Molecular Characterization of Colorectal Tumors
The pathogenesis of colorectal cancer (CRC) is a complex process caused by both genetic and environmental factors. The most widely accepted environmental risk factors include but are not limited to the so-called 'Western Diet9 - a diet high in saturated fat, low in fiber and fruits and vegetables, and low physical activity (Slattery et al. 1998). This is emphasized by studies that show that migrant populations, when moving from an area of low CRC risk to an area ofhigh CRC risk adopt that higher risk after only one generation, suggesting a strong environmental component to CRC (Warshauer et al. 1986; Haenszel and Kurihara 1968; Potter et al. 1993; McMichael et al. 1980). While many ofthese factors have been well-replicated across studies, there is a great deal of heterogeneity in measurement and no general consensus on the pathways by which the Western Diet and other environmental risk factors affect CRC risk.