What is PSA?
PSA stands for prostate-specific antigen. It is a common blood test that doctors order to screen for prostate cancer and/or monitor the progression of prostate cancer.
What does "prostate-specific" mean?
“Prostate-specific” means that the antigen is only produced by the prostate. This measure, however, is not cancer-specific. Other conditions may cause an elevated PSA.
What are the conditions that may cause an elevated serum PSA?
The following conditions can cause an elevated PSA:
Benign Prostatic Hyperplasia (BPH)
BPH is a benign (non-cancerous) enlargement of the prostate. As men get older, the prostate enlarges in size and increases the serum PSA. BPH can co-exist with prostate cancer. It is not uncommon for men to have both BPH and prostate cancer simultaneously.
Prostate Cancer
Most prostate cancers cause an increase in serum PSA. Due to this correlation, physicians use PSA tests to screen for prostate cancer. PSA is also used to monitor prostate cancer progression after treatments, such as surgery, radiation, or chemotherapy. However, patients with prostate cancer may have a normal PSA. For these patients, the cancer is detected via a digital rectal examination (finger exam) of the prostate. During this test, the urologist can detect a palpable nodule or lump on the prostate.
Urinary Tract Infections (UTI)
Prostatitis
Prostatitis is the inflammation of the prostate gland.
Instrumentation
Recent cystoscopies, catheterizations, or surgeries on the prostate, including biopsies, can also temporarily elevate the serum PSA.
Sexual Activity
Men should abstain from sex for 72 hours prior to a PSA test because studies show that ejaculation one to two days before a PSA test may increase PSA levels in the blood.
Riding a bicycle, or trauma to the groin caused by fall, impact, or accident
What is the normal value/reference range for the PSA?
When screening for prostate cancer, the cutoff PSA value has traditionally been considered to be 4.0. However, there is a debate about this cutoff value. In a recent study, researchers proposed using PSA levels of 1.5 as the cutoff value. There are also age-specific PSA cutoff values due to the prostate enlarging with age. Therefore, as men get older, the PSA cutoff for what is considered normal is higher.
What do I have to do if I have an abnormal or elevated serum PSA?
First, do a repeat PSA to ensure the test result was not an anomaly.
If your repeat PSA yields the same results, your urologist will likely recommend a prostate biopsy to exclude the possibility of prostate cancer. However, since not all patients with elevated PSA levels have prostate cancer, it is important to note that unnecessary biopsies can introduce significant side effects and complications, such as pain, bleeding, and infection. In response to this, recent biomarker tests have been developed to help determine the probability of detecting prostate cancer and the aggressiveness of it with a prostate biopsy.
It should also be acknowledged that not all cases of prostate cancer are life-threatening or aggressive, and over-treatment of prostate cancer can lead to unwanted side effects, such as erectile dysfunction and urinary incontinence. Therefore, these secondary biomarker tests may help you gain better insight into your chances of having aggressive prostate cancer before you decide to get a biopsy. If you are at low risk for developing aggressive prostate cancer, you may decide to continue with periodic digital rectal exams and PSA tests. If you are at high risk, you may consider a prostate biopsy.
What are my options for secondary biomarker tests?
There are several different biomarker tests available:
ExoDx
The ExoDx™ Prostate Test is a simple, non-DRE, urine-based, liquid biopsy test. Click here to learn more.
Select MDx
Select MDx, sometimes referred to as the “liquid biopsy”, is a urine test that screens for two cancer-related genes. For optimal results, post-DRE (digital rectal examination) first-void urine is required. The test looks at a combination of mRNA biomarkers, PSA level history, density, DRE results, age, and family history to determine the patient’s chances of developing low-grade and high-grade (Gleason Score > 7) prostate cancer. The urine sample can be collected in-office, and the sample will be sent to MDx’s laboratory for analysis. Click here for more information.
4Kscore
The 4Kscore test measures the plasma levels of four prostate-specific biomarkers and combines these results with the patient’s clinical information to identify individual risk for aggressive prostate cancer. This test can also predict the likelihood of cancer spreading to other parts of the body, but it is important to note that the 4Kscore test does not provide a diagnosis for cancer. This is a physician-ordered test that will help patients understand their probability of having aggressive cancer before deciding to perform a prostate biopsy. For optimal results, you must refrain from sexual activity for four days prior to the test. Click here for more information.
PCA3
The PCA3 test is a urine-based molecular test that measures the concentration of prostate cancer gene 3 (PCA3), as well as PSA, and determines the need for repeat prostate biopsies. This test is for patients who have had a previous negative biopsy, and because the PCA3 gene is highly specific for prostate cancer, this test helps reduce unnecessary repeat biopsies.
Prostate Health Index (PHI)
PHI is an FDA-approved blood test that looks at a combination of three isoforms (chemical variations) of PSA, including PSA, free PSA, and p2PSA to predict the likelihood of prostate cancer. The psPSA is an isoform of free PSA that has recently been found to be more accurate than PSA levels in predicting cancer. This test is to be done prior to digital rectal examinations and biopsy. Higher PHI values are correlated with more aggressive forms of prostate cancer (Gleason score of 7 or more).