eMedicineLive

American Cancer Society recommends annual PSA (prostate specific antigen) screening and digital rectal examination from the age of 50 years. The effectiveness and appropriateness of using PSA estimation as a screening tool for prostate cancer is controversial among the medical community. Now two large studies started since early 1990s, one US based and another Europe based has produced markedly different results, without any conclusive evidence for or against annual screening for prostate cancer.

In the ‘European randomized study of screening for prostate cancer’ (ERSPC), the PSA screening reduced the rate of death from prostate cancer by 20%. In contrast to that the American ‘Prostate, lung, colorectal, ovarian (PLCO) cancer screening trial’ found that screening did not significantly alter the rate of death between the two groups. Researchers claim that the differing results can be attributed to variety of reasons, one of which is the improvement in the survival of patients after prostate cancer diagnosis due to advancement in the treatment. Other reasons may include difference in the research design. For example European study had PSA> 3 ng as an indication for biopsy and further evaluation but it was PSA > 4 ng in the US study, which means European study would have picked up more prostate cancers (more sensitivity but less specificity).

Screening was associated with a 22% increase in the rate of prostate cancer diagnosis (PLCO study) but both studies indicated that there is a risk of over diagnosis and over treatment, when PSA is used as a screening tool. In the European study the rate of over diagnosis is as high as 50% in the group subjected to screening, which resulted in unwanted biopsies, anxiety and further evaluations. Based on the European study results to prevent one prostate cancer death, 1410 men have to be screened and 48 men have to be treated. Now health planners and the governments need to think if screening for prostate cancer should be made as a routine. Since studies differ in their results, further research is needed to ascertain the role of PSA as a screening tool for the diagnosis of prostate cancer.

Reference: New England Journal of Medicine (NEJM) March 2009. For more information visit New England Journal of Medicine: http://content.nejm.org/
European randomized study of screening for prostate cancer: http://media.erspc-media.org/ . Prostate, lung, colorectal, ovarian (PLCO) cancer screening trial: http://prevention.cancer.gov/programs-resources/groups/ed/programs/plco