Determining the cause of death in randomized screening trial(s) for prostate cancer

Which men benefit from prostate cancer screening? Prostate cancer mortality by subgroup in the European Randomised Study of Screening for Prostate Cancer

OBJECTIVE

To evaluate whether a subgroup of men can be identified that would benefit more from screening than others.

MATERIALS AND METHODS

This retrospective cohort study was based on three European Randomised Study of Screening for Prostate Cancer (ERSPC) centres, Finland, the Netherlands and Sweden. We identified 126 827 men aged 55-69 years in the study who were followed for maximum of 16 years after randomisation. The primary outcome was prostate cancer (PCa) mortality. We analysed three age groups 55-59, 60-64 and 65-69 years and PCa cases within four European Association of Urology (EAU) risk groups: low, intermediate, high risk, and advanced disease.

RESULTS

The hazard ratio (HR) for PCa mortality in the screening arm relative to the control arm for men aged 55-59 years was 0.96 (95% confidence interval [CI] 0.75-1.24) in Finland, 0.70 (95% CI 0.44-1.12) in the Netherlands and 0.42 (95% CI 0.24-0.73) in Sweden. The HR for men aged 60-64 years was 1.03 (95% CI 0.77-1.37) in Finland, 0.76 (95% CI 0.50-1.16) in the Netherlands and 0.97 (95% CI 0.64-1.48) in Sweden. The HR for men aged 65-69 years was 0.80 (95% CI 0.62-1.03) in Finland and 0.57 (95% CI 0.38-0.83) in the Netherlands, and this age group was absent in Sweden. In the EAU risk group analysis, PCa mortality rates were materially lower for men with advanced disease at diagnosis in all three countries: 0.67 (95% CI 0.56-0.82) in Finland, 0.28 (95% CI 0.18-0.44) in the Netherlands, and 0.48 (95% CI 0.30-0.78) in Sweden.

CONCLUSION

We were unable to unequivocally identify the optimal age group for screening, as mortality reduction differed among centres and age groups. Instead, the screening effect appears to depend on screening duration, and the number and frequency of screening rounds. PCa mortality reduction by screening is largely attributable to stage shift.

Prostate Cancer Mortality Among Elderly Men After Discontinuing Organised Screening: Long-term Results from the European Randomized Study of Screening for Prostate Cancer Rotterdam

BACKGROUND

The optimal timing for discontinuing screening of prostate cancer (PCa) in elderly men is currently not known and remains debated.

OBJECTIVE

To assess prostate cancer-specific mortality (PCSM) in elderly men who previously underwent prostate-specific antigen (PSA)-based screening and to identify those who may benefit from continued screening.

DESIGN, SETTING, AND PARTICIPANTS

A total of 7052 men, who participated in the screening arm of the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer and were aged 70-74 yr at their last screening visit after undergoing a maximum of three screening rounds without being diagnosed with PCa, were included.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The cumulative incidence of PCSM by the age of 85 yr was assessed. Additionally, a competing risk regression was performed to assess the potential predictors of PCSM.

RESULTS AND LIMITATIONS

The median follow-up was 16 yr. The cumulative incidence of PCSM by the age of 85 yr was 0.54% (95% confidence interval [CI]: 0.40-0.70) in all men, 0.11% (95% CI: 0.05-0.27) in men with PSA <2 ng/ml, 0.85% (95% CI: 0.47-1.5) in men with PSA 2-3 ng/ml, and 6.8% (95% CI: 3.1-15) in men with PSA ≥6.5 ng/ml and no previous benign biopsy. PSA (subdistribution hazard ratio [sHR]: 2.0; 95% CI: 1.7-2.3), previous benign prostate biopsy (sHR: 0.41; 95% CI: 0.23-0.72), and hypertension (sHR: 0.48; 95% CI: 0.25-0.91) were significantly associated with PCSM.

CONCLUSIONS

Men aged 70-74 yr who have previously undergone PSA-based screening without receiving a PCa diagnosis have a very low risk of dying from PCa by the age of 85 yr. These data suggest that screening may be discontinued in men with PSA <3.0 ng/ml or previous benign prostate biopsies. Those with higher PSA levels and no prior biopsies may consider continued screening if life expectancy exceeds 10 yr.

PATIENT SUMMARY

This study shows that men who participated in a prostate cancer screening trial have a very low risk of dying from prostate cancer if they have not been diagnosed with prostate cancer by the age of 74 yr.

A Detailed Evaluation of the Effect of Prostate-specific Antigen-based Screening on Morbidity and Mortality of Prostate Cancer: 21-year Follow-up Results of the Rotterdam Section of the European Randomised Study of Screening for Prostate Cancer

BACKGROUND

Considering the long natural history of prostate cancer (PCa), long-term results of the European Randomised Study of Screening for PCa (ERSPC) are crucial.

OBJECTIVE

To provide an update on the effect of prostate-specific antigen (PSA)-based screening on PCa-specific mortality (PCSM), metastatic disease, and overdiagnosis in the Dutch arm of the ERSPC.

DESIGN, SETTING, AND PARTICIPANTS

Between 1993 and 2000, a total of 42376 men, aged 55-74 yr, were randomised to a screening or a control arm. The main analysis was performed with men aged 55-69 yr (n = 34831). Men in the screening arm were offered PSA-based screening with an interval of 4 yr.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Intention-to-screen analyses with Poisson regression were used to calculate rate ratios (RRs) of PCSM and metastatic PCa.

RESULTS AND LIMITATIONS

After a median follow-up of 21 yr, the RR of PCSM was 0.73 (95% confidence interval [CI]: 0.61-0.88) favouring screening. The numbers of men needed to invite (NNI) and needed to diagnose (NND) to prevent one PCa death were 246 and 14, respectively. For metastatic PCa, the RR was 0.67 (95% CI: 0.58-0.78) favouring screening. The NNI and NND to prevent one metastasis were 121 and 7, respectively. No statistical difference in PCSM (RR of 1.18 [95% CI: 0.87-1.62]) was observed in men aged ≥70 yr at the time of randomisation. In the screening arm, higher rates of PCSM and metastatic disease were observed in men who were screened only once and in a selected group of men above the screening age cut-off of 74 yr.

CONCLUSIONS

The current analysis illustrates that with a follow-up of 21 yr, both absolute metastasis and mortality reduction continue to increase, resulting in a more favourable harm-benefit ratio than demonstrated previously. These data do not support starting screening at the age of 70-74 yr and show that repeated screening is essential.

PATIENT SUMMARY

Prostate-specific antigen-based prostate cancer screening reduces metastasis and mortality. Longer follow-up shows fewer invitations and diagnoses needed to prevent one death, a positive note towards the issue of overdiagnosis.

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

Background

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

Objective

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

Design setting and participants

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

Outcome measurements and statistical analysis

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

Results and limitations

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

Conclusions

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

Patient summary

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

Evidence of cancer progression as the cause of death in men with prostate cancer in Sweden

OBJECTIVE

To assess the strength of the evidence indicative of prostate cancer (PCa) progression as the adjudicated cause of death, according to age at death and PCa risk category.

PATIENTS AND METHODS

Using data from the Prostate Cancer data Base Sweden, we identified a study frame of 5543 men with PCa registered as the cause of death according to the Cause of Death Register. We assessed the evidence of PCa progression through a review of healthcare records for a stratified sample of 495/5543. We extracted data on prostate-specific antigen levels, presence of metastases on imaging, and PCa treatments, and quantified the evidence of disease progression using a points system.

