Genetic Epidemiology of Colorectal Cancer
Colorectal cancer is the third most common UK cancer with 35,000 cases p.a. Lifestyle and in particular diet are particularly important so that diets with high intake of red or processed meat have an increased risk while diets high in fruit and vegetables are protective.
The focus of our research is the understanding of the combined effects of genes and lifestyle on risk. Case- control studies of colorectal cancer and colorectal adenomas have been conducted (funded by Cancer Research UK and the FSA). The most recent study of the protective role of aspirin suggests that the effect may only apply to those with specific genotypes (with Prof Roland Wolf and Dr Gillian Smith, Dundee; Prof David Forman, Leeds). With Prof John Burn (Newcastle) we are conducting a chemoprevention study of aspirin and resistant starch in persons with hereditary predisposition to colorectal cancer. With Dr. Peter Zauber (South Orange, New Jersey, USA) we are exploring the genetic epidemiology of colorectal neoplasia among those of Ashkenazi dissent.
Testicular Cancer Testicular cancer is notable because of the increased risk to relatives of cases (about ten-fold). Taking this indication of inherited predisposition, we have been using gene-mapping approaches to identify susceptibility genes (with Dr Liz Rapley and Prof Mike Stratton, ICR; Prof Doug Easton, Cambridge). We have excluded inheritance being due to a few genes and are now exploring more complex modes of inheritance.
Figure 1. Folate intake, MTHFR 1298 genotype and risk of developing adenomas.
Figure 2. Testis cancer pedigree (affected men in red) showing some evidence for linkage to a region of chromosome 3.
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