THE PSA BIOMARKER FOR PROSTATE CANCER

The prostatic specific antigen (PSA) is a blood-test biomarker originally FDA-approved for use as a measure of prostate cancer activity NOT prostate cancer detection.
PSA-based screening for prostate cancer detection is highly UNRELIABLE.
The PSA is not prostate-specific and often fluctuates. The bigger the prostate, the greater the PSA. The so-called normal levels of 0-4 ng/ml are arbitrary and many situations can raise the PSA in the absence of cancer while other situations can lower the PSA without guaranteeing protective value.
PSA-based screening may be somewhat more informative by measuring several PSA formats before considering an mp-MRI and or, a prostate biopsy. The following PSA tests when considered together may improve screening reliability; the total PSA, PSA derivatives (free and percent free), PSA kinetics (velocity and doubling time), PSA density, age specific values, PCa3 test and evaluating the PSA after a 3 month course of finasteride (proscar). Sometimes this requires monitoring over some time before an MRI/ biopsy is considered.

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