Colon Cancer: A Civilization DisorderWatson A.J.M. · Collins P.D.
aNorwich Medical School, University of East Anglia, Norwich, and bDivision of Gastroenterology, School of Clinical Sciences, University of Liverpool, Liverpool, UK
Colorectal cancer arises in individuals with acquired or inherited genetic predisposition who are exposed to a range of risk factors. Many of these risk factors are associated with affluent Western societies. More than 95% of colorectal cancers are sporadic, arising in individuals without a significant hereditary risk. Geographic variation in the incidence of colorectal cancer is considerable with a higher incidence observed in the West. Environmental factors contribute substantially to this variation. A number of these risk factors are associated with a Western lifestyle and could be considered a product of ‘civilization’. Recently, smoking has been recognized as a risk factor. Energy consumption also influences colorectal cancer risk, with obesity increasing risk and exercise reducing risk. However, the strongest contribution to environmental risk for colorectal cancer is dietary. Consumption of fat, alcohol and red meat is associated with an increased risk. Fresh fruit and vegetables and dietary fibre may be protective. Much has been learnt recently about the molecular pathogenesis of colorectal cancer. Colorectal cancer always arises in the context of genomic instability. There is inactivation of the tumour suppressor genes adenomatous polyposis coli, p53, transforming growth factor-β, activation of oncogene pathways including K-ras, and activation of the cyclooxygenase-2, epidermal growth factor receptor and vascular endothelial growth factor pathways. The mechanisms by which some environmental factors modify the mutation risk in these pathways have been described.
Prof. Alastair Watson
School of Medicine, Health Policy and Practice
Faculty of Health, University of East Anglia
Norwich NR4 7TJ (UK)
Tel. +44 1603 5907 266, E-Mail email@example.com
Published online: July 05, 2011
Number of Print Pages : 7
Number of Figures : 0, Number of Tables : 0, Number of References : 82
Digestive Diseases (Clinical Reviews)
Vol. 29, No. 2, Year 2011 (Cover Date: July 2011)
Journal Editor: Malfertheiner P. (Magdeburg)
ISSN: 0257-2753 (Print), eISSN: 1421-9875 (Online)
For additional information: http://www.karger.com/DDI