PSA Blood Test

A part of the male reproductive system, the prostate gland, is found beneath the urinary bladder, and is as big as a walnut. The secretions produced by this gland are ejected with semen. Being alkaline in nature, these secretions balance the acidic environment of the vagina and enhance the motility of sperms. As in case of other organs, the prostate too is prone to developing problems like inflamed prostate and enlarged prostate. Even prostate cancer is found to be common in men, especially the elderly ones. As far as prostate cancer is concerned, the PSA blood test is found to be used as a screening test.

What is a PSA Blood Test

As mentioned above, this blood test is conducted to detect prostate cancer. PSA is the short form for prostate specific antigen, which is a protein produced by the cells of the prostate gland. (According to recent studies, prostate specific antigen is not a true antigen and is not produced by prostate alone. It is found in other body tissues, and even breast milk and amniotic fluid, is found to have small amounts of PSA.)

Once produced in the prostate, this protein is released to the blood stream, and the PSA test is intended to measure the PSA levels in blood. It is said that small amounts of PSA is found in young and healthy males, although, with age, this level may increase slightly. But, a considerable increase in PSA levels can be seen in men with enlarged prostate (prostatic hyperplasia (BPH) or benign prostatic hypertrophy), prostatitis (inflammation of the prostate gland) and prostate cancer.

Even though there is no conclusive evidence to prove that these conditions (enlarged or inflamed prostate) can cause cancer, there are chances that cancer may develop in those having any of these conditions. The effectiveness of the PSA blood test as a screening tool for prostate cancer is still a much debated topic, as it is seen that even men with normal PSA levels develop prostate cancer. However, as of now, it is considered an effective tool for detecting this type of cancer.

PSA Blood Test Results Explained

In order to understand interpretation of PSA results, you need to know about the normal PSA range. The normal levels of PSA is said to be 4 ng/mL. However, the upper limit of the normal PSA level is taken as less than 4. A PSA value of 4 ng/mL or higher, maybe an indication of prostate cancer. But, other benign conditions, like enlarged prostate and prostatitis may also result in elevated PSA levels. So, if a person is detected with high PSA levels, he will be asked to undergo a biopsy, digital rectal exam, transrectal ultrasound, and other tests (so as to confirm or rule out cancer). According to experts, normal PSA levels for younger man must be as below 2.5 ng/mL. This is because, PSA levels increase with age, and in elderly people, a PSA level from 2.5 to 4 ng/mL may be considered normal. But this is not the case with younger men, who normally have low PSA levels.

Another point to be taken into consideration is the level of free PSA. You can find two types of PSA in the blood - bound PSAs are found to be attached to certain blood proteins and free PSAs that are not bound. If the ratio of free PSA to total PSA is too low, then, there are chances that the person is having cancer. Studies show that if the ratio is below 10, the risk of cancer is 60%, and if it is 10 - 15, the risk level lowers to 35%. Risk of cancer becomes near to nil as the ratio gets higher than 25. Another point is the change in the PSA levels over time. If it is too rapid, then cancer may be there. Recent studies show that even though the PSA levels are below 4 ng/mL, such men have a 15% chance of having prostate cancer. If the PSA is between 4 and 10, those men too have a risk of 25%, and if it is above 10, then the risk factor rises to nearly 70%.

In short, a high PSA level may not be a conclusive evidence for prostate cancer, and a low PSA level may not mean that you are free of this cancer. So, the risk of prostate cancer is associated with all PSA levels. But, the percentage of risk varies. So, a PSA blood test result is often interpreted along with other factors, like age of the person, the velocity of rise in PSA level with time and level of free PSA.

Disclaimer: This article is for informational purposes only and should not be used as a replacement for expert medical advice.