Low Prostate-Specific Antigen Screening Has Limited Benefits

The epithelial cells in the prostate gland produce the protein prostate-specific antigen (PSA), some of which escapes into the bloodstream. When levels of PSA in the blood are high, it might be an indication of either prostate cancer or some kind of prostate condition.

The level of serum PSA is used as a screening test for diseases that involve the prostate, which include malignant cancer and benign prostatic hyperplasia. A high level of PSA will prompt aggressive therapy including sextant biopsies and biopsies of the affected organ. What constitutes an elevated PSA level varies from country to country.

The European Randomized Study of Screening for Prostate Cancer sections in Finland, Sweden and the Netherlands, screened for intervention 43,987 males, aged 55-70. In Northern Ireland, 42,503 males, aged 55-74 years, were included in the study as clinical participants. They were all followed-up from 1993 and 1999 for prostate cancer incidence and causes of death through to the end of 2006. Men with baseline PSA levels of >20.0 ng/mL were excluded from the study. .

The scientists found that males with low serum PSA levels often undergo biopsies and aggressive treatments, with no significant improvement in mortality, after examining details on 85,000 males aged between 55 and 74 years. The prostate cancer mortality rates intensify with increasing baseline PSA level in both groups. Relative to the men with a baseline serum PSA of <2.0 ng/mL at study entry, men with a higher baseline serum PSA level had a significant, increased, adjusted risk ratio of dying from prostate cancer in both groups. The absolute difference in prostate cancer specific mortality was 0.05 per 10,000 person years in men with a baseline serum PSA level of 0.0 ng/mL - 1.9 ng/mL and 8.88 per 10,000 person years in men with a baseline serum PSA of 10 ng/mL - 19.9 ng/mL, escalating with the increasing baseline PSA level.

For males with PSA levels below 2 ng/mL, in order to prevent just one prostate cancer death, 24,642 patients would need to be screened and 724 patients would need prostate cancer treatment. For men with PSA levels between 10 ng/mL and 19.9 ng/mL, 133 patients would need to be screened to save one life. For men with a low serum PSA level, the benefits of aggressive investigation and treatment may be limited because they are associated with a large increase in cumulative incidence and potential overtreatment.

Pim J. van Leuwen, M.D, Erasmus University Medical Center, (Rotterdam, Netherlands), said, "Screening for prostate cancer has the potential to reduce prostate cancer mortality, but there is a large group of men with a moderately low PSA that will hardly have any benefits of further screening and early detection strategies. In these men, screening and early detection is likely to have little effect on the reduction of prostate cancer mortality, but a major negative effect on the quality of life." The study was published online on September 13, 2010 in the journal Cancer.

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Erasmus University Medical Center