Term
Seeding of cavities
-primary cancers involved
-description |
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Definition
carcinomas of ovary, appendix
penetration of neoplasm into open space
metastases often remain in cavity
often coat the cavity with neoplastic mucus or glaze |
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Term
Lymphatic spread
-primary cancers involved
-description |
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Definition
carcinomas (esp breast)
lymph vessels located at tumor margins pick up metastatic cells, may remain in first LN ("sentinel")
Sentinel nodes may be bypassed in "skip metastasis" due to venous-lymphatic anastomoses |
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Term
Hematogenous spread
-primary cancers involved
-description |
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Definition
sarcomas
veins more easily penetrated than arteries
portal circulation deposits in liver, caval circulation in lungs
cancers close to vertebral column (prostate, thyroid) migrate via paravertebral plexus, end up in vertebrae |
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Term
| Steps of metastasis: step 1 |
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Definition
Detachment from cells
downregulation of cell-cell adhesion molecules
E-cadherin |
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Term
| Steps of metastasis: step 2 |
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Definition
Attachment to basement membrane
overexpression of binding molecules for ECM components
integrins for fibronectin, laminin, collagen, vitronectin |
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Term
| Steps of metastasis: step 3 |
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Definition
degradation of ECM
proteolytic cleavage of type IV collagen penetrates basement membrane, mobilizes VEGF, produces pro-motility factors
matrix metalloproteinases: MMP9 (collagen IV), MMP2 (laminin-5) |
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Term
| Steps of metastasis: step 4 |
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Definition
angiogenesis
angiogenic agents released by tumor cells outweight anti-angiogenic agents of collagen remnants
tortuous capillaries grow to tumor
VEGF, bFGF HIF-1 (hypoxia-induced factor)
Thrombospondin-1, antiostatin, tumstatin (anti-angiogenic) |
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Term
| Steps of metastasis: step 5 |
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Definition
Vascular dissemination
upon intravasation, tumor cells aggregate and bind to platelets
tumor cells extravasate through high-endothelial venules
CD44-hyaluronate binding to endothelium |
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Term
| Steps of metastasis: step 6 |
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Definition
Homing of tumor cells
chemokine receptors on tumor cell surfaces determine targets
organs secrete chemoattractants (e.g. insulin-like growth factor)
CXCR4/CCR7 chemokine receptors (esp. breast cancer mets) |
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Term
| Which primary tumors metastasize to the brain? |
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Definition
"lots of bad stuff kills glia"
lung
breast
skin
kidney
GI
usually see multiple well-circumscribed tumors at the gray/white matter junction |
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Term
| what is the best MARKER of malignancy? |
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Definition
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