The currently available knowledge of factors that dictate the development and
progression as well as the clinical outcome of colorectal cancers (CRC) is mainly derived
from Western countries. Considerable number of publications document different
incidence rates and contrasting clinical features of CRC in various groups such as the
differences between urban vs. rural areas, young vs. old age and the East vs. the West.
In particular, Egyptian CRC is a surprisingly young age disease with higher proportion of
poorly differentiated and advanced stage cancers as compared to the Western
counterparts. Less number of publications addressed the molecular genetics and
epigenetic basis of these differences. The available data on CRC and other cancers
support a substantial role of several environmental risk factors which impinge on the
epigenome and alter the overall cellular and tissue homeostasis. Thus, environmental
factors could play a role in predisposition to CRC in general as well as in shaping distinct
disease phenotypes in different settings. On the other hand, the environment offers a
wide range of preventive modalities including a selection of dietary chemopreventive
agents which could play a significant role in fighting cancer at early stages. We here
compare the clinical and molecular characteristics of Eastern and Western CRC based
on the latest literature. The genetic, epigenetic and environmental etiologies for the
observed differences are discussed. Finally, prospects for cancer prevention in light of
the increased etiologic understanding are outlined.
Keywords: Carcinogens, colon cancer, environment, epigenetics, ethnic variation, dietary chemoprevention.
Rights & PermissionsPrintExport