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45 Cards in this Set
- Front
- Back
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Tumor or neoplasms
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is an overgrowth of tissue
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Cancer
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is a malignant tumor
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Benign tumors
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are well defined, well-differentiated, slow growing (hence have a low rate of mitosis) and do not invade or metastasize
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Cancerous tumors
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are not encapsulated, are poorly-differentiated, grow rapidly (hence have a high rate of mitosis), and can invade local tissues or metastasize to distant tissues
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Carcinomas
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epithelial malignant
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Adenocarcinomas
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glandular cancer
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Sarcomas
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cancers of connective tissue
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Leukemias
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cancer of blood-forming cells
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Dysplasia
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is a pre-cancerous change in tissue
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Carcinoma in situ (CIS)
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is a pre-invasive cancerous growth of epithelial tissue that has not penetrated the basement membrane - also known as severe dysplasia
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Mutagens
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cause mutations - they are agents that can disrupt the DNA, which may cause a change in a base pair, which in turn causes a change in the amino acid and changing the function of the protein, or rendering it ineffective
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Carcinogens
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are agents that cause cells to mutate and to become cancer cells
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Examples of mutagens and carcinogens
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Viruses, ultraviolet light, x-rays and other radiation, cigarette smoke, asbestos, benzene
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What happens if a mutation disrupts a control DNA sequence?
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it can change the way the genes it controls work and turn them on or off abnormally
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Free radicals
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also called chemical mutagens are substances that can cause oxidation
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Primary cause of carcinogenesis
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mutations to cancer-causing or cancer prevention genes
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How many different mutations in different pathways does it take to produce cancer
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epidemiologic data shows five or six times
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Cancer cells lack social controls
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that prevent them from overgrowing neighbor cells
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Cancer cells are usually immortal
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and can divide for years (reference "The Immortal Life of Henrietta Locks)
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Anaplasia
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cancer cells often lacks differentiation
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The path to apoptosis
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is disabled in some cancers
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Cancer cells can secrete
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growth factors that stimulate their own growth
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Oncogens
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Mutations to genes that encode for growth factors cause hyperactivity of growth-related products
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Tumor suppressor genes
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mutations to genes that inhibit growth - allow continued growth of tumors
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Cancer cells can stimulate new blood vessels
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to grow around them (by angiogenesis) to supply them with nutrients and oxygen needed for their growth
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Chronic inflammation
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can contribute to carcinogenesis by producing free radicals
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Mutations produced by chronic inflammation
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accumulate with age so the incidence of cancer increases with age
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Mutations of the tumor suppressor genes can be
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inherited - thus some cancers run in families
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What is the protein that triggers cell death to prevent overgrowth
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p53 - mutations of this gene allow for uncontrolled cell growth
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How do tumors invade surrounding tissue
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cellular multiplication, mechanical pressure, release of lytic enzymes, decreased adhesion (slipperiness) and increased motility
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Metastasis is spread by
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1. Direct or continuous extension
2. Penetration into the lymph or blood vessels 3. Transport to secondary sites 4. Entry and growth into secondary sites |
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Tumor Staging
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Stage 1 - confirmed to the organ of origination alone
Stage 2 - local invasion Stage 3 - regional spread, including lymph nodes Stage 4 - distant metastases |
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Stage 1
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confirmed to the organ of origination
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Stage 2
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local invasion
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Stage 3
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regional spread, including lymph nodes
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Stage 4
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distant metastases
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World Health Organization TNM system for tumor staging
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T - the tumor size and spread
N - number of positive lymph nodes M - metastases |
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Clinical manifestations of cancer
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pain, fatigue, anemia, leukopenia, thrombocytopenia, and infection
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Anemia of cancer is due to
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bleeding, malnutrition (iron), replacement of bone marrow by tumor, suppression of erythropoietin
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Leukopenia and thrombocytopenia in cancer can be a result of
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replacement of bone marrow by tumor or a result of radiation therapy or chemotherapy
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Cancer therapies include
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1. Surgery to remove all of the tumor or as much as possible (de-bulking)
2. Radiation therapy for local spread 3. Chemotherapy for metastatic spread 4. Hormone therapy 5. Immunotherapy |
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Cancer prevention includes
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methods to improve or assist the immune system
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Antioxidants
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are agents that neutralize free radicals
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Common cancers in children
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leukemias, central nervous system tumors, sarcomas, and embryonic tumors (with immature, undifferentiated tissue)
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What is the percentage of children diagnosed with cancer that have been cured?
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78%
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