Cancer the disease and how its treated Flashcards
how does cancer spread
invasion
metastasis
non metastatic effects
invasion
- grows and invades
- pressure/construction on surrounding structures
- destruction and loss of function
metastasis
- they can set up smaller tumors around the body
- can be localised or distant
non metastatic effects
- 25% will die from cancer related cachexia
- whole body metabolic and physiologically effect, not directly due to the tumour
Invasion mode of spread-
- path of least resistance
- tissue destruction
- perineural spread, picks up nerves and grows along them therefore can travel from the primary area quicker
metastasis mode of spread
- invasion of vessels – embolism or permeation, gets through the wall of the vessel and can grow along the lumen of the vessel as a solid (permeation) or break off and flow in the flow of the lymph fluid to the lymph nodes
- spread to draining lymph nodes
lymphatic drainage
- runs throughout the body
- eventually returns lymphatic fluid into the blood supply just before the heart
- lots of lymph nodes along the lymphatic channels
what are under highest risk of metastasis
draining lymph nodes
types of metastasis spread
haematogenous spread
transcoelomic spread
haematogenous spread
- invasion mainly veins, then returned to heart
- organs most likely to have blood metastasis : liver, lung, bone and brain
transcoelomic spread
- spread across serous cavities
- cavities lined with a thin layer of fluid
- eg abdominal cavities
why is the liver most likely to be affected by haemoatogenous spread
- blood supply from the colon passes through the liver
- colon cancer can spread to liver via the blood stream
Metastatic cascade
1) Primary tumour invades into underlying tissue
2) eventually invades into vessel either blood or lymph via intravasation, for this it has to be able to degrade tissues i.e. get through vessel wall
3) survival in circulation, need to be robust to survive this
4) need to be able to arrest at distant organ site, correct adhesion molecules to stop at the specific site
5) then needs to exit and also be able to survive in the different environment
what do tumour cells interact with
cells and molecule in local envuroment
- need to gain new abilities to invade
metastatic cascade leads to
- motility is enhanced
- alter adhesion molecules
- make poor basement membrane
- increase protease production or reduce inhibitors
- alter ECM
patterns of spread for different cancers
1) Carcinomas
- firstly lymphatics
- blood (often later)
2) Sarcomas
- blood (lymphatic spread rare)
3) Predictable patterns of spread
- lung to local nodes, then liver, bone ad brain
- tongue to neck nodes, later lung to spine
carcinomas spread
firstly lympatics
blood
sarcoma spread
blood
lympatic rare
predictable patterns of spread
- lung to local nodes, then liver, bone ad brain
- tongue to neck nodes, later lung to spine
effect of tumour spread
1) Pressure and obstruction
2) destruction
3) haemorrhage
4) infection
5) pain
- often after spread to bone
6) anaemia
7) starvation and cachexia
what are non metastatic effects know as
paraneoplastic syndrome
- not directly related to the tumour there at the site
what causes non metastatic effects
often caused by biochemical substances released by tumour cells
non metastatic effects
1) Fever, anorexia and weight loss/cachexia
2) endocrine syndromes
- eg crushing syndrome
- metabolic effects eg hypocalcaemia
3) neurological problems
- eg neuropathy
4) haematological syndromes
- due to the upset to the bone marrow
- eg erthrocytosis
how to grade tumorus
histological assessmetn
relates to differentiator
links to proglnosos
staging of tumour defines the
clinical extent of tumour
staging of tumours system
TNM tumour nodes metastases these are graded 1.2.3.4
grades of tumours
T1-4 – T1 small tumours, 4 large that have invaded into structures
N0- no lymph nodes metastases, then increase 234 (either graded by the size of the metastasis or the number of nodes affected)
M0 or 1 – present of absent
Specific staging systems for tissue/tumour
Stage 1 (T1or 2)
- not in lymph nodes and not through the wall
stage 1 and 2 – early stage cancer, better prognosis
Stage 3
- tumour through wall and mestasiis
diagnosis of cancer
biopsy
cytologu
imaging - ct and MR
molecular analusis
incisions biopsy
small piece of tumour
excisional biopsy
removal of all the tumour
cytolocy
aspirate
sample of cells taken out
disrupted cells taken out
treatment of cancer
surgery radiotherapy chemotherapy biological therapy supportive care
side effects of radiotherapy
- tiredness
- feeling sick
- difficulty eating and drinking
- skin reaction
- hair loss
- haematological changes
- possible long term side effects
what do chemotherapy agents do
target DNA structure or segredation of DNA as chromosomes in mitorsis
