Mutation & Neoplasia Flashcards
Two types of Tumors
Benign = friendly Malignant = potentially fatal
Most common (>90%) cancer
Carcinomas [epihetalial cell origin]
Carcinomas
- Epithelial cells (they divide some continuously)
- Epithelial cancers increase in incidence as we age
- It takes many mutations to create a cancer cell & we acquire mutations over time
3 types of Cells
- Labile: continuously dividing
- Stable: quiescent/inactive
- permanent: non-dividing
Labile Cells
Epithelial e.g. Skin, GIT, reproductive, urinary tract, lining of exocrine ducts
Haemopoietic stem cells
Stable Cells
Epithelial e.g. Liver, kidney, lung, pancreas
Smooth muscle cells, fibroblasts, endothelial cells
Permanent Cells
Cardiac & skeletal myocytes, neurons
Mutagens
May act directly to cause damage or may do so through increasing oxidant production or reducing anti-oxidant defences
carcinogenesis
accumulating mutations
When are benign tumors life threatening
in the brain
Benign Tumors
- do not metastasize
- homogeneous
- well differentiated
- generally slower growing
- encapsulated
Malignant
- can metastasize
- heterogeneous with different degrees of differentiation, proliferation & aggressive
- some areas grow quickly
Sarcomas are very rare cancers but of all of the different types of sarcomas, osteosarcoma is the most common, can you explain why osteosarcomas are more commonly found in young people?
bones in young people are still growing & are at greater risk. when we stop growing risk diminishes
Three ways cancer may spread?
- via the blood (haematogenous)
- via lymph (lymphatic spreading)
- via direct seeding
Two cellular adaptations that increase the risk of tumor development
Hyperplasia & Metaplasia
what type of epithelium lines the conductive regions of the airways
Simple ciliated (initially pseudo-stratified columnar, then columnar then cuboidal) with goblet cells producing mucous interspersed
The chronic irritation caused by smoking results in what type of cellular adaptations
The ciliated epithelium: undergoes metaplasia to become stratified squamous epithelium.
The goblet cells: undergo hyperplasia
Which organs are frequently affected by metastatic or secondary cancers
Lungs: all venous blood returns to them & cancers usually spread first in the lymphatic & venous systems.
Liver:
basic risk factors for the development of mutation & tumor genesis
- cell division
- hyperplasia
- metaplasia
8 behavioral changes that occur in cancer cells as a result of multiple mutations
- self-sufficieny growth signals
- insensitivity to growth-inhibitory signals
- evasion of apoptosis
- defects in DNA repair
- Limitless replicative potential
- sustained angiogenesis
- ability to invade & metastasize
- predilection for glycolysis even in the presence of ocygen
importance of early detection/ the significance of metastatic disease
If we catch the cancer before it has metastasised, we are able to cure the person.
why are carcinomas the most common?
Epithelial cells are either labile (constantly dividing) or stable (able to divide). Epithelial cells are located on the ‘front line’ of our bodies between our inner tissues and anything entering our bodies via inhalation, ingestion etc.
