Prostate Specific Antigen Test & Its Significance In Prostate Cancer

Medically Reviewed by Dr Sravya, MBBS, MS 


The prostate gland, a tiny organ found in men that is vital for the reproductive system, produces the protein known as prostate-specific antigen (PSA).   The PSA test gauges the blood’s concentration of this protein and emerges as a crucial instrument for the early identification, diagnosis, and follow-up of prostate-related illnesses, particularly prostate cancer. In this article, we will discuss about what PSA is, what normal values look like, and how important it is in relation to prostate cancer.
Prostate specific antigen

Prostate Cancer:

Men are frequently diagnosed with prostate cancer, which highlights the significance of early detection and precise management. Prostate specific antigen (PSA) is an essential biomarker used in the detection, diagnosis, and follow-up of prostate cancer.

The purpose of this article is to examine the significance of PSA, its normal range, and its use in the early diagnosis and treatment of prostate cancer.

Table of Contents

Prostate specific antigen definition:

Both healthy and malignant cells of the prostate gland produce the protein known as PSA, which is specific to the prostate.

Prostate-Specific Antigen (PSA) is a protein produced by the cells of the prostate gland in men. It is typically present in small amounts in the blood, but higher levels can indicate certain prostate-related conditions. PSA is commonly used as a biomarker to screen for and monitor prostate health.

Prostate specific antigen test means

Prostate specific antigen test means:

The Prostate-Specific Antigen (PSA) test is a blood test that measures the levels of PSA in a man’s bloodstream. PSA is a protein produced by the prostate gland, which is a small gland located near the bladder and plays a role in the production of semen. The PSA test is commonly used as a screening tool to help detect potential prostate issues, particularly prostate cancer.

The Prostate Specific Antigen (PSA) test quantifies the PSA concentration in the blood. A blood sample is sent to a lab for analysis as part of this test. PSA levels in blood are typically expressed as nanograms (ng/mL) of PSA.

The PSA test was initially approved by the FDA in 1986 to track the progression of prostate cancer in men who had already been diagnosed with the disease. Prostate cancer patients frequently have elevated blood levels of PSA. The PSA test was given FDA approval in 1994 to be used in conjunction with a digital rectal examination (DRE) to help detect prostate cancer in men 50 years of age and older. Many medical professionals and organizations had, up until about 2008, advised yearly PSA testing for prostate cancer starting at age 50.

For patients who report prostate symptoms, health care professionals frequently use PSA testing (along with a DRE) to help them identify the nature of the issue.

A person’s PSA level can increase due to a number of benign (non-cancerous) conditions, including prostate inflammation (prostatitis) and prostate enlargement (benign prostatic hyperplasia, or BPH). Although there is no proof that either condition increases the risk of developing prostate cancer, a person with one or both of these conditions may still do so.

Interpreting prostate-specific antigen (PSA) test results involves analysing the levels of PSA in a man’s blood and considering various factors to understand their potential implications.

PSA value meaning:

The PSA value, in the context of a Prostate-Specific Antigen (PSA) test, refers to the measurement of the amount of PSA present in a man’s blood. PSA is a protein produced by the prostate gland, and its levels can be detected and quantified through a blood test. The PSA value is usually reported in nanograms per milliliter (ng/mL) of blood.

1. PSA normal values:

Age and laboratory standards can affect PSA levels. A PSA level of 4.0 ng/mL or less is considered normal for men aged 40 to 49. The upper limit of normal may rise with age, with men 50 to 59 years old having up to 4.5 ng/mL, men 60 to 69 years old having up to 6.5 ng/mL, and men over 70 years old having up to 7.5 ng/mL.

2. Need of PSA Test:

You can decide whether to undergo a PSA test to check for cancer. If you don’t catch a serious cancer early, it could spread, so you and your doctor may discuss your risk of developing it. The following factors could make you more likely to develop serious prostate cancer:

3. Age-Adjusted PSA:

The single upper normal limit of 4 ng/mL for serum PSA does not adequately reflect the expected age-related increase in serum prostate-specific antigen. Age and serum PSA concentration are directly correlated, with healthy 60-year-old males showing an expected 3.2% annual increase. Therefore, it is advised to use the age-adjusted ranges when analysing serum PSA values.