RESULTS

Both no evidence and moderate evidence for PCa progression was more common in men aged >85 years at death than those aged <85 years (29% vs 14%). Among the latter, the proportion with no evidence or moderate evidence for PCa progression was 21% for low-risk, 14% for intermediate-risk, 8% for high-risk, and 0% for metastatic PCa. In contrast, in men aged >85 years, there was little difference in the proportion with no evidence or moderate evidence of PCa progression between PCa risk categories; 31% for low-risk, 29% for intermediate-risk, 29% for high-risk, and 21% for metastatic PCa. Of the 5543 men who died from PCa, 13% (95% confidence interval 5-19%) were estimated to have either no evidence or moderate evidence of PCa progression.

CONCLUSIONS

Weak evidence for PCa progression as cause of death was more common in older men with PCa and in those with low-risk PCa. This has implications for interpretation of mortality statistics especially when assessing screening and early treatment of PCa because the beneficial effect of earlier diagnosis could be masked by erroneous adjudication of PCa as cause of death in older men, particular those with localised disease at diagnosis.

Young Age on Starting Prostate-specific Antigen Testing Is Associated with a Greater Reduction in Prostate Cancer Mortality: 24-Year Follow-up of the Göteborg Randomized Population-based Prostate Cancer Screening Trial

BACKGROUND

The risk of death from prostate cancer (PC) depends on age, but the age at which to start prostate-specific antigen (PSA) screening remains uncertain.

OBJECTIVE

To study the relationship between risk reduction for PC mortality and age at first PSA screening.

DESIGN, SETTING, AND PARTICIPANTS

The randomized Göteborg-1 trial invited men for biennial PSA screening between the ages of 50 and 70 yr (screening, n = 10 000) or no invitation but exposure to opportunistic PSA testing (control, n = 10 000).

INTERVENTION

Regular versus opportunistic PSA screening or no PSA.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We modeled the nonlinear association between starting age and the absolute risk reduction in PC mortality in three settings: (1) intention-to-screen (randomized arms); (2) historical control (screening group and 1990-1994 registry data); and (3) attendees only (screening attendees and matched controls). We tested whether the effect of screening on PC mortality depends on the age at starting screening by comparing survival models with and without an interaction between trial arm and age (intention-to-screen and attendees only).

RESULTS AND LIMITATIONS

Younger age on starting PSA testing was associated with a greater reduction in PC mortality. Starting screening at age 55 yr approximately halved the risk of PC death compared to first PSA at age 60 yr. The test of association between starting age and the effect of screening on PC mortality was slightly greater than the conventional level of statistical significance (p = 0.052) for the entire cohort, and statistically significant among attendees (p = 0.002). This study is limited by the low number of disease-specific deaths for men starting screening before age 55 yr and the difficulty in discriminating between the effect of starting age and screening duration.

CONCLUSIONS

Given that prior screening trials included men aged up to 70 yr on starting screening, our results suggest that the effect size reported in prior trials underestimates that of currently recommended programs starting at age 50-55 yr.

PATIENT SUMMARY

In this study from the Göteborg-1 trial, we looked at the effect of prostate-specific antigen (PSA) screening in reducing men's risk of dying from prostate cancer given the age at which they begin testing. Starting at a younger age reduced the risk of prostate cancer death by a greater amount. We recommend that PSA screening should start no later than at age 55 yr.

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.

Intervention-related Deaths in the European Randomized Study of Screening for Prostate Cancer

Background

Identification of intervention-related deaths is important for an accurate assessment of the ratio of benefit to harm in screening trials.

Objective

To investigate intervention-related deaths by study arm in the European Randomized Study of Prostate Cancer Screening (ERSPC).

Design, setting, and participants

ERSPC is a multicenter trial initiated in the 1990s to investigate whether screening on the basis of prostate-specific antigen (PSA) can decrease prostate cancer mortality. The present study included men in the core age group (55–69 yr: screening group n = 112 553, control group n = 128 681) with 16-yr follow-up.

Outcome measurements and statistical analysis

Causes of death among men with prostate cancer in ERSPC were predominantly evaluated by independent national committees via review of medical records according to a predefined algorithm. Intervention-related deaths were defined as deaths caused by complications during the screening procedure, treatment, or follow-up. Descriptive statistics were used for the results.

Results and limitations

In total, 34 deaths were determined to be intervention-related, of which 21 were in the screening arm and 13 in the control arm. The overall risk of intervention-related death was 1.41 (95% confidence interval 0.99–1.99) per 10 000 randomized men for both arms combined and varied among centers from 0 to 7.0 per 10 000 randomized men. A limitation of this study is that differences in procedures among centers decreased the comparability of the results.

Conclusions

Intervention-related deaths were rare in ERSPC. Monitoring of intervention-related deaths in screening trials is important for assessment of harms.

Patient summary

We investigated deaths due to screening or treatment to assess harm in a trial of prostate cancer screening. Few such deaths were identified.

Active monitoring, radical prostatectomy and radical radiotherapy in PSA-detected clinically localised prostate cancer: the ProtecT three-arm RCT

BACKGROUND

Prostate cancer is the most common cancer among men in the UK. Prostate-specific antigen testing followed by biopsy leads to overdetection, overtreatment as well as undertreatment of the disease. Evidence of treatment effectiveness has lacked because of the paucity of randomised controlled trials comparing conventional treatments.

OBJECTIVES

To evaluate the effectiveness of conventional treatments for localised prostate cancer (active monitoring, radical prostatectomy and radical radiotherapy) in men aged 50-69 years.

DESIGN

A prospective, multicentre prostate-specific antigen testing programme followed by a randomised trial of treatment, with a comprehensive cohort follow-up.

SETTING

Prostate-specific antigen testing in primary care and treatment in nine urology departments in the UK.

PARTICIPANTS

Between 2001 and 2009, 228,966 men aged 50-69 years received an invitation to attend an appointment for information about the Prostate testing for cancer and Treatment (ProtecT) study and a prostate-specific antigen test; 82,429 men were tested, 2664 were diagnosed with localised prostate cancer, 1643 agreed to randomisation to active monitoring (n = 545), radical prostatectomy (n = 553) or radical radiotherapy (n = 545) and 997 chose a treatment.

INTERVENTIONS

The interventions were active monitoring, radical prostatectomy and radical radiotherapy.

TRIAL PRIMARY OUTCOME MEASURE

Definite or probable disease-specific mortality at the 10-year median follow-up in randomised participants.

SECONDARY OUTCOME MEASURES

Overall mortality, metastases, disease progression, treatment complications, resource utilisation and patient-reported outcomes.

