Oncology Notes 2

Oncology Notes 2 - Cancer It is not a single disease with a...

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Cancer It is not a single disease with a single cause It is a group of distinct diseases with different causes, manifestations, treatments, and prognosis Begins when an abnormal cell is transformed by the genetic mutation of the cellular DNA These cells form a clone and begin to proliferate abnormally, ignoring growth-regulating signals in the environment surrounding the cell. The cells acquire invasive characteristics and changes occur in surrounding tissues The cells infiltrate these tissues and gain access to lymph and blood vessels, which carry the cells to other parts of the body. Proliferative patterns Hyperplasia increase in the number of cells of a tissue Most often associated with periods of rapid body growth Metaplasia Conversion of one type of mature cell into another type of cell Dysplasia Bizarre cell growth resulting in cells that differ in size, shape, or arrangement from other cells of the same type of tissue Anaplasia Cells that lack normal cellular characteristics and differ in shape and organization with respect to their cells of origin These are usually malignant Neoplasia Uncontrolled cell growth that follows no physiologic demand Cancerous cells Malignant neoplasm’s Demonstrate uncontrolled cell growth that follows no physiologic demand Malignant cells Cell membranes are altered which affects fluid movement in and out of the cell Contains proteins called tumor-specific antigens which develop as they become less differentiated (mature) over time o Distinguish malignant cell from a benign cell of the same tissue type o Useful in measuring the extent of disease in a person and in tracking the course of illness during tx or relapse Contains less fibronectin, a cellular cement o Less cohesive and don’t adhere to adjacent cells readily Mitosis (cell division) occurs more frequently than in normal cells o As the cells grow and divide, more glucose and oxygen are needed o If glucose and oxygen are unavailable, malignant cells use anaerobic metabolic channels to produce energy, which makes cells less dependent on availability of a constant oxygen supply. 1
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Invasion Growth of the primary tumor into the surrounding host tissues Mechanical pressure exerted by rapidly proliferating neoplasms Force fingerlike projections of tumor cells into surrounding tissue and interstitial spaces Malignant cells are less adherent and may break off from primary tumor to invade adjacent structures o Thought to possess or produce specific destructive enzymes Proteinases Collagenases Plasminogen activators Lysosomal hydrolysis o These enzymes are thought to destroy surrounding tissue, including the structural tissues of the vascular basement membrane, facilitating invasion of malignant cells Metastasis Dissemination or spread of malignant cells from the primary tumor to distant sites by direct spread of tumor cells to body cavities or through lymphatic and blood circulation
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Oncology Notes 2 - Cancer It is not a single disease with a...

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