A Comparison of Total, Free, and % Free PSA for the Serodiagnosis of Prostate Cancer in African-American and Caucasian-American Males

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Medical Technology


Biological, Environmental, and Earth Sciences


Although the major types of non-skin cancer among men are prostate cancer, lung cancer, and colorectal cancer, prostate cancer is the second leading cause of cancer death among men. In 2009, there were 192,280 new cases of prostate cancer and 27,360 deaths from this disease in the USA. It has been suggested that there is a disparity in the incidence and recognition of prostatic cancer between African-American males and Caucasian-American males [1]. One of the most widely used approaches for diagnosing prostate cancer involves measuring prostate specific antigen (PSA) serum levels. One objective of this study was to compare normal (healthy) adult PSA levels in African-Americans and Caucasian-Americans to determine if there is racial/genetic bias. A second objective was the comparison of a manual assay with an automated assay for PSA detection. It was hypothesized that the Diagnostic Automation (manual) assays would be superior to the Beckmann Access (automated) assays for the detection of prostate cancer and that there would be a genetic bias. Tumor marker assays were performed according to the manufacturer’s directions. Assays used in this study included total PSA and % free PSA (Diagnostic Automation, Inc. and Beckman, Inc.). A total of 1,056 patient samples and 809 healthy adult male subject samples were tested. We concluded that the manual assay was superior to the automated assay for Free PSA detection but not for total PSA. We also concluded that there was genetic bias for African-American males versus Caucasian-American males.

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The Chemist





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