MoD 10 (Neoplasia 3) Flashcards
Which tumour marker is often released by Lver cell carcinoma?
AFP (Alpha-fetoprotein)
Name the mould which produces Aflatoxins associated with Liver cell carcinoma:
Aspergillus flavus
Why is colonic carcinoma rare in Africa?
Africans have higher fibre diet:
- Decreases transit time through bowel
- Maintains bowel health (binds carcinogens)
- Reduces obesity and cholesterol
- Regulates blood sugar
Why is breast carcinoma rare in Africa?
Africans have less Oestrogen exposure, due to earlier and more frequent pregnancies = less time menstruating
What type of cancer is caused by 2-napthylamine?
Bladder cancer
How does a pro-carcinogen become a carcinogen in the body?
Metabolised by cytochrome P450 liver enzymes
What is meant by ‘complete carcinogens’?
- Act as both an initiator (cause DNA mutations) and a promoter (promote proliferation of cells)
What is the main type of ionising radiation we are exposed to?
Radon gas (from the Earth’s crust)
How does DNA damage DNA?
Damages DNA bases, and causes single/double strand breaks
How does HPV cause neoplasia? Which type of cancer is it strongly associated with?
- Expresses E6 and E& proteins which inhibit P53 and pRB
- Cervical cancer
How does H. pylori increase the risk of gastric cancer?
- Gastric inflammation = ^ amount of mediators produced by inflammatory leukocytes
- Higher rate of regeneration of cells
- Higher risk of DNA mutation
How doe HIV increase the risk of tumour growth?
Decreases immunity
Increasing risk of other carcinogenic infections occuring
Is Ras a tumour suppresor gene or a proto-oncogene?
Proto-oncogene
Explain Retinoblastoma’s 2-hit hypothesis:
Requires 2 mutations in 1 cell:
Familial cancer = 1st hit via germline, 2nd hit = somatic
Sporadic cancer = Both somatic hits must occur in same cell = unlikely
Xeroderma pigmentosum causes skin cancer at a young age. Mutations in which genes cause this?
Genes which affect DNA nucleotide excision repair
Mutations = Nucletide instability
Hereditary non-polyposis colon cancer increases the risk of colon carcinoma, why?
Mutated DNA mismatch repair gene
= Microsatellite instability
Why does a close family history of breast carcinoma increase your risk of developing it?
Associated with mutated BRCA1 and BRCA2 genes, which usually repair double-strand DNA breaks = linked to chromosomal instability
List the 6 hallmarks of cancer:
1) Sustain proliferative signalling
2) Evade growth suppressors
3) Enable replicative immortality
4) Induce angiogenesis
5) Resist cell death
6) Invade and produce metastases`
What enables cancer cells to have replicative immortality?
Activation of Telomerase gene
What allows cancer cells to induce angiogenesis?
Activation of VEGF expression
Which gene amplification in breast carcinoma allows cancer to cells to sustain proliferative signalling?
HER2
What are the 2 types of Lymphoma, and how are they microscopically differentiated?
Hodgekin’s lymphoma
= Reed-Sternburg cells (abnormal B cells), and usually eosinophils present, with proliferating lymphocytes
Non-Hodgekin’s lymphoma
= Only proliferating lymphocytes present
Which type of Lymphoma releases CD20?
Non-Hodgkein’s lymphoma
Name the system used to stage lymphoma:
Ann Arbor System
What is MALT lymphoma?
Mucosa-Associated Lymphoid Tissue lymphoma
Type of Non-Hodgkin’s lymphoma
Slow growing, often occurs in stomach due to chronic inflammation
Mutation in which gene causes Familial Adenomatous Polyposis (FAP)?
Tumour suppressor gene APC = Chromosomal instability
Name the inherited disease which causes almost 100% risk of colorectal cancer:
Familial Adenomatous Polyposis (FAP)
What are the symptoms of Retinoblastoma?
White pupil that doesn’t reflect light
Squint
Painful red eye
Why does inherited Retinoblastoma more commonly affect both eyes compared to sporadic Retinolastoma?
2-hit hypothesis:
- 1st mutation affects all cells (germline)
- 2nd mutation is sporadic
Risk of both mutations occuring in both eyes is increased, due to germline mutation.
Where does bladder carcinoma commonly metastasise to?
- Bone
- Liver
- Lung
What is the main cause of Kaposi’s sarcoma?
HHV8 (Human Herpes Virus 8)
Quickly forming skin lesions, swollen lymph glands, peripheral oedema and anaemia are all symptoms of what tumour?
Kaposi’s sarcoma
What types of cancer is EBV (Epstein-Barr Virus) associated with?
- Lymphoma (Hodgekin’s, Non-Hodgekin’s, and Burkitts)
- Nasopharyngeal carcinoma
