Molecular Genetics of Gastrointestinal Tract Cancers

Cancer has been intimately related to a large number of environmental and genetic factors. All these ultimately result in change of cellular behaviour which proliferate uncontrollably thus, leading to malignancy. Age, sex, geographical variation patterns, social differences, varied dietary habits are various environmental factors while oncogenes/ antioncogenes, chromosomal aberrations are various genetic factors that play an important role. Human papillomavirus has been associated with benign squamous papillomas which may progress to invasive lesions in all types of malignancies of the gastrointestinal tract. Various, tumor suppressor genes have been linked with malignancy leading to metastasis. Instability due to loss of chromosomal fragments and microsatellites allows sufficient amount of genetic damage that leads to imbalanced cellular proliferation. Thus, an insight of such factors would help in better understanding of the early activation events leading to malignancy and may be helpful in early identification of disease in high risk patients.