Is PSA test a public health disaster?

Sand art on the beach in Albufeira, Algarve, Portugal. (Dr. Noorali Bharwani)
Sand art on the beach in Albufeira, Algarve, Portugal. (Dr. Noorali Bharwani)

Dr. Richard J. Ablin, PhD, DSc (Hon), first discovered prostate-specific antigen (PSA) in 1970. At the time, Ablin and colleagues were trying to identify an antigen that was specific to prostate cancer.

PSA test was introduced in the United States around 1990 for early detection of prostate cancer.

In 2010, Ablin called the PSA test a public health disaster. So, what went wrong? Why do we still order PSA test?

Let us start from the begining.

All men have a prostate gland. The gland produces some of the ingredients of semen. It sits just in front of the rectum and below the bladder. It can be felt on a rectal examination. It weighs about 30 grams. It is vital for the proper functioning of the male reproductive system.

One of the enzymes in prostatic fluid is prostate-specific antigen (PSA). After ejaculation, PSA makes thickened semen runnier, helping sperm travel through it more easily. Thus, increasing their likelihood of successfully fertilizing an egg.

Why PSA test can do more harm than good?

Reviewing some literature, I found Ablin, who is now a research professor of immunobiology and pathology at the University of Arizona College of Medicine and the president of the Robert Benjamin Ablin Foundation for Cancer Research, has said, “in approving the procedure (PSA test), the Food and Drug Administration relied heavily on a study that showed testing could detect 3.8 per cent of prostate cancers, which was a better rate than the standard method, a digital rectal exam.” Was that a wise decision?

PSA test is costing health care system billions of dollars. It is estimated that each year, some 30 million men undergo PSA testing in the US, at a cost of $30 billion. Ablin has said the test is hardly more effective than a coin toss. The PSA test cannot distinguish between the two types of prostate cancer – the one that will kill you and the one that won’t.

The American Cancer Society now urges more caution in using the test and the American College of Preventive Medicine has concluded that there was insufficient evidence to recommend routine screening. Then why do we still use it?

“Many doctors have distorted perceptions of the value of medical tests,” says Dr. Miriam Shuchman in the Canadian Medical Association Journal (CMAJ February 04, 2019). And patients have the same distorted perceptions.

In 2014, the Canadian Task Force on Preventive Health Care recommended against using the PSA test to screen for prostate cancer in healthy men, concluding that it results in substantial harms via biopsies and surgeries that can lead to infections, impotence or urinary incontinence, and does not save men’s lives.

Canadian and American task forces recommend that any man considering screening for prostate cancer should have a chance to first discuss the pros and cons with a doctor. The CMAJ article says that if men knew what the risks were associated with PSA testing and how slim to nonexistent the benefits are, no man in his right mind would get tested.

Considering PSA screening results in only a 0.1 per cent reduction in death from prostate cancer, the harms associated with screening outweigh the benefits for most people.

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