RESULTS

There were no statistically significant differences between the groups for 17 prostate cancer-specific (p = 0.48) and 169 all-cause (p = 0.87) deaths. Eight men died of prostate cancer in the active monitoring group (1.5 per 1000 person-years, 95% confidence interval 0.7 to 3.0); five died of prostate cancer in the radical prostatectomy group (0.9 per 1000 person-years, 95% confidence interval 0.4 to 2.2 per 1000 person years) and four died of prostate cancer in the radical radiotherapy group (0.7 per 1000 person-years, 95% confidence interval 0.3 to 2.0 per 1000 person years). More men developed metastases in the active monitoring group than in the radical prostatectomy and radical radiotherapy groups: active monitoring, n = 33 (6.3 per 1000 person-years, 95% confidence interval 4.5 to 8.8); radical prostatectomy, n = 13 (2.4 per 1000 person-years, 95% confidence interval 1.4 to 4.2 per 1000 person years); and radical radiotherapy, n = 16 (3.0 per 1000 person-years, 95% confidence interval 1.9 to 4.9 per 1000 person-years; p = 0.004). There were higher rates of disease progression in the active monitoring group than in the radical prostatectomy and radical radiotherapy groups: active monitoring (n = 112; 22.9 per 1000 person-years, 95% confidence interval 19.0 to 27.5 per 1000 person years); radical prostatectomy (n = 46; 8.9 per 1000 person-years, 95% confidence interval 6.7 to 11.9 per 1000 person-years); and radical radiotherapy (n = 46; 9.0 per 1000 person-years, 95% confidence interval 6.7 to 12.0 per 1000 person years; p < 0.001). Radical prostatectomy had the greatest impact on sexual function/urinary continence and remained worse than radical radiotherapy and active monitoring. Radical radiotherapy's impact on sexual function was greatest at 6 months, but recovered somewhat in the majority of participants. Sexual and urinary function gradually declined in the active monitoring group. Bowel function was worse with radical radiotherapy at 6 months, but it recovered with the exception of bloody stools. Urinary voiding and nocturia worsened in the radical radiotherapy group at 6 months but recovered. Condition-specific quality-of-life effects mirrored functional changes. No differences in anxiety/depression or generic or cancer-related quality of life were found. At the National Institute for Health and Care Excellence threshold of £20,000 per quality-adjusted life-year, the probabilities that each arm was the most cost-effective option were 58% (radical radiotherapy), 32% (active monitoring) and 10% (radical prostatectomy).

LIMITATIONS

A single prostate-specific antigen test and transrectal ultrasound biopsies were used. There were very few non-white men in the trial. The majority of men had low- and intermediate-risk disease. Longer follow-up is needed.

CONCLUSIONS

At a median follow-up point of 10 years, prostate cancer-specific mortality was low, irrespective of the assigned treatment. Radical prostatectomy and radical radiotherapy reduced disease progression and metastases, but with side effects. Further work is needed to follow up participants at a median of 15 years.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN20141297.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 37. See the National Institute for Health Research Journals Library website for further project information.

Comparison of Tumor Volume Parameters on Prostate Cancer Biopsies

CONTEXT.—

Prostate biopsy reports require an indication of prostate cancer volume. No consensus exists on the methodology of tumor volume reporting.

OBJECTIVE.—

To compare the prognostic value of different biopsy prostate cancer volume parameters.

DESIGN.—

Prostate biopsies of the European Randomized Study of Screening for Prostate Cancer were reviewed (n = 1031). Tumor volume was quantified in 6 ways: average estimated tumor percentage, measured total tumor length, average calculated tumor percentage, greatest tumor length, greatest tumor percentage, and average tumor percentage of all biopsies. Their prognostic value was determined by using either logistic regression for extraprostatic expansion (EPE) and surgical margin status after radical prostatectomy (RP), or Cox regression for biochemical recurrence-free survival (BCRFS) and disease-specific survival (DSS) after RP (n = 406) and radiation therapy (RT) (n = 508).

RESULTS.—

All tumor volume parameters were significantly mutually correlated (R2 > 0.500, P < .001). None were predictive for EPE, surgical margin, or BCRFS after RP in multivariable analysis, including age, prostate-specific antigen, number of positive biopsies, and grade group. In contrast, all tumor volume parameters were significant predictors for BCRFS (all P < .05) and DSS (all P < .05) after RT, except greatest tumor length. In multivariable analysis including only all tumor volume parameters as covariates, calculated tumor length was the only predictor for EPE after RP (P = .02) and DSS after RT (P = .02).

CONCLUSIONS.—

All tumor volume parameters had comparable prognostic value and could be used in clinical practice. If tumor volume quantification is a threshold for treatment decision, calculated tumor length seems preferential, slightly outperforming the other parameters.

Predicting biochemical recurrence and prostate cancer-specific mortality after radical prostatectomy: comparison of six prediction models in a cohort of patients with screening- and clinically detected prostate cancer

OBJECTIVES

To perform a comparison and external validation of three models predicting biochemical recurrence (BCR) and three models predicting prostate cancer (PCa)-specific mortality (PCSM) in a screening setting, i.e. patients with screening-detected PCa (S-PCa) and in those with clinically detected PCa (C-PCa).

SUBJECTS AND METHODS

We retrospectively evaluated 795 men with S-PCa, from the European Randomized Study of Screening for Prostate Cancer, Rotterdam, and 1123 men with C-PCa initially treated with RP. The discriminative ability of the models was assessed according to the area under the curve (AUC) of the receiver-operating characteristic, and calibration was assessed graphically using calibration plots.

RESULTS

The median (interquartile range [IQR]) follow-up for the S-PCa group was 10.4 (6.8-14.3) years and for the C-PCa group it was 8.8 (4.8-12.9) years. A total of 123 men with S-PCa (15%) and 389 men with C-PCa (35%) experienced BCR. Of the men with S-PCa and BCR, 24 (20%) died from PCa and 29 (23%) died from other causes. Of the men with C-PCa and BCR, 68 (17%) died from PCa and 105 (27%) died from other causes. The discrimination of the models predicting BCR or PCSM was higher for men with S-PCa (AUC: BCR 0.77-0.84, PCSM 0.60-0.77) than for the men with C-PCa (AUC: BCR 0.75-0.79, PCSM 0.51-0.68) as a result of the similar patient characteristics of the men with S-PCa in the present study and those of the cohorts used to develop these models. The risk of BCR was typically overestimated, while the risk of PCSM was typically underestimated.

CONCLUSION

Prediction models for BCR showed good discrimination and reasonable calibration for both men with S-PCa and men with C-PCa, and even better discrimination for men with S-PCa. For PCSM, the evaluated models are not applicable in both settings of this Dutch cohort as a result of substantial miscalibration. This warrants caution when using these models to communicate future risks in other clinical settings.

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.

A 16-yr Follow-up of the European Randomized study of Screening for Prostate Cancer

BACKGROUND

The European Randomized study of Screening for Prostate Cancer (ERSPC) has previously demonstrated that prostate-specific antigen (PSA) screening decreases prostate cancer (PCa) mortality.

OBJECTIVE

To determine whether PSA screening decreases PCa mortality for up to 16yr and to assess results following adjustment for nonparticipation and the number of screening rounds attended.

DESIGN, SETTING, AND PARTICIPANTS

This multicentre population-based randomised screening trial was conducted in eight European countries. Report includes 182160 men, followed up until 2014 (maximum of 16yr), with a predefined core age group of 162389 men (55-69yr), selected from population registry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The outcome was PCa mortality, also assessed with adjustment for nonparticipation and the number of screening rounds attended.

