Yearly Prostate Specific Antigen and Digital Rectal Examination Fluctuations in a Screened Population
Received 11 September 2008 published online 16 March 2009.
Purpose
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.
Materials and Methods
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.
Results
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.
Conclusions
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.
aDepatment of Urology, University of Texas Health Sciences Center, San Antonio, Texas
bDepatment of Epidemiology and Biostatistics, University of Texas Health Sciences Center, San Antonio, Texas
Department of Urology, University of Texas Health Sciences Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229 (telephone: 210-567-5643; FAX: 210-567-6868)
Supported by U.S. Public Health Service Grants awarded by the National Cancer Institute, Department of Health and Human Services CA 37429, CA 35178, CA 45808, CA 86402 and 5UO1CA86402 (Early Detection Research Network, National Cancer Institute, National Institutes of Health).
Editor's Note: This article is the third of 5 published in this issue for which category 1 CME credits can be earned. Instructions for obtaining credits are given with the questions on pages 2392 and 2393.
‡ Financial interest and/or other relationship with the National Cancer Institute, AstraZeneca, Mission Pharmacal, Southwest Oncology Group and Veridex.
§ Financial interest and/or other relationship with Intuitive Surgical and Ethicon.
ABSTRACT