with a framework for the early detection of prostate cancer in asymptomatic average risk men.

MATERIALS AND METHODS

A systematic review was conducted and summarized evidence derived from over 300 studies that addressed the predefined outcomes of interest (prostate cancer incidence/mortality, quality of life, diagnostic accuracy and harms of testing). In addition to the quality of evidence, the panel considered values and preferences expressed in a clinical setting (patient-physician dyad) rather than having a public health perspective. Guideline statements were organized by age group in years (age <40; 40 to 54; 55 to 69; ≥ 70).

RESULTS

Except prostate specific antigen-based prostate cancer screening, there was minimal evidence to assess the outcomes of interest for other tests. The quality of evidence for the benefits of screening was moderate, and evidence for harm was high for men age 55 to 69 years. For men outside this age range, evidence was lacking for benefit, but the harms of screening, including over diagnosis and overtreatment, remained. Modeled data suggested that a screening interval of two years or more may be preferred to reduce the harms of screening.

CONCLUSIONS

The Panel recommended shared decision-making for men age 55 to 69 years considering PSA-based screening, a target age group for whom benefits may outweigh harms. Outside this age range, PSA-based screening as a routine could not be recommended based on the available evidence.

Counterpoint: Randomized trials provide the strongest evidence for clinical guidelines: The US Preventive Services Task Force and Prostate Cancer Screening

BACKGROUND

The US Preventive Services Task Force recommended against prostate-specific antigen (PSA) screening for prostate cancer based primarily on 2 large long-term randomized-controlled trials (RCTs) and a systematic review of harms resulting from screening.

OBJECTIVE

To support use of large, long-term randomized trials as the evidence base for clinical guidelines on screening and to draw attention to limitations of modeling studies used for this purpose.

METHODS

We respond to critiques of use of RCTs as the primary evidence base, considering the results of the Prostate, Lung, Colorectal and Ovarian (PLCO) and European Randomized Study of Screening for Prostate Cancer (ERSPC) trials, documented harms resulting from PSA screening, and methodological concerns with modeling studies.

RESULTS

The PLCO and ERSPC provided 11-13 years of follow-up on over 250,000 subjects. The PLCO, despite limitations, is most representative of US populations, screening and treatment practices, and showed no mortality benefit resulting from annual PSA testing after 13 years of follow-up. The confidence interval was narrow and precluded more than a 13% relative mortality reduction. Competing causes of mortality in older men make it progressively less likely that longer follow-up will demonstrate a large absolute reduction in disease-specific mortality. With continued screening, the increasing prevalence of asymptomatic cancers in older men will increase the rate of overdiagnosis. Potential harms from screening and treatment are significant.

CONCLUSIONS

Projections from models are subject to mistaken assumptions and investigator biases, and should not be accorded the same weight as evidence from RCTs. Current empiric evidence is sufficient to support the US Preventive Services Task Force guideline that clinicians should recommend against PSA screening for prostate cancer.

Response: Reading between the lines of cancer screening trials: using modeling to understand the evidence

In our article about limitations of basing screening policy on screening trials, we offered several examples of ways in which modeling, using data from large screening trials and population trends, provided insights that differed somewhat from those based only on empirical trial results. In this editorial, we take a step back and consider the general question of whether randomized screening trials provide the strongest evidence for clinical guidelines concerning population screening programs. We argue that randomized trials provide a process that is designed to protect against certain biases but that this process does not guarantee that inferences based on empirical results from screening trials will be unbiased. Appropriate quantitative methods are key to obtaining unbiased inferences from screening trials. We highlight several studies in the statistical literature demonstrating that conventional survival analyses of screening trials can be misleading and list a number of key questions concerning screening harms and benefits that cannot be answered without modeling. Although we acknowledge the centrality of screening trials in the policy process, we maintain that modeling constitutes a powerful tool for screening trial interpretation and screening policy development.

Limitations of basing screening policies on screening trials: The US Preventive Services Task Force and Prostate Cancer Screening

BACKGROUND

The US Preventive Services Task Force recently recommended against prostate-specific antigen screening for prostate cancer based primarily on evidence from the European Randomized Study of Screening for Prostate Cancer (ERSPC) and the US Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial.

OBJECTIVE

: To examine limitations of basing screening policy on evidence from screening trials.

