Tuomas P. Kilpeläinen

Prostate Cancer Mortality in the Finnish Randomized Screening Trial

BACKGROUND Prostate cancer (PC) screening with prostate-specific antigen (PSA) has been shown to decrease PC mortality by the European Randomized Study of Screening for Prostate Cancer (ERSPC). We evaluated mortality results in the Finnish Prostate Cancer Screening Trial, the largest component of ERSPC. The primary endpoint was PC-specific mortality. METHODS A total of 80 144 men were identified from the population registry and randomized to either a screening arm (SA) or a control arm (CA). Men in the SA were invited to serum PSA determination up to three times with a 4-year interval between each scan and referred to biopsy if the PSA concentration was greater than or equal to 4.0 ng/mL or 3.0 to 3.99 ng/mL with a free/total PSA ratio less than or equal to 16%. Men in the CA received usual care. The analysis covers follow-up to 12 years from randomization for all men. Hazard ratios (HRs) were estimated for incidence and mortality using Cox proportional hazard model. All statistical tests were two-sided. RESULTS PC incidence was 8.8 per 1000 person-years in the SA and 6.6 in the CA (HR = 1.34, 95% confidence interval [CI] = 1.27 to 1.40). The incidence of advanced PC was lower in the SA vs CA arm (1.2 vs 1.6, respectively; HR = 0.73, 95% CI = 0.64 to 0.82; P < .001). For PC mortality, no statistically significant difference was observed between the SA and CA (HR = 0.85, 95% CI = 0.69 to 1.04) (with intention-to-screen analysis). To avoid one PC death, we needed to invite 1199 men to screening and to detect 25 PCs. We observed no difference in all-cause mortality between trial arms. CONCLUSIONS At 12 years, a relatively conservative screening protocol produced a small, non-statistically significant PC-specific mortality reduction in the Finnish trial, at the cost of moderate overdiagnosis.

False-positive screening results in the Finnish prostate cancer screening trial

Background:There is evidence that prostate cancer (PC) screening with prostate-specific antigen (PSA) serum test decreases PC mortality, but screening has adverse effects, such as a high false-positive (FP) rate. We investigated the proportion of FPs in a population-based randomised screening trial in Finland.Methods:Finland is the largest centre in the European Randomized Study of Screening for Prostate Cancer. We have completed three screening rounds with a 4-year screening interval (mean follow-up time 9.2 years) using a PSA cutoff level of 4.0 ng ml−1; in addition, men with PSA 3.0–3.9 and a positive auxiliary test were referred. An FP result was defined as a positive screening result without cancer in biopsy within 1 year from the screening test.Results:The proportion of FP screening results varied from 3.3 to 12.1% per round. Of the screened men, 12.5% had at least one FP during three rounds. The risk of next-round PC following an FP result was 12.3–19.7 vs 1.4–3.7% following a screen-negative result (depending on the screening round), risk ratio 3.6–9.9. More than half of the men with one FP result had another one at a subsequent screen. Men with an FP result were 1.5 to 2.0 times more likely to not participate in subsequent rounds compared with men with a normal screening result (21.6–29.6 vs 14.0–16.7%).Conclusion:An FP result is a common adverse effect of PC screening and affects at least every eighth man screened repeatedly, even when using a relatively high cutoff level. False-positive men constitute a special group that receives unnecessary interventions but may harbour missed cancers. New strategies are needed for risk stratification in PC screening to minimise the proportion of FP men.

False-positive screening results in the European randomized study of screening for prostate cancer

BACKGROUND Screening for prostate cancer (PC) with prostate-specific antigen (PSA) has been shown to decrease mortality, but has adverse effects, such as false-positive (FP) screening results. We describe the frequency of FP results and assess their relation to subsequent screening attendance, test results and prostate cancer risk in a large randomized trial. MATERIALS AND METHODS We included data from five centres of the European Randomized Study of Screening for Prostate Cancer, altogether over 61,000 screened men. Men were screened with PSA test at a 2-7 year interval depending on the centre; PSA cut-off was 3.0-4.0 ng/ml. A positive screen with no histologically confirmed PC in biopsy within 1 year was defined as an FP result. RESULTS Of the 61,604 men who were screened at least once, 17.8% had one or more FP result(s). Almost 20% of men who participated at all screening rounds had one or more FP result(s). More than half of the men with an FP result had another FP if screened again. Men with FP results had a fourfold risk of PC at subsequent screen (depending on the round, 10.0% versus 2.6-2.7% of men with negative screen, risk ratio 3.8-3.9). The PCs following an FP result were in 92.8% of cases localised and low-grade versus 90.4% following a screen-negative result. CONCLUSIONS Our results show that FP results are common adverse effects in PC screening, as they affect at least one in six screened men. False-positive men are more prone to be diagnosed with PC but are also likely to have consistently high PSA levels.

