Prostate cancer screening: the problem of overdiagnosis and lessons to be learned from breast cancer screening.

Screening for prostate cancer is a relatively new procedure, still under experimental evaluation within prospective randomised trials. The design of prospective studies has been mainly based on the experience of other cancer screenings, particularly breast cancer, for which data of several controlled studies are available. Unfortunately, breast cancer is very different from prostate cancer, particularly for aspects such as early diagnosis and, thus the screening process, originally modelled on the basis of the lesson taught by breast cancer screening, needs continuous re-evaluation and adjustment, based on data which are now being produced from ongoing screening experiences. In this paper, we will consider the most controversial aspects of prostate cancer screening and compare prostate screening with breast cancer screening in order to promote a better understanding of the current problems and lessons to be learned.