Variation in harms and benefits of prostate-specific antigen screening for prostate cancer by socio-clinical risk factors: A rapid review

Objective

To analyse the latest evidence on the relative harms and benefits of screening and diagnostic pathways with close examination of (i) men aged 50 years or older, (ii) men whose ethnicity places them at higher risk and (iii) men with a family history.

Methods

We conducted a literature search using PubMed and Cochrane Central Register of Controlled Trials (CENTRAL) databases and other sources, from January 1990 to 25 January 2023. Two independent reviewers selected for randomised controlled trials (RCTs) and cohort studies which met our inclusion criteria.

Results

Twenty-eight articles were selected, from six trials, including the Göteborg trial-reported separately from European Randomised Study of Screening for Prostate Cancer (ERSPC). Prostate-specific antigen (PSA)-based screening led to the increased detection of low-grade cancer and reduction of advanced/metastatic disease but had contradictory effects on prostate cancer (PCa)-specific mortality (no difference or reduced), possibly due to issues of contamination or compliance. Screening men from a relatively young age (50-55) reduced risk of PCa-specific mortality in a subanalysis of an 18-year follow-up study and in a 17-year cohort study from the main Göteborg trial. Moreover, one Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial analysis reported a trend of reduced risk of PCa-specific mortality for men with a family history who were screened. [Correction added on 05 March 2024, after first online publication: "Cancer Screening Trial" has been added to the preceding sentence.] However, we did not find relevant studies for ethnicity.

Conclusion

Under current UK practice, the choice to conduct a PSA test relies on a shared decision-making approach guided by known risk factors. However, we found there was a lack of strong evidence on the harms and benefits of PSA screening by socio-clinical risk factors and suggest further research is required to understand the long-term impact of screening on high-risk populations in the current diagnostic setting.

Allopurinol and prostate cancer survival in a Finnish population-based cohort

BACKGROUND

Allopurinol is gout medication that inhibits uric acid formation. Its possible anti-carcinogenic properties have been under research in past years. Studies based on Taiwanese registries showed that long term allopurinol use might reduce prostate cancer (PCa) incidence. However, our studies based on Finnish registries did not support those findings. In this study, we evaluate whether allopurinol use is associated with prostate cancer-specific survival (CSS) or overall survival (OS) in a Finnish population-based cohort.

METHODS

The study cohort was originally enrolled for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). We included all newly diagnosed PCa cases during 1996-2015, 9252 men in total. Information on allopurinol purchases was from the national prescription registry of the Social Insurance Institution of Finland. Information about deaths, treatments, and use of other medications was obtained from registries, and tumor stage and PSA at diagnosis from medical records. Follow-up started at diagnosis, and we analysed separately two endpoints: PCa-specific death and overall death. We used an extended Cox regression with adjustment for age at diagnosis, Charlson comorbidity index, FinRSPC trial arm, use of other drugs and EAU PCa risk group.

RESULTS

During a median follow-up of 9.86 years, 2942 deaths occurred, including 883 from PCa. There was no difference in CSS between allopurinol user and non-users, but allopurinol users had lower OS (multivariable-adjusted hazard ratio 1.77; 95% CI: 1.57-2.00). However, this decrease in OS was mitigated along with increasing intensity of allopurinol use.

CONCLUSIONS

We found no marked difference in CSS by allopurinol use. Allopurinol users had lower OS but there were no significant differences by duration or intensity of allopurinol use. Allopurinol use may not have anticancer effects against prostate cancer; instead, it may be a surrogate for metabolic problems causing shorter OS among men with PCa.

Application and optimization of prostate-specific antigen screening strategy in the diagnosis of prostate cancer: a systematic review

Currently, prostate cancer (PCa) poses a global risk to the well-being of males. Over the past few years, the utilization of prostate-specific antigen (PSA) screening has become prevalent in the identification and management of PCa, which has promoted a large number of patients with advanced PCa to receive timely treatment and reduce the mortality. Nevertheless, the utilization of PSA in PCa screening has sparked debate, and certain research has validated the potential for overdiagnosis and overtreatment associated with PSA screening. Hence, in order to decrease the mortality rate of PCa patients and prevent unnecessary diagnosis and treatment, it is crucial to carefully choose the suitable population and strategy for PSA screening in PCa. In this systematic review, the clinical studies on PSA screening for the diagnosis and treatment of PCa were thoroughly examined. The review also delved into the effects and mechanisms of PSA screening on the prognosis of PCa patients, examined the factors contributing to overdiagnosis and overtreatment, and put forth strategies for optimization. The objective of this research is to offer valuable recommendations regarding the utilization of PSA screening for the detection and management of PCa.

Testosterone replacement therapy is not associated with increased prostate cancer incidence, prostate cancer-specific, or cardiovascular disease-specific mortality in Finnish men

BACKGROUND

Concerns have been expressed over the safety of testosterone replacement therapy (TRT) in men with late-onset hypogonadism (LOH). Previous studies have shown controversial results regarding the association of TRT with the risk of cardiovascular events or prostate cancer (PCa) incidence, aggressiveness, and mortality. This study explores the overall risk of PCa and risk by tumor grade and stage, as well as mortality from PCa and cardiovascular disease (CVD), among men treated with TRT compared to men without LOH and TRT use.

MATERIALS AND METHODS

The study included 78,615 men of age 55-67 years at baseline from the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). Follow-up started at randomization and ended at death, emigration, or a common closing date January 1st, 2017. Cox proportional hazards regression model with time-dependent variables and adjustment for age, trial arm, use of other medications, and Charlson comorbidity index was used. Comprehensive information on TRT purchases during 1995-2015 was obtained from the Finnish National Prescription Database. PCa cases were identified from the Finnish Cancer Registry and causes of death obtained from Statistics Finland.

RESULTS

Over the course of 18 years of follow-up, 2919 men were on TRT, and 285 PCa cases were diagnosed among them. TRT users did not exhibit a higher incidence or mortality rate of PCa compared to non-users. On the contrary, men using TRT had lower PCa mortality than non-users (HR = 0.52; 95% CI 0.3-0.91). Additionally, TRT users had slightly lower CVD and all-cause mortality compared to non-users (HR = 0.87; 95% CI 0.75-1.01 and HR = 0.93; 95% CI 0.87-1.0, respectively). No time- or dose-dependency of TRT use was evident in any of the analyses.

CONCLUSION

Men using TRT were not associated to increased risk for PCa and did not experience increased PCa- or CVD-specific mortality compared to non-users. Further studies considering blood testosterone levels are warranted.

Statin use and outcomes of oncological treatment for castration-resistant prostate cancer

To compare the effect of statin use in relation to castration-resistant prostate cancer (CRPC) treatment, we assessed the risk of ADT-treated PCa-patients to initiate CRPC treatment by statin use and the outcomes of CRPC treatment by statin use. Our study cohort consisted of 1169 men who participated in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) and initiated androgen deprivation therapy (ADT) during the follow-up (1996-2017). Statin use was associated with slightly decreased risk of initiating CRPC treatment (HR 0.68; 95% CI 0.47-0.97) with a 5.7 years' median follow-up until CRPC for non-users and 7.5 years for statin users. The risk of discontinuation of first or second line CRPC treatment due to inefficacy was not modified by statin use and the results remained similar in subgroup analysis assessing separately patients treated with taxans or androgen receptor signaling inhibitors. We observed an inverse association between statin use and the risk of initiation of the CRPC treatment. No beneficial risk modification by statin use during CRPC treatment was observed. These results suggest that statins might be beneficial during hormone-sensitive phase but not in the later phases of prostate cancer treatment.

Impact of modifiable lifestyle risk factors for prostate cancer prevention: a review of the literature

Introduction

Although prostate cancer (PCa) is one of the most common cancers among men, the impact of modifiable risk and protective factors is still being debated. This review aims to qualitatively summarize the most recent studies related to potential healthy lifestyle factors affecting the development of PCa.

