Does PSA Screening for Prostate Cancer lead to Overdiagnosis and Overtreatment?

Prostate cancer affects men, with over one million new cases diagnosed yearly. One way to detect prostate cancer is through a blood test that measures the levels of a protein called prostate-specific antigen (PSA) in the blood. While PSA screening can help reduce prostate cancer mortality, it can also lead to the overdiagnosis and overtreatment of low-risk cancers.

Clinical Trial

In a study, researchers evaluated the incidence of prostate cancer among men with PSA levels below 3 ng/mL and no prior prostate cancer diagnosis. The study followed the men from their first PSA screening attendance and ended with a prostate cancer diagnosis, emigration, death, or the study's closing date.

After a median follow-up of 17.6 years, the cumulative incidence of prostate cancer was 9.1 % among men with PSA levels below 3 ng/mL. The incidence was 3.6 % for men with PSA levels between 0 and 0.99 ng/mL, 11.5 % for men with PSA levels between 1.0 and 1.99 ng/mL, and 25.7 % for men with PSA levels between 2 and 2.99 ng/mL. The study found that the risk of prostate cancer increased significantly as PSA levels increased, particularly for low-risk cancers based on the Gleason score and the European Association of Urology (EAU) risk group.

The study suggests that men with PSA levels below 1 ng/mL have a low risk of developing clinically significant prostate cancer over 20 years. In contrast, men with PSA levels between 2 and 2.99 ng/mL have a much higher risk, with a 4- to 5-fold increased risk of developing aggressive prostate cancer.

The research suggests that risk stratification and appropriate rescreening intervals could help reduce the intensity of screening and overdiagnosis. Using the cumulative incidence of clinically significant prostate cancer as a criterion, the recommended rescreening intervals could range from approximately three years for men with initial PSA levels between 2 and 2.99 ng/mL, six years for men with PSA levels between 1 and 1.99 ng/mL, and ten years for men with PSA levels below 1 ng/mL.

Conclusion

PSA screening for prostate cancer can be beneficial in reducing mortality but can also lead to overdiagnosis and overtreatment of low-risk cancers. The study suggests that the risk of prostate cancer increases significantly as PSA levels increase, particularly for low-risk cancers based on the Gleason score and EAU risk group. Men with PSA levels below 1 ng/mL have a low risk of developing clinically significant prostate cancer over 20 years. Men with PSA levels between 2 and 2.99 ng/mL have a much higher risk of developing aggressive prostate cancer. The study recommends risk stratification and appropriate rescreening intervals to reduce screening intensity and overdiagnosis.
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