METHODS

We reviewed published modeling studies that examined population and trial data. The studies (1) project the roles of screening and changes in primary treatment in the US mortality decline; (2) extrapolate the ERSPC mortality reduction to the long-term US setting; (3) estimate overdiagnosis based on US incidence trends; and (4) quantify the impact of control arm screening on PLCO mortality results.

RESULTS

Screening plausibly explains 45% and changes in primary treatment can explain 33% of the US prostate cancer mortality decline. Extrapolating the ERSPC results to the long-term US setting implies an absolute mortality reduction at least 5 times greater than that observed in the trial. Approximately 28% of screen-detected cases are overdiagnosed in the United States versus 58% of screen-detected cases suggested by the ERSPC results. Control arm screening can explain the null result in the PLCO trial.

CONCLUSIONS

Modeling studies indicate that population trends and trial results extended to the long-term population setting are consistent with greater benefit of prostate-specific antigen screening-and more favorable harm-benefit tradeoffs-than has been suggested by empirical trial evidence.

Screening for prostate cancer

BACKGROUND

Any form of screening aims to reduce disease-specific and overall mortality, and to improve a person's future quality of life. Screening for prostate cancer has generated considerable debate within the medical and broader community, as demonstrated by the varying recommendations made by medical organizations and governed by national policies. To better inform individual patient decision-making and health policy decisions, we need to consider the entire body of data from randomised controlled trials (RCTs) on prostate cancer screening summarised in a systematic review. In 2006, our Cochrane review identified insufficient evidence to either support or refute the use of routine mass, selective, or opportunistic screening for prostate cancer. An update of the review in 2010 included three additional trials. Meta-analysis of the five studies included in the 2010 review concluded that screening did not significantly reduce prostate cancer-specific mortality. In the past two years, several updates to studies included in the 2010 review have been published thereby providing the rationale for this update of the 2010 systematic review.

OBJECTIVES

To determine whether screening for prostate cancer reduces prostate cancer-specific mortality or all-cause mortality and to assess its impact on quality of life and adverse events.

SEARCH METHODS

An updated search of electronic databases (PROSTATE register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CANCERLIT, and the NHS EED) was performed, in addition to handsearching of specific journals and bibliographies, in an effort to identify both published and unpublished trials.

SELECTION CRITERIA

All RCTs of screening versus no screening for prostate cancer were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

The original search (2006) identified 99 potentially relevant articles that were selected for full-text review. From these citations, two RCTs were identified as meeting the inclusion criteria. The search for the 2010 version of the review identified a further 106 potentially relevant articles, from which three new RCTs were included in the review. A total of 31 articles were retrieved for full-text examination based on the updated search in 2012. Updated data on three studies were included in this review. Data from the trials were independently extracted by two authors.

MAIN RESULTS

Five RCTs with a total of 341,342 participants were included in this review. All involved prostate-specific antigen (PSA) testing, with or without digital rectal examination (DRE), though the interval and threshold for further evaluation varied across trials. The age of participants ranged from 45 to 80 years and duration of follow-up from 7 to 20 years. Our meta-analysis of the five included studies indicated no statistically significant difference in prostate cancer-specific mortality between men randomised to the screening and control groups (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.86 to 1.17). The methodological quality of three of the studies was assessed as posing a high risk of bias. The European Randomized Study of Screening for Prostate Cancer (ERSPC) and the US Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial were assessed as posing a low risk of bias, but provided contradicting results. The ERSPC study reported a significant reduction in prostate cancer-specific mortality (RR 0.84, 95% CI 0.73 to 0.95), whilst the PLCO study concluded no significant benefit (RR 1.15, 95% CI 0.86 to 1.54). The ERSPC was the only study of the five included in this review that reported a significant reduction in prostate cancer-specific mortality, in a pre-specified subgroup of men aged 55 to 69 years of age. Sensitivity analysis for overall risk of bias indicated no significant difference in prostate cancer-specific mortality when referring to the meta analysis of only the ERSPC and PLCO trial data (RR 0.96, 95% CI 0.70 to 1.30). Subgroup analyses indicated that prostate cancer-specific mortality was not affected by the age at which participants were screened. Meta-analysis of four studies investigating all-cause mortality did not determine any significant differences between men randomised to screening or control (RR 1.00, 95% CI 0.96 to 1.03). A diagnosis of prostate cancer was significantly greater in men randomised to screening compared to those randomised to control (RR 1.30, 95% CI 1.02 to 1.65). Localised prostate cancer was more commonly diagnosed in men randomised to screening (RR 1.79, 95% CI 1.19 to 2.70), whilst the proportion of men diagnosed with advanced prostate cancer was significantly lower in the screening group compared to the men serving as controls (RR 0.80, 95% CI 0.73 to 0.87). Screening resulted in a range of harms that can be considered minor to major in severity and duration. Common minor harms from screening include bleeding, bruising and short-term anxiety. Common major harms include overdiagnosis and overtreatment, including infection, blood loss requiring transfusion, pneumonia, erectile dysfunction, and incontinence. Harms of screening included false-positive results for the PSA test and overdiagnosis (up to 50% in the ERSPC study). Adverse events associated with transrectal ultrasound (TRUS)-guided biopsies included infection, bleeding and pain. No deaths were attributed to any biopsy procedure. None of the studies provided detailed assessment of the effect of screening on quality of life or provided a comprehensive assessment of resource utilization associated with screening (although preliminary analyses were reported).