Methods for data acquisition

The literature focusing on modifiable risk factors for prostate cancer was reviewed. Medline and Embase via the Ovid database were searched, and all relevant and inherent articles were analyzed. Non-eligible publications, such as review articles, editorials, comments, guidelines, or case reports, were excluded.

Synthesis of the evidence obtained from data analysis

This review confirms that there is strong evidence that being overweight or obese increases the risk of advanced prostate cancer (assessed by body mass index (BMI), waist circumference, and waist-hip ratio), particularly considering central adiposity and ethnicity as contributing factors. The possible contribution of smoking still seems not entirely clear, while alcohol seems to affect PCa prevention in patients taking 5α-reductase inhibitors (5-ARIs). Dietary fibers may have anti-inflammatory properties and improve insulin sensitivity by reducing IGF bioactivity. In particular, dietary fiber intake like insoluble and legume fibers may be inversely associated with prostate cancer risk. Also, hyperglycemia and hyperinsulinemia, with untreated diabetic fasting blood glucose levels, could be modifiable prostate cancer risk factors. In two studies, aspirin was associated with a lower risk of lethal PCa and overall mortality. Concerning the role of vitamins, despite conflicting and divergent results, serum retinol concentration seems to be associated with an increased risk of prostate cancer and high-grade prostate cancer. Some studies resulted in disagreement about the role of selenium and vitamin E. We found inconsistent and controversial findings about the association between vitamin D and prostate cancer risk.

Conclusion

Far from being conclusive evidence, our findings confirm some strong evidence already found in the previous literature and highlight the need to clarify the role of some risk factors whose role is not yet completely known. This effort would facilitate the cultural and social change that may allow the shift from the treatment of prostate cancer when diagnosed to the real efforts needed for systematic prevention.

Paper II: thematic framework analysis of registry-based randomized controlled trials provided insights for designing trial ready registries

OBJECTIVES

Registry-based randomized controlled trials (RRCTs) are increasingly used, promising to address challenges associated with traditional randomized controlled trials. We identified strengths and limitations reported in planned and completed RRCTs to inform future RRCTs.

STUDY DESIGN AND SETTING

We conducted an environmental scan of literature discussing conceptual or methodological strengths and limitations of using registries for trial design and conduct (n = 12), followed by an analysis of RRCT protocols (n = 13) and reports (n = 77) identified from a scoping review. Using framework analysis, we developed and refined a conceptual framework of RRCT-specific strengths and limitations. We mapped and interpreted strengths and limitations discussed by authors of RRCT articles using framework codes and quantified the frequencies at which these were mentioned.

RESULTS

Our conceptual framework identified six main RRCT strengths and four main RRCT limitations. Considering implications for RRCT conduct and design, we formulated ten recommendations for registry designers, administrators, and trialists planning future RRCTs.

CONCLUSION

Consideration and application of empirically underpinned recommendations for future registry design and trial conduct may help trialists utilize registries and RRCTs to their full potential.

Knowledge and Attitudes towards Prostate Cancer and Screening among Males in Limpopo Province, South Africa

Inadequate knowledge and poor attitudes about prostate cancer (PC) negatively affect early screening practices among males. The PC mortality rate is increasing due to late reporting, screening, and treatment. This study explored the awareness, attitudes, and PC screening behaviours among males in the Limpopo, Thulamela municipality. This descriptive cross-sectional study involved 245 males that were randomly selected. A structured questionnaire was used to collect data. Fisher's exact tests and logistic regression analysis were used to examine the association between sociodemographic variables, awareness, and attitudes towards PC. Our findings revealed that 64.1% demonstrated inadequate awareness about PC. The overall score (84.9%) showed a positive attitude towards PC. However, 87.4% had a negative attitude towards the effectiveness of treatment for PC. The majority (96.7%) of respondents had never undergone a PSA test, although 53.1% were willing to undergo a PSA test. There was a significant positive correlation between awareness of prostate cancer and attitudes toward prostate cancer (r = 0.280, p < 0.001). Health status predicted awareness about PC, while age and health status predicted attitudes towards PC among men. Rural community-based programmes and heightened awareness campaigns are needed to conscientize men about the risk factors, symptoms, diagnosis, and treatment of PC in rural areas of Limpopo.

Prostate cancer incidence in men with prostate-specific antigen below 3 ng/mL: The Finnish Randomized Study of Screening for Prostate Cancer

Prostate-specific antigen (PSA)-based screening for prostate cancer (PCa) can reduce PCa mortality, but also involves overdetection of low-risk disease with potential adverse effects. We evaluated PCa incidence among men with PSA below 3 ng/mL and no PCa diagnosis at the first screening round of the Finnish Randomized Study of Screening for PCa. Follow-up started at the first screening attendance and ended at PCa diagnosis, emigration, death or the common closing date (December 2016), whichever came first. Cox regression analysis was used to estimate hazard ratios and their confidence intervals (CI). Among men with PSA <3 ng/mL, cumulative PCa incidence was 9.1% after 17.6 years median follow-up. Cumulative incidence was 3.6% among men with baseline PSA 0 to 0.99 ng/mL, 11.5% in those with PSA 1.0 to 1.99 ng/mL and 25.7% among men with PSA 2 to 2.99 ng/mL (hazard ratio 9.0, 95% CI: 7.9-10.2 for the latter). The differences by PSA level were most striking for low-risk disease based on Gleason score and EAU risk group. PSA values <1 ng/mL indicate a very low 20-year risk, while at PSA 2 to 2.99 ng/mL risks are materially higher, with 4- to 5-fold risk for aggressive disease. Using risk-stratification and appropriate rescreening intervals will reduce screening intensity and overdetection. Using cumulative incidence of clinically significant PCa (csPCa) as the criterion, rescreening intervals could range from approximately 3 years for men with initial PSA 2 to 2.99 ng/mL, 6 years for men with PSA 1 to 1.99 ng/mL to 10 years for men with PSA <1 ng/mL.

Antidiabetic drugs, glycemic control and risk of benign prostatic hyperplasia

BACKGROUND

Diabetes has been associated with an increased risk of benign prostatic hyperplasia (BPH). However, the role of antidiabetic drugs as a BPH risk factor is unclear. The objective of our study was to examine the risk of BPH by antidiabetic drug use and glycemic control in a large population-based cohort of Finnish men.

METHODS

A total of 74,754 men in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) free of BPH at baseline in 1996-1999 were linked to the national medication reimbursement database for information on physician-prescribed antidiabetic drug purchases. Information on recorded BPH procedures and diagnoses was obtained from the National Care Register for Health Care, and for a subgroup of 17,739 men, information on blood glucose levels (BGLs) from the Fimlab Laboratories database. Cox regression with antidiabetic drug use and BGL as time-dependent variables was used to analyze the risks for starting BPH medication, recorded BPH diagnosis, and undergoing BPH surgery. The analysis was adjusted for age, use of statins, antihypertensive medication, and nonsteroidal anti-inflammatory drugs.

RESULTS

Of the subjects, 14,012 men (18.7%) used antidiabetic medication. Of the subgroup with fasting blood glucose data available, 7487 (42.2%) had diabetic level. The risks for BPH diagnosis (HR: 1.08, 95% CI: 1.03-1.13) and surgery (HR: 1.16, 95% CI: 1.09-1.24) were slightly elevated among antidiabetic drug users compared to nonusers. The association was strongest for insulin use. Similarly, risk of BPH surgery was increased in men with diabetic blood glucose compared to normoglycemic men. The risk association was attenuated by use of antidiabetic drugs.

