Exogenous factors in colonic carcinogenesis

摘要

Colorectal cancers (CRC) are frequent cancers with well-clarified genetic background and high mortality rates, ranking as number one on the incidence list in Germany. They are probably also the tumour types most strongly linked to dietary factors. Epidemiological evidence suggests that high consumption of processed meats and alcohol increases risk. The attempt to identify the carcinogenic compounds involved has traditionally focussed on food-borne toxicants, such as heterocyclic amines or polycyclic aromatic hydrocarbons that are muta-gens in S. typhimurium or carcinogens in rats. Additionally, endogenous products are expected to contribute. Iron and alcohol metabolism can cause oxidative stress in the gut and the products of oxidative stress [reactive oxygen species (ROS)] induce lipid peroxidation. Both ROS and products of lipid peroxidation