Prostate specific antigen is a certain type of glycoprotein encoded in the human body by the gene known as KLK3. It is also sometimes referred to as Kallikrein-3, gamma seminoprotein or simply PSA. It belongs to the family of kallikrein related peptidase and it gets secreted in the epithelial cells of the prostate gland. Its main purpose is to liquefy the semen in the seminal coagulum once the ejaculation occurs. This is done so that the sperm may be able to swim freely. It also has another important purpose and that is to dissolve the cervical mucus so that the sperm may enter freely. Men with healthy prostates usually have it present only in small quantities, but those who suffer from various different types of prostate related medical problems such as the prostate cancer usually have elevated levels of PSA present in their prostates. The best way of early detection of prostate cancer is a certain type of blood test which measures the PSA. The predictive value of such tests is somewhere around 35 per cent.
PSA Is Not without Risk
There are certain risks associated with the screening tests. This is mainly due to the fact that those tests may not be perfect and that they miss some cancers which are present in the prostates of patients. They may also show things that may seem like tumors but in actuality they are not. The screening tests are utterly unreliable as they may also find certain types of cancer which will never be associated with any health problems. In most cases, there is no possible way of determining which cancers are harmful and which are not, so they all get treated the same way. In cases of harmful ones this is a good thing, but there may also be cases in which the cancer treatment such as radiation, chemotherapy and surgical interventions are unnecessary and may cause more harm than good. Blood samples taken from the vein are associated with much less risks than the screening tests. A person may only experience slight bruising at the site where the needles was inserted into the vein. Some rare cases may also involve swelling of the veins after taking the blood sample. This condition is medicinally referred to as phlebitis. People who suffer from different types of bleeding disorders may also experience certain troubles with ongoing bleeding after taking a blood sample. Blood sample tests should not be performed on people treated with medications called dutasteride and finasteride (these are used for the prevention of the enlargement of the prostate), people treated with larger doses of methotrexate or cyclophosphamide (used for the treatment of cancer), people who had recent prostate surgery, prostate biopsy or a recent digital rectal exam, people who recently suffered from some sort of urinary tract infections, people who recently had a catheter for the draining of urine or people who were recently sexually active.
Research for Improvement of PSA Test
There are still numerous studies conducted simply to determine the exact benefits of screening for prostate cancer. The PLCO trial currently conducted by the National Cancer Institute includes the evaluation of prostate, lung, colorectal and ovarian cancer screening tests. The main goal is to determine which tests are the most efficient in reducing the number of deaths triggered by cancers. The PSA test is one of the tests which is also evaluated, because there are chances of yearly screenings being able to detect prostate cancer and increase the patients’ chances of surviving this dreaded medical condition. The trial and the initial results have unfortunately showed that the PSA tests which lasted for 6 years did not actually reduce the number of deaths in patients who suffer from prostate cancer. On the other hand, these tests were successful in increasing the number of prostate cancer detected and diagnosed by 23 per cent. The outcome of the results suggests that men diagnosed with prostate cancer were treated with the usual treatment methods, but unfortunately there were cases in which the treatment options such as radiation therapy, chemotherapy and surgical intervention were completely unnecessary and sometimes even harmful. There were several other large controlled trials of prostate cancer screening which have showed that the PSA testing every 4 years can reduce the number of deaths triggered by prostate cancer by 20 per cent. The world of science is also constantly trying to improve all the features and abilities of the PSA test. The most efforts are focused on much more accurate distinguishing of cancerous conditions from benign ones, slow growing cancers from fast growing ones and potentially lethal cancers from the harmless ones, and so on. There are certain types of methods which are studies and those include PSA velocity and PSA density. PSA velocity focuses on following the changes in the levels of PSA over time. Sharp changes in the levels of PSA commonly indicate that there is something wrong going on in the prostate. PSA density is completely different as it focuses on the relationship between the size of the prostate and the levels of PSA contained in it. Another method which is currently studied is called free versus attached PSA. It focuses on the relation between the free PSA and the PSA attached to molecules of proteins. The last method currently studied is the alteration of the PSA cutoff level. It may be very efficient in reducing the risk of unnecessary medical procedures.