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

BACKGROUND: The European Randomised Study of Screening for Prostate Cancer trial has shown a 21% reduction in prostate cancer (PC) mortality with prostate-specific antigen (PSA)-based screening. Sweden used a 2-yr screening interval and showed a larger mortality reduction than Finland with a 4-yr interval and higher PSA cut-off. OBJECTIVE: To evaluate the impact of screening interval and PSA cut-off on PC detection and mortality. DESIGN, SETTING, AND PARTICIPANTS: We analysed the core age groups (55-69 yr at entry) of the Finnish (N=31 866) and Swedish (N=5901) screening arms at 13 yr and 16 yr of follow-up. Sweden used a screening interval of 2 yr and a PSA cut-off of 3.0ng/ml, while in Finland the screening interval was 4 yr and the PSA cut-off 4.0ng/ml (or PSA 3.0-3.9ng/ml with free PSA<16%). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We compared PC detection rate and PC mortality between the Finnish and Swedish centres and estimated the impact of different screening protocols. RESULTS AND LIMITATIONS: If the Swedish screening protocol had been followed in Finland, 122 additional PC cases would have been diagnosed at screening, 84% of which would have been low-risk cancers, and four leading to PC death. In contrast, if a lower PSA threshold had been applied in Finland, at least 127 additional PC would have been found, with 19 PC deaths. CONCLUSIONS: The small number of deaths among cases that would have been potentially detectable in Finland with the Swedish protocol (or those that would have been missed in Sweden with the Finnish approach) is unlikely to explain the differences in mortality in this long of a follow-up. PATIENT SUMMARY: A prostate-specific antigen threshold of 3ng/ml versus 4ng/ml or a screening interval of 2 yr instead of 4 yr is unlikely to explain the larger mortality reduction achieved in Sweden compared with Finland.

Family history in the Finnish Prostate Cancer Screening Trial.

Family history (FH) is one of the few known risk factors for prostate cancer (PC). There is also new evidence about mortality reduction in screening of PC with prostate-specific antigen (PSA). Therefore, we conducted a prospective study in the Finnish Prostate Cancer Screening Trial to evaluate the impact of FH on outcomes of PC screening. Of the 80,144 men enrolled, 31,866 men were randomized to the screening arm and were invited for screening with PSA test (cut-off 4 ng/ml) every 4 years. At the time of each invitation, FH of PC (FH) was assessed through a questionnaire. The analysis covered a follow-up of 12 years from randomization for all men with data on FH. Of the 23,702 (74.3%) invited men attending screening, 22,756 (96.0%) provided information of their FH. Altogether 1,723 (7.3%) men reported at least one first-degree relative diagnosed with PC and of them 235 (13.6%) were diagnosed with PC. Men with a first-degree FH had increased risk for PC (risk ratio (RR) 1.31, p < 0.001) and the risk was especially elevated for interval cancer (RR 1.65, 95% CI 1.27-2.15). Risk for low-grade (Gleason 2-6) tumors was increased (RR 1.46, 95% CI 1.15-1.69), but it was decreased for Gleason 8-10 tumors (RR 0.48, 95% CI 0.25-0.95). PSA test performance (sensitivity and specificity) was slightly inferior for FH positives. No difference in PC mortality was observed in terms of FH. Our findings provide no support for selective PSA screening targeting men with FH of PC.