Early Detection Research Network

Yearly prostate specific antigen and digital rectal examination fluctuations in a screened population.

Prostate biopsy is often recommended based on increases in prostate specific antigen and/or abnormal digital rectal examination. We investigated the stability of a single positive test during the next 3 consecutive years.

A total of 2,578 participants in a San Antonio screening cohort with 2 or more consecutive annual prostate specific antigen and digital rectal examination tests were identified. Occurrences of an increased prostate specific antigen (2.5 ng/ml or greater) followed by 1 or more nonincreased prostate specific antigen results were compared with similar fluctuations of digital rectal examination from abnormal to normal.

In 2,272 men who did not have a biopsy during the study, in 23.3% of 744 incidences of an increased prostate specific antigen with 1 year of followup, the next prostate specific antigen was not increased. In 19.5% of 462 incidences of an increased prostate specific antigen with 2 years of followup, the next 2 consecutive prostate specific antigen levels were not increased. Finally, in 17.5% of 285 incidences of an increased prostate specific antigen with 3 years of followup, the next 3 consecutive prostate specific antigens were not increased. Rates were similar but lower in 221 men with 1 or more negative biopsies during the study and in 85 men in whom prostate cancer eventually developed during the study. In contrast, approximately 70% of abnormal digital rectal examinations were normal the following year even in patients with prostate cancer, and in the majority of incidences remained normal the next 2 to 3 consecutive years.

Occurrences of reversed prostate specific antigen cut point or abnormal digital rectal examination based decisions to biopsy 1 or more years after the initial test are not uncommon, suggesting repetition of these tests.

Ankerst DP, Miyamoto R, Nair PV, Parekh DJ, Pollock BH, Thompson IM

19286205

J. Urol., 2009, 181 (5)

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