Methods are changing rapidlyBMJ 1995; 310 doi: https://doi.org/10.1136/bmj.310.6987.1140 (Published 29 April 1995) Cite this as: BMJ 1995;310:1140
- F C Hamdy,
- D E Neal
- Senior lecturer in urological surgery Professor of surgery University Urology Unit, Freeman Hospital, Newcastle upon Tyne NE7 7DN
EDITOR,—Fritz H Schroder discusses the controversies surrounding the early detection of prostate cancer and some differences in attitude between Europe and North America.1 It is unfortunate that he emphasises screening rather than treatment. The uncertainty about the ability of treatment to modify the natural course of the disease should be resolved much more urgently than uncertainty about the value of screening, which can be addressed only when certain conditions are met—namely, that the natural course is understood, there is an agreed policy on whom to treat and by which method, and the cost of finding cases is economically balanced in relation to expenditure on medical care.2 All these questions have yet to be answered in prostate cancer.
One flaw in screening studies is the rapidity with which methods of detection change. Testing for prostate specific antigen has been used routinely only in the past decade; already, different molecular forms of the antigen discovered recently suggest that newer assays may be more specific.3 In the next five years a multiplicity of tests will probably emerge, with a higher detection rate than the 5.8% recently reported in a screening study.4 The second problem with screening trials is that they do not specify the type of treatment for cancer provided. It is therefore essential and logical that the efficacy of treatment should be tested before the benefits of screening are assessed. Schroder refers to such studies being carried out in Scandinavia and Britain. These trials are unlikely to provide the answers required. In Scandinavia the randomisation protocol, which excludes high grade tumours, will prevent a clear resolution of the problem. In Britain the Medical Research Council's study, launched last year, will find it hard to recruit sufficient patients as no provision was made for finding cases, which is the only means of recruiting enough men for randomisation.
A valid and ethically justified study comparing radical surgery with watchful waiting could be conducted only by targeting a population of men who had been fully informed about the consequences of screening and understood that watchful waiting might be offered. Such a trial is currently being organised on a pan-European scale, and it is now the responsibility of governments, the Medical Research Council, and the European Commission to identify priorities and respond to the urgency of providing a definitive answer to the problem by giving adequate support where it is most needed.