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‘Advanced prostate cancer is incurable; PSA can be used to identify prostate cancer at an early stage, enabling it to be cured by radical prostatectomy. As early prostate cancer is usually asymptomatic, men aged > 50 years should have a regular PSA test’.

‘PSA is not a specific test and most men with a mild increase will not have prostate cancer. Prostate cancer curable by radical surgery has a good prognosis and any benefit from this intervention will not be apparent for many years. Invasive treatment with significant side-effects is unnecessary for many, as they will die from other diseases before their prostate cancer becomes fatal. There is no evidence that PSA testing will save life and its use should be discouraged’.

The purpose of this article is not to adjudicate on the merits or otherwise of PSA testing, either in clinical practice or in the context of screening. There is an element of truth in both the preceding statements, and it is because of this that the honest clinician finds it difficult to answer the patient's question ‘Should I have a PSA test? The official view of PSA testing in the NHS has been proscriptive, with clinicians at one time discouraged from using, it on the grounds that there was no evidence that its use would reduce prostate cancer mortality [1] (although neither was there evidence that it would not). Subsequently, it has been recognized that men should not be denied the opportunity to have the test, but on condition that they are first fully informed of its advantages and disadvantages [2]. Is this reasonable, and if so, what information should be given? The January 2003 edition of Urology published a panel of eight editorials on ‘Informed consent for PSA testing’ from a variety of authors, urologists and others. The arguments for and against the practice of informing patients are rehearsed in different ways, ranging from the philosophical to the practical (do clinicians have time to do it?). Catalona [3] expressed concern that the process might deter patients from undergoing a test for which he is certain of the value. Others argue that while information is necessary before patients enter a screening programme, in the patient-to-physician relationship, the duty of care resting on the doctor does not extend to providing information before testing [4].

The published arguments usually rehearsed for or against PSA testing concern its value in reducing prostate cancer mortality. The outcome of the current studies of PSA screening will largely be measured by this same variable. However, what concerns the clinician should be the impact on the individual patient. It is inconceivable that lives will not be saved by treating PSA-detected prostate cancer, although it is unlikely that all those so treated would have died from prostate cancer if not treated. Many men will have prostate cancer diagnosed and as a result of treatment their disease will be eradicated. Many seek the test as reassurance that they do not have the disease, and for most of these the test will be reassuringly negative. If this were the whole story, the argument could be considered in the terms used by most authors of the Urology editorials; would it save lives? However, for each man there is another, stronger, reason for caution before proceeding. The diagnostic process from the consulting room to confirmation of the disease is imperfect. In the PSA range of ‘curable’ disease, most men with a ‘positive test’ will not have cancer. However, the diagnostic biopsy has the opposite defect; a significant number of cancers will not be diagnosed on the first attempt. Thus, most men whose PSA is in the ‘grey’ area are left in a form of limbo. The follow-up of these men has probably had a greater effect on urological practice, involving many more urologists, than has the rise in the use of radical prostatectomy. With refinements in PSA or other tumour markers, and improvements in biopsy techniques, this may improve. Until then, presenting the PSA test in over-simplistic terms is to condemn many men to a long period of anxiety and concern for which they must be prepared.

If patients are informed of the issues surrounding PSA testing, does this make a difference? Several studies suggest that it does. In one American study, men seeking PSA testing were randomized to two groups, one of which, having been shown an information video, had a lower uptake of testing than the control group [5].

A MORI survey carried out for the Institute of Cancer Research asked men about their knowledge of prostate cancer (Dearnaley, personal communication). About 30% did not know much about prostate cancer, rising to 80% where knowledge of PSA was concerned. After an explanation about the value of PSA testing, although 58% (73% of those aged < 55 years) said they would have their PSA tested, 36% (24% at < 55 years) would not be likely to have it. As this is not a ‘first past the post’ election, the needs of that 36% would seem to demand that PSA is explained before testing. Clearly there are defects in this type of study; was the explanation balanced or did it present too pessimistic a view? Importantly, as worried Catalona [3], was the result of this explanation to deprive those who then decline the test an opportunity of a live-saving intervention?

Prostate cancer is not like other cancers. Many men with the disease do not need immediate treatment; many will never need it. Even where a man needs treatment for early cancer, it represents a considerable investment in immediate discomfort and potential morbidity to forestall a disease process which may have no adverse effects for many years. Diagnosis, despite the strides made in the last decade, remains imprecise. Publicity about cancer in general repeatedly emphasizes the need for early diagnosis and treatment, and most men will not appreciate the somewhat different issues surrounding prostate cancer. If clinicians use a PSA test without prior discussion with the patient, do they not abdicate their responsibilities as doctors?

REFERENCES

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  2. REFERENCES
  • 1
    NHS Centre for Reviews and Dissemination. Screening for prostate cancer. Effectiveness Matters 1997; 2
  • 2
    Anonymous. The NHS Prostate Cancer Programme. CCR/Prost 01/3
  • 3
    Catalona WJ. Informed consent for prostate-specific antigen screening. Urology 2003; 61: 179
  • 4
    Brawley OW. Informed consent for prostate-specific antigen screening. Urology 2003; 61: 102
  • 5
    Volk RJ, Cass AR, Spann SJ. A randomised controlled trial of shared decision making for prostate cancer screening. Arch Fam Med 1999; 8: 33340