The biology of colorectal cancer. Implications for pretreatment and follow-up management

摘要: The biology of colorectal cancer is discussed in terms multistage carcinogenesis. Colorectal evolves through the stepwise acquisition mutations at certain critical genetic loci, many which have been identified recently. earliest step neoplastic pathway a shift proliferation from normally restricted zone base colonic crypt and retention cells capable top crypt. This appears to be mediated by mutation APC gene. adenoma, collection benign cells, first pathologically recognizable lesion. Adenomas may grow or involute. Additional lesions, such as Ki-ras gene, contribute growth progressive dysplasia adenoma. Critical lesions p53 gene appear responsible for malignant transformation appearance instability cell, greatly increases likelihood that additional events will occur progressively more aggressive phenotype. Genetic phenotypic diversity develop within primary tumor, metastasis occurs consequence complex series events. Opportunities detection therapeutic intervention neoplasia are this framework.