RESULTS AND LIMITATIONS

The rate ratio of PCa mortality was 0.80 (95% confidence interval [CI] 0.72-0.89, p<0.001) at 16yr. The difference in absolute PCa mortality increased from 0.14% at 13yr to 0.18% at 16yr. The number of men needed to be invited for screening to prevent one PCa death was 570 at 16yr compared with 742 at 13yr. The number needed to diagnose was reduced to 18 from 26 at 13yr. Men with PCa detected during the first round had a higher prevalence of PSA >20ng/ml (9.9% compared with 4.1% in the second round, p<0.001) and higher PCa mortality (hazard ratio=1.86, p<0.001) than those detected subsequently.

CONCLUSIONS

Findings corroborate earlier results that PSA screening significantly reduces PCa mortality, showing larger absolute benefit with longer follow-up and a reduction in excess incidence. Repeated screening may be important to reduce PCa mortality on a population level.

PATIENT SUMMARY

In this report, we looked at the outcomes from prostate cancer in a large European population. We found that repeated screening reduces the risk of dying from prostate cancer.

Uniform and blinded cause of death verification of the NELSON lung cancer screening participants

Primary outcome of the Dutch-Belgian lung cancer screening trial (NELSON) is lung cancer-specific mortality. Accurate assessment of the cause of death (CoD) is crucial. As death certificates regarding the CoD can be inaccurate, a clinical expert committee (CEC) was formed to assign the CoD. In this study, the medical files of deceased lung cancer patients were reviewed and the outcomes were compared with official death certificates. The first 266 completed medical files of Dutch deceased participants who were diagnosed with lung cancer during the study or of those with lung cancer on the death certificate were selected and blinded towards arms and patients identity. The end product of the review process consisted of six possible categories which defined the graduation of certainty that lung cancer was the primary CoD. The percentage agreement and the Cohen's kappa statistics between the two CEC-memberswere calculated. The sensitivity and specificity of the official death certificates were determined. The results indicated that, the overall concordance and the Cohen's kappa between the CEC-memberswere 86.1% and 0.57(0.45-0.69, p<0.001), respectively. This level increased with the numbers of cases evaluated. The sensitivity and the specificity of the official death certificate were 92.6% and 98.8%; 6.5% cases were reclassified to lung cancer specific death, which is lower than in the National Lung Screening trial(22.0%). Concluding, each death should be reviewed by at least two members. So far, in the NELSON trial, possible biases related to lung cancer death seem relatively small.

Impact of cause of death adjudication on the results of the European prostate cancer screening trial

BACKGROUND

The European Randomised Study of Prostate Cancer Screening has shown a 21% relative reduction in prostate cancer mortality at 13 years. The causes of death can be misattributed, particularly in elderly men with multiple comorbidities, and therefore accurate assessment of the underlying cause of death is crucial for valid results. To address potential unreliability of end-point assessment, and its possible impact on mortality results, we analysed the study outcome adjudication data in six countries.

METHODS

Latent class statistical models were formulated to compare the accuracy of individual adjudicators, and to assess whether accuracy differed between the trial arms. We used the model to assess whether correcting for adjudication inaccuracies might modify the study results.

RESULTS

There was some heterogeneity in adjudication accuracy of causes of death, but no consistent differential accuracy by trial arm. Correcting the estimated screening effect for misclassification did not alter the estimated mortality effect of screening.

CONCLUSIONS

Our findings were consistent with earlier reports on the European screening trial. Observer variation, while demonstrably present, is unlikely to have materially biased the main study results. A bias in assigning causes of death that might have explained the mortality reduction by screening can be effectively ruled out.

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

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

Contemporary accuracy of death certificates for coding prostate cancer as a cause of death: Is reliance on death certification good enough? A comparison with blinded review by an independent cause of death evaluation committee

BACKGROUND

Accurate cause of death assignment is crucial for prostate cancer epidemiology and trials reporting prostate cancer-specific mortality outcomes.

METHODS

We compared death certificate information with independent cause of death evaluation by an expert committee within a prostate cancer trial (2002-2015).

RESULTS

Of 1236 deaths assessed, expert committee evaluation attributed 523 (42%) to prostate cancer, agreeing with death certificate cause of death in 1134 cases (92%, 95% CI: 90%, 93%). The sensitivity of death certificates in identifying prostate cancer deaths as classified by the committee was 91% (95% CI: 89%, 94%); specificity was 92% (95% CI: 90%, 94%). Sensitivity and specificity were lower where death occurred within 1 year of diagnosis, and where there was another primary cancer diagnosis.

CONCLUSIONS

UK death certificates accurately identify cause of death in men with prostate cancer, supporting their use in routine statistics. Possible differential misattribution by trial arm supports independent evaluation in randomised trials.

Disease-specific survival of patients with invasive cribriform and intraductal prostate cancer at diagnostic biopsy

Invasive cribriform and intraductal carcinoma in radical prostatectomy specimens have been associated with an adverse clinical outcome. Our objective was to determine the prognostic value of invasive cribriform and intraductal carcinoma in pre-treatment biopsies on time to disease-specific death. We pathologically revised the diagnostic biopsies of 1031 patients from the first screening round of the European Randomized Study of Screening for Prostate Cancer (1993-2000). Ninety percent of all patients (n=923) had received active treatment, whereas 10% (n=108) had been followed by watchful waiting. The median follow-up was 13 years. Patients who either had invasive cribriform growth pattern or intraductal carcinoma were categorized as CR/IDC+. The outcome was disease-specific survival. Relationships with outcome were analyzed using multivariable Cox regression and log-rank analysis. In total, 486 patients had Gleason score 6 (47%) and 545 had ≥7 (53%). The 15-year disease-specific-survival probabilities were 99% in Gleason score 6 (n=486), 94% in CR/IDC- Gleason score ≥7 (n=356) and 67% in CR/IDC+ Gleason score ≥7 (n=189). CR/IDC- Gleason score 3+4=7 patients did not have statistically different survival probabilities from those with Gleason score 6 (P=0.30), while CR/IDC+ Gleason score 3+4=7 patients did (P<0.001). In multivariable analysis, CR/IDC+ status was independently associated with a poorer disease-specific survival (HR 2.6, 95% CI 1.4-4.8, P=0.002). We conclude that CR/IDC+ status in prostate cancer biopsies is associated with a worse disease-specific survival. Our findings indicate that men with biopsy CR/IDC- Gleason score 3+4=7 prostate cancer could be candidates for active surveillance, as these patients have similar survival probabilities to those with Gleason score 6.

Non-Steroidal Anti-Inflammatory Drugs and Cancer Death in the Finnish Prostate Cancer Screening Trial

Non-steroidal anti-inflammatory drugs (NSAIDs), especially aspirin, have been associated with lowered cancer incidence and mortality. We examined overall cancer mortality and mortality from specific cancer sites among the 80,144 men in the Finnish Prostate Cancer Screening Trial. Information on prescription drug use was acquired from the national drug reimbursement database. Over-the-counter use information was gathered by a questionnaire. Hazard ratios (HR) and 95% confidence intervals (CI) by prescription and over-the-counter NSAID use for overall and specific cancer deaths were calculated using Cox regression. During the median follow-up time of 15 years, 7,008 men died from cancer. Men with prescription NSAID use had elevated cancer mortality (HR 2.02 95% CI 1.91–2.15) compared to non-users. The mortality risk was increased for lung, colorectal and pancreas cancer mortality (HR 2.68, 95%CI 2.40–2.99, HR 1.91, 95% CI 1.57–2.32 and HR 1.93, 95% CI 1.58–2.37, respectively). The increased risk remained in competing risks regression (HR 1.11, 95% CI 1.05–1.18). When the usage during the last three years of follow-up was excluded, the effect was reversed (HR 0.69, 95% CI 0.65–0.73). Cancer mortality was not decreased for prescription or over-the-counter aspirin use. However, in the competing risk regression analysis combined prescription and over-the-counter aspirin use was associated with decreased overall cancer mortality (HR 0.76, 95% CI 0.70–0.82). Cancer mortality was increased for NSAID users. However, the risk disappeared when the last 3 years were excluded.

