[Prostate-specific antigen: appropriate and inappropriate use]

PSA is a diffuse blood test, either for the follow-up of prostate cancer patients, or for the differential diagnosis of suspicious prostate lesions, or for "opportunistic" screening of healthy asymptomatic subjects. PSA is extremely useful in the two former instances, whereas screening is still in experimental phase: its efficacy in reducing prostate cancer mortality has not been demonstrated by ongoing studies which, on the contrary, have shown a relevant degree of "overdiagnosis" and "overtreatment" of "latent" carcinomas, which are not aggressive and would not have surfaced as symptomatic during lifetime. Screening should be banned from current practice until its efficacy is demonstrated, but bad and triumphalistic information by the media make a "prohibitionistic" approach rather impossible. If opportunistic screening can not be avoided, we should at least avoid too an aggressive diagnostic approach (e.g. random biopsy for borderline [4-10 ng/ml] PSA values).