AUTHORS' CONCLUSIONS

Prostate cancer screening did not significantly decrease prostate cancer-specific mortality in a combined meta-analysis of five RCTs. Only one study (ERSPC) reported a 21% significant reduction of prostate cancer-specific mortality in a pre-specified subgroup of men aged 55 to 69 years. Pooled data currently demonstrates no significant reduction in prostate cancer-specific and overall mortality. Harms associated with PSA-based screening and subsequent diagnostic evaluations are frequent, and moderate in severity. Overdiagnosis and overtreatment are common and are associated with treatment-related harms. Men should be informed of this and the demonstrated adverse effects when they are deciding whether or not to undertake screening for prostate cancer. Any reduction in prostate cancer-specific mortality may take up to 10 years to accrue; therefore, men who have a life expectancy less than 10 to 15 years should be informed that screening for prostate cancer is unlikely to be beneficial. No studies examined the independent role of screening by DRE.

Prostate cancer specific survival in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial

BACKGROUND

The prostate component of the Prostate, Lung, Colorectal, and Ovarian (PLCO) randomized screening trial demonstrated no mortality effect of screening. Here we analyze prostate cancer specific survival in PLCO and its relation to screening.

METHODS

76,693 men aged 55-74 were randomized to usual care (n = 38,350) or intervention (n = 38,343). Intervention arm men received annual prostate-specific antigen (6 years) and digital rectal exam (4 years). Men were followed for cancer diagnosis and mortality through 13 years. Medical record abstractors confirmed prostate cancer diagnoses, stage and grade. Prostate-specific survival in PLCO cases was analyzed using Kaplan-Meier analysis and proportional hazards modeling. We utilized data from the Surveillance, Epidemiology and End Results (SEER) program to compute expected survival in PLCO and compared this to observed.

RESULTS

There was no significant difference in prostate-specific survival rates between arms; 10 year survival rates were 94.7% (intervention, n = 4250 cases) versus 93.5% (usual care, n = 3815 cases). Within the intervention arm, cases never screened in PLCO had lower 10 year survival rates (82%) than screen detected or interval (following a negative screen) cases, both around 95.5%. The ratio of observed to expected 10 year prostate-specific death (1-survival) rates was 0.59 (95% CI: 0.51-0.68) for all PLCO cases, 0.66 (95% CI: 0.51-0.81) for Gleason 5-7 cases and 1.07 (95% CI: 0.87-1.3) for Gleason 8-10 cases.

CONCLUSION

Prostate cancer specific survival in PLCO was comparable across arms and significantly better than expected based on nationwide population data. How much of the better survival is due to a healthy volunteer effect and to lead-time and overdiagnosis biases is not readily determinable.

Limited PSA testing in indigent men in South Texas: an appropriate care or missing a prevention opportunity?

BACKGROUND

No previous study has examined racial ethnic differences in prostate-specific antigen (PSA) testing and followup in primary care practices serving an indigent population.