Screening for Prostate Cancer Starting at Age 50-54 Years. A Population-based Cohort Study

BACKGROUND

Current prostate cancer screening guidelines conflict with respect to the age at which to initiate screening.

OBJECTIVE

To evaluate the effect of prostate-specific antigen (PSA) screening versus zero screening, starting at age 50-54 yr, on prostate cancer mortality.

DESIGN, SETTING, AND PARTICIPANTS

This is a population-based cohort study comparing 3479 men aged 50 yr through 54 yr randomized to PSA-screening in the Göteborg population-based prostate cancer screening trial, initiated in 1995, versus 4060 unscreened men aged 51-55 yr providing cryopreserved blood in the population-based Malmö Preventive Project in the pre-PSA era, during 1982-1985.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cumulative incidence and incidence rate ratios of prostate cancer diagnosis, metastasis, and prostate cancer death.

RESULTS AND LIMITATIONS

At 17 yr, regular PSA-screening in Göteborg of men in their early 50s carried a more than two-fold higher risk of prostate cancer diagnosis compared with the unscreened men in Malmö (incidence rate ratio [IRR] 2.56, 95% confidence interval [CI] 2.18, 3.02), but resulted in a substantial decrease in the risk of metastases (IRR 0.43, 95% CI 0.22, 0.79) and prostate cancer death (IRR 0.29, 95% CI 0.11, 0.67). There were 57 fewer prostate cancer deaths per 10000 men (95% CI 22, 92) in the screened group. At 17 yr, the number needed to invite to PSA-screening and the number needed to diagnose to prevent one prostate cancer death was 176 and 16, respectively. The study is limited by lack of treatment information and the comparison of the two different birth cohorts.

CONCLUSIONS

PSA screening for prostate cancer can decrease prostate cancer mortality among men aged 50-54 yr, with the number needed to invite and number needed to detect to prevent one prostate cancer death comparable to those previously reported from the European Randomized Study of Screening for Prostate Cancer for men aged 55-69 yr, at a similar follow-up. Guideline groups could consider whether guidelines for PSA screening should recommend starting no later than at ages 50-54 yr.

PATIENT SUMMARY

Guideline recommendations about the age to start prostate-specific antigen screening could be discussed.

Absolute Effect of Prostate Cancer Screening: Balance of Benefits and Harms by Center within the European Randomized Study of Prostate Cancer Screening

PURPOSE

The balance of benefits and harms in prostate cancer screening has not been sufficiently characterized. We related indicators of mortality reduction and overdetection by center within the European Randomized Study of Prostate Cancer Screening (ERSPC).

EXPERIMENTAL DESIGN

We analyzed the absolute mortality reduction expressed as number needed to invite (NNI = 1/absolute risk reduction; indicating how many men had to be randomized to screening arm to avert a prostate cancer death) for screening and the absolute excess of prostate cancer detection as number needed for overdetection (NNO = 1/absolute excess incidence; indicating the number of men invited per additional prostate cancer case), and compared their relationship across the seven ERSPC centers.

RESULTS

Both absolute mortality reduction (NNI) and absolute overdetection (NNO) varied widely between the centers: NNI, 200-7,000 and NNO, 16-69. Extent of overdiagnosis and mortality reduction was closely associated [correlation coefficient, r = 0.76; weighted linear regression coefficient, β = 33; 95% confidence interval (CI), 5-62; R(2) = 0.72]. For an averted prostate cancer death at 13 years of follow-up, 12 to 36 excess cases had to be detected in various centers.

CONCLUSIONS

The differences between the ERSPC centers likely reflect variations in prostate cancer incidence and mortality, as well as in screening protocol and performance. The strong interrelation between the benefits and harms suggests that efforts to maximize the mortality effect are bound to increase overdiagnosis and might be improved by focusing on high-risk populations. The optimal balance between screening intensity and risk of overdiagnosis remains unclear.

Metastatic Prostate Cancer Incidence and Prostate-specific Antigen Testing: New Insights from the European Randomized Study of Screening for Prostate Cancer

BACKGROUND

The European Randomized Study of Screening for Prostate Cancer (ERSPC) has shown a 21% reduction in prostate cancer (PCa) mortality and a 1.6-fold increase in PCa incidence with prostate-specific antigen (PSA)-based screening (at 13 yr of follow-up). We evaluated PCa incidence by risk category at diagnosis across the study arms to assess the potential impact on PCa mortality.

DESIGN, SETTING, AND PARTICIPANTS

Information on arm, centre, T and M stage, Gleason score, serum PSA at diagnosis, age at randomisation, follow-up time, and vital status were extracted from the ERSPC database. Four risk categories at diagnosis were defined: 1, low; 2, intermediate; 3, high; 4, metastatic disease. PSA (≤100 or >100 ng/ml) was used as the indicator of metastasis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Incidence rate ratios (IRRs) for screening versus control arm by risk category at diagnosis and follow-up time were calculated using Poisson regression analysis for seven centres. Follow-up was truncated at 13 yr. Missing data were imputed using chained equations. The analyses were carried out on an intention-to-treat basis.

RESULTS AND LIMITATIONS

In the screening arm, 7408 PCa cases were diagnosed and 6107 in the control arm. The proportion of missing stage, Gleason score, or PSA value was comparable in the two arms (8% vs 10%), but differed among centres. The IRRs were elevated in the screening arm for the low-risk (IRR: 2.14; 95% CI, 2.03-2.25) and intermediate-risk (IRR: 1.24; 95% CI, 1.16-1.34) categories at diagnosis, equal to unity for the high-risk category at diagnosis (IRR: 1.00; 95% CI, 0.89-1.13), and reduced for metastatic disease at diagnosis (IRR: 0.60; 95% CI, 0.52-0.70). The IRR of metastatic disease had temporal pattern similar to mortality, shifted forwards an average of almost 3 yr, although the mortality reduction was smaller.

CONCLUSIONS

The results confirm a reduction in metastatic disease at diagnosis in the screening arm, preceding mortality reduction by almost 3 yr.

PATIENT SUMMARY

The findings of this study indicate that the decrease in metastatic disease at diagnosis is the major determinant of the prostate cancer mortality reduction in the European Randomized study of Screening for Prostate Cancer.

Prostate cancer: net survival and cause-specific survival rates after multiple imputation

Background

Estimations of survival rates are diverse and the choice of the appropriate method depends on the context. Given the increasing interest in multiple imputation methods, we explored the interest of a multiple imputation approach in the estimation of cause-specific survival, when a subset of causes of death was observed.

