Does a PSA Test Really Matter?

Prostate cancer screening recommendations in the USA are established by the U.S. Preventive Services Task Force

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Prostate cancer screening with the prostate-specific antigen (PSA) test remains controversial.

This ongoing debate is because the potential benefits of prostate cancer screening may be outweighed by the perceived harms from overtreatment.

Other than the cost of PSA tests, which is generally under $100, a leading concern is the PSA test may produce false results, positive or negative.

This can mean that men without cancer may have abnormal results and get tests that are not necessary.

It could also mean, that the test could miss cancer in men who may need to be treated.

To answer this question, the largest-ever randomized trial of using the prostate-specific antigen (PSA) test in asymptomatic men over the age of 50 reported that there was not a significant difference in prostate cancer-related deaths between men who were screened with a single PSA test, and those who weren’t screened.

After 10 years of study, the authors found both tested cohorts had the same percentage of men dying from prostate cancer.

And that percentage was just 0.29 percent.

In this study, 4.3% of the ‘screened’ group was diagnosed with prostate cancer, as compared with 3.6% of the ‘unscreened’ group.

These authors attribute most of this difference to low-grade, non-aggressive cancers.

The Cluster Randomized Trial of PSA Testing for Prostate Cancer (CAP) findings were published in JAMA. The goal of this study was to assist health policy makers in their decisions about how to achieve the best use of resources.

This study’s conclusion is similar to the previous study published in the New England Journal Medicine during 2017.

In the United States, the Centers for Disease Control and Prevention (CDC) estimates 180,890 cases will be diagnosed in 2016, and 26,120 men will die from the disease.

In the USA, the CDC follows the prostate cancer screening recommendations set forth by the U.S. Preventive Services Task Force, which recommended in 2013 against PSA-based screening for men who do not have symptoms.

In a 2017 draft recommendation, the USPSTF recommended that clinicians inform men ages 55 to 69 years about the potential benefits and harms of PSA–based screening for prostate cancer.

There are organizations, like the American Urological Association, the American Cancer Society, and the American College of Physicians who may have other recommendations.

The decision to screen for prostate cancer can be very confusing, given the various, conflicting media reports

PSA test services can be obtained from various companies, or at-home tests can be purchased from a local pharmacy.

This testing decision requires guidance, says the CDC.

And that guidance should be balanced and involve the participation of your doctor, nurse, or pharmacist.

There is not a prostate cancer vaccine available in the USA.

But, in late 2017, a small, phase 1 clinical trial reported positive results. 

OncBioMune Pharmaceuticals, Inc. is engaged in the development of a proprietary cancer vaccine technology and targeted cancer therapies.  'ProscaVax is OncBioMune’s novel immunotherapeutic cancer vaccine consisting of a combination of prostate cancer associated PSA with the biological adjuvants interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating factor (GM-CSF).' 

The phase 1 results showed 80% of the participants demonstrated stable disease/no prostate cancer progression.

Research funding information: University of Bristol (UK). Cancer Research UK (CRUK) (UK) (refs: C11043/A4286, C18281/A11326, C18281/A8145 and C18281/A15064). No conflicts of interest were disclosed.