Molecular and cellular biology of pre-malignancy in the gastrointestinal tract

Important pathogenic alterations within established cancers are acquired during the pre-malignant stage. These genetic alterations can be grouped into specific neoplastic pathways that differ within and between anatomical sites. By understanding the mechanisms that determine the initiation and progression of each pathway, it will be possible to develop novel approaches to the diagnosis, prevention and treatment of cancer. This chapter outlines the principles underlying the molecular characterization of pre-malignant lesions, taking colorectal neoplasia as the main model.