Tumor environment: A potent driving force in colorectal cancer?

Current models predict that colorectal carcinogenesis proceeds primarily through the progressive accumulation of fixed genetic changes in key tumor suppressor genes, oncogenes and DNA repair components. However, recent studies found evidence of dynamic changes in cellular adhesion and β-catenin localization occurring during invasion, metastasis and expansion of well-differentiated colorectal cancers. It is proposed that such changes might be driven by the local tumor environment, which, if validated, would necessitate a revision of the current linear tumor progression model.