Cancer

Question 1

Define cancer

Answer 1

Uncontrolled cell division

Question 2

Define metastasis

Answer 2

1.early tumour
2. Enlarging tumour developing blood and lymphatic vessels
3.tumour cells squeeze into blood and lymphatic vessels
4.tumour cells circulating via blood
5.tumour cells adhere to blood vessel walls and squeeze through to form metastases
6. Metastasis forms in lymph node

Question 3

Describe malignant tumours

Answer 3

Undifferentiated cells
Grow at the edges
can grow quickly
invading the surrounding tissues and organs
Cells may break off and set up secondary tumours
Metastasis

Question 4

Describe benign tumours

Answer 4

Enclosed in a capsule
Often slow growing
Don’t invade other tissues causing damage
Don’t metastasise

Question 5

What do oncogene mutations lead to?

Answer 5

Cells losing ability to control cell division

Question 6

Define Proto oncogenes

Answer 6

Can mutate to form oncogenes (permanently causing cells to divide )

Question 7

Define tumour suppressors

Answer 7

Genes can mutate to become non functional (cannot stop cell division)

Question 8

Why is cancer more common in old people?

Answer 8

Cancer is more common in older people as their somatic cells accumulate mutations. These mutations occur in gametes. The mutated genes are passed on to the next generation – genetic preposition.

Question 9

What are the environmental factors ?

Answer 9

-tar in cigarette smoke
-diet-alcohol-> oesophageal mouth and throat ; lack of fibre and lots of red meat –%> Colon and rectum

-ionising radiation – damages DNA for example UV light, ionising radiation leads to leukaemia

Chemical carcinogen – asbestos benzene formaldehyde diesel exhaustion

Some microorganisms, e.g. HPV leads the cervical cancer

Question 10

Define radiotherapy

Answer 10

Controlled radiatation oblates the tumour

Question 11

Pros and cons of radiotherapy

Answer 11

Pros

Shrinks tumours

Destroys cancerous cells

Preserves organs
Cons

Damages nearby sites

Can’t remove all cells

Can’t instantly relieve symptoms

Question 12

Describe chemotherapy

Answer 12

Killing dividing cells by blocking part of cell cycle, typically prevents DNA replicating and inhibits a specific stage of cell division such as metaphase or anaphase

Question 13

Cons of chemotherapy

Answer 13

Side effects - target fast dividing cells eg hair follicles

Question 14

Pros of surgery for cancer

Answer 14

Resistant cancer cells can be eliminated from the body

Question 15

Cons of surgery for cancer

Answer 15

Risky
May Leave tumour cells