- Prostate-specific antigen (PSA) is a biomarker that allows both the detection and evaluation of tumors and oncological development in the prostate.
- It is recommended that people with a family history of prostate cancer begin the test from the age of 40 and those who do not have a family risk, from the age of 45.
Prostate-specific antigen, also known as PSA, is a glycoprotein that is found circulating in the bloodstream and is released from the prostate, a gland specific to males.
Dr. Daniel Aguirre Chavarría, head of the clinical laboratory at ABC Medical Center, Santa Fe Campus, indicates that this protein is considered a biomarker because it can be measured and, based on its results, the prostate state can be interpreted and it is possible to detect a risk situation for the patient.
“In America, prostate cancer is the most common cancer in men, with 413,000 new cases and 85,000 deaths each year. Caribbean countries, especially Barbados, Trinidad and Tobago, and Jamaica, have the highest rates of prostate cancer in the region.”1
In general terms, this protein is generated in the prostate, it has two fractions, one that is free in the bloodstream (free PSA) and another bound to a carrier protein, which, in short, is known as total PSA.
Performing the tests will allow us to detect elevations of the antigen in the blood in advance.
The ranges considered normal depend on various factors such as age and the correlation between free PSA and total PSA.
A total PSA of:
- 0 to 4 ng/ml* is a normal range.
- 4 and 10 ng/ml*, is considered a prostatic hypertrophy, where the free PSA helps to discriminate between benign or oncological conditions.
- Greater than 10 ng/ml* are highly likely to suffer from prostate cancer.
The biggest problem with the range between 4 and 10 is being a gray area because with age it is normal to increase the gland development or have a controlled and normal growth of the prostate due to benign prostatic hypertrophy; but, on the other hand, this increase could be due to tumor development.
That is why the free PSA/total PSA ratio detects 95% of prostate cancer cases, being one of the tests used to screen for prostate cancer, which, derived from the result, medical intervention and complementary tests will be required to confirm the diagnosis.
It must be remembered that there is biological variability in each person, this means that there are variations in the levels of chemical substances circulating in our blood, including prostate antigen, due to this, the results must be interpreted by a doctor, to correlate and integrate important information for an adequate diagnosis, timely follow-up and correct treatment.
To perform the prostate antigen test, a blood sample will be taken that will allow the free PSA and the total PSA to be known individually or together. But there are certain restrictions before taking the sample to achieve an adequate measurement. These include not having sexual intercourse for two or three days before going to the lab, avoiding anal sexual stimulation or instrumental or non-instrumental examinations, and, in case of suffering from a prostatic infection, treatment must first be completed before the screening.
How often should total and free PSA be performed?
As there are changes in the prostate due to age and the presence of other risk factors, it is recommended that if you have some type of family inheritance or if a close relative (father, grandfather, siblings, or uncles) has suffered from this disease, the test to be performed from the age of 40. On the other hand, if there is no family inheritance, the test can be performed from the age of 45.
Thus, it is recommended to perform the test at least once a year, this will make it possible to identify a possible risk situation from the early stages.
At the ABC Medical Center’s Clinical Laboratory, we can provide you with specialized care. Contact us!
Dr. Daniel Aguirre Chavarría – head of the Clinical Laboratory of the ABC Medical
* ng/ml = nanogram per milliliter
Lowrance WT, Breau RH, Chou R et al: Advanced Prostate Cancer: AUA/ASTRO/SUO Guideline PART I. J Urol 2021; 205: 14 Cáncer de próstata avanzado: Guía AUA/ASTRO/SUO (2020) – Asociación Americana de Urología (auanet.org)
Prostate Cancer – Uroweb