The Effects Cancer has on the body Flashcards
What number cause of death is cancer?
second.
how does cancer occur?
damage to DNA.
- acquired (exposure to carcinogens)
- inherited (mutations in dna from parents)
what does the outcome and prognosis of the cancer depends on?
cell type of origin and the tissue of origin.
how can primary tumours in breasts be removed?
surgically.
examples of slow growing cancers that rarely spreads?
basal cell carcinoma.
features of malignant melanoma?
spreads fast and can be fatal.
examples of changes that can occur from cancer?
- increased cell growth.
- resistance to apoptosis.
- altered tissue invasiveness - can spread and invade to other tissues.
- angiogenic proliferation.
- ability to escape immune surveillance - immune system does not pick them up as being different.
what is cell transformation called?
the change from a normal cell to a cancer cell. –> spectrum of changes.
what do cancer cells look like?
not like normal cells.
how do pathologists diagnose cancer?
use the change in appearance. the pathologists are able to trace back the origin of the cancer. e.g. can identify that cancer cell comes from liver as it vaguely resembles normal liver cell.
features of cancer cells?
enlarged nucleus, changes to the cytoskeleton, loss of specialised features.
- could be due to changes in chromosome number or regulation of nuclear envelope.
- cell change shape.
why do these changes in chromosome number occur?
- could be due to changes in chromosome number or regulation of nuclear envelope.
- cell changes shape.
how do cancer cells function in terms of functions?
cancer cells are immature and are not fully differentiated or specialised so do not carry out the function of a normal cell.
how different is the appearance of the cancer cells between different cancer cells?
there is a spectrum of changes in the appearance to the cancer cell.
-as cancer moves into malignant stage it will change.
benign tumour features? (8)
- appear under microscopes like the tissues they came from?
- low level genetic damage.
- have growth advantage.
- look physically like normal healthy tissue.
- remain localised and do not spread.
- grow in capsule which does not allow it to spread and restricts the size. fibrous capsule.
- usually do not cause problems unless grow in confined space.
- can develop mutations and become malignant.
malignant tumour features? (4)
- do not resemble the tissue or cell origin.
- often have irregular structures
- invade surrounding tissues
- spread out and enlarged
what is metastasis?
when cancers invade other tissues and spread to other parts of the body.
how can metastasis occur?
spread through lymphatic system or blood supply.
what does the spread of cancer depend on?
the type of cancer.
how do cancers spread?
- eventually some cells will have ability to spread.
- secrete enzymes which break through basal lamniane nearby capillaries.
- they have enzymes that punch holes in neraby capillaries and they squeeze through capillaries or into lymphatic system. intravasation.
what types of enzymes break through basal lamina?
proteolytic enzymes.
what happens after intravasation?
- cells circulate.
- cells adhere to capillary walls or simply get stuck in distant capillary bits.
- once they’re stuck to the capillary they can move out of the capillary or lymphatic system by extravasation into a secondary site.
- cells proliferate to form metastasis.
things a cancer cell needs to metastasise?
- genetic change.
- change in cells function and appearance.
- decreased ability of the cells to adhere to neighbouring cells.
- increased ability of the cancer cells to move.
how do cancer cells extend into surrounding tissues?
by degrading ECM. they secrete proteolytic enzymes so cancer cells migrate into lymphatics and blood vessel
what do cancer cells need to survive?
angiogenesis - development of new microcirculation.
Why do cancer cells need angiogenesis?
bc if there wasn’t eventually there would be a build up of waste products, lack of oxygen, lack of nutrients.
how does angiogenesis happen with cancer cells?
cancer cells secrete angiogenic hormones.
what do angiogenic hormones do?
they secrete growth factors - one of them is specifically called VEGF.
what does VEGF?
- it signals to nearby epithelial cells, signals nearby capillary cells and causes them to start to out branch.
- the branches of the capillaries feed into the tumour.
- the tumour now has access to nutrients, oxygen, and can get rid of waste products
- antiangiogenic treatment are being researched.
what are carcinomas?
they arise from the skin and epithelial cells that line the organs.
examples of carcinomas?
breast cancer, lung cancer, colon cancer.
what are sarcomas?
arise from blood, muscle, blood vessels. mesenchymal origin.
what are lymphomas?
arise from lymphoid cells.
what are leukemias?
arise from white cells of the bone marrow.
what percentage of cancers are carcinomas?
85%
what are some local effects of cancer?
- cancer displaces normal adjacent tissue. thus organ can fail as the tumour displaces normal tissue so the normal tissue cannot carry out normal function.
- cancer cells are immature and cannot carry out specialised function.
- cancer cells block off vital passages.
- tumours may block normal arterial, venous or lymphatic supply leading to significant symptoms.
what proliferation rate do cancer cells have?
very rapid growth and high turnover rate.
what does the proliferation of cancer cells lead to?
high metabolic rate.
- cachexia
- fatigue
what are some symptoms the patient may experience?
- weight loss
- fatigue
- tiredness
- weight loss is massive and dramatic the patient becomes profoundly wasted - called cachexia.
what hormones may cancer cells release?
cortisol.
lung cancer cells may release cortisol which will circulate through body and cause increase in blood pressure and increase in blood glucose and a decrease in immune response.
What is lymphoedema?
build up of fluid in the limbs, causing it to swell up. - lymphatic system is unable to be drained properly.
Where is lymphoedema commonly seen?
in the limbs.
How does cancer cause lymphoedema?
cancer cells can enter the lymphatic system, and block the lymph nodes.
How is lymphoedema treated?
By a compression bandage to slowly drain lymph fluid.
What is ascites?
build up of fluid in the abdominal cavity = peritoneum.
What cancers is ascites common in?
ovarian, prostate, colon, stomach, liver and cancer.
What is treatment for ascites?
insert needle and tube into stomach and drain fluid out.
How do metastasis occurs?
- Cancer cells can escape primary tumour, inflitrate blood supply into capillary.
- cells travel via circulation.
- cancer cells are quite alrge and can get stuck into distant capillary beds.
- can move out of capillary beds via extravasation.
What are common places for metastasis tumours?
lung and liver.
How do colon cancer cells spread?
hepatic portal vein to the liver.
What organ is a metastasis common with colon cancer?
liver.
How many women will get breast cancer?
1/10.
What can bone metastases lead to?
- hypercalcaemia
- osteolytic lesions (holes in bone)
- fractures
- osteoporosis.
What types of cancers often result in bone metastases?
prostate and breast.
What stimulates cells of the bone to degrade?
PTHRP
What does the degradation of the bone do?
cause calcium levels to rise.
What are the effects of the cancer spread to bone?
- may cause severe pain
- weaken bone and causes pathological fractures.
- weaken bone and cause deformities.
- hypercalcaemia.