METHODS

From electronic medical records of primary care practices affiliated with one health care system in San Antonio, we identified 9,267 men aged 50 to 74 with 2+ clinic visits from 2008 through 2010 and no prior prostate cancer diagnosis. Logistic regression was used to examine the association of race ethnicity with the use of PSA testing and, if tested, with an abnormal result (≥4 ng/mL) adjusted for demographics, health care, and clinical factors. Time to a follow-up activity after an abnormal PSA was assessed using Cox proportional models.

RESULTS

The race ethnicity of this cohort was 63% Hispanic, 27% non-Hispanic white, 7% African-American, and 3% other. In a 3-year period, 26.8% of men had at least one PSA test. Compared with African-Americans, non-Hispanic whites were less likely to be tested [OR, 0.68; 95% confidence interval (CI), 0.55-0.83] but Hispanics did not differ (OR = 0.95; 95% CI 0.79-1.15). African-Americans were more likely to have an abnormal PSA than others (12.4% vs. 5.2%, P < 0.001) and the shortest adjusted time to follow-up (P = 0.004).

CONCLUSIONS

In this 3-year indigent cohort, about one quarter had a PSA test, approximately half of the national testing rate.

IMPACT

African-Americans were more likely to be tested than non-Hispanic whites but had more abnormal results, raising concerns about missed prevention opportunities. African-Americans with high PSA results had the shortest time until follow-up, reflecting awareness of the threat of prostate cancer for African-Americans by physicians.

The prostate cancer conundrum revisited: treatment changes and prostate cancer mortality declines

BACKGROUND

Prostate cancer mortality rates in the United States declined by >40% between 1991 and 2005. The impact of changes in primary treatment and adjuvant and neoadjuvant hormone therapy on this decline is unknown.

METHODS

The authors applied 3 independently developed models of prostate cancer natural history and disease detection under common assumptions about treatment patterns, treatment efficacy, and survival in the population. Primary treatment patterns were derived from the Surveillance, Epidemiology, and End Results registry; data on the frequency of hormone therapy were obtained from the CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) database; and treatment efficacy was based on estimates from randomized trials and comparative effectiveness studies of treatment alternatives. The models projected prostate cancer mortality without prostate-specific antigen screening and in the presence and absence of treatment benefit. The impact of primary treatment was expressed as a fraction of the difference between observed mortality and projected mortality in the absence of treatment benefit.

RESULTS

The 3 models projected that changes in treatment explained 22% to 33% of the mortality decline by 2005. These contributions were accounted for mostly by surgery and radiation therapy, which increased in frequency until the 1990s, whereas hormone therapies contributed little to the mortality decline by 2005. Assuming that treatment benefit was less for older men, changes in treatment explained only 16% to 23% of the mortality decline by 2005.

CONCLUSIONS

Changes in primary treatment explained a minority of the observed decline in prostate cancer mortality. The remainder of the decline probably was because of other interventions, such as prostate-specific antigen screening and advances in the treatment of recurrent and progressive disease.

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

PURPOSE

To quantify the extent to which a clinically significant prostate cancer mortality reduction due to screening could have been masked by control arm screening (contamination) in the Prostate, Lung, Colorectal, and Ovarian (PLCO) trial.

METHODS

We used three independently developed models of prostate cancer natural history to conduct a virtual PLCO trial. Simulated participants underwent pre-trial screening based on population patterns. The intervention arm followed observed compliance during the trial then resumed population screening. A contaminated control arm followed observed contamination during the trial then resumed population screening, while an uncontaminated control arm discontinued screening upon entry. We assumed a clinically significant screening benefit, applied population treatments and survival patterns, and calculated mortality rate ratios relative to the contaminated and uncontaminated control arms.

RESULTS

The virtual trial reproduced observed incidence, including stage and grade distributions, and control arm mortality after 10 years of complete follow-up. Under the assumed screening benefit, the three models found that contamination increased the mortality rate ratio from 0.68-0.77 to 0.86-0.91, increased the chance of excess mortality in the intervention arm from 0-4 % to 15-28 %, and decreased the power of the trial to detect a mortality difference from 40-70 % to 9-25 %.

CONCLUSIONS

Our computer simulation models indicate that contamination substantially limited the ability of the PLCO to identify a clinically significant screening benefit. While the trial shows annual screening does not reduce mortality relative to population screening, contamination prevents concluding whether screening reduces mortality relative to no screening.