CONCLUSIONS

Diabetic BGL and antidiabetic medication use, especially insulin, are associated with an elevated risk of BPH surgery compared to nondiabetic men. These findings support the roles of insulin use and untreated hyperglycemia as possible BPH risk factors.

Results from 22 years of Followup in the Göteborg Randomized Population-Based Prostate Cancer Screening Trial

PURPOSE

Our goal was to analyze results from 22 years of followup in the Göteborg randomized prostate cancer (PC) screening trial.

MATERIALS AND METHODS

In December 1994, 20,000 men born 1930-1944 were randomly extracted from the Swedish population register and were randomized (1:1) into either a screening group (SG) or to a control group (CG). Men in the SG were repeatedly invited for biennial prostate specific antigen testing up to an average age of 69 years. Main endpoints were PC incidence and mortality (intention-to-screen principle).

RESULTS

After 22 years, 1,528 men in the SG and 1,124 men in the CG had been diagnosed with PC. In total, 112 PC deaths occurred in the SG and 158 in the CG. Compared with the CG, the SG showed a PC incidence rate ratio (RR) of 1.42 (95% CI, 1.31-1.53) and a PC mortality RR of 0.71 (95% CI, 0.55-0.91). The 22-year cumulative PC mortality rate was 1.55% (95% CI, 1.29-1.86) in the SG and 2.13% (95% CI, 1.83-2.49) in the CG. Correction for nonattendance (Cuzick method) yielded a RR of PC mortality of 0.59 (95% CI, 0.43-0.80). Number needed to invite and number needed to diagnose was estimated to 221 and 9, respectively. PC death risk was increased in the following groups: nontesting men, men entering the program after age 60 and men with >10 years of followup after screening termination.

CONCLUSIONS

Prostate specific antigen-based screening substantially decreases PC mortality. However, not attending, starting after age 60 and stopping at age 70 seem to be major pitfalls regarding PC death risk.

Inverse Association between Statin Use and Cancer Mortality Relates to Cholesterol Level

Simple Summary

We observed that the inverse association between statin use and cancer mortality is limited to men with a reduction in cholesterol after the commencement of statins. These findings demonstrate that the observed inverse association between the use of statins and mortality from cancer is related to cholesterol level. To our knowledge, this is the first study to evaluate the separate effects of cholesterol level and statin use on cancer mortality.

Abstract

Statins have been associated with a decreased cancer mortality. However, cholesterol level as such may modify the risk of cancer death. To clarify the complex interplay between statins, cholesterol level, and cancer mortality, we conducted a comprehensive analysis to separate the effects of cholesterol level and statin medication on cancer mortality. Our study population consisted of 16,924 men participating in the Finnish Randomized Study of Screening for Prostate Cancer with at least one cholesterol measurement during follow-up (1996–2017). Cox proportional regression was used to estimate hazard ratios. In total, 1699 cancer deaths were observed during the median follow-up of 19 years. When statins’ association with the risk of cancer death was estimated without adjustment for cholesterol level, statin use was associated with a lowered cancer mortality (HR 0.87; 95% CI 0.79–0.97) compared to non-users. However, with further adjustment for total cholesterol level, statin use was no longer associated with a lower cancer mortality (HR 1.08; 95% CI 0.97–1.20). Upon stratified analysis, statin use was associated with a decreased cancer mortality only if the total cholesterol level decreased after the initiation of statin use (HR 0.66; 95% CI 0.58–0.76). The inverse association between statin use and cancer mortality is limited to men with a reduction in total cholesterol level after the commencement of statins, i.e., statin use is associated with a lowered cancer mortality only if the total cholesterol level decreases. This suggests that the effect of statin use on cancer mortality relates to the decreased total cholesterol level.

Anti-epileptic drugs and prostate cancer-specific mortality compared to non-users of anti-epileptic drugs in the Finnish Randomized Study of Screening for Prostate Cancer

BACKGROUND

Drugs with histone deacetylase inhibitory (HDACi) properties have shown to decrease prostate cancer (PCa) cell growth in vitro.

METHODS

A cohort of 9261 PCa cases from the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) was used to evaluate prostate cancer-specific mortality in men using anti-epileptic drugs (AEDs). A national subscription database was used to obtain information on medication use. Cox regression with AED use as a time-dependent variable was used to analyse prostate cancer mortality in men using AEDs compared to non-users, and in men using HDACi AEDs compared to users of other AEDs. The analysis was adjusted for age, screening trial arm, PCa risk group, primary treatment of PCa, Charlson co-morbidity score and concomitant use of other drugs.

RESULTS

The use of AEDs, in general, was associated with an increased risk of PCa death. The use of HDACi AEDs was not significantly associated with decreased PCa mortality compared to use of other AEDs (HR 0.61, 95% CI 0.31-1.23).

CONCLUSIONS

AED usage is associated with elevated PCa mortality compared to non-users, likely reflecting the differences between men with epilepsy and those without. No benefit was observed from HDACi drugs compared to other AEDs.

Outcomes of Screening for Prostate Cancer Among Men Who Use Statins

Importance

Prostate-specific antigen (PSA) screening for prostate cancer has resulted in a slight reduction in prostate cancer mortality but also a concomitant overdiagnosis of low-risk tumors. Prostate-specific antigen levels are affected by use of cholesterol-lowering statin drugs, but the association of statin use with PSA screening performance is unknown.

Objective

To investigate whether statin use was associated with outcomes of a randomized PSA-based prostate cancer screening intervention.

Design, Setting, and Participants

This post hoc subgroup analysis of a cohort from a population-based randomized clinical trial used data from the population-based Finnish Randomized Study of Prostate Cancer Screening, which randomized men to PSA screening or routine care from March 1, 1996, to December 31, 1999, with follow-up continuing until December 31, 2015. The population included all men aged 55 to 67 years at baseline and residing in the Tampere or Helsinki districts of Finland. Information on statin purchases from 1996 to 2009 was obtained from a national prescription registry. Eligible men were identified from the population registry of Finland. Prevalent prostate cancer cases at baseline were excluded. Data were analyzed from January 1, 2019 to March 31, 2021.

Interventions

Three invitations for PSA screening at 4-year intervals from 1996 to 2007 vs routine care.

Main Outcomes and Measures

Risk for prostate cancer overall, high-risk disease, and prostate cancer mortality in the screening group vs the control group as an intention-to-treat analysis. The analysis was stratified by statin use.

Results

The study comprised 78 606 men (median age, 59 years [range, 55-67 years]) with statin purchase data available. Although PSA screening was associated with increased prostate cancer incidence among statin nonusers (screening vs control, 11.2 vs 8.6 per 1000 person-years); rate ratio [RR], 1.31; 95% CI, 1.24-1.38), no similar increase in incidence was observed among statin users (6.9 vs 5.9 per 1000 person-years; RR, 1.02; 95% CI, 0.95-1.10; P < .001 for interaction). Incidence of low-risk (Gleason score 6) and localized tumors was lower among statin users, whereas detection of tumors with a Gleason score of 8 to 10 was similar. Screening was associated with a lower incidence of metastatic tumors regardless of statin use.

Conclusion and Relevance

In this post hoc subgroup analysis of a cohort from a population-based randomized clinical trial, PSA screening among statin users was associated with a decreased incidence of advanced prostate cancer that was similar among statin nonusers, but with less increase in detection of low-grade localized tumors in statin users than in nonusers. These findings suggest that statin use does not materially compromise benefits of PSA-based screening.

