Prostate cancer screening (PSA tests)

What is a PSA test?

The PSA test is a blood test that measures the level of prostate-specific antigen (PSA) in the blood, which is beneficial for prostate cancer screening. PSA is a protein produced by cells in the prostate, whether cancerous or benign. Elevated levels of PSA may indicate the presence of prostate cancer. However, high PSA levels can be due to other conditions, such as benign prostatic hyperplasia (BPH) or an inflamed prostate. Therefore, it can be challenging to determine the root cause of high PSA scores.

Results of PSA tests are reported in nanograms per milliliter of blood (ng/mL). Normal ranges of PSA vary according to your age. Your PSA level gradually increases as you age, even if you do not have prostate cancer or any other prostate conditions.

Below are normal PSA scores by age range

If the results of your PSA tests are within normal ranges, a new test is required only every two years. However, abnormal levels of PSA may call for a PSA test and other screening tests every 6 to 12 months.

As mentioned above, high PSA levels may indicate prostate cancer. Despite being asymptomatic at times, prostate cancer can manifest symptoms such as:

• Dysuria
• Frequent urination, especially at night
• Pain in the chest, hip, or lower back
• Urinary incontinence
• Weak urinary stream

Types of PSA tests

A doctor may use certain types of PSA tests to determine if he or she should order a prostate biopsy or recommend that a patient have one.  

Types of the PSA tests include:

• PSA velocity: PSA velocity refers to the change in PSA levels over time. A swift increase in PSA levels may signify cancer. However, recent studies have raised skepticism about the reliability of PSA velocity in predicting the existence of prostate cancer.
• Percentage of free PSA: PSA in the blood is of two forms, bound and unbound to blood proteins. If a PSA level is high but the percentage of free PSA is low, it indicates that you may have prostate cancer.
• PSA density: PSA density of cancerous prostate is higher than other benign conditions of the prostate. PSA density measurement requires an MRI or transrectal ultrasound.

Benefits of a PSA test

A PSA test can lead to the early detection of prostate cancer. Early detection of diseases, including cancer, contributes to effective treatment. Prostate cancers, however, are different from other cancers, given that they usually progress slowly and do not always cause death. Despite that fact, some prostate cancers are life-threatening. Since there are still no perfect methods to determine whether the prostate cancer one is having is deadly, it is better to catch prostate cancer early. For patients with prostate cancer, doctors use a PSA test to assess the effectiveness of the treatment or detect prostate cancer recurrence.

When a PSA test is necessary

It is recommended for those with a substantial risk of developing prostate cancer, such as individuals with a first-degree family history of prostate cancer, to start a PSA test at 40 years old. People with an average risk of prostate cancer, such as older adults, can have regular PSA tests at the age of 50.

However, individuals can decide for themselves whether they should have PSA tests by consulting a doctor and asking themselves questions about the potential benefits and harms of the test. The questions include:

• Do I wish to know if I have prostate cancer?
• Would I be willing to receive treatment for prostate cancer even if side effects could occur?
• How would I feel if I knew my risks of developing prostate cancer?

PSA test Procedure

Before a PSA test, you should inform your doctor if you are taking BPH medications, are having a urinary tract infection or have had one in the last three months, have undergone surgery for BPH, have had a prostate biopsy in the past six weeks, or have recently had a urinary catheter. These medications or procedures can lead to inaccurate readings. It is advised to avoid certain activities, such as biking, masturbation, and sexual intercourse, 48 hours before a PSA test due to their transient effects on PSA levels.

For a PSA test, a blood sample will be drawn after disinfecting the skin over a vein and sent for analysis. You may have a bruise after your blood test, which usually fades away within a few days. After the blood test, it is advisable to avoid exercising. The results of your PSA test may be available within a week. Further discussion and a follow-up appointment may be required.

Limitations of the test

The limitation of a PSA test is that the results can be misleading. Inaccurate results can happen. As mentioned above, high PSA levels do not always indicate the presence of prostate cancer. Heightened levels of PSA may be due to conditions such as an enlarged prostate and prostatitis, not prostate cancer. Low PSA levels may be due to medications for BPH and some chemotherapy. Moreover, PSA levels of individuals with prostate cancer can overlap with the normal range.

A Note from MedPark's doctor

A PSA test informs you about your prostate health. Men should begin regular PSA tests at age 50, with early testing advised for those at high risk of prostate cancer. Follow your doctor’s guidance for accurate results before the test.

Related Package

• Prostate Cancer Screening Package