Prostate Specific Antigen

The prostate is a gland which makes up a major portion of the male reproductive system and is located just below the bladder and in front of the rectum. The prostate is about the size and shape of a walnut and wraps around the urethra, through which urine passes on its way out the penis. The prostate has the responsibility of producing semen, which is then squeezed out through the penis during ejaculation. Because the urethra is responsible for carrying urine from the bladder during the penis as well as semen during ejaculation, problems with the prostate gland may affect urinary as well as sexual function. Not all of the seminal fluid that is ejaculated during orgasm is produced in the prostate; another portion of the fluid is secreted by the seminal vesicles. Part of the seminal fluid that is ejaculated during orgasm is produced by the prostate gland, while the remaining fluid is produced by two seminal vesicles. Androgens, also known as male hormones, help the prostate to function properly. The main male hormone, testosterone, is produced by the testicles and is critical to healthy prostate gland function.

Antigens are a type of substance that stimulates the production of antibodies by the immune system and are found on the surface of cells. While antigens are normal in the human body, cancer cells release higher levels of antigens into the bloodstream, than are normally present. The release of antigens makes it possible to detect cancer through blood tests.

An antigen referred to as prostate specific antigen is a protein that is produced exclusively by the prostate gland. A blood test can be performed to determine the presence of prostate cancers and is in fact one of the most effective ways to detect prostate specific antigen. A high level of prostate specific antigen may not always indicate the presence of prostate cancer, as high levels may also be present in the case of other prostate disorders such as an inflamed or enlarged prostate. A prostate specific antigen blood test is a good place to begin, however when a patient is experiencing symptoms related to prostate cancer.

Prostate cancer is one of the leading types of cancers diagnosed in American men. Each year almost a quarter of a million new cases are diagnosed. It is estimated that prostate cancer will affect one out of every ten men. Each year more than 30,000 men die from prostate cancer. Because of the seriousness of the problem, prostate cancer is perhaps the most serious of all the different types of prostate disease. Prostate cancer generally occurs in men who are over the age of 65, although cases in younger men have been reported. There is a high incidence of prostate cancer occurring in men who are shown to have a family history of this type of prostate disease. African-American men are considered to be particularly at risk for prostate cancer and suffer from the highest death rates related to this disease. Physicians now recommend that all men over the age of 50 have a prostate disease and cancer screening once a year and that men who are considered to be in high risk groups, such as African-Americans, begin to have annual screenings by age 45. Prostate cancer begins with a tumor growing on the outside of the prostate. Prostate cancer can develop slowly over a period of years and because it may not initially show any symptoms, it may go unchecked until it has spread to other parts of the body. One of the most serious concerns regarding the spread of prostate cancer is the proximity of nearby lymph nodes which may be compromised by the growing cancer. Symptoms of prostate cancer can include changes in urination. Pain the lower back, upper pelvis, legs and thighs is also considered to be a symptom of prostate cancer. Men who fall into one of the high risk groups or who are experiencing prostate cancer related symptoms should have a prostate specific antigen blood test performed.

The prostate specific antigen blood test is a very simple procedure and only involves minor blood work so there is no need for a hospital stay or even for the use of anesthesia. Usually a prostate specific antigen blood test can be performed right in the doctor's office or in a lab. The prostate specific antigen blood test is conducted by taking a blood sample from the patient's arm. The technician will then expose the blood sample to an antibody that is known to attack prostate specific antigen and the amount of prostate specific antigen present will then be measured. Normally, a prostate specific antigen range is between 0-4 ng/mL. Older men, however; do tend to have higher levels of prostate specific antigen. It is recommended that men who are at least 50 years of age have an annual rectal exam as well as a digital rectal exam.

If the physician feels what he or she believes to be an abnormality during the exam, they may order a prostate specific antigen to make a determination regarding the presence of prostate cancer. The presence of a higher prostate specific antigen does not always indicate prostate cancer. Sometimes the prostate simply becomes inflamed due to bacteria that are present and this can sometimes account for a raised prostate specific antigen level. In other cases, the prostate may be enlarged which can contribute to symptoms similar to prostate cancer as well as a raised prostate specific antigen level. If the test if positive, the doctor will most likely need to perform a biopsy in order to make a positive or negative prostate cancer diagnosis. The biopsy is more invasive than the prostate specific antigen test and comes with more risks, however; it is necessary to diagnose the presence of prostate cancer. If the test turns out to be negative, but there have been some prostate disorder related symptoms or the doctor believes there was an abnormality felt during the rectal exam, they may need to repeat the test. The test results can sometimes be inconclusive if there was not enough blood drawn. If a patient is diagnosed with prostate cancer, the prostate specific antigen may also be used to monitor the prostate specific antigen levels of the patient during treatment.