PSA Test Accuracy

PSA stands for prostate specific antigen, and the PSA test helps in identifying the levels of this antigen present in the blood. The PSA is a protein which is produced by the prostate gland which is present in a man's body. A healthy prostate gland is almost the size of a walnut and is located at the neck of the bladder and surrounds the tube that helps the exit sperms and urine - known as urethra. However, due to various factors like age, ethnicity, family history, etc., cancer may develop in the prostate gland and result in elevated PSA levels in the body. It should be noted that prostate cancer is not the only reason why PSA levels may be elevated. This is the reason why there is a conflict in the accuracy of PSA blood test and its contribution in detecting prostate cancer.

How Accurate is the PSA Test?

Prostate cancer is the second leading cancer in men after skin cancer. The PSA test help in detecting the chances of a person to suffer from prostate cancer by monitoring the PSA levels. The test results work this way - It is measured in nanograms per milliliter (ng/mL), and normally the test results between 0-4 ng/mL, are considered to be normal. Men who have their PSA levels lying between the range of 4-10 ng/mL have 25% chances of developing prostate cancer, which is why this range is also considered to be as the 'gray zone'. Apart from setting these ranges and levels of PSA, it has happened many a time, that in spite of getting a PSA test done, doctors have failed to diagnose prostate cancer! In fact, some men still have normal PSA levels despite suffering from prostate cancer.

According to the National Cancer Society, 1 out of 4 men having prostate cancer have relatively lower PSA values. On the contrary, there have been men who have had high PSA levels but no development of prostate cancer was found. Therefore, the accuracy of PSA test comes into place only when combined with other tests and examinations like free PSA, Digital Rectal Examination (DRE) and biopsy. Experts suggest that biopsy should be recommended only if the results are less than 25%. Many times, multiple sessions of biopsy are required to diagnose the presence of prostate cancer. Therefore, the accuracy of PSA test is questionable, if taken into consideration without the supporting tests.

It is due to the aforementioned factors that the bodies of experts, which includes the American Cancer Society and the American Urological Association, have strictly recommended the doctors to conduct PSA tests only on men who are more than 50 years old. Apart from the age, this test can be conducted on men who have a family history for the disease or come from a different ethnicity. For example, men from African-American descent are more prone to develop prostate cancer. Anyone who is suffering from symptoms similar to prostate cancer like frequent urination, back pain, pelvic pain, and painful urination; and has a close relative who has suffered from prostate cancer is also eligible for conducting the PSA test. The American Cancer Society advises doctors to conduct tests and examination on these men on an annual basis, so that the prostate cancer may be diagnosed before it is too late for treatment.

The bottom line is that diagnosing prostate cancer based on the PSA results alone, is not recommended. According to a report published in the Journal of American Medical Association and the New England Journal of Medicine, PSA test when conducted with DRE, results in 70% increased chances of detecting prostate cancer! Therefore, it is best to conduct the PSA test with DRE tests. Have a safe tomorrow.