Prostate cancer – to screen or not

Today’s British Medical Journal has 2 articles and an editorial on PSA testing for prostate cancer.

• Why men with prostate cancer want wider access to prostate specific antigen testing: qualitative study
• Natural experiment examining impact of aggressive screening and treatment on prostate cancer mortality in two fixed cohorts from Seattle area and Connecticut
• Editorial: Prostate specific antigen testing for prostate cancer

Quoting from the editorial

In this issue we see contributions to the debates about risk in relation to prostate cancer. Yu-Lao and colleagues seem to bolster the arguments for caution in the debate on screening for prostate cancer by prostate specific antigen testing. Their findings show that more intensive screening and treatment with prostatectomy and external beam radiotherapy are not associated with lower prostate cancer specific mortality through 11 years of follow up.

Although the experts continue to argue about the evidence on screening, the public has come to different conclusions, as shown by Chapple and colleagues, who show that trial, epidemiological, or clinical evidence may play a small part in the public’s demand for screening for prostate cancer by prostate specific antigen testing. Instead, the irresistible logic of finding the cancer early, the drive to avoid regretting later the decision not to have the test, the right to obtain information about oneself by testing, and a perceived right to parity with women’s access to screening may all be more important arguments.

These lay arguments for prostate specific antigen testing have their own logic and validity. What they mostly do not recognise are the costs of screening.8 Screening is the business of changing identities; it is the business of producing patients. Becoming a patient is not a trivial matter. It has profound health, social, psychological, and economic consequences. Screening therefore raises important ethical problems. As Cochrane and Holland pointed out three decades ago: “If a patient asks a medical practitioner for help, the doctor does the best possible. The doctor is not responsible for defects in medical knowledge. If, however, the practitioner initiates screening procedures the doctor is in a very different situation. The doctor should, in our view, have conclusive evidence that screening can alter the natural history of disease in a significant proportion of those screened.” Reconciliation between today’s risk conscious citizens demanding tests or pressing to initiate screening programmes and authorities becoming more cautious about their provision will come only through initiatives that engage with the public not through authoritarian insistence on the “rightness” of the science.

I have included a short excerpt from a powerful, thoughtful discussion. Why should we screen for a disease? I have considered this issue many times during my career. My philosophy has centered on ‘First Do No Harm’. I have assumed that screening when early detection does not change outcomes probably had negative effects. This discussion argues that patients may find knowing a diagnosis beneficial.

I do not have a strong position here. In general, I try to dissuade patients from routine prostate screening. I personally choose not to have screening (although I always have to argue with my primary care physician). When patients feel strongly, I do screen. Perhaps this decision is more about philosophy and one’s ability to handle uncertainty than it is about science. Perhaps the medical community with the assistance of the media have sold the concept of screening at face value. This issue bothers me greatly. Does it bother you?