PSA blood tests are essential to screen for prostate cancer. They are commonly used along with a digital rectal exam and other diagnostic tools.
Symptomatic and asymptomatic patients may be tested with a PSA test, depending on their circumstances.
In most cases, health organizations such as the American Cancer Society and the U.S. Preventive Services Task Force recommend doctors to discuss with patients the pros and cons of a PSA test.
Even though it is useful to screen prostate cancer, there are many false positives and false negatives. In other words, you can have a positive result without having prostate cancer. This often leads to further investigations and unnecessary prostate biopsies. However, if you have risk factors and make an informed decision with your doctor, a PSA test can be beneficial.
But PSA tests detect more than just prostate cancer. Many other conditions in the prostate gland may cause an elevation in PSA levels.
For example, benign prostatic hyperplasia (BPH) usually causes an increase in PSA. The same goes for bacterial prostatitis and other prostate health issues.
As you can see, PSA tests can be subject to many discussions. Doctors have different opinions and may use PSA tests differently.
To make it easier for you, we’re covering the most critical questions about PSA tests in this article. For example, “does alcohol affect the psa test?” Talk to your doctor if you have additional questions or don’t know how to apply this information to your case.
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What is a PSA test?
PSA is short for Prostate Specific Antigen. It is a protein produced in prostate cells. The prostate is a small gland located below the bladder. As a gland, it creates fluid that is released in ejaculation. It also synthesizes PSA and introduces this protein as a part of our seminal fluids.
PSA is meant to be released into the semen to make it more fluid. It is an enzyme that prevents conglomerates in semen and improves sperm mobility. However, PSA can also leak into the blood in a minimal amount.
In most cases, only a minimal trace of PSA will be found in male blood samples. But this is also a tumor marker because it increases when there’s a prostate tumor.
In BPH and prostate cancer, there’s an enlarged prostate. Thus, more cells are creating PSA, and more of it is leaked into the blood.
Additionally, there is inflammation in prostate cancer that increases blood flow. More PSA is then released into the blood when the prostate is inflamed (1).
A PSA test is a blood test performed to measure our serum levels of this protein.
PSA can be found in the blood in two primary forms:
- Free PSA: It is not bound to any protein
- Bound PSA: It is bound to other proteins, usually carrier proteins in the blood
In most cases, doctors order a total PSA measure. This screening test does not discriminate between free and bound PSA (1).
A PSA contributes to the diagnosis of cancer, but it is not a diagnostic test by itself. You can get a high PSA reading when your prostate is inflamed, after having sex, and in other conditions.
For more information about this, refer to the section “What should you avoid before a PSA test?”
Who should get a PSA test?
In the past, the only indication to receive a PSA test was the patient’s age. Men who reach 40 years of age usually started prostate cancer screening with PSA testing and a digital rectal exam. Nowadays, the protocol has changed dramatically, and additional factors are taken into consideration.
The current understanding of PSA tests highlights the importance of testing patients at a high risk of prostate cancer. If your risk is low or average, you might not need this test.
The current recommendation by health authorities can be summarized as followed (1, 2, 3):
- Healthy men can be screened for prostate cancer, even if they have no symptoms. However, they should wait until they are at least 50 years old. The age recommendation by the American Urological Association is 55-69 years for asymptomatic men.
- No PSA screening is recommended after 70 years old and for people with less than 10 years of life expectancy.
- African American men have an increased risk of prostate cancer than the general population. Thus, they should start to screen for prostate cancer after age 40 years.
- Another important risk factor is having a first-degree family member with prostate cancer. This is mainly your father or brother. If that is your case, self-awareness is recommended to detect urinary symptoms. A PSA test can be performed before 50 years of age, depending on each particular case.
- Patients with urinary symptoms or prostate symptoms should be evaluated accordingly. Depending on the physical exam, age, and other tests, a PSA test could be ordered.
- PSA tests should be interpreted along with a digital rectal examination, a clinical evaluation of symptoms, and imaging tests for an accurate diagnosis.
It is also important to highlight that patients with an elevated PSA level may require additional testing. In many cases, a confirmatory PSA test is ordered. When the results are still high, doctors may decide to keep ordering PSA tests every once in a while.
Patients with diagnosed prostate cancer may also require frequent PSA measures. They are useful to monitor tumor growth and make clinical decisions.
Lower PSA measures may suggest that cancer therapy is doing the work as it should. Higher levels show that the tumor is still growing. Also, a sudden increase in PSA levels in patients after surgery may suggest cancer recurrence (3).
How do you prepare for a PSA test?
PSA tests can be very inaccurate if you don’t take the sample at the right moment. The results can be affected by many day-to-day activities and other health problems. So, preparing for a PSA test requires you to consider a list of dos and don’ts.
So, consider this list if you want to prepare for your upcoming test (4, 5):
- If you have a urinary tract infection, leave the PSA test for later. This is not the right time.
- Practice abstinence for all types of sexual behavior and masturbation for two days. Your PSA test should be scheduled after this period.
- If you had an appointment with the urologist and got a rectal exam, wait 3 days before your PSA test. The same goes for prostate biopsies and surgical interventions. Talk to your doctor and ask for advice if this is your case.
