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32 Cards in this Set
- Front
- Back
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What is the major cause of illness and death from cancer?
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Metastasis is the major cause of illness and death from cancer.
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What percent of malignancies are curred by current therapies?
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About 40-50% of malignant tumors are cured by current therapies
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T/F • Most cancer patients experience multiple metastases, too small to be detected, at the time the primary tumor is treated.
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True
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What does tumor spread depend on?
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• Tumor spread depends on:
– Rate of growth of the tumor – The degree of differentiation of the tumor – The presence or absence of anatomic barriers – Other biological factors |
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What kind of spread may be 1.Local spread by direct invasion of contiguous organs
2.Metastasis to distant organs by lymphatic and blood vessels 3.Metastasis by implantation |
Tumor Spread
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What is the first step in metastasis?
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Local spread (local invasion) is the first step in metastasis and a
prerequisite of metastasis. |
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How does local invasion occur?
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At first, local invasion occurs as a direct tumor extension.
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What happens after local invasion occurs?
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Eventually, cells or clumps of cells detach from the primary tumor and invade the surrounding interstitial spaces.
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What are the mechanisms of local invasion?
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Cellular multiplication, Mechanical pressure, Release of lytic enzymes, Decrease cell to cell adhesions, and Increased motility of individual tumor cells
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What depends on the rate of cell division and cell loss?
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Cellular multiplication
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What kind of mechanism of local invasion does the following describe:
- Pressure that forces fingerlike projection along the lines of least resistance, similar to plants forcing roots into the soil – Pressure from the growing mass could block local blood supply, leading to local tissue death and thus reducing the mechanical resistance of the normal tissue |
Mechanical Pressure
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What proteins to lytic enzymes digest?
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Tumor cells release lytic enzymes that digest proteins such as collagen (collagenase) and destroy normal tissue (plasmin)
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What kind of mechanism of local invasion does the following describe:
–Cancer cells do not adhere to one another as well as normal cells due to low levels, loss of, or defective fibronectin –Thus, cancer cells slip between normal cells for invasion |
Decreased cell to cell adhesions
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What kind of mechanism of local invasion does the following describe:
–After detaching from the original tissue, cancer cells infiltrate adjacent tissue or migrate through the circulation Thus, increased cell motility is essential for invasion –Tumor cells make and secrete a protein named autocrine motility factor (AMF) AMF causes cancer cells to grow pseudopodia ("arms“), enabling them to migrate to other parts of the body Thus, locomotion is integral to the entire process of metastasis |
Increased motility of individual tumor cells
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What is the three-step theory of tumor cell invasion of the extracellular matrix?
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attachment, dissolution, and locomotion
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What part of the theory of invasion is the following: surface receptors on the tumor cell bind to the basement membrane in the extracellular matrix?
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Attachment
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What part of the theory of invasion is the following: the extracellular matrix is degraded by lytic enzymes secreted by the tumor cell (proteases).
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Dissolution
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What part of the theory of invasion is the following: : the tumor cell migrates through the degraded basement membrane
• Finger-like projections (pseudopodia) of the tumor cell cross the basement membrane enabling it to move in and out of blood and lymph vessels. |
Locomotion.
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What is the spread of tumor cells from a primary site of origin to a distant site, and the life threatening characteristic of cancer
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metastasis
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What kind of tumors are more easy to eradicate by therapies than controlling metastasis?
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Primary tumors
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T/F Often, the primary tumor is not diagnosed before secondary spread occurs.
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True
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Metastasis involves a series of sequential steps, which are:
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1. Direct or continuous extension of local invasion of tumor cells into the surrounding tissue, 2. Penetration into lymphatics, blood vessels, or body cavities, 3. Release into lymph or blood, 4.Transport to secondary site, and 5. Entry into the secondary site (metastasis).
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What sequential step is the following:
–The earliest invasion is continuous extension The tumor cells extend into the surrounding tissue as they grow, without breaking away from the primary mass –Then the loss of adhesions allows the tumor cells to slip past one another |
Direct or continuous extension of local invasion of tumor cells into the surrounding tissue
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What step of metastasis is the following:
-Penetration into body cavities –Known as seeding: cancer cells invade through serous membranes (such as the peritoneum) and implant to become distant metastases in abdominal cavity Penetration into lymphatics & blood vessels –Tumor cells spread to distant site by penetrating blood or lymph vessels –Thin-walled venules or capillaries as well as lymph vessels do not offer much mechanical resistance to penetration by tumor cells –Clusters or singe cells separate from the primary tumor mass and disseminate through lymph & blood |
Penetration into lymphatics, blood vessels, or body cavities
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The most common route for distant metastases is through the what?
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The most common route for distant metastases is through the lymphatics.
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What stage of metastasis is the following:
–Once in the blood (emboli), in order to spread to distant organs tumor cells have to: •Escape host defenses •Lodge in the vascular bed of the target organ |
Transport to secondary site
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What stage of metastasis is the following:
–Once in the vascular bed of the target organ, tumor cells can actively invade the vascular wall and grow in the tissue –Patterns of metastasis are regulated by: •Blood flow and location of capillary beds: many types of cancer invade the first capillary bed they encounter •Organ tropism: some types of cancer prefer certain target organs due to chemotactic factors and/or specific local growth factors |
Entry into the secondary site (metastasis)
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Patterns of metastasis are regulated by what?
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–Patterns of metastasis are regulated by:
•Blood flow and location of capillary beds: many types of cancer invade the first capillary bed they encounter •Organ tropism: some types of cancer prefer certain target organs due to chemotactic factors and/or specific local growth factors |
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The stage of the tumor depends on the what?
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The stage of the tumor depends on the:
–Size of the tumor –The degree of local invasion –The extent of spread (metastasis) |
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A common way for standardizing staging is the what?
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A common way for standardizing staging is the TNM system.
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What does TNM stand for?
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–T: tumor spread
–N: (lymph) node involvement –M: presence of distant metastasis |
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What does the clinical manifestation include?
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1. Pain 2. Fatigue 3. Cachexia 4. Anemia 5. Leukopenia and thrombocytopenia 6. Infection
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