Outcomes of prostate cancer screening among men using antidiabetic medication

Diabetic men have decreased risk for prostate cancer (PCa) overall and lower PSA compared to non-diabetics. This may affect the outcomes of PSA-based screening. We investigated the effect of PSA-based screening at 4-year intervals on PCa incidence and mortality separately among users and non-users of antidiabetic medication with the hypothesis that screening would detect less low-grade cancer and more high-grade cancer in diabetic men. A cohort of 80,458 men from the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) were linked to national prescription database to obtain information on antidiabetic medication purchases. PCa risk and mortality were compared between the FinRSPC screening arm (SA) and the control arm (CA) separately among users and non-users of antidiabetic medication. Among antidiabetic medication users median PSA was lower than in non-users (0.93 and 1.09 ng/ml, respectively, P for difference = 0.001). Screening increased overall PCa incidence compared to CA after the first screen both among medication users and non-users (HR 1.31, 95% CI 1.08–1.60 and HR 1.55, 95% CI 1.44–1.66, respectively). On the second and third screen the difference between SA and CA attenuated only among medication users. Detection of Gleason 6 tumors was lower among medication users, whereas no difference was observed in detection of Gleason 8–10 cancers. Concordantly, screening affected PCa mortality similarly regardless of antidiabetic medication use (HR 0.38, 95% CI 0.14–1.07 and HR 0.19, 95% CI 0.11–0.33 among users and non-users after three screens, respectively. P for difference = 0.18). Median PSA is lower in men using antidiabetic drugs than among non-users. Systematic PSA screening detects less low-risk tumors among medication users, whereas detection of high-risk tumors and mortality effects are similar regardless of medication use. This suggests that antidiabetic medication users may form a suitable target group for PCa screening, with less screening-related overdiagnosis of indolent tumors.

Antidiabetic Drugs and Prostate Cancer Prognosis in a Finnish Population-Based Cohort

BACKGROUND

Hyperinsulemia and glycemic control may play a role as prostate cancer prognostic factors, whereas use of certain antidiabetic drugs, that is metformin, could improve the prognosis. We examined the link between antidiabetic medication use and prostate cancer survival taking into account simultaneous use of multiple drugs.

METHODS

The study cohort composed of 6,537 men in The Finnish Randomized Study of Screening for Prostate Cancer with prostate cancer diagnosed 1996 to 2009. Use of medication was attained from the nationwide prescription database of the Social Insurance Institution of Finland. Median follow-up was 9.2 years postdiagnosis. A total of 1,603 (24,5%) men had used antidiabetic medication. A total of 771 men died of prostate cancer during the follow-up. We used multivariable-adjusted Cox regression to evaluate the risk of prostate cancer death and onset of androgen deprivation therapy (ADT) with adjustment for prostate cancer clinical characteristics, comorbidities and use of other drugs. Separate analyses were further adjusted for blood glucose.

RESULTS

Risk of prostate cancer death was higher among antidiabetic drug users overall (HR = 1.42; 95% CI, 1.18-1.70) compared with nonusers, separately among insulin and metformin users. Adjustment for blood glucose level abolished the risk increase. Risk of ADT initiation was increased among the medication users (HR = 1.26; 95% CI, 1.05-1.49).

CONCLUSIONS

Men with prostate cancer using antidiabetic medication are generally at increased risk of dying from prostate cancer compared with nonusers. The risk association is driven by underlying diabetes, as adjustment for blood glucose level ameliorates the risk increase.

IMPACT

Type 2 diabetes should be considered as a risk factor when considering prostate cancer prognosis.

Prostate cancer prognosis after initiation of androgen deprivation therapy among statin users. A population-based cohort study

PURPOSE

Statins' cholesterol-lowering efficacy is well-known. Recent epidemiological studies have found that inhibition of cholesterol synthesis may have beneficial effects on prostate cancer (PCa) patients, especially patients treated with androgen deprivation therapy (ADT). We evaluated statins' effect on prostate cancer prognosis among patients treated with ADT.

MATERIALS AND METHODS

Our study population consisted of 8253 PCa patients detected among the study population of the Finnish randomized study of screening for prostate cancer. These were limited to 4428 men who initiated ADT during the follow-up. Cox proportional regression model adjusted for tumor clinical characteristics and comorbidities was used to estimate hazard ratios for risk of PSA relapse after ADT initiation and prostate cancer death.

RESULTS

During the median follow-up of 6.3 years after the ADT initiation, there were 834 PCa deaths and 1565 PSA relapses in a study cohort. Statin use after ADT was associated with a decreased risk of PSA relapse (HR 0.73, 95% CI 0.65-0.82) and prostate cancer death (HR 0.82; 95% CI 0.69-0.96). In contrast, statin use defined with a one-year lag (HR 0.89, 95% CI 0.76-1.04), statin use before ADT initiation (HR 1.12, 95% CI 0.96-1.31), and use in the first year on ADT (HR 1.02, 95% CI 0.85-1.24) were not associated with prostate cancer death, without dose dependency.

CONCLUSION

Statin use after initiation of ADT, but not before, was associated with improved prostate cancer prognosis.

Sojourn-time-corrected receiver operating characteristic curve (ROC) for prostate specific antigen (PSA) test in population-based prostate cancer screening

Evaluating the performance of serum prostate-specific antigen (PSA) test in population-based screening with receiver operating characteristics (ROC) curve often neglects the time dimension. Asymptomatic cases with negative PSA test would have been missed if sojourn time is not taken into account to allow for cases surfacing into the clinical phase. Data included 20,796 men with PSA test at the first screening round was used from population-based Finnish prostate cancer screening trial during 1996–1999. Cancers detected at the first screen, together with interval cancers ascertained during 4-year follow-up were expediently used to estimate sensitivity and specificity. A sojourn-time-corrected model was applied to estimating the possible false negative cases for those with PSA < 4 ng/ml for correcting the ROC curve. The estimated sensitivity estimate was reduced from 94.4% without correction to 68.8% with correction but the estimated specificity was identical (89.4% vs. 89.2%) at cutoff of 3 ng/ml. The corrected area under curve (AUC) [77.0% (74.9–79.1%)] of the PSA test was significantly lower than the uncorrected AUC [95.9% (95.3–96.6%)]. The failure of considering the time since last negative screen due to incomplete ascertainment for asymptomatic cancer led to the overestimation of PSA test performance that further affects the cut-off value of PSA tests for population-based prostate cancer screening.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Antihypertensive drug use and prostate cancer-specific mortality in Finnish men

The aim of this study was to investigate pre- and post-diagnostic use of antihypertensive drugs on prostate cancer (PCa)-specific survival and the initiation of androgen deprivation therapy (ADT). The cohort investigated 8,253 PCa patients with 837 PCa-specific deaths during the median follow-up of 7.6 years after diagnosis. Information on drug use, cancer incidence, clinical features of PCa, and causes of death was collected from Finnish registries. Hazard ratios with 95% confidence intervals were calculated using Cox regression with antihypertensive drug use as a time-dependent variable. Separate analyses were performed on PCa survival related to pre- and post-diagnostic use of drugs and on the initiation of ADT. Antihypertensive drug use overall was associated with an increased risk of PCa-specific death (Pre-PCa: 1.21 (1.04–1.4), Post-PCa: 1.2 (1.02–1.41)). With respect to the separate drug groups, angiotensin II type 1 receptor (ATr) blockers, were associated with improved survival (Post-PCa: 0.81 (0.67–0.99)) and diuretics with an increased risk (Post-PCa: 1.25 (1.05–1.49)). The risk of ADT initiation was slightly higher among antihypertensive drug users as compared to non-users. In conclusion, this study supports anti-cancer effect of ATr blockers on PCa prognosis and this should be investigated further in controlled clinical trials.

Patients' education level and treatment modality for prostate cancer in the Finnish Randomized Study of Screening for Prostate Cancer

BACKGROUND

In prostate cancer (PCa), lower education level is associated with less screening, more advanced stage at diagnosis and worse survival. The aim of this study was to estimate the association between education level and treatment modality and subsequently survival.

