Our incomplete understanding of carcinogenesis may be a significant reason why some cancer mortality rates are still increasing. This lack of understanding is likely due to a research approach that relies heavily on genetic comparison between cancerous and non-cancerous tissues and cells, which has led to the identification of genes of cancer proliferation rather than differentiation. Recent observations showing that a tremendous degree of natural human genetic variation occurs are likely to lead to a shift in the basic paradigms of cancer genetics, in that there is a need to consider both the nature of the genes involved, and the idea that not every genetic variation identified in these genes may be associated with carcinogenesis. Based on studies using LCM and micro-genetic analyses, we propose that significant cancer initiating events may take place during the very early stages of development of cancer-susceptible tissues and that using such techniques might greatly help us in our understanding of carcinogenesis.
(c) 2007 Wiley Periodicals, Inc.