Antidiabetic drug use and prostate cancer risk in the Finnish Randomized Study of Screening for Prostate Cancer. Haring A, Murtola TJ, Talala K, Taari K, Tammela TL, Auvinen A. Scand J Urol. 2017 Jan 13:1-11.
Summary: Diabetic men have lowered overall prostate cancer (PCa) risk, while their risk of high-grade disease may be elevated. The antidiabetic drug metformin may reduce the risk. This study evaluated PCa incidence among users of metformin and other antidiabetic drugs in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). Among antidiabetic drug users, metformin lowered the overall PCa risk, while the risk of metastatic disease was elevated in sulphonylurea users. As sulphonylureas stimulate insulin secretion, the results suggest that hyperinsulinemia may be a risk factor for PCa.
Impact of cause of death adjudication on the results of the European prostate cancer screening trial. Walter SD, de Koning HJ, Hugosson J, Talala K, Roobol MJ, Carlsson S, Zappa M, Nelen V, Kwiatkowski M, Páez Á, Moss S, Auvinen A; ERSPC Cause of Death Committees. Br J Cancer. 2017 Jan 3;116(1):141-148.
Summary: 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 endpoint assessment, and its possible impact on mortality results, we analysed the study outcome adjudication data in six countries. 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. 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. A bias in assigning causes of death that might have explained the mortality reduction by screening can be effectively ruled out.
Estimate of opportunistic prostate-specific antigen testing in the Finnish Randomized Study of Screening for Prostate Cancer. Kilpeläinen T, Pogodin-Hannolainen D, Kemppainen K, Talala K, Raitanen J, Taari K, Kujala P, Tammela TLJ, Auvinen A. 2017.
Summary: The purpose of this study was to estimate the degree of opportunistic prostate-specific antigen testing in the control arm (CA) of the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). Our findings demonstrate considerable frequency of non-organized PSA testing (i.e. contamination) in the CA of the FinRSPC. Approximately 1.4% of men had been tested with PSA 1-3 years before randomization. By the first four, eight and twelve years of follow-up, 18.1%, 47.7% and 62.7% of the men in the CA had been tested with PSA at least once, respectively. In the screening arm (SA), the corresponding proportions were 69.8%, 81.1% and 85.2%.