Chemotherapy

Question 1

What drugs treat cancer?

Answer 1

• cytotoxic chemotherapy
• PARP inhibitors
• tyrosine kinase inhibitors
• monoclonal antibodies
• mTOR inhibitors
• immune checkpoint inhibitors
• CDK4/6 inhibitors

Question 2

What is the growth fraction of tumours?

Answer 2

Proportion of cells dividing at any given time
- useful indicator of sensitivity to chemotherapeutic agents
- more responsive tumours have larger growth fractions

Question 3

What is the fractional cell kill hypothesis?

Answer 3

• a given dose kills a constant proportion of tumour cells rather than number of tumour cells
• so repeated doses are required

Question 4

What is adjuvant chemotherapy?

Answer 4

Chemo given after surgery to remove any remaining cells

Question 5

What is neoadjuvant chemotherapy?

Answer 5

Chemo given before surgery to reduce tumour size

Question 6

Relationship between tumour size + growth fraction

Answer 6

The bigger tumour, the smaller the growth fraction
This means less actively dividing cells to be dividing by chemo

Question 7

Tumours that are highly chemo sensitive

Answer 7

Lymphomas
Germ cell tumours
Small cell lung
Neuroblastoma

Question 8

Tumours that are modestly chemo sensitive

Answer 8

Breast
Colorectal
Bladder
Ovary
Cervix

Question 9

Tumours that are lowly chemo sensitive

Answer 9

Prostate
Renal cell
Brain tumours
Endometrial

Question 10

6 properties of cancer

Answer 10

• sustained angiogenesis
• limitless replicative potential
• tissue invasion + metastasis
• insensitivity to anti growth signals
• self sufficiency in growth signals
• evading apoptosis

Question 11

What is the mechanism of action of alkylating agents

Answer 11

• alkyl groups on drug can form covalent bonds with cell constituent > inter strand cross linking
• DNA helix can’t unwrap + replicate

Question 12

Examples of alkylating agents

Answer 12

Cisplatin
Oxaliplatin

Question 13

What are uses of alkylating agents?

Answer 13

Malignancy

Question 14

Adverse effects of chemotherapy

Answer 14

• alopecia
• mucositis
• N+V
• cardio toxicity
• diarrhoea
• cystitis
• infertility
• renal failure
• local reaction
• pulmonary fibrosis
• myelosuppression

Question 15

Types of spindle poisons + example

Answer 15

• vinca alkaloids: vincristine
• taxanes: paclitaxel

Question 16

What is the mechanism of action of spindle poisons

Answer 16

• vinca alkaloids: prevent spindle formation by inhibition of depolymerisation - microtubule assembly inhibitor e.g. vincristine
• taxoids: prevent disassembly + promote assembly - microtubule depolymerisation inhibitor e.g. paclitaxel

Question 17

Examples of antimetabolites

Answer 17

5-fluorouracil
Methotrexate

Question 18

What is the mechanism of action of 5-fluorouracil?

Answer 18

Inhibition thymidylate synthase
Prevents DNA production

Question 19

What is the mechanism of action of methotrexate in malignancy?

Answer 19

• Dihydrofolate reductase inhibition
• Interrupts folate cycle
• reduction of thymine production
• reduces DNA production

Question 20

Mechanisms of cancer cell resistance

Answer 20

• decrease uptake of drug
• increased drug metabolism
• alter drug targets
• impair apoptotic pathways
• alter cell cycle checkpoints
• efflux pumps

Question 21

What is chemotherapy?

Answer 21

Treatment of cancer with cytotoxic drugs

Question 22

What is salvage chemo?

Answer 22

Chemo for relapsed disease

Question 23

What is palliative chemo?

Answer 23

To treat current or anticipated symptoms without the intention to cure