Prostate specific antigen

Prostate gland The prostate gland is located just below the bladder in men and surrounds the top portion of the tube that drains urine from the bladder (urethra). The prostate's primary function is to produce the fluid that nourishes and transports sperm (seminal fluid). The PSA test is a blood test used primarily to screen for prostate cancer. The test measures the amount of prostate-specific antigen (PSA) in your blood. PSA is a protein produced by both cancerous and noncancerous tissue in the prostate, a small gland that sits below the bladder in males. PSA is mostly found in semen, which also is produced in the prostate. Small amounts of PSA ordinarily circulate in the blood. The PSA test can detect high levels of PSA that may indicate the presence of prostate cancer. However, many other conditions, such as an enlarged or inflamed prostate, also can increase PSA levels. Therefore, determining what a high PSA score means can be complicated. There is a lot of conflicting advice about PSA testing. To decide whether to have a PSA test, discuss the issue with your doctor, considering your risk factors and weighing your personal preferences. Why it's done Prostate cancer is common, and it is a frequent cause of cancer death. Early detection may be an important tool in getting appropriate and timely treatment. Prostate cancer can cause elevated levels of PSA. However, many noncancerous conditions also can increase the PSA level. The PSA test can detect high levels of PSA in t...

Prostate-specific antigen (PSA) is a glycoprotein produced by the prostate gland, the lining of the urethra, and the bulbourethral gland. Normally, very little PSA is secreted in the blood. Increases in glandular size and tissue damage caused by benign prostatic hypertrophy, prostatitis, or prostate cancer may increase circulating PSA levels. PSA exists in serum in multiple forms: complexed to alpha-1-anti-chymotrypsin (PSA-ACT complex), unbound (free PSA), and enveloped by alpha-2-macroglobulin (not detected by immunoassays). Higher total PSA levels and lower percentages of free PSA are associated with higher risks of prostate cancer. Most prostate cancers are slow growing, so the utility of prostate cancer screening is marginal in most men with a life expectancy of less than 10 years. TOTAL PROSTATE-SPECIFIC ANTIGEN (PSA) Males: Age (years) PSA upper limit (ng/mL) or =80 or =70 years 0.25 9% 12% 16% Females: Not applicable When total prostate-specific antigen (PSA) concentration is below 2.0 ng/mL, the probability of prostate cancer in asymptomatic men is low, further testing and free PSA may provide little additional information. When total PSA concentration is above 10.0 ng/mL, the probability of cancer is high and prostate biopsy is generally recommended. The total PSA range of 4.0 to 10.0 ng/mL has been described as a diagnostic "gray zone," in which the free PSA:total PSA ratio helps to determine the relative risk of prostate cancer (see table). Therefore, some ur...

Learn more about the PSA Test, a blood test to screen for the risk of prostate cancer in men. What is a prostate-specific antigen (PSA)? Prostate-specific antigen, or PSA, is a protein produced by the prostate gland. When there’s a problem with the prostate gland, it releases more PSA. High levels of PSA can be a sign of What is considered an elevated prostate-specific antigen (PSA) level? Researchers haven’t settled on a single normal PSA level. Previously, a level of 4.0 ng/mL or higher would lead to more testing, usually a However, healthcare providers now consider other issues together with the PSA level to decide whether to perform a biopsy. Your age, general health, family history and health history factor into the decision. Does my PSA level determine whether I have prostate cancer? Your provider looks at two factors related to your PSA: • Your PSA level: A higher level means a higher risk of prostate cancer. • A continuous rise: PSA levels that continue to rise after two or more tests may mean you have cancer. But the PSA level alone doesn’t determine if you have cancer or not. Two men can even have the same PSA levels but different risks of prostate cancer. And a high PSA level may reflect prostate problems that aren’t cancer. What are other risk factors for prostate cancer? You may be at higher risk for prostate cancer if you: • Are older than 50 years. • Are of African-American or Caribbean descent. • Have a family history of prostate cancer. • Have certain gene...

• • • • • Sources: Species Human Mouse RefSeq (mRNA) RefSeq (protein) Location (UCSC) Prostate-specific antigen ( PSA), also known as gamma-seminoprotein or kallikrein-3 ( KLK3), P-30 antigen, is a KLK3 PSA is produced for the PSA is present in small quantities in the Medical Diagnostic Uses [ ] Prostate cancer [ ] Screening [ ] Main article: [ medical citation needed] The patient is required to be informed of the risks and benefits of PSA testing prior to performing the test. [ medical citation needed] In the United Kingdom, the PSA levels between 4 and 10 ng/mL (nanograms per milliliter) are considered to be suspicious, and consideration should be given to confirming the abnormal PSA with a repeat test. If indicated, [ citation needed] While PSA testing may help 1 in 1,000 avoid death due to prostate cancer, 4 to 5 in 1,000 would die from prostate cancer after 10 years even with screening. This means that PSA screening may reduce mortality from prostate cancer by up to 25%. Expected harms include anxiety for 100 – 120 receiving false positives, biopsy pain, and other complications from biopsy for false positive tests. [ medical citation needed] Use of PSA screening tests is also controversial due to questionable test accuracy. The screening can present abnormal results even when a man does not have cancer (known as a false-positive result), or normal results even when a man does have cancer (known as a false-negative result). [ medical citation needed] Of those found to ...