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Flashcards in MOD Deck (186)
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150

In order to invade at a primary site what changes must tumour cells undergo and how?

Alter adhesion - e-cadherin and integrin must change
Lyse basement membrane - alter niche cells to cause proteolysis
Change cell mobility - alter cytoskeleton such as. Changes to rho family proteins

151

What are the changes in a primary epithelial malignant tumour preparing for metastasis called?

Epithelial to mesenchymal transition

152

What is the difference between e-cadherin and integrin?

E-cadherin is cell to cell anchoring
Integrin is cell to basement membrane anchoring

153

What routes can tumours spread?

Blood
Lymphatics
Transcelomic

154

What is the easiest route for metastasis? Why?

Lymphatics - thin membranes

155

What are the common sites of secondaries (very generally!) in each of the three routes of metastasis?

Lymph - regional lymph nodes
Blood - first capillary bed reached
Transcoelomic - gravity assisted (eg. Pouch of Douglass)

156

What explains variation in then common rules of tumour metastasis distribution?

Seed and soil theory - metastases can only settle where the niche is correct (e.g. Why bronchial tumours metastasis are found in the adrenals but not the kidneys)

157

What is the main route of carcinoma spread

Lymphatics

158

What is the main route of sarcoma spread?

Blood

159

What common cancers cause bone mets?

Breast
Bronchus
Kidney
Thyroid
Prostate

160

What is growth at secondary site of cancer also known as?

Colonisation

161

What is the theory behind cancer relapse?

Formation of micrometastases at secondary sites that dont develop can reactivate

162

What are causes of micrometastases dormancy?

Immune response
Hostile niche
Failure of angiogenesis

163

What are local clinical effects of neoplasms?

Direct invasion and tissue destruction
Blockage of tubes and ducts
Ulceration
Compression of adjacent structures

164

What are the systemic effects of neoplasm?

Increased tumour burden - weight loss, malaise, immunosuppression, thrombosis

Hormone production (especially well differentiated tumours, therefore more common in benign tumours)

Poorly understood issues such as clubbing, fever, myositis

165

What are extrinsic causes of cancer?

Environmental factors (e.g. UV exposure)
Lifestyle factors (e.g. Smoking, overweight, alcohol, low exercise, low fruit and veg)

166

What are examples of intrinisic risk factors for cancer?

Age
Sex
Ethnicity
Hereditary defects

167

What are the three categories of extrinsic carcinogens?

Chemicals
Radiation
Infection

168

What are the typical characteristics of chemical carcinogens?

Long delay between exposure and cancer
Increased risk with increased dose
Can be organ specific

169

Give some examples of chemical carcinogens

Asbestos - mesothelioma
Tobacco - bronchial carcinoma

170

What is the term for a chemical which is a initiator and a promotor of cancer?

Complete carcinogen

171

What are the types of nuclear radiation?

Alpha
Beta
Gamma

172

What are the electromagnetic carcinogenes?

UV
Xray
Gamma ray

173

Which radiationn carcinogens cause ionisation?

Alpha, beta and gamma as well as xrays.

174

Which electormagentic carcinogen has the shortest wavelenght?

Gamma rays

175

How does ionising radiation work?

Strips electrons off atoms

176

What are examples of direct and indirect damage from radiation?

Direct - alteration of bases etc
Indirect - production of ROS

177

What are direct and indirect carcinogenic mechanisms of infection?

Direct - influencing protooncogene and tsg
Indirect - cause chronic injury necessitating regeneration (acting as a promotor)

178

How does HPV cause cancer?

Expresses proteins E6 (inhibits p53) and E7 (inhibits RB)

179

What infections cause cancer by the indirect route?

Hep b/c
H pylori
Liver flukes