METHODS

The 9255 men diagnosed with PCa in the Finnish Randomized Study of Screening for Prostate Cancer were included. Cancer stage, comorbidity, education level and primary treatment modality were extracted from the patient records, the Finnish Cancer Registry, Statistics Finland and the National Institute of Health and Welfare, and these covariates were used in logistic regression (treatment selection) and Cox regression (survival analysis).

RESULTS

In high-risk cancers, men with tertiary education were more likely to be treated with radical prostatectomy (odds ratio [OR] = 1.76; 95% confidence interval [CI] = 1.27-2.44) than men with primary education. Men with secondary (OR = 0.57; 95% CI = 0.38-0.84) or tertiary (OR = 0.42; 95% CI = 0.29-0.60) education were managed less frequently with mere hormonal therapy. In locally advanced cases, tertiary education was associated with more curatively aimed therapies and less hormonal therapy (OR for radical prostatectomy = 2.34; 95% CI = 1.49-3.66; OR for radiotherapy = 1.42; 95% CI = 1.09-1.85; OR for hormonal therapy = 0.45; 95% CI = 0.33-0.60). The hazard ratio for PCa death was lower in men with secondary (0.81; 95% CI = 0.69-0.95) and tertiary (0.75; 95% CI = 0.65-0.87) education than in the patients with primary education.

CONCLUSIONS

When controlled for the cancer risk group, comorbidity and patient's age, low education level is independently associated with less curatively aimed treatment in men with high-risk or locally advanced PCa and subsequently worse prognosis.

Contamination in control group led to no effect of PSA-based screening on prostate cancer mortality at 9 years follow-up: Results of the French section of European Randomized Study of Screening for Prostate Cancer (ERSPC)

INTRODUCTION

European Randomized Study of Screening for Prostate Cancer (ERSPC) mortality results were reported for 7 European countries (excluding France) and showed a significant reduction in Prostate cancer (PCa) mortality. As those results have not been part of the global ERSPC results, it is of interest to report PCa mortality at a median follow-up of 9 years for French section of ERSPC.

MATERIAL AND METHODS

Two administrative departments were involved in the study. Only men after randomization in the screening group were invited by mail to be screened by PSA testing with two rounds at 4-6 year intervals. Biopsy was recommended if PSA>=3.0 ng/mL. No information other that the French Association of Urology recommandations on the use of PSA was offered to the control group (own decision of physicians and patients). Follow up was based on cancer registry database. Contamination defined as the receipt of PSA testing in control arm was measured. Poisson regression models were used to estimate the Rate Ratio (RR) of PCa mortality and incidence in the screening vs. control arm.

RESULTS

Starting from 2003, 80,696 men aged 55-69 years were included. The percentage of men in the screening arm with at least one PSA test (compliance) was 31%. Compared to the control arm, PCa incidence increased by 10% in the screening arm (RR=1.10; 95% CI=[1.04-1.16], P=0.001), but PCa mortality did not differ (0.222 and 0.215 deaths/1000 person-years; RR=1.03[0.75-1.42], P=0.9).

DISCUSSION

Limitations include low participation rate. PSA testing in the control arm was observed in 32% of men (contamination).

CONCLUSIONS

Contamination in control group led to no effect of PSA-based screening on prostate cancer mortality at 9 years follow-up.

LEVEL OF EVIDENCE

3.

Cost-effectiveness analysis of PSA-based mass screening: Evidence from a randomised controlled trial combined with register data

In contrast to earlier studies which have used modelling to perform cost-effectiveness analysis, this study links data from a randomised controlled trial with register data from nationwide registries to reveal new evidence on costs, effectiveness, and cost-effectiveness of organised mass prostate-cancer screening based on prostate-specific antigen (PSA) testing. Cost-effectiveness analyses were conducted with individual-level data on health-care costs from comprehensive registers and register data on real-world effectiveness from the two arms of the Finnish Randomised Study of Screening for Prostate Cancer (FinRSPC), following 80,149 men from 1996 through 2015. The study examines cost-effectiveness in terms of overall mortality and, in addition, in terms of diagnosed men’s mortality from prostate cancer and mortality with but not from prostate cancer. Neither arm of the FinRSPC was clearly more cost-effective in analysis in terms of overall mortality. Organised screening in the FinRSPC could be considered cost-effective in terms of deaths from prostate cancer: averting just over one death per 1000 men screened. However, even with an estimated incremental cost-effectiveness ratio of below 20,000€ per death avoided, this result should not be considered in isolation. This is because mass screening in this trial also resulted in increases in death with, but not from, prostate cancer: with over five additional deaths per 1000 men screened. Analysis of real-world data from the FinRSPC reveals new evidence of the comparative effectiveness of PSA-based screening after 20 years of follow-up, suggesting the possibility of higher mortality, as well as higher healthcare costs, for screening-arm men who have been diagnosed with prostate cancer but who do not die from it. These findings should be corroborated or contradicted by similar analyses using data from other trials, in order to reveal if more diagnosed men have also died in the screening arms of other trials of mass screening for prostate cancer.

Anticoagulants and cancer mortality in the Finnish randomized study of screening for prostate cancer

PURPOSE

Anticoagulants may reduce mortality of cancer patients, though the evidence remains controversial. We studied the association between different anticoagulants and cancer death.

METHODS

All anticoagulant use during 1995-2015 was analyzed among 75,336 men in the Finnish Randomized Study of Screening for Prostate Cancer. Men with prevalent cancer were excluded. Multivariable Cox regression was performed to compare risk of death from any cancer and disease-specific death from 9 specific cancer types between (1) anticoagulant users overall and (2) warfarin users compared to anticoagulant non-users and (3) warfarin or (4) low-molecular-weight heparins (LMWH) compared to users of other anticoagulants. Medication use was analyzed as time-dependent variable to minimize immortal time bias. 1-, 2- and 3-year lag-time analyses were performed.

RESULTS

During a median follow-up of 17.2 years, a total of 27,233 men died of whom 8033 with cancer as the primary cause of death. In total, 32,628 men (43%) used anticoagulants. Any anticoagulant use was associated with an increased risk of cancer death (HR = 2.50, 95% CI 2.37-2.64) compared to non-users. Risk was similar independent of the amount, duration, or intensity of use. The risk increase was observed both among warfarin and LMWH users, although not as strong in warfarin users. Additionally, cancer-specific risks of death were similar to overall cancer mortality in all anticoagulant categories.

CONCLUSION

Our study does not support reduced cancer mortality among anticoagulant users. Future studies on drug use and cancer mortality should be adjusted for anticoagulants as they are associated with significantly higher risk of cancer death.

Could Differences in Treatment Between Trial Arms Explain the Reduction in Prostate Cancer Mortality in the European Randomized Study of Screening for Prostate Cancer?

BACKGROUND

Differential treatment between trial arms has been suggested to bias prostate cancer (PC) mortality in the European Randomized Study of Screening for Prostate Cancer (ERSPC).

OBJECTIVE

To quantify the contribution of treatment differences to the observed PC mortality reduction between the screening arm (SA) and the control arm (CA).

DESIGN, SETTING, AND PARTICIPANTS

A total of 14 136 men with PC (SA: 7310; CA: 6826) in the core age group (55-69yr) at 16yr of follow-up.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The outcomes measurements were observed and estimated numbers of PC deaths by treatment allocation in the SA and CA, respectively. Primary treatment allocation was modeled using multinomial logistic regression adjusting for center, age, year, prostate-specific antigen, grade group, and tumor-node-metastasis stage. For each treatment, logistic regression models were fitted for risk of PC death, separately for the SA and CA, and using the same covariates as for the treatment allocation model. Treatment probabilities were multiplied by estimated PC death risks for each treatment based on one arm, and then summed and compared with the observed number of deaths.