Results of the three rounds of the Finnish Prostate Cancer Screening Trial—The incidence of advanced cancer is decreased by screening

Screening for prostate cancer (PC) remains a controversial issue despite some new evidence on the mortality benefits of PC screening. We conducted a prospective, randomized screening trial in Finland to investigate whether screening decreases PC incidence. Here, we report the incidence results from three screening rounds during a 12‐year period. Of the 80,144 men enrolled, 31,866 men were randomized to the screening arm (SA) and invited for screening with prostate‐specific antigen test (cut‐off 4.0 ng/ml) every 4 years, while the remaining men formed the control arm (CA) that received no interventions. The mean follow‐up time for PC incidence in both arms was over 9 years. The incidence rate of PC (including screen‐detected and interval cancers as well as cases among nonparticipants) was 9.1 per 1,000 person‐years in the SA and 6.2 in the CA, yielding an incidence rate ratio (IRR) 1.5 (95% confidence interval 1.4–1.5). The incidence of advanced PC was 1.1 in the SA and 1.5 in the CA, IRR = 0.7 (0.6–0.8) and the difference emerges after 5–6 years of follow‐up. The incidence of localized PC was 7.5 in the SA and 4.6 in the CA, IRR = 1.6 (1.5–1.7). The results from our large population‐based trial indicate that screening for PC decreases the incidence of advanced PC. When compared with the CA, the PC detected in the SA there were substantially more often localized, low‐grade PCs due to overdiagnosis.

The Finnish prostate cancer screening trial: analyses on the screening failures.

Prostate cancer (PC) screening with prostate‐specific antigen (PSA) has been shown to decrease PC mortality in the European Randomized Study of Screening for Prostate Cancer (ERSPC). However, in the Finnish trial, which is the largest component of the ERSPC, no statistically significant mortality reduction was observed. We investigated which had the largest impact on PC deaths in the screening arm: non‐participation, interval cancers or PSA threshold. The screening (SA) and control (CA) arms comprised altogether 80,144 men. Men in the SA were screened at four‐year intervals and referred to biopsy if the PSA concentration was ≥4.0 ng/ml, or 3.0–3.99 ng/ml with a free/total PSA ratio ≤16%. The median follow‐up was 15.0 years. A counterfactual exclusion method was applied to estimate the effect of three subgroups in the SA: the non‐participants, the screen‐negative men with PSA ≥3.0 ng/ml and a subsequent PC diagnosis, and the men with interval PCs. The absolute risk of PC death was 0.76% in the SA and 0.85% in the CA; the observed hazard ratio (HR) was 0.89 (95% confidence interval (CI) 0.76–1.04). After correcting for non‐attendance, the HR was 0.78 (0.64–0.96); predicted effect for a hypothetical PSA threshold of 3.0 ng/ml the HR was 0.88 (0.74–1.04) and after eliminating the effect of interval cancers the HR was 0.88 (0.74–1.04). Non‐participating men in the SA had a high risk of PC death and a large impact on PC mortality. A hypothetical lower PSA threshold and elimination of interval cancers would have had a less pronounced effect on the screening impact.

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.

Hand-assisted laparoscopic versus open partial nephrectomy in patients with T1 renal tumor: Comparative perioperative, functional and oncological outcome

Abstract Objective: Studies comparing hand-assisted laparoscopic partial nephrectomy (HALPN) and open partial nephrectomy (OPN) for T1 kidney tumors are scarce. This study investigated the perioperative, functional and oncological outcomes of these methods. Materials and methods: A prospective institutional kidney tumor register was used to identify patients between January 2006 and May 2014 undergoing HALPN (n = 139) or OPN (n = 165) for tumors 7 cm or smaller with non-absolute indication for nephron-sparing surgery. The outcomes were compared using univariate and multivariate statistical methods. Results: HALPN and OPN groups were similar with regard to tumor characteristics but HALPN patients were 2 years younger (p = 0.001) and had less comorbidity. Fewer intraoperative complications were encountered in HALPN than in OPN patients (7.2% vs 12.7%, p = 0.043). HALPN patients had less all-grade postoperative 30 day complications than OPN patients (27% vs 41%, p = 0.037), but there was no significant difference in Clavien 3–5 complications. Glomerular filtration rate 3 months after operation was lower in the HALPN than in the OPN group (7.1 ± 12.7% vs 10.0 ± 12.4%, p = 0.054). There was no difference in overall survival or recurrence-free survival during the median follow-up of 35 months. Conclusions: HALPN is a feasible method to achieve equal perioperative, functional and oncological outcomes compared to OPN in patients with tumors 7 cm or smaller in diameter.