Prostate-specific antigen screening for prostate cancer in older men in the United States of America

Prostate cancer, like many diseases, is more common in older men. Although an estimated 1 in 7 men will be diagnosed with it, the majority of these men will not die from prostate cancer. The latent nature of this disease, the use of screening with prostate-specific antigen (PSA) testing and the greater risk of dying from causes other than prostate cancer contribute to this disparity. As the US population continues to age, prostate cancer screening and disease management presents an increasingly important public health issue. We discuss the current PSA screening recommendations and practices in the USA and the benefits and harms of screening older populations.

Prostate cancer screening in the randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial: mortality results after 13 years of follow-up

BACKGROUND

The prostate component of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial was undertaken to determine whether there is a reduction in prostate cancer mortality from screening using serum prostate-specific antigen (PSA) testing and digital rectal examination (DRE). Mortality after 7-10 years of follow-up has been reported previously. We report extended follow-up to 13 years after the trial.

METHODS

A total of 76 685 men, aged 55-74 years, were enrolled at 10 screening centers between November 1993 and July 2001 and randomly assigned to the intervention (organized screening of annual PSA testing for 6 years and annual DRE for 4 years; 38 340 men) and control (usual care, which sometimes included opportunistic screening; 38 345 men) arms. Screening was completed in October 2006. All incident prostate cancers and deaths from prostate cancer through 13 years of follow-up or through December 31, 2009, were ascertained. Relative risks (RRs) were estimated as the ratio of observed rates in the intervention and control arms, and 95% confidence intervals (CIs) were calculated assuming a Poisson distribution for the number of events. Poisson regression modeling was used to examine the interactions with respect to prostate cancer mortality between trial arm and age, comorbidity status, and pretrial PSA testing. All statistical tests were two-sided.

RESULTS

Approximately 92% of the study participants were followed to 10 years and 57% to 13 years. At 13 years, 4250 participants had been diagnosed with prostate cancer in the intervention arm compared with 3815 in the control arm. Cumulative incidence rates for prostate cancer in the intervention and control arms were 108.4 and 97.1 per 10 000 person-years, respectively, resulting in a relative increase of 12% in the intervention arm (RR = 1.12, 95% CI = 1.07 to 1.17). After 13 years of follow-up, the cumulative mortality rates from prostate cancer in the intervention and control arms were 3.7 and 3.4 deaths per 10 000 person-years, respectively, resulting in a non-statistically significant difference between the two arms (RR = 1.09, 95% CI = 0.87 to 1.36). No statistically significant interactions with respect to prostate cancer mortality were observed between trial arm and age (P(interaction) = .81), pretrial PSA testing (P(interaction) = .52), and comorbidity (P(interaction) = .68).

CONCLUSIONS

After 13 years of follow-up, there was no evidence of a mortality benefit for organized annual screening in the PLCO trial compared with opportunistic screening, which forms part of usual care, and there was no apparent interaction with age, baseline comorbidity, or pretrial PSA testing.

The case for prostate cancer risk reduction by 5-alpha reductase inhibitors

Prostate cancer remains a significant public health problem. The current approach with prostate-specific antigen (PSA)-based screening has questionable effects on prostate cancer-specific mortality but is clearly associated with overdiagnosis of prostate cancer, especially relatively low-risk and low-volume tumors. Methods to decrease overdiagnosis include alterations in screening practices and, potentially, the use of 5-alpha reductase inhibitors. This article reviews the major trials that have evaluated 5-alpha reductase inhibitors in this setting: the Prostate Cancer Prevention Trial (PCPT) and the Reduction by Dutasteride Prostate Cancer Events Trial (REDUCE). Although these trials enrolled different patient populations, their findings are complementary and suggest a potential role for these agents in prostate cancer risk reduction. Use of 5-alpha reductase inhibitors results in an approximate 25% reduction in the detection of prostate cancer, reduces diagnosis of high-grade prostatic intraepithelial neoplasia (PIN), and improves benign prostatic hyperplasia (BPH)-related outcomes and the performance of PSA as a diagnostic test for aggressive prostate cancer. Side effects occur in a small percentage of men and consist of decreased sexual function and libido as well as gynecomastia. The risk of high-grade tumor development while receiving these agents is uncertain.