Methods

By using European Randomized Study of Screening for Prostate Cancer (ERSPC), 20 multiply imputed datasets were created and analyzed with a Multivariate Imputation by Chained Equation (MICE) algorithm. Then, cause-specific survival was estimated on each dataset with two methods: Kaplan-Meier and competing risks. The two pooled cause-specific survival and confidence intervals were obtained using Rubin’s rules after complementary log-log transformation. Net survival was estimated using Pohar-Perme’s estimator and was compared to pooled cause-specific survival. Finally, a sensitivity analysis was performed to test the robustness of our constructed multiple imputation model.

Results

Cause-specific survival performed better than net survival, since this latter exceeded 100 % for almost the first 2 years of follow-up and after 9 years whereas the cause-specific survival decreased slowly and than stabilized at around 94 % at 9 years. Sensibility study results were satisfactory.

Conclusions

On our basis of prostate cancer data, the results obtained by cause-specific survival after multiple imputation appeared to be better and more realistic than those obtained using net survival.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-015-0048-4) contains supplementary material, which is available to authorized users.

Impact of Early Diagnosis of Prostate Cancer on Survival Outcomes

CONTEXT

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

OBJECTIVE

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

PATIENT SUMMARY

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

Do Treatment Differences between Arms Affect the Main Outcome of ERSPC Rotterdam?

PURPOSE

We assessed differences in treatment between the screening and control arms of ERSPC Rotterdam and studied whether possible treatment differences could explain the positive study outcome.

MATERIALS AND METHODS

In ERSPC Rotterdam men 55 to 74 years old were randomized to a screening arm of 21,210 and a control arm of 21,166. Treatment after diagnosis was at the discretion of the care provider chosen by the patient. Initial treatment was compared in 4 risk groups. The relation between prostate cancer incidence and prostate cancer mortality was assessed by risk group by correlating the incidence RR and the mortality RR. A direct relation would have supported a stage shift as the main cause of changes in prostate cancer mortality.

RESULTS

Initial treatment differed between the arms in the low, intermediate and high risk groups but not in the metastatic group. The RRs of prostate cancer incidence and mortality per risk group were related 1:1 (regression line slope 1.00, 95% CI 0.30-1.74). Of changes in prostate cancer mortality 94% could be explained by changes in prostate cancer incidence. This made treatment differences unlikely as the reason for the observed decrease in prostate cancer mortality.

CONCLUSIONS

Differences in treatment between the ERSPC Rotterdam screening and control arms were unlikely to explain the differences in prostate cancer mortality. Results are instead consistent with a decrease in prostate cancer mortality as the result of a favorable stage through screening.

Standardisation of information submitted to an endpoint committee for cause of death assignment in a cancer screening trial – lessons learnt from CAP (Cluster randomised triAl of PSA testing for Prostate cancer)

BACKGROUND

In cancer screening trials where the primary outcome is target cancer-specific mortality, the unbiased determination of underlying cause of death (UCD) is crucial. To minimise bias, the UCD should be independently verified by expert reviewers, blinded to death certificate data and trial arm. We investigated whether standardising the information submitted for UCD assignment in a population-based randomised controlled trial of prostate-specific antigen (PSA) testing for prostate cancer reduced the reviewers' ability to correctly guess the trial arm.

METHODS

Over 550 General Practitioner (GP) practices (>415,000 men aged 50-69 years) were cluster-randomised to PSA testing (intervention arm) or the National Health Service (NHS) prostate cancer risk management programme (control arm) between 2001 and 2007. Assignment of UCD was by independent reviews of researcher-written clinical vignettes that masked trial arm and death certificate information. A period of time after the process began (the initial phase), we analysed whether the reviewers could correctly identify trial arm from the vignettes, and the reasons for their choice. This feedback led to further standardisation of information (second phase), after which we re-assessed the extent of correct identification of trial arm.

RESULTS

1099 assessments of 509 vignettes were completed by January 2014. In the initial phase (n = 510 assessments), reviewers were unsure of trial arm in 33% of intervention and 30% of control arm assessments and were influenced by symptoms at diagnosis, PSA test result and study-specific criteria. In the second phase (n = 589), the respective proportions of uncertainty were 45% and 48%. The percentage of cases whereby reviewers were unable to determine the trial arm was greater following the standardisation of information provided in the vignettes. The chances of a correct guess and an incorrect guess were equalised in each arm, following further standardisation.

CONCLUSIONS

It is possible to mask trial arm from cause of death reviewers, by using their feedback to standardise the information submitted to them.

TRIAL REGISTRATION

ISRCTN92187251.

Screening and prostate cancer mortality: results of the European Randomised Study of Screening for Prostate Cancer (ERSPC) at 13 years of follow-up

BACKGROUND

The European Randomised study of Screening for Prostate Cancer (ERSPC) has shown significant reductions in prostate cancer mortality after 9 years and 11 years of follow-up, but screening is controversial because of adverse events such as overdiagnosis. We provide updated results of mortality from prostate cancer with follow-up to 2010, with analyses truncated at 9, 11, and 13 years.

METHODS

ERSPC is a multicentre, randomised trial with a predefined centralised database, analysis plan, and core age group (55-69 years), which assesses prostate-specific antigen (PSA) testing in eight European countries. Eligible men aged 50-74 years were identified from population registries and randomly assigned by computer generated random numbers to screening or no intervention (control). Investigators were masked to group allocation. The primary outcome was prostate cancer mortality in the core age group. Analysis was by intention to treat. We did a secondary analysis that corrected for selection bias due to non-participation. Only incidence and no mortality data at 9 years' follow-up are reported for the French centres. This study is registered with Current Controlled Trials, number ISRCTN49127736.

FINDINGS

With data truncated at 13 years of follow-up, 7408 prostate cancer cases were diagnosed in the intervention group and 6107 cases in the control group. The rate ratio of prostate cancer incidence between the intervention and control groups was 1·91 (95% CI 1·83-1·99) after 9 years (1·64 [1·58-1·69] including France), 1·66 (1·60-1·73) after 11 years, and 1·57 (1·51-1·62) after 13 years. The rate ratio of prostate cancer mortality was 0·85 (0·70-1·03) after 9 years, 0·78 (0·66-0·91) after 11 years, and 0·79 (0·69-0·91) at 13 years. The absolute risk reduction of death from prostate cancer at 13 years was 0·11 per 1000 person-years or 1·28 per 1000 men randomised, which is equivalent to one prostate cancer death averted per 781 (95% CI 490-1929) men invited for screening or one per 27 (17-66) additional prostate cancer detected. After adjustment for non-participation, the rate ratio of prostate cancer mortality in men screened was 0·73 (95% CI 0·61-0·88).

INTERPRETATION

In this update the ERSPC confirms a substantial reduction in prostate cancer mortality attributable to testing of PSA, with a substantially increased absolute effect at 13 years compared with findings after 9 and 11 years. Despite our findings, further quantification of harms and their reduction are still considered a prerequisite for the introduction of populated-based screening.