Repeat multiparametric MRI in prostate cancer patients on active surveillance

Introduction This study was conducted to describe the changes in repeat multiparametric MRI (mpMRI) occurring in prostate cancer (PCa) patients during active surveillance (AS), and to study possible associations between mpMRI-related parameters in predicting prostate biopsy (Bx) Gleason score (GS) upgrading >3+3 and protocol-based treatment change (TC). Materials and methods The study cohort consisted of 76 AS patients with GS 3+3 PCa and at least two consecutive mpMRIs of the prostate performed between 2006–2015. Patients were followed according to the Prostate Cancer Research International Active Surveillance (PRIAS) protocol and an additional mpMRI. The primary end points were GS upgrading (GU) (>3+3) in protocol-based Bxs and protocol-based TC. Results Out of 76 patients, 53 (69%) had progression (PIRADS upgrade, size increase or new lesion[s]), while 18 (24%) had radiologically stable disease, and 5 (7%) had regression (PIRADS or size decrease, disappearance of lesion[s]) in repeat mpMRIs during AS. PIRADS scores of 4–5 in the initial mpMRI were associated with GU (p = 0.008) and protocol-based TC (p = 0.009). Tumour progression on repeat mpMRIs was associated with TC (p = 0.045) but not with GU (p = 1.00). PIRADS scores of 4–5 predict GU (sensitivity 0.80 [95% confidence interval (CI); 0.51–0.95, specificity 0.62 [95% CI; 0.52–0.77]) with PPV and NPV values of 0.34 (95% CI; 0.21–0.55) and 0.93 (95% CI; 0.80–0.98), respectively. Conclusion mpMRI is a useful tool not only to select but also to monitor PCa patients on AS.

Estimating bias in causes of death ascertainment in the Finnish Randomized Study of Screening for Prostate Cancer

BACKGROUND Precise cause of death (CoD) ascertainment is crucial in any cancer screening trial to avoid bias from misclassification due to excessive recording of diagnosed cancer as a CoD in death certificates instead of non-cancer disease that actually caused death. We estimated whether there was bias in CoD determination between screening (SA) and control arms (CA) in a population-based prostate cancer (PCa) screening trial. METHODS Our trial is the largest component of the European Randomized Study of Screening for Prostate Cancer with more than 80,000 men. Randomly selected deaths in men with PCa (N=442/2568 cases, 17.2%) were reviewed by an independent CoD committee. Median follow-up was 16.8 years in both arms. RESULTS Overdiagnosis of PCa was present in the SA as the risk ratio for PCa incidence was 1.19 (95% confidence interval (CI) 1.14-1.24). The hazard ratio (HR) for PCa mortality was 0.94 (95%CI 0.82-1.08) in favor of the SA. Agreement with official CoD registry was 94.6% (κ=0.88) in the SA and 95.4% (κ=0.91) in the CA. Altogether 14 PCa deaths were estimated as false-positive in both arms and exclusion of these resulted in HR 0.92 (95% CI 0.80-1.06). CONCLUSIONS A small differential misclassification bias in ascertainment of CoD was present, most likely due to attribution bias (overdiagnosis in the SA). Maximum precision in CoD ascertainment can only be achieved with independent review of all deaths in the diseased population. However, this is cumbersome and expensive and may provide little benefit compared to random sampling.

Renal Tumor Invasion Depth and Diameter are the Two Most Accurate Anatomical Features Regarding the Choice of Radical Versus Partial Nephrectomy

Background and Aims: To evaluate simple tumor characteristics (renal tumor diameter and parenchymal invasion depth) compared with more complex classifications, that is, Renal Tumor Invasion Index (RTII) and Preoperative Aspects and Dimensions Used for an Anatomical classification, in predicting the type of nephrectomy (radical vs partial) performed. Material and Methods: A total of 915 patients who had undergone either partial nephrectomy (n = 388, 42%) or radical nephrectomy (n = 527, 58%) were identified from the Helsinki University Hospital kidney tumor database between 1 January 2006 and 31 December 2014. Tumor maximum diameter and depth of invasion into the parenchyma were estimated from computed tomography or magnetic resonance imaging images and compared with Preoperative Aspects and Dimensions Used for an Anatomical and Renal Tumor Invasion Index. Logistic regression and receiver operating curves were used to compare the parameters at predicting the type of nephrectomy. Results and conclusion: All the anatomical variables of receiver operating curve/area under the curve analyses were significant predictors for the type of nephrectomy. Parenchymal invasion (area under the curve 0.91; 95% confidence interval, 0.89–0.93), RTII (area under the curve 0.91; 95% confidence interval, 0.89–0.93), and diameter (area under the curve 0.91; 95% confidence interval, 0.89–0.93) performed significantly better than Preoperative Aspects and Dimensions Used for an Anatomical classification (area under the curve 0.88; 95% confidence interval, 0.85–0.89). In multivariable analysis, invasion depth was the best predictor of nephrectomy type (percentage correct, 85.6%). Addition of one anatomic parameter into the model of non-anatomical cofactors improved the accuracy of the model significantly, but the addition of more parameters did not. Parenchymal invasion depth and tumor diameter are the most accurate anatomical features for predicting the nephrectomy type. All potential anatomical classification systems should be tested against these two simple characteristics.