Special remarks:

Prostate cancer is the most frequent type of cancer found in the man and the second cause of death due to the cancer in man, Until recently, digital rectal examination was the most accepted diagnostic modality for early stage of prostate cancer but the measurement of serum PSA has become the most accepted test to indicate men who are at risk of having prostate cancer and who should be examined by other tests. Other biochemical markers used in this context (PAP, total alkaline phosphatase, carcinoembryonic antigen, etc,), are not as specific for prostate cancer. In 1979, Wang et al isolated a specific antigen for normal prostate tissue and called this protein PSA.
As demonstrated by Immunohistological studies, PSA is localized in the cytoplasm of prostate acinar cells, ductal epithelium and in the secretion on the ductal lumina, present in normal, benign hyperplastic and malignant prostate tissues as well metastatic prostate cancer and in seminal plasma. An elevation of the serum concentration is reported in patients with both benign prostatic hypertrophy Prostate carcinoma, but rarely in healthy men and is absent in normal womenl.
The recent literature indicates that serum testing for PSA has become a very important tool to screen for prostate cancer and to monitor therapy of this disease, Serial measurement of PSA concentration in the serum is an important tool in monitoring patients with prostate cancer and determining the potential and actual effectiveness of surgery or other therapies, or may allow for earlier discovery of residual or recurrent carcinoma after radical prostatectomy or radiotherapy.