The age-adjusted normal reference ranges are as follows, with the 95th percentile PSA value being used for each:

4. Free and total PSA:

A portion of intact PSA is called free PSA. When initial total PSA values are between 4 ng/mL and 10 ng/mL, a reduction in the ratio of this serum biomarker [free PSA/total PSA] may be used to increase the sensitivity of prostate cancer detection. Pro-PSA has been incorporated into some studies’ intact PSA assays, which is an improvement over intact PSA’s sole predictive value.

Free% PSA can be used when the total PSA is between 4 and 10 ng/mL.

Prostate specific antigen definition

5. PSA Density:

By multiplying the prostate’s width, height, and length by 0.52, one can determine its cubic centimeter volume. Either a prostatic ultrasound or an MRI are used to measure these values. When the prostate’s volume is known, the total PSA in ng/mL can be divided by the prostate’s volume in ccs to determine the PSA density. A PSA density of 0.15 or higher is regarded as cancer-related suspicion.

6. PSA Velocity:

A gradual rise in PSA level is normal over time, but a rise that is more abrupt could be a sign of cancer. A PSA increase of up to 0.75 ng/mL per year and no more than 25% is typically regarded as acceptable. Increases that are greater are regarded as suspicious. Three different PSA determinations spread out over at least 18 months are necessary to calculate the PSA velocity.

Significance of PSA Testing in Prostate Cancer Management:

1. Biopsy Guidance:

When PSA levels are elevated or rising, a prostate biopsy may be recommended to confirm the presence of cancer. A biopsy involves the removal of small tissue samples from the prostate gland, which are then examined under a microscope. The results of the biopsy help determine the grade and stage of the cancer, providing valuable information for treatment decisions.

2. Treatment Decision-making:

PSA levels, along with other clinical factors, help guide treatment decisions. Depending on the PSA level, stage of cancer, and the overall health of the patient, treatment options may include active surveillance (watchful waiting), surgery (prostatectomy), radiation therapy, hormone therapy, or a combination of these approaches.

3. Prognosis and Recurrence Monitoring:

After initial treatment, PSA levels are monitored regularly to assess treatment effectiveness and to detect any potential cancer recurrence. A rising PSA level after treatment may indicate cancer recurrence or the presence of metastasis (spread of cancer to other parts of the body).

4. Response to Hormone Therapy:

In advanced or metastatic prostate cancer, hormone therapy is often used to suppress the production of testosterone, which fuels the growth of cancer cells. Monitoring PSA levels helps assess the response to hormone therapy, as decreasing PSA levels may indicate a positive response to treatment.

Additional Considerations:

1. Age and Risk Stratification:

PSA screening recommendations may vary based on age and individual risk factors. For men with a higher risk of prostate cancer, such as those with a family history of the disease or African-American men, discussions about PSA testing may start earlier and be more frequent.

2. Individualized Decision-making:

The decision to undergo PSA screening should be individualized, taking into account the patient’s preferences, overall health, and life expectancy. For older men or those with significant health issues, the benefits of screening may be outweighed by potential harms.

3. Follow-up Testing:

Elevated PSA levels on initial screening may not always indicate cancer. Additional tests, such as digital rectal examination (DRE), imaging studies (e.g., MRI or ultrasound), or repeat PSA tests, may be necessary to further evaluate the situation.

4. PSA Velocity and Doubling Time:

PSA velocity refers to the rate at which PSA levels change over time, while PSA doubling time indicates how long it takes for PSA levels to double. These parameters may provide additional information on the aggressiveness of the cancer and help guide treatment decisions.


The complex web of prostate cancer necessitates thorough understanding and proactive participation. Early detection is a powerful ally in the fight against this formidable foe and is made possible by routine screenings and increased awareness of potential symptoms. We can confidently advance towards better prevention, detection, and treatment outcomes by decoding the complexities of prostate cancer and educating people. Consultation with medical experts is still crucial because personalized approaches to treating prostate cancer show promise for achieving long-term wellbeing.