“Many men get treated unnecessarily – and risk life-altering side effects including impotence and incontinence”
Pathologist Richard Ablin discovered the PSA antigen 40 years ago. He says it should never have been used as a cancer screening tool for all men
Your book condemns the use of PSA for cancer screening. What do you hope to accomplish? I hope to expose how the urology community and drug industry misused the PSA test, putting money over the best interests of patients. I also want to show how the US Food and Drug Administration failed in its duty to the public: its advisers warned that routine PSA screening would cause a public health disaster, but it was approved under pressure from advocacy groups and drug companies.
How did you discover PSA back in 1970? In animals, freezing prostate tissue in situ produced an immune response – antibodies to proteins in the tissue. We did a trial of the freezing technique in men with prostate cancer that had spread, and saw regression. I wondered if freezing spurred an immune response by releasing a cancer-specific antigen, or protein, from the prostate tissue. So I studied prostate tissue and I found an antigen, but it was characteristic of normal and malignant tissue – specific to the prostate, not to the cancer.
That is one of four major concerns you highlight about PSA. What are the others? So, first is that PSA is not cancer-specific. Second, the level of PSA deemed worrying is arbitrary – 4 nanograms per millilitre or higher. As PSA is not cancer-specific, no level is diagnostic. Third, prostate cancer can be aggressive or, more often, very slow-growing. We can’t tell which is which.
Last, many men will develop prostate cancer by age 70. If an older man has a PSA level that prompts a biopsy, it is likely you will find cancer. Since you can’t tell if it’s aggressive, many men get treated unnecessarily – and risk life-altering side effects including impotence and incontinence.
But surely PSA has its diagnostic uses? PSA can be a useful predictor of recurrence; after treatment for prostate cancer, if the PSA level increases it can indicate they didn’t get all the tissue, or that cancer that began in the prostate has spread. But that is not how it is primarily used.
You note that men with a family history of the disease may benefit from PSA tests to watch for major changes. As your father died of prostate cancer, does that include you? If your father had prostate cancer, your chances are 2:1, so theoretically you may benefit from PSA monitoring. But the decision depends on how well you deal with risk. My father was diagnosed at 67. He died a year later. I am 73. If I had a biopsy today, there’s an 80 per cent chance that I would have prostate cancer. But the data show that at my age treatment wouldn’t extend my life, and it would be likely to leave me with debilitating side effects.
What do you advise men grappling with this? Ideally, it should be an informed decision between a man and his doctor. The unfortunate reality is that no current data show that men who undergo PSA screening live longer than men who decide against it. So if you have no symptoms, no family history of prostate cancer, and a normal digital rectal exam, I would say, do nothing. Because once you’re on that train, it’s hard to get off.
This article appeared in print under the headline “More harm than good”
Richard Ablin is professor of pathology at the University of Arizona. He discovered PSA in 1970, and co-wrote The Great Prostate Hoax: How big medicine hijacked the PSA test and caused a public health disaster (Palgrave Macmillan)17 February 2014 by Tiffany O’Callaghan Magazine issue 2956. Subscribe and save For similar stories, visit the Interviews and Cancer Topic Guides http://www.newscientist.com/article/mg22129564.400-prostate-cancer-test-has-been-misused-for-money.html#.UwMbaHyYZp8