RESULTS AND LIMITATIONS

The difference between the observed and estimated treatment distributions (hormonal therapy, radical prostatectomy, radiotherapy, and active surveillance/watchful waiting) in the two arms ranged from -3.3% to 3.3%. These figures, which represent the part of the treatment differences between arms that cannot be explained by clinicopathological differences, are small compared with the observed differences between arms that ranged between 7.2% and 10.1%. The difference between the observed and estimated numbers of PC deaths among men with PC was 0.05% (95% confidence interval [CI] -0.1%, 0.2%) when applying the CA model to the SA, had the two groups received identical primary treatment, given their clinical characteristics. When instead applying the SA model to the CA, the difference was, as expected, very similar-0.01% (95% CI -0.3%, 0.2%). Consistency of the results of the models demonstrates the robustness of the modeling approach. As the observed difference between trial arms was 4.2%, our findings suggest that differential treatment explains only a trivial proportion of the main findings of ERSPC. A limitation of the study is that only data on primary treatment were available.

CONCLUSIONS

Use of prostate-specific antigen remains the predominant explanation for the reduction in PC mortality seen in the ERSPC trial and is not attributable to differential treatment between trial arms.

PATIENT SUMMARY

This study shows that prostate cancer deaths in the European screening trial (European Randomized Study of Screening for Prostate Cancer) were prevented because men were diagnosed and treated earlier through prostate-specific antigen screening, and not because of different, or better, treatment in the screening arm compared with the control arm.

Blood glucose, glucose balance, and disease-specific survival after prostate cancer diagnosis in the Finnish Randomized Study of Screening for Prostate Cancer

INTRODUCTION

Diabetes mellitus has been linked with adverse prostate cancer (PCa) outcomes. However, role of hyperglycemia in PCa progression is unclear. We evaluated the link between hyperglycemia and PCa survival among Finnish PCa patients.

METHODS

The study cohort included 1770 men with data on fasting glucose and diagnosed with PCa within the Finnish Randomized Study of Screening for PCa in 1995-2009. Additionally, 1398 men had data on glycated hemoglobin (HbA1c). Information on fasting glucose and HbA1c measurements was obtained from the regional laboratory database. Antidiabetic medication use was obtained from the prescription database of the Social Insurance Institution (SII). Time-dependent Cox regression analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals for PCa death among diabetic, impaired glucose tolerant, and normoglycemic men.

RESULTS

During median follow-up of 9.9 years after the diagnosis, 182 men died from PCa. After adjustment for tumor stage, Gleason grade, and PSA level at diagnosis, diabetic fasting glucose level after PCa diagnosis was associated with elevated risk of PCa death compared to normoglycemic men (HR 1.67 95% CI 1.18-2.36). The risk association was strongest among participants with localized cancer at diagnosis; HR 2.39, 95% CI 1.45-3.93. The risk elevation was observed for glucose measurements taken up to 5 years earlier. Diabetic glucose levels measured before the diagnosis were not associated with PCa death.

CONCLUSION

Our study cohort suggests an increased risk of PCa death in men with diabetic fasting blood glucose levels, supporting the role of hyperglycemia as a risk factor for PCa progression.

Cancer mortality does not differ by antiarrhythmic drug use: A population-based cohort of Finnish men

In-vitro studies have suggested that the antiarrhythmic drug digoxin might restrain the growth of cancer cells by inhibiting Na+/K+-ATPase. We evaluated the association between cancer mortality and digoxin, sotalol and general antiarrhythmic drug use in a retrospective cohort study. The study population consists of 78,615 men originally identified for the Finnish Randomized Study of Screening for Prostate Cancer. Information on antiarrhythmic drug purchases was collected from the national prescription database. We used the Cox regression method to analyze separately overall cancer mortality and mortality from the most common types of cancer. During the median follow-up of 17.0 years after the baseline 28,936 (36.8%) men died, of these 8,889 due to cancer. 9,023 men (11.5%) had used antiarrhythmic drugs. Overall cancer mortality was elevated among antiarrhythmic drug users compared to non-users (HR 1.43, 95% CI 1.34–1.53). Similar results were observed separately for digoxin and for sotalol. However, the risk associations disappeared in long-term use and were modified by background co-morbidities. All in all, cancer mortality was elevated among antiarrhythmic drug users. This association is probably non-causal as it was related to short-term use and disappeared in long-term use. Our results do not support the anticancer effects of digoxin or any other antiarrhythmic drug.

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).

Fasting blood glucose, glycaemic control and prostate cancer risk in the Finnish Randomized Study of Screening for Prostate Cancer

Background

Diabetic men have lowered overall risk of prostate cancer (PCa), but the role of hyperglycaemia is unclear. In this cohort study, we estimated PCa risk among men with diabetic fasting blood glucose level.

Methods

Participants of the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) were linked to laboratory database for information on glucose measurements since 1978. The data were available for 17,860 men. Based on the average yearly level, the men were categorised as normoglycaemic, prediabetic, or diabetic. Median follow-up was 14.7 years. Multivariable-adjusted Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for prostate cancer overall and separately by Gleason grade and metastatic stage.

Results

In total 1,663 PCa cases were diagnosed. Compared to normoglycaemic men, those men with diabetic blood glucose level had increased risk of PCa (HR 1.52; 95% CI 1.31–1.75). The risk increase was observed for all tumour grades, and persisted for a decade afterwards. Antidiabetic drug use removed the risk association. Limitations include absence of information on lifestyle factors and limited information on BMI.

Conclusions

Untreated diabetic fasting blood glucose level may be a prostate cancer risk factor.

A mini-review of quality of life as an outcome in prostate cancer trials: patient-centered approaches are needed to propose appropriate treatments on behalf of patients

Background

Patients with prostate cancer (PC) may be ready to make trade-offs between their quantity and their quality of life. For instance, elderly patients may prefer the absence of treatment if it is associated with a low-risk of disease progression, compared to treatments aiming at preventing disease progression but with a substantial deterioration of their Health-Related Quality of Life (HRQoL). Therefore, it seems relevant to compare the treatments by considering both survival and HRQoL. In this mini-review, the aim was to question whether the potential trade-offs between survival and HRQoL are considered in high impact factor journals.

Methods

The study was conducted from the PubMed database for recent papers published between May 01, 2013, and May 01, 2015. We also restricted our search to nine medical journals with 2013 impact factor > 15.

Results

Among the 30 selected studies, only six collected individual HRQoL as a secondary endpoint by using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire. In four studies, the time to HRQoL change was analyzed, but its definitions varied. In two studies, the mean changes in HRQoL between the baseline and the 12- or 16-week follow-up were analyzed. None of the six studies reported in a single endpoint both the quantity and the quality of life.

Conclusions

Our mini-review, which only focused on recent publications in journals with high-impact, suggests moving PC clinical research towards patient-centered outcomes-based studies. This may help physicians to propose the most appropriate treatment on behalf of patients. We recommend the use of indicators such as Quality-Adjusted Life-Years (QALYs) as principal endpoint in future clinical trials.

Electronic supplementary material

The online version of this article (10.1186/s12955-018-0870-6) contains supplementary material, which is available to authorized users.

Allopurinol and risk of benign prostatic hyperplasia in a Finnish population-based cohort

BACKGROUND

Metabolic syndrome and obesity are linked with hyperuricemia, and it has also been proposed that oxidative stress associated with hyperuricemia may promote benign prostatic hyperplasia (BPH). However, it is currently unknown whether use of antihyperuricemic medication is associated with risk of developing BPH. We studied the association between BPH and use of antihyperuricemic allopurinol in a Finnish population-based cohort.

