Intrinsic risk factors - Answers - Random errors in DNA replication (unmodifiable)
- especially in oncogene or tumour suppressor gene
Non-intrinsic risk factors - Answers - endogenous risk factors
- exogenous risk factors
endogenous risk factors - Answers Biological aging
Hormones
Genetic susceptibility
Inflammation
DNA repair machinery
Partially Modifiable
Exogenous risk factors - Answers Radiation
Chemical carcinogens
Tumour causing viruses
Bad lifestyles choices
describe cancer evolution - Answers 1. first mutagenic event affects cell cycle or loss of tumour
suppressor gene - increased growth
2. In hyperplasia (may not be cancerous — neoplasms) , mutagenic event
3. Another mutagenic event, cells become dysplastic - behave abnormal
4. mutagenic event 4 - become metastatic
- Vogelstein molecular model
- doesn't explain childhood cancers
, Give an overview of how tumours grow - Answers - cell lose control = tumour/neoplasm
- growth advantage of tumour to produce selective pressure for more mutations
1. becomes benign (harmless) tumour, can't travel to distal sites; needs secondary for more mutations
2. Becomes invasive tumour cells - cancer is usually screened here
3. Have to now treat both primary and secondary cancer after spreading - becomes malignant
benign - Answers unable to invade healthy surrounding tissue, incapable of indefinite growth
malignant - Answers becomes progressively more invasive - metasize
- genetically unstable - more mutations needed
difference between abnormal and cancer cells - Answers abnormal divide and replicate under limit -
Hayflick's limit, cancer cells ignore it, upreg telomerase
What are the classification of cancers - Answers - from embryonic tissue origin
- Carcinomas
- sarcomas
- Lymphomas (90%), myelomas (b cell tumour in bone) (1%) and leukaemia (9%) (blood cancer)
Carcinomas - Answers - from epithelial origins
- skin, gut, epithelial linings
sarcomas - Answers - in mesodermal connective tissue
- bone, fat, cartilage tissue
Lymphomas (90%), myelomas (b cell tumour in bone) (1%) and leukaemia (9%) (blood cancer - Answers
in haemopoietic stem cells
Hallmarks of cancer - Answers - sustaining proliferative signalling
- evading growth suppressors