Recent Advances in Histopathology of Gastrointestinal Cancers: Prognostic and Therapeutic Assessment of Colorectal Cancers

摘要: The genetics and molecular biology, precursor lesions predisposing conditions, hereditary syndromes of gastrointestinal cancers, especially colorectal are well characterized. Fifteen to twenty percent sporadic carcinomas have microsatellite instability (MSI; replication-error phenotype), characterized by defective DNA repair resulting in alterations short tandem repeat sequences, including mononucleotide, dinucleotide, tetranucleotide repeats. This is due alteration mismatch enzymes. Patients with cancers MSI a better prognosis than do those without. In contrast, about 50% 60% loss the long arm (q) chromosome 18, chromosomal location deleted cancer, SMAD4, SMAD2 genes. Chromosome 18q has been associated poor outcome patients cancer. Growth factors growth factor receptors play major role development progression Gastrointestinal express epidermal receptor (EGFR) related that activate intrinsic tyrosine kinase activity result signals cell proliferation. can be modulated variety therapeutic options, monoclonal antibody against EGFR or selective inhibition activity. Immunohistochemical analysis for select who EGFR-overexpressing cancer thus potential candidates anti-EGFR therapy.