Oncology

Question 1

What is cancer?

Answer 1

When abnormal cells divide in an uncontrolled way

Question 2

Why can cancer be called a clonal disease?

Answer 2

It can arise from a single cell

Question 3

What makes a cell divide?

Answer 3

Specific positive signals, e.g. growth factors and hormones

Question 4

What is contact inhibition?

Answer 4

When in contact with neighbouring cells, cells initiate cell cycle arrest and down regulate proliferation so they stop dividing so as not to grow over neighbouring cells

Question 5

What is DNA damage response?

Answer 5

If there’s something wrong with the DNA of a cell, it won’t divide until that DNA is repaired

Question 6

What are somatic mutations?

Answer 6

Mutations in a single cell

Question 7

Define oncogene

Answer 7

A gene which, in certain circumstances, can transform a cell into a tumour cell

Question 8

Define proto-oncogene

Answer 8

A normal gene which, when altered by mutation, becomes an oncogene that can contribute to cancer

Question 9

What are all known photo-oncogenes involved in?

Answer 9

Positive control of cell growth and division

Question 10

What are the 5 main classes of photo-oncogene?

Answer 10

Class I- Growth factors
Class II- Receptors for growth factors and hormones
Class III- Intracellular signal transducers
Class IV- Nuclear transcription factors
Class V- Cell-cycle control proteins

Question 11

What happens when an oncogene is mutated?

Answer 11

Control of growth is relaxed, allowing unregulated proliferation

Question 12

At the cellular level, are mutations of oncogenes dominant or recessive?

Answer 12

Dominant

Question 13

Are mutations of tumour suppressor genes dominant or recessive?

Answer 13

Recessive

Question 14

In most inherited cancer syndromes due to tumour suppressor gene mutations, are the 2 mutations inherited or somatic?

Answer 14

1 mutation is inherited and the other is somatic

Question 15

What is the significance of TP53 gene?

Answer 15

TP53 codes for p53 protein, which inhibits cell replication if DNA damage is detected or virus replication is detected in the cell. If the damage is not repaired, p53 signals apoptosis. In many tumours, TP53 is inactivated due to mutation, gene deletion or both

Question 16

How does HPV increase the risk of cervical cancer?

Answer 16

HPV infects cervical epithelium and inhibits p53, so there’s no apoptosis of cells with damaged DNA

Question 17

How do mutations in DNA repair genes increase risk of cancer?

Answer 17

Mutations in DNA repair genes increases the risk of mutations in oncogenes/ tumour suppressor genes

Question 18

What is epigenetics?

Answer 18

The study of changes in gene expression caused by mechanisms other than changes in the underlying DNA sequence (DNA methylation and histone modification

Question 19

Name the 3 types of cancer treatment

Answer 19

Surgery
Radiotherapy
Drug therapy

Question 20

Name the 4 types of drug therapy

Answer 20

Chemotherapy
Targeted therapy
Immunotherapy
Endocrine therapy

Question 21

What is combination therapy?

Answer 21

Therapy in which the patient is given 2 or more drugs for a single disease

Question 22

What is Neo-adjuvant therapy?

Answer 22

Administration of a therapeutic agent before the main treatment

Question 23

What is adjuvant therapy?

Answer 23

Therapy applied after an initial treatment of cancer, often to suppress secondary tumour formation

Question 24

What is prophylactic therapy?

Answer 24

Therapy intended to prevent cancer from occurring before it has

Question 25

What are the 5 stages of cancer?

Answer 25

Stage 0- Carcinoma in situ
Stage 1- Localised
Stage 2- Early; locally advanced
Stage 3- Late; locally advanced
Stage 4- Metastasised

Question 26

How does radiotherapy work?

Answer 26

High energy X-rays or gamma rays cause breaks in DNA, damaging the DNA in cancer cells, as well as healthy cells, so they undergo apoptosis

Question 27

Why is radiotherapy given in multiple fractions?

Answer 27

So there are fewer side effects- healthy cells repair themselves better after radiotherapy than cancer cells, so doing radiotherapy in fractions allows healthy cells to recover

Question 28

Name 5 possible side effects of radiotherapy

Answer 28

Oedema, alopecia, pain, fibrosis and secondary cancers caused by DNA damage from X-rays

Question 29

How does chemotherapy work?

Answer 29

Cytotoxic drugs are used to treat cancer. The drugs damage the DNA of cancer cells, leading to the breakage of the DNA double strands, inhibiting mitosis and DNA replication, leading to apoptosis.

Question 30

What type of cancers is chemotherapy most effective against?

Answer 30

Fast-growing cancers that replicate at the fastest rate, so the cells will be killed faster.

Question 31

Aside from fast-growing cancers, what other type of cancer responds best to chemotherapy?

Answer 31

Clonal cancers in which all the cells are the same

Question 32

Name 3 drugs used for chemotherapy

Answer 32

Cisplatin, paclitaxel and bleomycin

Question 33

Name 7 possible side effects of chemotherapy

Answer 33

Damage to rapidly dividing normal cells
Fatigue
Myelosuppression
Risk of infection
Skin toxicity (rash, alopecia)
GI disturbance (nausea, diarrhoea, mucositis)
Venous thromboembolism

Question 34

What can biopsies determine about cancers?

Answer 34

The subtype of tumour, or a specific mutation in the cancer

Question 35

How does immunotherapy work?

Answer 35

Imunotherapy switches the immune system back on against cancers that evade the immune system. Monoclonal antibodies can block pathways that cancer has unregulated to evade the immune system.

Question 36

In what types of cancers does immunotherapy work better?

Answer 36

Cancers with a lot of mutations and Neo-antigens

Question 37

Name 4 side effects of immunotherapy

Answer 37

Inflammatory and auto-immune conditions such as:
Rashes
Colitis
Thyroid dysfunction
Pneumonitis