Prostate Cancer Screening: Biases and the Need for Consensus
Cet éditorial et ce commentaire analysent les biais présents dans trois essais cliniques (américain, européen et suédois) évaluant l'efficacité du dépistage du cancer de la prostate par dosage du PSA et des traitements délivrés pour réduire la mortalité spécifique
In the 1990s, several studies were published showing that serum prostate specific antigen (PSA) aided in the diagnosis of localized prostate cancer (1,2). Widespread screening was adopted quickly in the United States, where it is dogma that early detection and aggressive treatment saves lives.
This bias toward screening would delay and hinder study to determine whether screening truly saves lives. It would be more than 20 years before the results of well-designed prospective randomized studies would be published assessing the effectiveness of PSA screening—notably, the Prostate, Lung, Colon and Ovarian Cancer Screening Trial (PLCO)(3,4), which suggested that screening does not reduce mortality at 13 years median follow-up, and the European Randomized Study of Prostate Cancer (ERSPC)(5,6) study and Goteborg (7) trial, which suggested that screening does save lives after 11 and 14 years median follow-up, respectively.
In this issue of the Journal, Haines and Gabor (8) provide some much needed critical examination of these trials. Biases are preventing us from determining which finding is correct. No clinical study is perfect. The scientific process is at its best when there is publication of studies and thorough discussion in the literature. When proper analysis of a study defines its limitations, it actually increases the value of the study. Careful examination of a study and its results leads to a better understanding of the truth and, often defines additional important questions.
Many show bias in their interpretation of these trials. Those who had faith in the value …
Journal of the National Cancer Institute , éditorial, 2013