Prognosis - pancreatic cancers. The rasN oncogene is...

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Prognosis A persons prognosis is less favorable with the occurrence of each step below: 1. the tumor has invaded surrounding tissues 2. there is lymph node involvement 3. malignant tumors occur in other parts of the body Genes and Cancer Oncogenes Proto-oncogenes are normal genes that are somehow involved in this process of cell division. Their DNA may contain the code for growth factors or some chemical that needs to be activated in order to stimulate cell division. When a proto-oncogene becomes mutated , it may no longer function properly, leading to uncontrolled cell growth. Mutated proto-oncogenes that cause cancer are called oncogenes . Approximately 100 oncogenes have been identified. Examples of Oncogenes The rasK oncogene is found in 25% of lung cancers, 50% of colon cancers, and 90% of
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Unformatted text preview: pancreatic cancers. The rasN oncogene is associated with leukemias and lymphomas. These oncogenes stimulate growth even when there is no growth factor produced. Carcinogens Carcinogens are chemicals that cause cancer by causing mutations. Cancer may result if the mutations produce some of the characteristics described above. Generally, chemicals that produce mutations are more likely to cause cancer than those that do not produce mutations. The likelihood that any particular chemical will cause cancer can be determined by observing the rate at which it causes mutations in bacteria. This is the basis of the Ames test....
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