Genetic Predisposition for Cancer Risks in Man

Abstract

In considering cancer risks and strategies for their elimination it is vitally important to keep in mind the diverse nature of the disease. Not only are there many different kinds of cancer, each with subtypes, but also it seems likely that for any one cancer there may be a variety of interacting causal factors. Moreover, there is good evidence that the same cancer type may be the end result of a number of quite different causal pathways. Such considerations will have both advantages and disadvantages in trying to understand cancer. On the negative side, the sheer complexity of the causal mechanisms makes both analysis of the aetiology and proposals for preventive action extremely difficult and, of course, the existence of multiple pathways can mean that even a successful strategy may not deal adequately with all the risks. On the other hand our growing power to resolve subclasses of disease often means that we can see a causal pattern clearly for the first time even though the number of cases in that category may be small. Furthermore, the existence of multiple factors in the aetiology of a cancer, while it may make complete elucidation of mechanisms difficult, means that removal of only one of the causal factors may make a major impact in reducing incidence even in the absence of complete understanding.