FUNDING

Each centre had its own funding responsibility.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

[Early detection of prostate cancer: harm verified, benefit not verifiable]

The results of randomized studies on the early detection of prostate cancer and those of a systematic Cochrane review are compiled and interpreted. Some fundamental and inherent weaknesses of screening studies are pointed out and discussed. The meta-analysis of studies involving a total of 321,594 participants shows no reduction in prostate cancer mortality or all-cause mortality, but describes disadvantages such as unnecessary biopsies, overdiagnosis, and overtreatment. A relevant increase in overall mortality cannot be excluded. Even in future trials, the possible reduction of prostate cancer mortality or all-cause mortality by prostate cancer screening will not be detectable because of inherent methodological problems, e.g., an extremely high number of participants are needed. Furthermore, by nature, studies on the early detection of cancer last very long, such that the results are inevitably outdated at the end of the study. There is a risk that studies on the early detection of cancer suggest an advantage and at the same time overlook a relevant increase in overall mortality. Prostate cancer screening also ignores important WHO criteria for screening programs: There is evidence that early treatment of prostate cancer is not better than late treatment. There is no suitable or reliable test to identify the early stages of the disease. The benefit-risk ratio is not clearly favorable, and there is doubt whether the costs and the benefits are in an acceptable balance. There are valid reasons to advise against population-based prostate cancer screening.

A different method of evaluation of the ERSPC trial confirms that prostate-specific antigen testing has a significant impact on prostate cancer mortality

The advantages and disadvantages of two different methods of analyzing the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial with respect to the effect of prostate-specific antigen (PSA) screening on prostate cancer (PCa) mortality (ie, disease-specific mortality analysis and excess mortality analysis) are discussed in depth. The traditional disease-specific mortality is the best end point, but it could be biased by misclassification of causes of death, and it does not take into account the possible effect of the screening process on other causes of death. Excess mortality analysis overcomes these problems, but the results could be biased if the expected mortality is not corrected for attendance status. Both methods, when applied to the ERSPC trials, demonstrate that no increase in non-PCa mortality occurred in the screening group and confirm that PSA screening decreases PCa mortality.

Excess all-cause mortality in the evaluation of a screening trial to account for selective participation

OBJECTIVE

In addition to disease-specific mortality, a randomized controlled cancer screening trial may be evaluated in terms of excess mortality, in which case no patient-specific information on causes of death is needed. We studied the effect of not accounting for attendance on the calculated excess mortality in a prostate cancer screening trial.

METHODS

The numerator of the excess mortality rate related to prostate cancer diagnoses in each study arm equals the excess number of deaths observed in the cancer patients. The estimation of the expected number of deaths in the absence of the prostate cancer diagnoses has to account for the self-selection of those participating in the trial, particularly if the proportion of non-participants is substantial.

SETTING

The European prostate cancer screening trial (ERSPC).

RESULTS

In the screening arm, non-attendees had roughly twice the mortality rate of attendees. Approximately twice as many cancers were detected in the screening arm compared with the control arm, primarily in attendees. Unless attendance is properly accounted for, the expected mortality of prostate cancer patients in the screening arm is overestimated by 0.9-3.6 deaths per 1000 person-years.

CONCLUSIONS

Attendees have a lower all-cause mortality rate (are healthier) and a higher probability of a prostate cancer diagnosis than non-attendees and the men randomized to the control arm. If attendance is not accounted for, the excess mortality and the between-arm excess mortality rate ratio are underestimated and screening is considered more effective than it actually is. These effects may be sizeable, notably if non-attendance is common. Correcting for attendance status is important in the calculation of the excess mortality rate in prostate cancer patients that can be used in conjunction with a disease-specific mortality analysis in a randomized controlled cancer screening trial.

Efficacy versus effectiveness study design within the European screening trial for prostate cancer: consequences for cancer incidence, overall mortality and cancer-specific mortality

OBJECTIVE

To assess the impact of different study designs on outcome data within the European Randomized Study of Screening for Prostate Cancer (ERSPC).

METHODS

Observed data from the Gothenburg centre (effectiveness trial with upfront randomization before informed consent) and the Rotterdam centre (efficacy trial with randomization after informed consent) were compared with expected data, which were retrieved from national cancer registries and life tables. Endpoints were 11-year cumulative prostate cancer (PC) incidence, overall mortality and PC-specific mortality.

RESULTS

In Gothenburg, the 11-year PC incidence was higher than predicted (5.8%) in both the intervention (12.4%) and control arms (7.3%). The observed overall mortality was higher than predicted (15.9%) in both the intervention (17.8%) and control arms (18.5%). The observed PC-specific mortality in the intervention arm was 0.56% versus 0.83% in the control arm, while the expected mortality was 0.83%. In Rotterdam, the observed PC incidence in the intervention arm (10.4%) was higher than expected (4.4%). The incidence in the control arm was 4.6%. The observed overall mortality was lower than expected: 13.6% in the intervention arm and 14.0% in the control arm versus an expected mortality of 16.1%. The observed PC-specific mortality was lower than expected (0.65%) in both the intervention (0.27%) and control arms (0.41%).

CONCLUSIONS

Our results suggest that an efficacy trial with informed consent prior to randomization may have introduced a 'healthy screenee bias'. Therefore, an effectiveness trial with consent after randomization may more accurately estimate the PC-specific mortality reduction if population-based screening is introduced.

Long-term radical prostatectomy outcomes among participants from the European Randomized Study of Screening for Prostate Cancer (ERSPC) Rotterdam

Study Type--Therapy (cohort) Level of Evidence 2b. What's known on the subject? and What does the study add? Radical prostatectomy was previously shown to improve long-term outcomes among men with clinically-detected prostate cancer. Our data suggests that radical prostatectomy is also associated with improved outcomes in men with screen-detected prostate cancer.

OBJECTIVE

• To examine the long-term outcomes of radical prostatectomy (RP) among men diagnosed with prostate cancer from the screening and control arms of the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer (ERSPC).

PATIENTS AND METHODS

• Among 42,376 men randomised during the period of the first round of the trial (1993-1999), 1151 and 210 in the screening and control arms were diagnosed with prostate cancer, respectively. • Of these men, 420 (36.5%) screen-detected and 54 (25.7%) controls underwent RP with long-term follow-up data (median follow-up 9.9 years). • Progression-free (PFS), metastasis-free (MFS) and cancer-specific survival (CSS) rates were examined, and multivariable Cox proportional hazards models were used to determine whether screen-detected (vs control) was associated with RP outcomes after adjusting for standard predictors.

RESULTS

• RP cases from the screening and control arms had statistically similar clinical stage and biopsy Gleason score, although screen-detected cases had significantly lower prostate-specific antigen (PSA) levels at diagnosis. • Men from the screening arm had a significantly higher PFS (P = 0.003), MFS (P < 0.001) and CSS (P = 0.048). • In multivariable models adjusting for age, PSA level, clinical stage, and biopsy Gleason score, the screening group had a significantly lower risk of biochemical recurrence (hazard ratio [HR] 0.43, 95% confidence interval [CI] 0.23-0.83, P = 0.011) and metastasis (HR 0.18, 95% CI 0.06-0.59, P = 0.005). • Additionally adjusting for tumour volume and other RP pathology features, there was no longer a significant difference in biochemical recurrence between the screening and control arms. • Limitations of the present study include lead-time bias and non-randomised treatment selection.

CONCLUSIONS

• After RP, screen-detected cases had significantly improved PFS, MFS and CSS compared with controls within the available follow-up time. • The screening arm remained significantly associated with lower rates of biochemical recurrence and metastasis after adjusting for other preoperative variables. • However, considering also RP pathology, the improved outcomes in the screening group appeared to be mediated by a significantly lower tumour volume.

