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

Introduction: European Randomized Study of Screening for Prostate Cancer (ERSPC) mortality results were reported for 7 European countries (excluding France) and showed a significant reduction in Prostate cancer (PCa) mortality. As those results have not been part of the global ERSPC results, it is of interest to report PCa mortality at a median follow-up of 9 years for French section of ERSPC.
Material and methods: Two administrative departments were involved in the study. Only men after randomization in the screening group were invited by mail to be screened by PSA testing with two rounds at 4–6 year intervals. Biopsy was recommended if PSA > = 3.0 ng/mL. No information other that the French Association of Urology recommandations on the use of PSA was offered to the control group (own decision of physicians and patients). Follow up was based on cancer registry database. Contamination defined as the receipt of PSA testing in control arm was measured. Poisson regression models were used to estimate the Rate Ratio (RR) of PCa mortality and incidence in the screening vs. control arm.
Results: Starting from 2003, 80,696 men aged 55–69 years were included. The percentage of men in the screening arm with at least one PSA test (compliance) was 31%. Compared to the control arm, PCa incidence increased by 10% in the screening arm (RR = 1.10; 95% CI = [1.04–1.16], P = 0.001), but PCa mortality did not differ (0.222 and 0.215 deaths/1000 person-years; RR = 1.03[0.75–1.42], P = 0.9).
Discussion: Limitations include low participation rate. PSA testing in the control arm was observed in 32% of men (contamination).
Conclusions: Contamination in control group led to no effect of PSA-based screening on prostate cancer mortality at 9 years follow-up. Level of evidence: 3.