This week, I want to talk about an interview between Dr. Eric Topol and Dr. Richard Ablin that was published on Medscape. Dr. Ablin is credited with helping to discover the prostate-specific antigen (PSA) protein that ultimately led to the PSA test. He has recently written a book called The Great Prostate Hoax, [1] in which he raises several concerns about what has occurred as a result of routine PSA screening.

Dr. Ablin believes that the PSA test never should have been approved for screening, because the data were inadequate to demonstrate whether it was truly helping people. He is also concerned that although men are now given a choice about whether they want to be screened for prostate cancer, it is based on 2 studies that both have flaws, so the information being used is less than ideal.

Another of his concerns is that there is a high false-positive rate (approximately 80%). Many people who commented on this interview were critical of that number, but the fact is, that it is very close to being correct. Many men who undergo PSA testing and subsequently have a biopsy do not have prostate cancer.

Finally, Dr. Ablin raised the issue of cost, and whether the large number of dollars being spent on screening and unnecessary treatment could be better used in our healthcare system in other areas, with greater net benefit.

More than 175 people (to date) posted comments in response to this interview. Some of the commenters, particularly patients, wrote that they are grateful that the test was done; they believe it saved their lives. To those men, I strongly hope and pray that that is true, but the fact is that we will never know. Simply having their cancer diagnosed and treated does not mean they benefitted. There is no way of knowing whether the treatment was necessary or the cancer would ever have harmed them if not treated,[2] but we can hope that at least some of those men are correct.

Another issue has to do with the ethical dilemma that is created by the screening process. We have a test that can help us diagnose prostate cancer, but most of the men who undergo testing and are diagnosed with prostate cancer don’t benefit from the process. What is better for us as a society? What is better for an individual? Should we test a large number of men to help some, while potentially harming many others with side effects and unnecessary therapy, or should we withhold doing the test, realizing that some men will lose their lives or suffer from their cancer, but many more men will be spared the unnecessary treatment and the harms that might occur? That ethical dilemma needs some resolution.

Cost is another issue. It is estimated that to prevent a single cancer death through screening and treatment costs more than $5 million. Could those dollars be better used to have a greater impact on society? Because although we may prevent a man from dying from prostate cancer, in many cases that doesn’t mean that he is going to live a whole lot longer than he would have lived anyway.

We have a net dilemma in trying to resolve these controversies. They are not going to be resolved tomorrow. Ultimately, we can hope that 2 things occur. One, going forward, it would be great if the gene tests that are in development[3,4] turn out to be able to tell us which men need to be diagnosed and treated and which men can be spared.

Two, we need to ensure that a similar fiasco does not occur. By that, I mean another screening test for early cancer that is not specific for that cancer being developed, without the right studies being done before it is used. We must avoid approving tests when we don’t know for certain that they will be associated with more benefit than harm.

 

References

  1. Ablin RJ, Piana R. The Great Prostate Hoax: How Big Medicine Hijacked the PSA Test and Caused a Public Health Disaster. New York: Macmillian Publishers; 2014.
  2. Agency for Healthcare Research and Quality. Guide to clinical preventive services. Prostate cancer. June 2014.http://www.ahrq.gov/professionals/clinicians-providers/guidelines-recommendations/guide/section2c.html#prostateAccessed July 24, 2014.
  3. Cuzick J, Stone S, Yang, ZH, et al. Validation of a 46-gene cell cycle progression (CCP) RNA signature for predicting prostate cancer death in a conservatively managed watchful waiting needle biopsy cohort. Program and abstracts of the American Urological Association Annual Meeting; May 16-21, 2014; Orlando, Florida. Abstract MP79-17.
  4. Lin D, McGee S, Rieger-Christ K, et al. The 4KScore test as a predictor of high-grade prostate cancer on biopsy. Program and abstracts of the American Urological Association Annual Meeting; May 16-21, 2014; Orlando, Florida. Abstract PI-06.

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