Week 1 Oncology Nursing 1 Flashcards
(33 cards)
What is Cancer?
A disease characterised by uncontrolled growth and spread of abnormal cells
Where do cancer cells derive from?
From normal cells and have undergone neoplastic transportation
What is neoplastic transportation?
an irreversible process leading to transformation of healthy cell into a cancer cell
What is a common feature of all cancers?
loss of cellular proliferation where cancer cells are not subject to usual restriction of cell growth and proliferation
What are the different types of differentiation?
Well: tumour cells reproduce features well
Poorly: tumour cells reproduce features poorly
Undifferentiated: cannot tell, no maturation
Stages of Tumour Growth
Cancer can take months/years to become detectable
Palpable = approx. 30 doublings, Death = approx. 40 doublings
What are proto-oncogenes?
normal growth promoting genes
in normal cells proto-oncogenes are:
- growth factor
- cell survival gene
- cell cycle controlling genes
What are oncogenes?
A mutation of proto-oncogenes when they are inappropriately activated by mutations in themselves or other genes normally controlling their function.
The resulting oncogene causes excessive production of growth factors responsible for tumorigenesis
What is tumorigenesis?
Formation of a tumor in the body, which can be benign or malignant
What is PDGF? (mediators of cell growth)
Platelet-derived growth factor:
one of the numerous proteins that regulate growth and divisions
What is EGF? (mediators of cell growth)
Epidermal growth factor: protein with 53 amino acid residues and three intramolecular disulfide bonds - plays an important role in regulation of cell growth and proliferation
What is TGF? (mediators of cell growth)
Transforming growth factor: plays crucial roles in tissue development, cell differentiation, and embryonic development, as well as other signalling pathways
What is VEGF? (mediators of cell growth)
Vascular endothelial growth factors: an important signal protein involves in angiogenesis
Tumour Suppresor Genes
They function by encoding proteins that block growth promoting proteins - when function lost, uncontrolled growth occurs. When mutation occurs in a tumour suppressor gene, the cell loses its ‘switch off’, allowing cell growth to proceed unabated
What is the most common tumour suppressor gene mutation?
Found in the p53 gene
How does the P53 gene function?
P53 functions by halting cell cycle in G1 phases, allowing DNA repair genes to correct mistakes in DNA copying. If mistakes cannot be corrected, p53 induces apoptosis. When p53 is mutated, cells are able to replicate without repairing DNA damage, resulting in uncontrolled abnormal cell growth
Apoptosis
Programmed cell death, maintains healthy tissues and organs that are dependent upon the proper balance of cell division
Carcinogen
A substance capable of causing cancer in living tissue
Metastatic Cascade
1.Tumour initiation
2.Progression
3.Proliferation
4.Angiogenesis
5.Invasion and/or Intravasation
6.Extravasation
7.Colony formation
8.Evasion of host defences
How is cancer staging determined?
- Location of tumour
- Type of cells
- Tumour grade
- Measurement of tumour size
- Lymph node spread of tumour cells
- Metastatic spread to other sites
Type of staging system
TNM
- T (tumour): size and extent of primary tumour
- N (nodes): number of nearby lymph nodes that contain cancer/cells
- M (metastasis): spread to other sites and organs
Examples of screening & prevention
- Breast screen: women (>40 years) focus age group 50-69yrs
- National bowel cancer screening program: 50-74yrs receive at home test kit
- Cervical screening: if HPV screening test negative, pap testing can be delayed/less frequent
How can you reduce cancer development and progression?
Be aware of changes to body
- Skin checks
- Urinary and bowel changes
- Prostate checks
Modifiable risk factors
- Quit smoking, limit alcohol
- Eat for health
- Maintain healthy body weight, exercise regularly
- Be sun smart
What are some emotional responses following a diagnosis?
- Shock
- Disbelief
- Confusion
- Anger
- Depression