Prostate-cancer mortality at 11 years of follow-up

BACKGROUND

Several trials evaluating the effect of prostate-specific antigen (PSA) testing on prostate-cancer mortality have shown conflicting results. We updated prostate-cancer mortality in the European Randomized Study of Screening for Prostate Cancer with 2 additional years of follow-up.

METHODS

The study involved 182,160 men between the ages of 50 and 74 years at entry, with a predefined core age group of 162,388 men 55 to 69 years of age. The trial was conducted in eight European countries. Men who were randomly assigned to the screening group were offered PSA-based screening, whereas those in the control group were not offered such screening. The primary outcome was mortality from prostate cancer.

RESULTS

After a median follow-up of 11 years in the core age group, the relative reduction in the risk of death from prostate cancer in the screening group was 21% (rate ratio, 0.79; 95% confidence interval [CI], 0.68 to 0.91; P=0.001), and 29% after adjustment for noncompliance. The absolute reduction in mortality in the screening group was 0.10 deaths per 1000 person-years or 1.07 deaths per 1000 men who underwent randomization. The rate ratio for death from prostate cancer during follow-up years 10 and 11 was 0.62 (95% CI, 0.45 to 0.85; P=0.003). To prevent one death from prostate cancer at 11 years of follow-up, 1055 men would need to be invited for screening and 37 cancers would need to be detected. There was no significant between-group difference in all-cause mortality.

CONCLUSIONS

Analyses after 2 additional years of follow-up consolidated our previous finding that PSA-based screening significantly reduced mortality from prostate cancer but did not affect all-cause mortality. (Current Controlled Trials number, ISRCTN49127736.).

Increased non-prostate cancer death risk in clinically diagnosed prostate cancer

Study Type - Prognosis (case control). Level of Evidence 3a. What's known on the subject? and What does the study add? Treatment of advanced PC might put patients at an increased risk of cardiovascular events. Recent studies have suggested that the excess mortality is lower among men who were diagnosed with screen detected PC in comparison to men with clinically diagnosed PC, possibly due to the use of medications for cardiovascular disease and the change to a healthier lifestyle of men with a screen detected PC. Men with clinically diagnosed PC have an increased risk of death unrelated to PC itself, i.e., the excess mortality is based on an increased risk of dying from other neoplasm and diseases of the circulatory or respiratory system.

OBJECTIVE

• To assess the cause-specific mortality unrelated to prostate cancer (PC) itself in patients with screen- and clinically diagnosed PC.

PATIENTS AND METHODS

• The present study was conducted among participants of the European Randomized Study of Screening for Prostate Cancer. • Based on consensus of the causes of death committee (CODC), all patients who died from PC were excluded. • In the intervention arm, cases were patients with a screen-detected PC, aged 55-74 years, between 1993 and 2001. • These cases were matched to two controls in whom no cancer was found after biopsy, and two controls in whom no cancer was suspected after screening. In the control arm, cases were patients with clinically diagnosed PC, aged 55-74 years, between 1993 and 2001. These cases were matched to four controls without PC. Matching was done with respect to date of birth, screening and/or diagnosis. Men were followed up to 31 December 2007.

RESULTS

• No statistically significant difference in overall mortality between cases and controls in the intervention arm was observed: relative risk (RR) 1.26 (95% confidence interval [CI] 0.96-1.65; P = 0.102) and RR 1.13 (95% CI 0.86-1.47; P = 0.381). • In the control arm, the overall mortality was statistically significantly higher in cases relative to controls: RR 1.43 (95% CI 1.03-2.00; P = 0.033). • This difference was because of an increased risk of dying from neoplasms and disease of the circulatory or respiratory system among cases: RR 1.61 (95% CI 1.12-2.29; P = 0.009). • The present study was limited by the relatively small sample size.

CONCLUSIONS

• Increased mortality unrelated to PC itself was observed in men with clinically diagnosed PC, but not in screen-detected PC. • The excess mortality in men with clinically diagnosed PC seems to be as a result of a significantly increased risk of dying from neoplasm and disease of the circulatory or respiratory system. • Results have to be studied more thoroughly in further clinical trials.

Disease-specific mortality may underestimate the total effect of prostate cancer screening

OBJECTIVES

To study the difference between the disease-specific and excess mortality rate in the European Randomized Study of Screening for Prostate Cancer section Rotterdam.

METHODS

A total of 42,376 men were randomized to systematic screening or usual care. The excess number of deaths was defined as the difference between the observed number of deaths in the prostate cancer (PC) patients and the expected number of deaths up to 31 December 2006. The expected number was derived from mortality of all study participants before a possible diagnosis with PC. The disease-specific mortality rate was based on the number of men who died from PC. The excess mortality rate based on the arm-specific excess number of deaths and the disease-specific mortality rate were compared between the two study arms.

RESULTS

The overall mortality rate was not significantly different between the intervention and the control arms of the study: RR 1.02 (95% CI 0.98-1.07). The disease-specific mortality rate was 0.42 men per 1000 person-years in the intervention and 0.48 men per 1000 person-years in the control arm: RR 0.86 (95% CI 0.64-1.17). The excess mortality rate was 0.40 per 1000 person-years in the intervention arm and 0.61 men per 1000 person-years in the control arm, and the RR for excess mortality was 0.66 (95% CI 0.39-1.13).

CONCLUSIONS

In contrast to the disease-specific mortality rates an increased difference in the excess mortality rates was observed between the two arms. This observation may be due to a systematic underestimation of the disease-specific deaths, and/or an additional disease-related mortality that is measured by an excess mortality analysis but not by a disease-specific mortality.

Latest results from the UK trials evaluating prostate cancer screening and treatment: the CAP and ProtecT studies

The European Randomised Study of Screening for Prostate Cancer (ERSPC) demonstrated a significant reduction in prostate cancer-specific mortality. The ongoing Comparison Arm for ProtecT (CAP) cluster randomised controlled trial (RCT) evaluates prostate cancer screening effectiveness by comparing primary care centres allocated to a round of prostate specific antigen (PSA) testing (intervention) or standard clinical care. Over 550 centres (around 450,000 men) were randomised in eight United Kingdom areas (2002-2008). Intervention group participants were also eligible for the ProtecT (Prostate testing for cancer and Treatment) RCT evaluating active monitoring, radiotherapy and radical prostatectomy treatments for localised prostate cancer. In ProtecT, over 1500 of around 3000 men with prostate cancer were randomised from over 10,000 with an elevated PSA in around 111,000 attendees at clinics. Investigation of the psychological impact of screening in a sub-sample showed that 10% of men still experienced high distress up to 3 months following prostate biopsies (22/227), although most were relatively unaffected. The risk of prostate cancer with a raised PSA was lower if urinary symptoms were present (frequent nocturia odds ratio (OR) 0.44, 95% confidence interval (CI) 0.22-0.83) or if a repeat PSA decreased by > or = 20% prior to biopsy (OR 0.43, 95% CI 0.35-0.52). Men aged 45-49 years attended PSA clinics less frequently (442/1299, 34%) in a nested cohort with a cancer detection rate of 2.3% (10/442). The CAP and ProtecT trials (ISRCTN92187251 and ISRCTN20141217) will help resolve the prostate cancer screening debate, define the optimum treatment for localised disease and generate evidence to improve men's health.