- Rest your body for at least one day before the PSA test. It would help if you didn’t do any vigorous exercise. Biking is a forbidden activity before a PSA test.
- Talk to your doctor thoroughly. It is imperative to tell him if you’re taking drugs like Avodart, Proscar, or Propecia. Also, tell him if you have known liver problems, especially liver cirrhosis.
- If you are taking herbal supplements, give your doctor a list of each and their constituents. Some of them may affect PSA levels.
- Check yourself for the hepatitis C virus if you’re a baby boomer. This is a one-time check, so if you already have, you can dismiss this recommendation.
What should you avoid before a PSA test?
Total PSA measures are often elevated by different reasons besides prostate cancer or BPH. If you follow the advice listed above, PSA test results will likely be accurate.
It would be best if you avoided everything that increases PSA levels and acts like confounders.
For example (4, 5):
- Getting tested with a urinary infection: A urinary infection increases your PSA levels. This is especially true in bladder infections because the prostate is adjacent to it. Thus, the inflammation of the bladder causes mild inflammation of the prostate, too. This leads to more blood flow to the prostate due to inflammation. As the blood flow increases in the prostate, the same happens with PSA levels. More PSA leaks into the circulation. That’s why you shouldn’t get tested if you have a urinary infection.
- Getting tested after strenuous activity: Depending on the type of activity, you’re probably using different body muscles. You could be applying pressure upon the prostate with pelvic muscles. Core muscles also create abdominal pressure to stabilize the body, and they can affect the prostate. Thus, it is recommended not to exercise before a PSA test.
- Obtaining the sample after sexual activity: When you have sexual activity, a contractile portion of the prostate activates. This projects the ejaculation and contributes to the volume of semen. At the same time, this prostate contraction increases the leakage of PSA into the blood. So, you would get a false reading because PSA was temporarily rising. So, it is recommended to avoid sexual activity 2 days before a PSA test.
- Applying pressure upon the prostate: Direct pressure upon the prostate can increase PSA levels significantly. For example, in a digital rectal examination or after a prostate biopsy. Any pelvic procedure near the prostate can have the same effect, including radiation therapy. In these cases, you need to wait for 2-3 days before getting tested.
- Taking certain medications when you get tested: Different medications can increase or decrease PSA levels in the blood. You might initially think that you want to reduce PSA levels. But that is not a good idea if you’re masking a real problem with your prostate. So, even PSA-lowering substances should be avoided. Talk to your doctor if you’re receiving any type of herbal supplement or drugs such as finasteride.
All of the above can give you skewed PSA test results. But all of this will be avoided if you prepare as instructed by your doctor.
If your PSA results are elevated, the doctor may order a second PSA test a few weeks later. They are ruling out the possibility of an accidental increase by one of the elements listed above. So, if you’re doing a repeated PSA test, try to avoid known confounders.
Does alcohol affect the psa test?
Alcohol has been established as a carcinogen in some cases. However, it is not listed as one of the main risk factors for prostate cancer. Studies show some evidence that heavy drinkers have an increased prostate cancer risk.
However, this increase is mild compared to African American origin and other risk factors.
Then, does alcohol affect the psa test?
The answer is yes, and no. It depends on each case.
Does alcohol affect PSA test?
According to studies, alcohol does affect your PSA test levels. Your alcohol intake can lower your PSA test levels by 0.96-1.01 for every 10 units of alcohol you drink every week. But this is not good news because it is also associated with high-grade prostate cancer (6).
In other words, chronic alcohol consumption can silence your PSA while increasing the risk of aggressive prostate cancer if you ever develop the condition. In this regard, it would be wise to stop drinking alcohol altogether, and not just for the exam.
So, should I change my drinking habit before the exam?
Comparing your PSA readings is fundamental to diagnose prostate problems. Doctors will create a historical record of your PSA if there’s a problem or if you’re at risk. This is known as PSA velocity. You could get skewed results by consuming more and then less alcohol every week.
So, many professionals recommend maintaining your lifestyle habits as they are. While it is not necessary to stop drinking alcohol for the PSA test since it shouldn’t affect the results, it is always a bit of good advice to drink in moderation and make this a part of your lifestyle.
A PSA test is an important screening test to detect prostate cancer. Cancer cells and other forms of prostate enlargement causes an increase in PSA. However, it also detects additional types of prostate disease. It may even have false-negative and false-positive results, especially if we do not prepare for it.
If you have a urinary infection or chronic prostatitis, it is better to leave the PSA test for later. Complete your treatment and then go ahead and take your sample. The prostate tissue also releases PSA when you ejaculate and after a medical procedure in the gland. So, it is recommended to wait sometime before the test.
Changes in alcohol intake are not explicitly requested before the PSA test since it shouldn’t affect the results. However, you might want to consider moderation in drinking alcohol to reduce aggressive prostate cancer risk.
This test is not appropriate for everybody. It is often requested from patients who have risk factors for prostate cancer or urinary symptoms. Still, if you’re worried about prostate cancer, talk to your doctor. After considering the pros and cons, you will be able to make an informed decision about PSA testing.
Find out What Can Skew A PSA Test.