How Accurate Are At-Home Prostate Cancer Tests?

What do PSA tests measure, and can you trust the results?

Scott Fotheringham, PhD

Medically reviewed by

Andre C. King, MD

and

Prostate Cancer Screening Test

At a higher risk for prostate cancer? Check your PSA levels today.

Questions About Your Health?

Curious what your blood has to say about your current health? Try a test today.

Highlights

  • You can visit your healthcare professional for a simple prostate cancer blood test, or you can take one at home.
  • There are limitations to all prostate cancer tests, no matter where you take them.
  • A combination of tests is usually required for a definitive prostate cancer diagnosis.

Prostate cancer is the most common cancer among men in the United States. Because it is usually a slow-growing cancer, early screening and detection are useful for catching it when it’s easier to manage. 

The most common prostate screening techniques are digital rectal exams (DRE), performed by healthcare professionals during routine checkups, and PSA blood tests, which can be done at a doctor’s office, laboratory or at home. 

What is a PSA test?

PSA blood tests are simple, widely-used screening tools for the early detection of prostate cancer. They measure the level of prostate-specific antigen, a protein made by cancerous and non-cancerous cells of the prostate. 

Sometimes elevated PSA can indicate a non-cancerous condition, like prostate inflammation (prostatitis) or prostate overgrowth (benign prostatic hyperplasia).

There is no normal PSA level, though most healthcare professionals once considered levels of 4 ng/mL or lower as normal.¹ Recent studies have shown that, in some cases, men with a PSA lower than 4 ng/mL can still develop prostate cancer.² 

Should I take a PSA test?

While PSA screening can benefit some men, reducing their potential likelihood of death from prostate cancer, for others screening can lead to over-diagnosis and over-treatment.³ 

The US Preventive Services Task Force recommends that men aged 55–69 should decide whether to have a PSA test after discussing potential benefits and harms with their healthcare professional and recommends against screening for PSA in men who are 70 or older.⁴       

If you’re African-American or have a father or brother who had prostate cancer, your doctor might recommend screening as early as age 40 or 45, as these factors are associated with higher risk. 

Many organizations recommend combining the digital rectal exam (DRE) with a PSA test, in part because a DRE can sometimes detect cancers in men who have lower PSA levels.

Are PSA tests accurate? 

PSA tests are simple and easy, but they aren’t perfect. Like most screening tests, they have their limitations.

False positives

Almost three-quarters of men with high PSA levels will not have prostate cancer, which is ultimately determined by prostate biopsy. This high rate of false positives can lead to anxiety and potentially unnecessary follow-up tests, including prostate biopsies, which carry the risk of infection, bleeding and pain.

However, it can be reassuring to know that if your healthcare professional is concerned about your elevated PSA, the next step is often an MRI of the prostate — a painless and non-invasive procedure that can help limit unnecessary biopsies.

False negatives

On the other hand, low PSA or “negative” results can be misleading: around 15% of men with a PSA of 4 ng/mL or less will have prostate cancer.¹⁰

Despite this, your healthcare professional may find the results helpful when combined with other tests and your medical history. Your doctor may also use age-adjusted PSA levels (remember, they naturally rise over the years) to determine if your results are a problem, or simply a benign sign that you’re getting older. 

How to get the most accurate PSA test results

Preparing for your PSA test will help improve its accuracy. PSA levels can be affected by a variety of factors, including prostate enlargement, inflammation and infection, as well as recent exercise or sexual activity.

 Here’s what you can do to ensure your test is as accurate as possible:

  • Delay the test until you’ve healed from a recent urinary tract infection, which can elevate PSA levels.
  • Avoid ejaculating for at least 48 hours before taking the test.
  • Avoid heavy exercise before the test.
  • Take the test in the morning.
  • Do not have a DRE right before your test, as this can release PSA into the bloodstream.

Does a high PSA level mean you have prostate cancer?

Not necessarily. Remember, high PSA levels aren’t enough to diagnose cancer on their own. Instead, PSA tests screen for the possibility of the disease. Your PSA levels will indicate to your healthcare professional whether more tests are needed.

The future of prostate cancer screening

Science is constantly advancing, and tests are evolving. In the future, we expect to have more refined tests, especially for men with an increased risk of prostate cancer. 

So far, research is leading towards tests may use a combination of genetic information, urine and blood for advanced screening and diagnoses.¹¹ ¹² ¹³

Summary

It isn’t perfect, but the PSA blood test continues to be integral for the early detection of prostate cancer. Your healthcare professional can use the results — along with other tests and your medical history — to assess your risk.

If you’re a man 55 and up (or 40 and older with a family history of prostate cancer or other risk factors) you might consider an at-home PSA blood test. If you take the PSA test, be sure to discuss the results with your healthcare professional.

Updated on
February 17, 2022
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REFERENCES

1. National Cancer Institute. Prostate-Specific Antigen (PSA) Test. Accessed December 13, 2021.

2. American Cancer Society. Screening Tests for Prostate Cancer. Accessed December 10, 2021.

3. US Preventive Services Task Force. Final recommendation statement. Prostate Cancer: Screening. Accessed December 13, 2021.

4. US Preventive Services Task Force. Final recommendation statement. Prostate Cancer: Screening. Accessed December 13, 2021.

5. New England Journal of Medicine. Prostate-specific-antigen testing for early diagnosis of prostate cancer. Accessed December 10, 2021.

6. Canadian Cancer Society. The 2 tests for prostate cancer you should know about. Accessed December 10, 2021.

7. New England Journal of Medicine. Prevalence of prostate cancer among men with a prostate-specific antigen level < or =4.0 ng per milliliter. Accessed December 10, 2021.

8. National Cancer Institute. Prostate-Specific Antigen (PSA) Test. Accessed December 13, 2021.

9. New England Journal of Medicine. Prostate-specific-antigen testing for early diagnosis of prostate cancer. Accessed December 10, 2021.

10. NHS. Should I have a PSA test? Accessed December 13, 2021.

11. American Cancer Society. What’s New in Prostate Cancer Research? Accessed December 10, 2021.

12. The Journal of Urology. Use of the MyProstateScore Test to Rule Out Clinically Significant Cancer: Validation of a Straightforward Clinical Testing Approach. Accessed December 27 2021.

13. The Journal of Urology. Non-invasive Detection of Clinically Significant Prostate Cancer Using Circulating Tumor Cells. Accessed December 27, 2021.

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