ON1 Intro to oncology

What is cancer ?
Cancer is a ❌ tumor, a mass of cell in which cell division/cell cycle is no longer regulated. The tumor is ❌ if it does not spread (but may still cause tissue damage). The spread of a cancer to a secondary site is called ❌.
Some common carcinomas(a type of cancer that starts in cells that make up the skin or the tissue lining organs):
- ❌
Leukemias:
- Blood stream
Lymphomas:
- Lymph nodes
Some common sarcomas(a type of cancer that can occur in various locations in your body):
-❌

Epidemiology:
- Leading cause of ❌ in NZ – 30.6%.
- 70% of cases & deaths in ❌60
- ❌ most common in men, ❌ most common in women
- ❌ cancer most lethal
- Rates higher for those residing in ❌ deprivedareas

Screening:
Detects the possibility of cancer, is not ❌. Are often population based tests. Can be done at ❌ or in clinics.
Has ❌ sensitivity & specificity. E.g.: Prostate-specific antigen (❌) testing, mammography, Pap smears, breast self examination, blood in stools, mole checks

Diagnosis:
❌ of cancer. Can be done: with imaging - ❌, biochemical tests - tumor ❌ in the blood e.g. carcinoembryonic antigen (CEA), or by ❌. To grade the cancer, ❌.

Cancer Grading
• grading system depends on that ❌ of cancer
• 4 ❌ 10 point scale, higher number = ❌
• Low grade - normal tissue ❌, cells well differentiated
• High grade – ❌differentiated, ❌ mass

Cancer Staging:
Extent of tumor – how large, has it spread.
Different methods
• TNM:
- Tumour – size, ❌
- Nodes – local ❌ to ❌ node, number/location 0-4
- Metastases – 0 (❌ spread) or 1 (distant metastases)
• Stage & grade used by oncologist, along with information on the patient age & health, to determine ❌

(Healthy) Cell cycle:
• cell numbers are ❌ at homeostasis in the body
• cell turnover is different for different tissue types - most cells are ❌ and are ❌ lived.
Exceptions - ❌ marrow, ❌ surfaces, skin.
• cell is formed by ❌ (by mitosis), functions, wears out, ❌ (apoptosis)
• in homeostasis division is ❌ apoptosis
In a tumour division is ❌ apoptosis.

The cell cycle is carefully regulated and there are a number of checkpoints. The cell must check that all necessary ❌ etc, are present, and also for DNA integrity and ❌ (mutations). If DNA damage is present, the cell should ❌ enter cell cycle (❌) or mitosis is delayed until damage is repaired (❌).
If DNA damage is not repaired ❌ is initiated - this is a ❌ regulatory pathway . Genes/proteins involved include
p53, Bax, and Rb. If these genes are mutated, the checkpoints are removed and damaged cells can ❌…. and a tumour can develop.
• ❌ is mutated in > 70% of tumours

Telomeres
• Are an internal divisional ❌ that regulates the replicative lifespan of a cell
• They are non-❌ repetitive DNA located at the ❌ of all chromosomes, with each division telomeres ❌ & when they reach a threshold - cell is targeted for ❌
• Tumours prevent this by ❌ telomere length by activating ❌ (80-95% of tumours)

Uncontrolled cell ❌ differentiates cancerous cells from healthy cells and so it is a good drug ❌.
• Some drugs act in:
- specific ❌ of cell cycle (❌ dependent mechanism of action)
Others not cycle–specific (❌ dependent).

Label the process of metastasis from start (1) to finish (8)
1. ❌ (cell cycle unregulated)
2. avoid ❌ (ON02)
3. ❌ (angiogenesis)
4. ❌ invasion
5. penetration of ❌ vessel
6. spread - accumulation of cells in ❌
7. ❌ from the vessels
8. ❌

Vascularisation/Angiogenesis is necessary to supply ❌ and nutrients for ❌ of the tumour.
• Multiple factors used/pathways means ❌/short term nature of anti-angiogenic therapies
• Also get development of new ❌ vessels (lymphangiogenesis)
• New vessels (blood & lymphatic) that develop are ❌

Spread:
• Cells move towards vessels in response to ❌
• Enter into ❌ new vessels, or acquire ❌ (mostly unknown) to breach intact vessels
• Once in vessel they need to survive factors such as physical ❌ stress & ❌ adhesion
• Getting out – adhesion ❌
• Local lymph nodes (new lymphatic
vessels)
Spread can be distant.
- Mechanical lodging – platelet + tumour cell ❌ get lodged in small ❌

Growth of Metastasis"
• After extravasation many tumours can not grow/thrive (are ❌)
Why?
• No ❌
• Some can’t enter back into cell ❌
Knowledge of these angiogenic ❌ allows for development of new molecular ❌ therapies. However – drug ❌ is an issue.
Metastatic cells are less ❌ stable. Not all primary tumours, or cells in the primary tumour, can ❌ (will be benign). Some cancers can be ❌, others are treatable.