Prostate cancer screening a ‘hoax’ says UA professor

When Richard J. Ablin discovered the prostate-specific antigen in 1970, he had no idea that the protein would one day be the gold standard in prostate cancer screening.

But, instead of earning him a cozy spot in the annals of medical history, the achievement has led Ablin on a personal crusade against a test that he describes as “misused” and “unreliable.”

In a recently published book entitled, “The Great Prostate Hoax: How Big Medicine Hijacked the PSA Test and Caused a Public Health Disaster,” Ablin claims that the test has led to over-diagnosis for decades, costing billions of dollars and lowering the quality of life of men who get their prostates removed when the procedure may not have been necessary.

“I’ve been trying to tell people for 30 years that [PSA screening] can’t work,” he said. “The test is no good.”

Ablin discovered the PSA in 1970 while searching for a “cancer-specific antigen,” a protein that would show up only in prostates with cancer. Instead, he found a protein that was secreted by both healthy and diseased prostates. The enzyme was dubbed the “prostate-specific antigen” because it is only produced in the prostate or in cancer cells that originate there.

In 1986, the Food and Drug Administration approved PSA testing to monitor men who had their prostates removed surgically.

Because the protein is secreted only in the prostate, the level of PSA should go down after the prostate is removed. If PSA levels rise after surgery, it means that part of the prostate wasn’t removed or that the cancer had spread and grown since the operation.

At his lectures, Ablin emphasizes the fact that he has always been in favor of PSA being used in this way.

“It was great for a harbinger for the recurrence of disease, but then [urologists and pharmaceutical companies] wanted the bucks and they pushed it,” he said.

Over the next decade, clinics popped up advertising free PSA tests for men—who were not showing symptoms—as a way to screen for prostate cancer. A threshold of four nanograms of PSA per milliliter of blood, or 4 ng/ml, was established.

“What they said is, ‘If you have a level of PSA less than four, you’re okay. If you have a level of PSA greater than four, you should be followed up’” he said.

This is where PSA testing goes awry, according to Ablin. An arbitrary cutoff like 4ng/ml, he said, tells doctors nothing about whether the patient has indolent or aggressive cancer, or whether they have cancer at all.

Ablin explained that PSA levels can be elevated for many reasons. Conditions like prostatitis (an infection of the prostate) and BPH (an enlarging of the prostate) can cause elevated levels of PSA. Exercise and sex can also cause an increased amount of PSA to enter the bloodstream. In fact, some men naturally exhibit a higher-than-average PSA, he said.

“A man can have a PSA of one and have cancer, and a man can have a PSA of 11 and not have cancer,” he said. “ So what good is the test if the numbers don’t mean anything?”

Despite Ablin’s concerns, PSA screening quickly gained popularity as a non-invasive alternative to getting a digital rectal examination.

After the screenings, men were advised, based on their PSA level, whether they should get a biopsy. If the biopsy came back positive, a radical prostatectomy may be done. Ablin contends that the surgical removal of the prostate, which can lead to incontinence and sexual dysfunction, is in many cases unnecessary.

“Most men over the age of 40 have prostate cancer, but most of those cancers are very slow-growing and will never cause any health detriment to that individual,” said Kimberly McDermott, assistant professor in the UA’s Department of Cellular and Molecular Medicine.

In 1994, the FDA approved the PSA test as a way to screen for prostate cancer despite a 78 percent false-positive rate, meaning that patients had elevated levels of PSA but when they were biopsied there was no cancer.

Although he has no proof, Ablin said he believes there was some sort of payoff involved—how else would one explain the approval of a test that’s wrong nearly 80 percent of the time?

“They never should have approved it” Ablin said.

The great prostate hoax is ultimately driven by money, Ablin said. Urologists profit by administering the test, surgeons profit from cutting out the organ, and drug companies profit from the sale of medications aimed at men with erectile dysfunction, many of whom underwent radical prostatectomies.

“This is a billion dollar industry,” Ablin said. “The test doesn’t cost a lot of money. But the test leads to the ultrasound, the ultrasound leads to the biopsy, the biopsy leads to the treatment, the treatment [which may cause impotence] leads to Viagra and Cialis.”

The screening system rakes in about $3 billion a year, Ablin said, more than half of the annual research budget for the Cancer Research Institute.

Others in the urology community contend that PSA screenings can be extremely valuable when used properly.

“I think it’s still a useful thing to do, especially for people with risk factors,” said Dr. Susan Tarry, a urologist at the University of Texas Medical Branch, in Galveston, Texas.

Tarry suggested that men over 40 should consider getting their PSA periodically checked in combination with a digital rectal exam. The doctor should counsel the patient on the risks and benefits of treatment, she added. Although Tarry acknowledges the limitations of PSA screening, she said the test is a urologist’s best bet for detecting prostate cancer.

“Despite some of the issues with over-testing and people getting unnecessary procedures,” Tarry said, “there is nothing better than PSA, unfortunately.”

Currently, there are a dozen or so tests being developed as a replacement for PSA screening.

“Some of [the new tests] look promising,” Ablin said, “but none of them are at the level where they are specific to prostate cancer.”

In 2012, the U.S. Preventive Services Task Force finalized its recommendation that PSA screening not be used to screen asymptomatic men for prostate cancer.

In lieu of hasty treatment, Ablin suggests that older men, in coordination with their doctor, participate in active surveillance—monitoring their PSA levels, but not taking action unless significant changes are seen.

 

Contact Mark Armao at marmao@email.arizona.edu