Lecture 9 - Neoplasia II Flashcards
define invasion
ability of cells to break through the basement membrane and spread
define metastasis
spread of a malignant tumour to a distant site
how are cell-cell interactions altered?
reduced expression of cadherins (which bind cells together) allows cells to move apart
how are cell-stroma interactions altered?
reduced expression of integrins in malignant cells allows movement
what do metastatic cells do?
synthesis and release matrix metalloproteinases
what are matrix metalloproteinases?
enzymes
digest collagen so metastatic cells can digest the ecm and break through the basement membrane
what matrix metalloproteinases digest type 1 collagen?
mmp1
what matrix metalloproteinases digest type 4 collagen?
mmp2/9
what happens when a tumour reaches 1-2mm^3?
growth is halted due to lack of nutrients and oxygen
alters cell environment - hypoxic
upregulation of pro-angiogenesis factors
what are pro-angiogenesis factors?
angiopoietin
vegf
what do pro-angiogenesis factors do?
cause growth of new thin wall blood vessels
allows for continued growth of tumour and provides and opportunity for it to enter the blood stream
what are the routes of metastasis?
lymphatic
vascular
describe lymphatic spread of metastasis
spread to local and distant lymph nodes
frequent route of spread of carcinomas
can involve lymphatics of lung
describe vascular spread of metastasis
spread through capillaries and veins to various organs
describe vascular metastasis to the lung
wide range of malignant neoplasms
sarcomas, carcinomas, kidney, testis
describe vascular metastasis to the liver
common site for carcinomas of large intestine
carcinomas
describe vascular metastasis to bone
can cause destruction of bone leading to pathological fracture - carcinomas
can cause production of dense bone - prostate
describe vascular metastasis to the brain
cause a wide range of neurological symptoms
space occupying lesion
bronchial, breast, testicular carcinoma, malignant melanoma
what are the effects of benign neoplasms?
cause compression - pressure atrophy and altered function
in a hollow viscus cause partial or complete obstruction
ulceration of surface mucosa
space occupying lesion in brain
what are the effects of malignant neoplasms?
destroy surrounding tissue
in a hollow viscus cause partial or complete obstruction
ulceration
infiltration around and into nerve, blood vessels and lymphatics
space occupying lesion in brain
what are the haematological effects of neoplasms?
anaemia (malignant infiltration of bone marrow)
low white cell and platelets (infiltration of bone marrow, consequence of treatment)
thrombosis (carcinoma of pancreas)
what are the endocrine effects of neoplasms?
excessive secretion of hormones (neoplasms of endocrine glands)
ectopic hormone secretion (acth by small cell carcinoma of bronchus)
what are the skin effects of neoplasms?
increased pigment (many carcinomas)
pruritis (jaundice, hodgkins disease)
herpes zoster (lymphoma)
dermatomyositis (bronchial carcinoma)
what are the neuromuscular effects of neoplasms?
problems with balance sensory/sensorimotor neuropathies myopathy and myasthenia progressive multifocal leucoencepalopathy not due to metastasis to brain