Long-term projections of the harm-benefit trade-off in prostate cancer screening are more favorable than previous short-term estimates

OBJECTIVE

To project long-term estimates of the number needed to screen (NNS) and the additional number needed to treat (NNT) to prevent one prostate cancer death with prostate-specific antigen (PSA) screening in Europe and in the United States.

STUDY DESIGN AND SETTING

A mathematical model of disease-specific deaths in screened and unscreened men given information on overdiagnosis, disease-specific survival in the absence of screening, screening efficacy, and other-cause mortality is presented. A simulation framework is used to incorporate competing causes of death.

RESULTS

Assuming overdiagnosis and screening efficacy consistent with European Randomized study of Screening for Prostate Cancer (ERSPC) results, we project that, after 25 years, 262 men need to be screened and nine additional men need to be screen detected to prevent one prostate cancer death. Corresponding estimates of the NNS and the additional NNT under a range of overdiagnosis rates that are consistent with U.S. incidence are 186-220 and 2-5.

CONCLUSIONS

Long-term estimates of the NNS and the additional NNT are an order of magnitude lower than the short-term estimates published with the results of the ERSPC trial and may be consistent with cost-effective PSA screening in the general U.S. population.

Optimization of PSA screening policies: a comparison of the patient and societal perspectives

OBJECTIVE

To estimate the benefit of PSA-based screening for prostate cancer from the patient and societal perspectives.

METHOD

A partially observable Markov decision process model was used to optimize PSA screening decisions. Age-specific prostate cancer incidence rates and the mortality rates from prostate cancer and competing causes were considered. The model trades off the potential benefit of early detection with the cost of screening and loss of patient quality of life due to screening and treatment. PSA testing and biopsy decisions are made based on the patient's probability of having prostate cancer. Probabilities are inferred based on the patient's complete PSA history using Bayesian updating.

DATA SOURCES

The results of all PSA tests and biopsies done in Olmsted County, Minnesota, from 1993 to 2005 (11,872 men and 50,589 PSA test results).

OUTCOME MEASURES

Patients' perspective: to maximize expected quality-adjusted life years (QALYs); societal perspective: to maximize the expected monetary value based on societal willingness to pay for QALYs and the cost of PSA testing, prostate biopsies, and treatment.

RESULTS

From the patient perspective, the optimal policy recommends stopping PSA testing and biopsy at age 76. From the societal perspective, the stopping age is 71. The expected incremental benefit of optimal screening over the traditional guideline of annual PSA screening with threshold 4.0 ng/mL for biopsy is estimated to be 0.165 QALYs per person from the patient perspective and 0.161 QALYs per person from the societal perspective. PSA screening based on traditional guidelines is found to be worse than no screening at all.

CONCLUSIONS

PSA testing done with traditional guidelines underperforms and therefore underestimates the potential benefit of screening. Optimal screening guidelines differ significantly depending on the perspective of the decision maker.

The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial: the prostate cancer screening results in context

BACKGROUND

The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) was conducted in sites around USA during a period of marked secular changes in the use of prostate specific antigen (PSA) screening for prostate cancer.

MATERIAL AND METHODS

Trends in prostate cancer incidence, stage at presentation and mortality are useful when interpreting the results from a screening trial that commenced in 1993 and enrolled participants through 2001. The last participants completed active screening in 2006. Incidence and mortality data published to date on PLCO need to be placed into the context of the secular trends. Additional data analyses have been conducted on subsets of the participants and these results can also enhance the interpretation of the trial. Additionally, the accompanying biospecimen repository has served as a rich research resource yielding informative findings.

RESULTS

The PLCO is best viewed as a trial comparing a regimented active annual screening program of PSA screening for six rounds, four of which had accompanying digital rectal examination (DRE) to patterns of screening that were occurring in the population in many academic and community settings across the USA. The epidemiology and molecular genetics of prostate cancer is becoming better understood and analyses of the PLCO resource have contributed. One approach to risk assessment utilizing genetic markers from selected members of the PLCO prostate cancer cohort has been developed. A modeling effort with CISNET-ERSPC-PLCO is underway to compare and contrast findings such as effects of different PSA thresholds and screening intervals.

CONCLUSIONS

The information emerging from PLCO is useful to inform the debate around prostate cancer screening. An understanding of the biologic differences underpinning indolent and aggressive prostate cancer will better guide the future development of screening and treatment strategies.