[Prostate cancer: the evidence weighs against screening]

The risk of death from prostate cancer is very small before age 75: if one follows 1000 men from birth until age 75, one will observe 7 prostate cancer deaths. Prostate cancer is extremely frequent: if one were to autopsy 1000 men aged 75, one would find a cancer in the prostate of 800. Therefore, screening by systematic PSA measurement in the population induces an epidemic. The benefit associated with screening is not clearly established. The assertion that screening reduces prostate cancer mortality by 20% is based on the best result observed in the best subgroup (population aged 55 to 69) in the only trial that shows a benefit. Even if screening reduced prostate cancer mortality by 20%, its drawbacks: a doubling of the number of cancers diagnoses and the unwanted effects of treatments (50% of patients incontinent and/or impotent), weigh against systematic screening. Even if screening reduced prostate cancer mortality by 20%, the absolute benefit of screening in a population of 1000 men aged 55 to 69 followed 9 years will be the avoidance of one prostate cancer death, since the expected number of these deaths without screening is 4, a 20% reduction corresponds to less than 1 death.