L3 - Causes, Detection and Epidemiology Flashcards
What has changed in cancer treatments?
- Improved screening and early detection
- Advances in treatment
- Increased access to care
- Better understanding of the biology of cancer
- Decreased exposure
Principles of cancer diagnosis
- Clinical presentation
- Biopsy
- Imaging studies
- Laboratory tests
- Staging
- Prognosis
Warburg effect
Cancer cells promote anaerobic respiration so that they can thrive in hypoxic locations
2-Deoxy-2-(18F)fluoro-d-glucose positron-emission tomography: what is it and what is it used for?
FGD-PET
Visualize tumours in the body that have concentrated large amounts of glucose because of the hyperactivity of the GLUT1 transporter
Why are men more likely to die from cancer?
- Riskier behaviours
- Different biological susceptibilities: higher risk due to differences in anatomy and biology
- Delayed diagnosis and treatment
Occupational exposure:
* Construction workers
* Miners
* Manufacturing workers
* Agriculture workers
* Firefighters
* Painters
* Truck drivers
Cancer risk factors
- Age
- Smoking
- Genetic predisposition
- Etc
Age: why is it such a large risk factor?
In various cases, someone is born with/out an oncogene/TSG
One mutation often isn’t enough
As you get older, more mutations accumulate and the step-wise effect occurs where mutations cooperate and cause cancer to occur
Alcohol: what is the process behind it causing cancer?
The body breaking down alcohol creates toxic by-products, including acetaldehyde, which can damage DNA and proteins in cells and increase the risk of cancer
Alcohol can increase hormone levels, such as estrogen, which can stimulate the growth of certain cancers, such as breast cancer
Alcohol can lead to:
* Inflammation
* Oxidative stress
* Weakened immune system
Mutations: the types that cause cancer
Somatic mutations - occur in developed tissues and the carrier has the change
Germline mutations - occur in ovaries and testes and produces offspring carrying the change
Why may cancer treatments fail?
Heterogeneity is the primary cause of treatment failure - the more exposure, the more changes, the more variants (monoclonal tumours form polyclonal tumours)
Step-wise cance formation may result in a polyclonal tumour arising from a monoclonal tumour, so acting to destroy one tumour may leave the others alive
Carbon-based carcinogenic agents: what are some examples, what do they do, and when are they mostly active?
Tobacco, smoke, candle, paints, dyes, grilled meats, etc
Integrates into metabolic pathways and causes failures. (DNA damage, mitochondrial dysfunction)
Some are only active after processing in the liver
Chronic inflammation
- Intrinsic pathways (genetic lesions) and extrinsic pathways (infections/injury) cause inflammation
- Cancerogenesis - NF-kB, HIF-1a etc, which cause cancer hallmark activation
- Cancer causes inflammation