METHODS

The study cohort consisted of 74,754 men originally identified for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). Information on gout and BPH medication usage (5α-reductase inhibitors, 5ARIs) during 1996-2014 was obtained from the National medication reimbursement database. Information on BPH diagnoses from in- and outpatient hospital visits and BPH-related surgery was obtained from the National Health Care Registry. Men with a record of BPH at baseline was excluded. We used Cox regression to analyze risk of starting BPH medication, having a recorded diagnosis or undergoing BPH surgery by allopurinol use with adjustment for age and simultaneous use of statins, antidiabetic or antihypertensive drugs and aspirin or other NSAIDs. Medication use was analyzed as a time-dependent variable to minimize immortal time bias.

RESULTS

Men using allopurinol had a decreased risk for all three BPH endpoints: BPH medication (HR 0.81; 95% CI 0.75-0.88), BPH diagnosis (HR 0.78; 95% CI 0.71-0.86) and BPH-related surgery (HR 0.67; 95% CI 0.58-0.76) after multivariable adjustment. The risk association did not change by cumulative use. The risk decrease disappeared after 1-2 years lag time. Only BMI modified the risk association; the risk decrease was observed only among men with BMI above the median (27.3 kg/m²); p for interaction <0.05 for each endpoint.

CONCLUSIONS

We found that allopurinol use is associated with lowered risk of BPH medication, diagnosis and surgery. A possible explanation could be antioxidative effects of urate-lowering allopurinol.

Eighteen-year follow-up of the Göteborg Randomized Population-based Prostate Cancer Screening Trial: effect of sociodemographic variables on participation, prostate cancer incidence and mortality

OBJECTIVE

This study examined whether previously reported results, indicating that prostate-specific antigen (PSA) screening can reduce prostate cancer (PC) mortality regardless of sociodemographic inequality, could be corroborated in an 18 year follow-up.

MATERIALS AND METHODS

In 1994, 20,000 men aged 50-64 years were randomized from the Göteborg population register to PSA screening or control (1:1) (study ID: ISRCTN54449243). Men in the screening group (n = 9950) were invited for biennial PSA testing up to the median age of 69 years. Prostate biopsy was recommended for men with PSA ≥2.5 ng/ml. Last follow-up was on 31 December 2012.

RESULTS

In the screening group, 77% (7647/9950) attended at least once. After 18 years, 1396 men in the screening group and 962 controls had been diagnosed with PC [hazard ratio 1.51, 95% confidence interval (CI) 1.39-1.64]. Cumulative PC mortality was 0.98% (95% CI 0.78-1.22%) in the screening group versus 1.50% (95% CI 1.26-1.79%) in controls, an absolute reduction of 0.52% (95% CI 0.17-0.87%). The rate ratio (RR) for PC death was 0.65 (95% CI 0.49-0.87). To prevent one death from PC, the number needed to invite was 231 and the number needed to diagnose was 10. Systematic PSA screening demonstrated greater benefit in PC mortality for men who started screening at age 55-59 years (RR 0.47, 95% CI 0.29-0.78) and men with low education (RR 0.49, 95% CI 0.31-0.78).

CONCLUSIONS

These data corroborate previous findings that systematic PSA screening reduces PC mortality and suggest that systematic screening may reduce sociodemographic inequality in PC mortality.

A Four-kallikrein Panel and β-Microseminoprotein in Predicting High-grade Prostate Cancer on Biopsy: An Independent Replication from the Finnish Section of the European Randomized Study of Screening for Prostate Cancer

BACKGROUND

A panel of four kallikrein markers (total, free, and intact prostate-specific antigen [PSA] and human kallikrein-related peptidase 2 [hK2]) improves predictive accuracy for Gleason score ≥7 (high-grade) prostate cancer among men biopsied for elevated PSA. A four-kallikrein panel model was originally developed and validated by the Dutch center of the European Randomized Study of Screening for Prostate Cancer (ERSPC). The kallikrein panel is now commercially available as 4Kscore™.

OBJECTIVE

To assess whether these findings could be replicated among participants in the Finnish section of ERSPC (FinRSPC) and whether β-microseminoprotein (MSP), a candidate prostate cancer biomarker, adds predictive value.

DESIGN, SETTING, AND PARTICIPANTS

Among 4861 biopsied screening-positive participants in the first three screening rounds of FinRSPC, a case-control subset was selected that included 1632 biopsy-positive cases matched by age at biopsy to biopsy-negative controls.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The predictive accuracy of prespecified prediction models was compared with biopsy outcomes.

RESULTS AND LIMITATIONS

Among men with PSA of 4.0-25ng/ml, 1111 had prostate cancer, 318 of whom had high-grade disease. Total PSA and age predicted high-grade cancer with an area under the curve of 0.648 (95% confidence interval [CI] 0.614-0.681) and the four-kallikrein panel increased discrimination to 0.746 (95% CI 0.717-0.774). Adding MSP to the four-kallikrein panel led to a significant (Wald test; p=0.015) but small increase (0.003) in discrimination. Limitations include a risk of verification bias among men with PSA of 3.0-3.99ng/ml and the absence of digital rectal examination results.

CONCLUSIONS

These findings provide additional evidence that kallikrein markers can be used to inform biopsy decision-making. Further studies are needed to define the role of MSP.

PATIENT SUMMARY

Four kallikrein markers and β-microseminoprotein in blood improve discrimination of high-grade prostate cancer at biopsy in men with elevated prostate-specific antigen.

Prostate cancer-specific survival among warfarin users in the Finnish Randomized Study of Screening for Prostate Cancer

Background

Venous thromboembolic events (VTE) are common in cancer patients and associated with higher mortality. In vivo thrombosis and anticoagulation might be involved in tumor growth and progression. We studied the association of warfarin and other anticoagulant use as antithrombotic medication and prostate cancer (PCa) death in men with the disease.

Methods

The study included 6,537 men diagnosed with PCa during 1995-2009. Information on anticoagulant use was obtained from a national reimbursement registry. Cox regression with adjustment for age, PCa risk group, primary therapy and use of other medication was performed to compare risk of PCa death between warfarin users with 1) men using other types of anticoagulants and 2) non-users of anticoagulants. Medication use was analyzed as a time-dependent variable to minimize immortal time bias.

Results

In total, 728 men died from PCa during a median follow-up of 9 years. Compared to anticoagulant non-users, post-diagnostic use of warfarin was associated with an increased risk of PCa death (overall HR 1.47, 95% CI 1.13-1.93). However, this was limited to low-dose, low-intensity use. Otherwise, the risk was similar to anticoagulant non-users. Additionally, we found no risk difference between warfarin and other types of anticoagulants. Pre-diagnostic use of warfarin was not associated with the risk of PCa death.

Conclusions

We found no reduction in risk of PCa death associated with warfarin use. Conversely, the risk was increased in short-term use, which is probably explained by a higher risk of thrombotic events prompting warfarin use in patients with terminal PCa.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3579-8) contains supplementary material, which is available to authorized users.

Impact of Prostatic-specific Antigen Threshold and Screening Interval in Prostate Cancer Screening Outcomes: Comparing the Swedish and Finnish European Randomised Study of Screening for Prostate Cancer Centres

BACKGROUND

The European Randomised Study of Screening for Prostate Cancer trial has shown a 21% reduction in prostate cancer (PC) mortality with prostate-specific antigen (PSA)-based screening. Sweden used a 2-yr screening interval and showed a larger mortality reduction than Finland with a 4-yr interval and higher PSA cut-off.

OBJECTIVE

To evaluate the impact of screening interval and PSA cut-off on PC detection and mortality.

DESIGN, SETTING, AND PARTICIPANTS

We analysed the core age groups (55-69 yr at entry) of the Finnish (N=31 866) and Swedish (N=5901) screening arms at 13 yr and 16 yr of follow-up. Sweden used a screening interval of 2 yr and a PSA cut-off of 3.0ng/ml, while in Finland the screening interval was 4 yr and the PSA cut-off 4.0ng/ml (or PSA 3.0-3.9ng/ml with free PSA<16%).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We compared PC detection rate and PC mortality between the Finnish and Swedish centres and estimated the impact of different screening protocols.

