PSA

Prostate Specific Antigen (PSA) is a serine protease
with chymotrypsin-like activity (1,2). The protein is a
single chain glycoprotein with a molecular weight of
28.4 kDa (3). The name PSA derives from the
observation that PSA is a specific antigen of the
prostrate and it is not found in other tissues.
PSA is found in benign, malignant and metastatic
prostrate cancer. Since prostate cancer is the second
most prevalent form of male malignancy, the
detection of elevated PSA levels plays an important
role in the early diagnosis. Due to increased
sensitivity, serum PSA levels are more useful than
prostatic acid phosphatase (PAP) in the diagnosis
and management of patients (4).