Neoplasia 2 Flashcards
Describe the 3 steps of invasion and metastasis
Grow and invade at primary site
Enter a transport system and lodge at a secondary site
Grow at the secondary site to form a new tumour (colonisation)
When is metastasis most likely to fail?
Entering a vessel and lodging at a distant site
OR
Growing at the secondary site
Invasion involves which 3 important alterations?
Altered adhesion
Stromal proteolysis
Motility
In carcinomas, what change happens upon invasion?
Epithelia-to-mesenchymal transition
How is adhesion altered between malignant cells for invasion?
Reduction in E-Cadherin expression
How is adhesion altered between malignant cells and stromal proteins in invasion?
Changes in integrin expression
Which enzymes are used to degrade the basement membrane and stroma?
Matrix metalloproteinases
What do we call the surrounding cells in the microenvironment that help with cancer invasion?
Niche
How do we change motility?
Changes in actin cytoskeleton
How does signalling through integrins occur?
Via small G proteins such as members of Rho family
What are the 3 routes of transport for metastasis?
Blood vessels (capillaries and venules)
Lymphatic vessels
Body cavities - transcoelomic spread
What are the 2 stages that malignant cells must achieve at the secondary site?
Extravasation (get out of the vessel)
Colonisation
Define micrometastases
Surviving microscopic deposits of malignant cells that fail to grow
Why might someone who has just has an organ transplant develop cancer?
They are taking immunosuppressant drugs
Any micrometastases in their/the donor organ(s) may begin to develop with the compromised immune system
Tumour dormancy is usually due to which 3 things?
Immune attack
Reduced angiogenesis
Hostile secondary site
What are the 2 most common sites of blood-borne metastases?
Lung
Liver
(Next capillary bed encountered)
Describe the seed and soil phenomenon
Interactions between malignant cells and local tumour environment at the secondary site
There are patterns to where many cancers spread
Different cancers ‘prefer’ different areas
How do carcinomas typically spread?
Lymphatics
How do sarcomas typically spread?
Blood stream
What are the 4 most common sites of blood-borne metastases?
Lung
Bone
Liver
Brain
Cancers of which origins most commonly metastasise to bone?
Breast Bronchus Kidney Thyroid Prostate
What effect does prostate cancer have on bone?
Increases bone production
Give an examples of an aggressive tumour that often metastasises early
Small cell bronchial carcinoma
Give an example of a tumour that almost never metastasises
Basal cell carcinoma of skin
What is the likelihood of metastasis related to?
Size of the primary neoplasm
Describe some local effects of tumours
Direct invasion and destruction of normal tissue
Ulceration at a surface, leading to bleeding
Compression of adjacent structures
Blocking tubes or orifices
Give examples of some of the systemic effects that an increased tumour burden can have
Reduced appetite and weight loss
Malaise
Immunosuppression
Thrombosis
What do we call extreme weight loss and loss of appetite?
Cachexia
Which hormones are most commonly secreted by tumours?
ACTH
ADH
PTH like hormone
Name some of the miscellaneous systemic effects of tumours
Neuropathies Skin problems Fever Myositis Clubbing
Describe some features of astrocytomas
More common in children
Most common glioma
Unlikely to metastasise
Locally aggressive
Are malignant melanomas likely to metastasise?
Yes
Early
What are the most common sites for malignant melanoma to metastasise to?
Skin
Brain
GI tract
What is another name for a carcinoid tumour?
Neuron doctrine/endocrine tumour
What is the most common and 2nd most common sites of carcinoid tumours?
Most common = appendix
2nd = small bowel
What is carcinoid syndrome?
Effects of extensive metastasis of neuroendocrine tumours Tachycardia Sweating Skin flushing Anxiety Diarrhoea
Which chemical mediators are responsible for carcinoid syndrome?
Serotonin
Prostaglandins
What is a very important risk factor for carcinoma of the pancreas?
Cigarette smoking
Why does carcinoma of the pancreas usually have a poor prognosis?
Symptoms occur at a late stage therefore not detected until late on
(Weight loss and obstructive jaundice)
What is Trousseau’s sign?
With carcinoma of the pancreas, often patients develop venous thromboses
Name 3 symptoms of lung cancer
Breathlessness
Pain on breathing
Hoarseness
Which 3 sites are most likely to lead to secondary lung tumours?
Breast
Kidney
GI tract