RESULTS AND LIMITATIONS

If the Swedish screening protocol had been followed in Finland, 122 additional PC cases would have been diagnosed at screening, 84% of which would have been low-risk cancers, and four leading to PC death. In contrast, if a lower PSA threshold had been applied in Finland, at least 127 additional PC would have been found, with 19 PC deaths.

CONCLUSIONS

The small number of deaths among cases that would have been potentially detectable in Finland with the Swedish protocol (or those that would have been missed in Sweden with the Finnish approach) is unlikely to explain the differences in mortality in this long of a follow-up.

PATIENT SUMMARY

A prostate-specific antigen threshold of 3ng/ml versus 4ng/ml or a screening interval of 2 yr instead of 4 yr is unlikely to explain the larger mortality reduction achieved in Sweden compared with Finland.

Outcomes of Prostate-specific Antigen-based Prostate Cancer Screening Among Men Using Nonsteroidal Anti-inflammatory Drugs

BACKGROUND

The Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC), the largest component of the European Randomized Study of Screening for Prostate Cancer (ERSPC), showed a smaller, nonsignificant reduction in prostate cancer-specific mortality by systematic prostate-specific antigen (PSA)-based screening compared with the overall ERSPC results. Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce inflammation and also PSA elevations due to intraprostatic inflammation.

OBJECTIVE

To explore whether NSAID usage modifies the effects of PSA-based screening on prostate cancer incidence and mortality.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 78 165 men from the FinRSPC were linked to a comprehensive national prescription database to obtain information on NSAID reimbursements prior to screening.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Prostate cancer risk and mortality were compared between the FinRSPC screening arm and the control arm among NSAID users and nonusers using an age-adjusted Cox regression model.

RESULTS AND LIMITATIONS

Screening increased the detection of Gleason 6 (hazard ratio [HR] 1.59, 95% confidence interval [CI] 1.47-1.72 and HR 1.39, 95% CI 1.26-1.54) and localized prostate tumors (HR 1.25, 95% CI 1.18-1.32 and HR 1.11, 95% CI 1.03-1.20) more among baseline NSAID nonusers than among users, respectively (p for interaction <0.04 for both). This difference was observed in all three screening rounds. Detection of metastatic prostate cancer was similar in both NSAID users and nonusers. Screening decreased prostate cancer mortality among men using NSAIDs at FinRSPC randomization (HR 0.66, 95% CI 0.49-0.90) but not among nonusers (HR 0.95, 95% CI 0.81-1.12); p for interaction=0.04.

CONCLUSIONS

Screening detected fewer well-differentiated localized tumors among NSAID users than among nonusers. This suggests that PSA screening may cause less overdiagnosis within this subgroup, whereas mortality benefit may be greater among NSAID users.

PATIENT SUMMARY

Prostate cancer screening causes less overdiagnosis of well-differentiated localized prostate tumors among men who use nonsteroidal anti-inflammatory drugs.

Stage-specific mortality and survival trends of prostate cancer patients in Finland before and after introduction of PSA

BACKGROUND

The early diagnosis and right treatment strategy of localized prostate cancer (PCa) remains problematic. In order to characterize the survival of PCa patients, we compared patients' all-cause and cancer-specific mortalities between pre- and post-PSA periods by stage in Finland.

MATERIAL AND METHODS

All PCa cases diagnosed in Finland between 1985 and 2013 (N = 91,329) were identified from the Finnish Cancer Registry (FCR). PCa stage at diagnosis was defined as localized, local node positive or metastasized. Standardized mortality ratios (SMRs), and relative and cause-specific survival were assessed by stage and introduction of PSA testing. The main limitation was the high proportion of men with unknown stage (28%).

RESULTS

A clear decreasing trend in the SMR of PCa patients was evident when pre- and post-PSA eras were compared: for localized PCa, the SMR was 1.43 (95%CI 1.38-1.48) in 1985-1989 and 0.98 (95%CI 0.95-1.01) in 2000-2004, and for metastasized PCa, the SMRs were 4.51 (95%CI 4.30-4.72) and 3.01 (95%CI 2.89-3.12), respectively. Difference between cause-specific and relative survival was pronounced in localized PCa in post-PSA period: 10-year relative survival was 94.6% (95%CI 91.4-97.8) and cause-specific 84.2% (95%CI 82.9-85.5%). In metastasized PCa the difference was not that significant.

CONCLUSIONS

From 1985 to 2009, the SMR among men diagnosed with PCa decreased significantly in Finland. Among men with localized PCa, the SMR decreased even below that of the Finnish male population. This and the increased difference between relative and cause-specific survival reflects most likely selection of men to opportunistic PSA testing. The results highlight the importance of caution in the use of PSA testing in healthy men.

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.

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.

Prostate Cancer and Socioeconomic Status in the Finnish Randomized Study of Screening for Prostate Cancer

Prostate cancer (PC) screening remains controversial. We investigated whether screening reduces the difference in prostate cancer risk by socioeconomic status (SES). In 1996-2011, a total of 72,139 men from the Finnish Randomized Study of Screening for Prostate Cancer were analyzed. Outcome measures were PC incidence, mortality, and participation in screening. SES indicators were educational level, income, and home ownership status (data obtained from the Statistics Finland registry). The mean duration of follow-up was 12.7 years. Higher SES was associated with a higher incidence of low- to moderate-risk PC but with a lower risk of advanced PC. Higher education was associated with significantly lower PC mortality in both control and screening arms (risk ratio = 0.48-0.69; P < 0.05). Higher income was also associated with lower PC mortality but only in the control arm (risk ratio = 0.45-0.73; P < 0.05). There were no significant differences in SES gradient by arm (Pinteraction = 0.33 and Pinteraction = 0.47 for primary vs. secondary education and primary vs. tertiary education, respectively; Pinteraction = 0.65 and Pinteraction = 0.09 for low vs. intermediate income and low vs. high income, respectively; and Pinteraction = 0.27 among home ownership status strata). Substantial gradients by SES in PC incidence and mortality were observed in the control arm. Higher SES was associated with overdiagnosis of low-risk PC and, conversely, lower risk of incurable PC and lower PC mortality. Special attention should be directed toward recruiting men with low SES to participate in population-based cancer screening.

Digoxin and prostate cancer survival in the Finnish Randomized Study of Screening for Prostate Cancer

BACKGROUND

Protective effects have been suggested for digoxin against prostate cancer risk. However, few studies have evaluated the possible effects on prostate cancer-specific survival. We studied the association between use of digoxin or beta-blocker sotalol and prostate cancer-specific survival as compared with users of other antiarrhythmic drugs in a retrospective cohort study.

METHODS

Our study population consisted of 6537 prostate cancer cases from the Finnish Randomized Study of Screening for Prostate Cancer diagnosed during 1996-2009 (485 digoxin users). The median exposure for digoxin was 480 DDDs (interquartile range 100-1400 DDDs). During a median follow-up of 7.5 years after diagnosis, 617 men (48 digoxin users) died of prostate cancer. We collected information on antiarrhythmic drug purchases from the national prescription database. Both prediagnostic and postdiagnostic drug usages were analysed using the Cox regression method.

RESULTS

No association was found for prostate cancer death with digoxin usage before (HR 1.00, 95% CI 0.56-1.80) or after (HR 0.81, 95% CI 0.43-1.51) prostate cancer diagnosis. The results were also comparable for sotalol and antiarrhythmic drugs in general. Among men not receiving hormonal therapy, prediagnostic digoxin usage was associated with prolonged prostate cancer survival (HR 0.20, 95% CI 0.05-0.86).

CONCLUSIONS

No general protective effects against prostate cancer were observed for digoxin or sotalol usage.