L28. Neoplasia 1 Flashcards
What proportion of deaths in Australia is due to malignancy?
30% of deaths
What group of people account for the 68% of all diagnosed with malignancy?
Aged >60
What is meant by Neoplasia?
“New Growth”
An Excessive and Unregulated cell proliferation
What is the process of neoplasia?
A multi-step process starting with a SINGLE cell that has abnormalities that develop from aberrant genetic and epigenetic control mechanisms on the
- CELL CYCLE
- APOPTOSIS
- DNA REPAIR
What does neoplastic tissue comprise of?
Neoplastic cells and reactive stroma
What does the reactive stroma of neoplastic tissue usually include?
Inflammatory cells
Fibroblasts
Endothelial cells
Blood vessels
What are the 2 main groups of neoplasia?
Benign and Malignant
What is the definition of a tumour?
Any mass lesion
Can be inflammatory, hyperplastic, neoplastic or any accumulation of mass
But it is a VAGUE term that often implies a neoplasm (but not strictly speaking)
What is the definition of a tumour?
Any mass lesion
Can be inflammatory, hyperplastic, neoplastic or any accumulation of mass
But it is a VAGUE term that often implies a neoplasm (but not strictly speaking)
What are the six classical characteristics/hallmarks that malignant cells possess?
- Resist Cell Death
- Induce Angiogenesis
- Sustain proliferative signalling
- Evade growth suppression
- Activate invasion and metastasis
- Enable a replicative imortality
What are some emerging hallmarks of cancer?
Immune system involvement
Metabolism
Paediatric Cancer doesn’t occur as commonly. They often have a certain characteristic/type called Blastoma. What does this mean?
Blastomas are consistent of primitive and less differentiated cells (called blasts) and these are what form the embryo.
List some common paediatric cancers
Certain leukaemias Certain brain tumours Neuroblastoma Certain lymphomas Retinoblastoma Certain Bone Cancers Wilm's Tumour
What are the characteristics of a Benign tumour?
LOCAL expansile
SLOW growth
well CIRCUMSCRIBED (sometimes encapsulated)
well DIFFERENTIATED (looks like normal cells)
UNABLE TO METASTASISE
rarely life threatening
These cancers have NO evasion or destruction of surrounding tissue and instead tends to pus it aside
What are the characteristics of a Malignant tumour?
LOCALLY INVASIVE
DESTRUCTIVE growth
Often poorly circumscribed with IRREGULAR MARGINS
Frequently induce DESMOPLASIA in the stroma
Sometimes NECROSIS (tumour cells outgrow their blood supply)
Variable DIFFERENTIATION
Potential to METASTASISE
What are the three major ways that malignant tumours can metastasise? Describe each one.
Lymphatic: tumour extends along the lymphatic vessels into the draining lymph nodes
Haematogenous (blood): Tumour can enter the draining veins and the systemic circulation (or can also enter via invasion into the bloodstream)
Transcoelomic (through body cavities): the tumour migrates along the body cavity space
What are uncertain malignant/ potential/borderline tumours?
Lesions with histologically intermediate features between benign and malignant. Difficult to predict what they are but are often not aggressive and have a slow course (some do metastasise)
What are the clinical features of benign tumours?
Benign tumours are rarely symptomatic (depends on where and what it is)
They rarely cause death and rarely become malignant
Is local spread considered metastasis?
No - the tumour growth needs to be completely SEPARATE from the original primary cancer
What are some common sites of metastasis?
Liver
Brain
Ling
Bone
Note: lymphadenopathy is local metastasis
Are metastasise usually multiple of single? What does this mean for treatment?
Usually multiple (sometimes single) and to multiple sites. This means it is very difficult to treat
Are metastasise usually multiple of single? What does this mean for treatment?
Usually multiple (sometimes single) and to multiple sites. This means it is very difficult to treat