Cancer

Question 1

Compare proto-oncogene vs oncogene

Answer 1

A proto-oncogene is an inactive oncogene. Oncogenes cause cancers by stimulating growth factors (oncogenes are in cancer cells, not normal cells)

Question 2

Aside from cancer cells, which cells in the body rapidly proliferate, therefore leading to some side effects?

Answer 2

Skin, hair, blood / bone marrow (myeloid cells), GIT lining

Question 3

Name an alkylating agent

Answer 3

Cyclophosphamide

Question 4

Are alkylating agents cytotoxic?

Answer 4

Yes

Question 5

Explain the MOA of alkylating agents.

Answer 5

Once activated in the liver, they cause covalent cross linking of DNA. Apoptosis is induced due to the damaged DNA

Question 6

Unique ADR of alkylating agents?

Answer 6

Can cause cancer due to DNA damage

Question 7

Name an anti-metabolite

Answer 7

Methotrexate, 5-fluoro-uracil

Question 8

Methotrexate MOA?

Answer 8

Inhibits DHFR, preventing the production of purines for DNA production

Question 9

Side effects and their management for methotrexate?

Answer 9

Other than the usual cytotoxic ADRs, methotrexate causes pulmonary and liver toxicity.
Can co-administer with folate to manage this

Question 10

What class of drugs does doxorubicin belong to

Answer 10

Cytotoxic antibiotics

Question 11

Explain the MOA of doxorubicin

Answer 11

It is a topoisomerase II inhibitor. Too toxic to be used as an antibiotic.
Inhibiting topoisomerase II = prevents DNA replication

Question 12

ADR unique to doxorubicin?

Answer 12

Cardio toxicity

Question 13

Name a drug belonging to the cytotoxic class of tubulin binding drugs

Answer 13

Vincristine

Question 14

Vincristine MOA?

Answer 14

Inhibits microtubule formation. It is cell-cycle specific as it prevents cell division during metaphase

Question 15

Unique ADRs of vincristine

Answer 15

Numbness and tingling due to microtubule’s role in nerve function

Question 16

Are hormone antagonists cytotoxic

Answer 16

No

Question 17

Name a hormone antagonist + explain its’ MOA

Answer 17

Tamoxifen - an estrogen antagonist used in estrogen dependent cancers. It competes for binding with estrogen. Inhibits the transcription of estrogen-dependent genes and decreases the expression of growth factors

Question 18

ADRs of tamoxifen

Answer 18

Similar to menopause (flushes, etc)
Can increase uterine cancer risk and blood clot risk

Question 19

What class does anastrazole belong to

Answer 19

Aromatase inhibitors

Question 20

Explain the role of aromatase

Answer 20

It converts androgens into estrogen

Question 21

Name a protein kinase inhibitor

Answer 21

Imatinib

Question 22

Explain the MOA of imatinib

Answer 22

Inhibits protein kinases involved in growth factor signalling

Question 23

Which drug binds to the human epidermal growth factor 2 and promotes internalisation of the receptor?

Answer 23

Trastuzumab

Question 24

Explain use of bevacizumab

Answer 24

It is an anti-VEGF antibody. Inhibits vessel growth to block blood supply to the tumour.

Careful when using in combination, as it could prevent other drugs from reaching the tumour by limiting the blood supply

Question 25

What is VEGF

Answer 25

Vascular endothelial growth factor.
Tumours secrete VEGF to stimulate angiogenesis

Question 26

Treatment for neutropenia?

Answer 26

Colony stimulating factors such as filgrastim

Question 27

Explain use of the CSF filgrastim

Answer 27

Stimulates the bone marrow to increase proliferation of immune cells - specifically the proteins that increase neutrophil production