PSA blood test
The Prostate Specific Antigen (PSA) test enables the medical practitioner to detect prostate cancer at an early stage. prostate Specific Antigen (PSA) is a protein produced in small amounts in the cells of the prostate gland. A PSA blood test helps to determine whether stage of prostate cancer is advanced enough to perform a biopsy of the prostate gland or not. When the prostate gland enlarges, PSA level in the blood tends to rise. This is indicative of cancer or benign non-cancerous conditions. PSA is called biological marker or tumor. As men age, both benign prostate conditions and prostate cancer become more frequent. The most common benign prostate conditions are prostatitis which is inflammation of the prostate, and benign prostatic hyperplasia - BPH which refers to the enlargement of the prostate.
BPH - Benign Prostatic Hyperplasia is not usually dangerous by itself. Any strain on the bladder owing to urine retention can lead to complications like bladder/kidney damage, kidney stones, Urinary tract infection (UTI) or incontinence. The etiology of BPH is still not clear while most agree that the metabolism of testosterone can partially exacerbate BPH. A part of the secreted testosterone ends up as DHT - Dihydrotestosterone which may accentuate other conditions other than BPH - like male pattern baldness.
When the PSA test is combined with rectal examination, 90% of prostate cancers can be detected. In the U.S., the American Cancer Society recommends PSA blood test at least once a year to avoid the risk of prostate cancer.
The PSA test has been called the 'male PAP test'. The normal range for a PSA blood test is between 0 - 4 ng/ml (nanograms per milliliter). A PSA level of 4 - 10 ng/ml is considered slightly elevated. Levels between 10 -20 ng/ml are considered moderately elevated. Anything about 20 ng/ml is considered highly elevated. Although the higher the PSA level, the higher the risk of cancer, one abnormal PSA test result does not necessarily mean it is cancer that is present, as various other factors may cause PSA levels to fluctuate.
The PSA test is a radioimmunoassay. In a diagnostic laboratory, the patient's blood sample is exposed to the antibody against PSA. That moment the amount of antigen (PSA) can be measured. It should be borne in mind that a man who is undergoing hormone therapy for prostate cancer may have a low PSA test reading during or immediately after the treatment. The low level may not be a true measurement of PSA in the patient's body. It is essential that such patients brief the doctor who may probably advise him to wait a few months after hormone treatment before having a PSA test done.
PSA test does not help a man with fast-growing tumors or aggressive cancer. It helps only in detection of small tumor and slow growing tumors which are unlikely to threaten a man's life. PSA test also cannot detect cancers spreading to the other parts of the body beforehand. There is a fear of false positives test results in PSA testing. Sometimes PSA level could be elevated but that does not necessarily mean cancer is present. A fear of false negative test result can also occur in PSA testing. That is the PSA test result will show negative even if prostate cancer is actually present in the patient. PSA blood test is often followed by other diagnostic tests such as ultrasound, x rays and cystoscopy to determine the presence of cancer or any other problem in the prostate.
Bibliography / Reference
Collection of Pages - Last revised Date: February 16, 2019