PSA with Free PSA Ratio Test
PSA with Free PSA Ratio Test
PSA or Prostate Specific Antigen is a protein that is produced by the cells of the prostate gland. These cells may or may not be cancerous. This protein is generally present in the semen. But, the levels of this protein gets elevated in people who are older in age, prostate cancer patients and with larger prostate gland due to non-cancerous reasons. In these people, this protein can also be detected in the blood. In the blood, PSA may be present bound with other proteins or unbound. Unbound PSA is called Free PSA and total PSA consists of both unbound and bound PSA. To better understand the risks of prostate cancer and further course of diagnosis, doctors prefer assessing the level of this antigen as a ratio of free PSA and total PSA
What is the PSA with Free PSA Ratio Test Used For?
After testing the total PSA levels, if the levels of the total PSA are higher than a certain cut-off based on age and statistics, doctors will recommend testing free PSA to total PSA ratio. This ratio would help diagnosing conditions such as
Prostate Cancer
Benign Prostatic Hyperplasia which is a non-cancerous enlargement of the prostate gland
Symptoms of Prostate Cancer
This test helps evaluating the risks of prostate cancer. People having a family history of prostate cancer or having the symptoms of prostate cancer should discuss with their physician the future course of action. Some of the symptoms of prostate cancer, non-cancerous prostate gland enlargement or inflammation can be
Frequent urination at night
Blood in urine or semen
Difficulty or taking time while urinating
Feeling that the bladder is not empty
Sudden urges and needing to rush to the toilet
Preparation for Test
Before the test, please let your general physician know of any medication, supplements or treatments that you are undergoing. Medications like finasteride (belonging to a class of drugs called 5-alpha reductase inhibitors) which are used for treating benign prostatic hyperplasia or cholesterol lowering medications like aspirin and statins might cause a lower level of total PSA. Medications that raise testosterone levels can also result in higher PSA level.
Your doctor may also ask you to abstain from ejaculation one to two days before the test is conducted. Certain medical procedures such as prostate biopsy, digital rectal exams of the prostate gland may raise PSA levels
Interpretation of Test Results
The normal serum levels of total PSA varies based on the age of the patient, increasing with age. Doctors consider people with 0-2 nanograms per millilitre (ng/mL) of total PSA in blood serum to be at a low risk for prostate cancers. If the total PSA levels are less than 4 ng/mL, or between 4 ng/mL and 10 ng/mL, which is considered as a borderline zone, doctors would recommend checking for free PSA levels.
Free to total PSA ratio would be high in the case of non-cancerous prostate gland enlargement, which would mean that the free PSA is higher than the total PSA. If the free to total PSA ratio is low, meaning free PSA is lower than total PSA, there might be an increased risk of prostate cancer
FAQs
How is the sample collected for the PSA with Free PSA Ratio test?
A blood sample is collected from a vein in your arm. You may be asked abstain from ejaculation, and other procedures that may risk elevating or reducing the total PSA levels
What is the turnaround time (TAT) for PSA with Free PSA Ratio test?
The tests results should come within 1-3 days after the sample is taken. This time would depend on the diagnostic laboratory that has taken the sample for analysis
What should we do if the Free PSA to Total PSA ratio is low?
Doctors might advise a repeat of the tests after some time and if the free PSA to total PSA ratio continues to be low, they may refer you to a urologist who might recommend other tests such as digital rectal exam, prostate biopsy, or imaging studies like MRI to rule out the risk of prostate cancer
How does age affect the total PSA and what are the odds of having prostate cancer with age?
With age, the total PSA in the blood serum increases. If the free PSA to total PSA ratio is lower than 0.1, based on the age group you are in, the chances of your having prostate cancer is higher. For the same ratio, a 50-year-old may have a 49% chance of having prostate cancer, while a 70-year-old may have a 65% chance.
If the ratio is greater than 0.25, a 50-year-old may have a 9% chance of having prostate cancer, while a 70-year-old may have a 16% chance. These numbers should be carefully interpreted by a doctor
When should we start routine examinations for prostate cancer?
If there is a family history of prostate cancer, please contact your doctor for further advice. Based on the family history and your general health condition, doctors might recommend starting screening at the age of 40-45.
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