Cancer Chemotherapy

Question 1

What special characteristics are exhibited by cancer cells?

Answer 1

Uncontrolled proliferation
Loss of original function (anaplasia)
Invasiveness
Metastasis

Question 2

What types of cancer can be treated by surgical removal?

Answer 2

Solid tumours which have not metastasised

Question 3

Chemotherapy drugs are specific to cancer cells. T/F?

Answer 3

False - this accounts for their wide range of side effects

Question 4

What are the general toxic side effects of cancer chemotherapy?

Answer 4

Bone marrow suppression causing anaemia, immune depression, recurrent infections and impaired wound healing
Loss of hair
Damage to GI epithelium
Liver, heart and kidney damage
Depression of growth in children
Sterility
Teratogenicity

Question 5

Cancer chemotherapy drugs only attack cell division and therefore do not reverse…?

Answer 5

De-differentiaition
Invasiveness
Metastasis

Question 6

Why do cancer chemotherapy drugs only attack a subpopulation of the cancer cells?

Answer 6

Even in a rapidly dividing cell population, such as in cancers, not all cells are undergoing mitosis at any one time.

Question 7

Why must chemotherapy aim to kill all malignant cells?

Answer 7

The host immune system does not destroy the remaining cells and so these will divide again and the cancer will recur

Question 8

Why is it necessary that chemotherapy is a prolonged treatment regimen?

Answer 8

Severe cumulative toxicity is required to ensure all malignant cells are destroyed. Also, chemotherapy only attacks actively dividing cells and only some of the cells in a cancer will be actively dividing at any one time.

Question 9

What are the main classes of chemotherapy agents?

Answer 9

Alkylating agents
Antimetabolites
Cytotoxic antibiotics
Microtubule inhibitors
Steroid hormones and antagonists

Question 10

How do alkylating agents work as anticancer drugs?

Answer 10

Alkylating agents form covalent bonds with DNA
Most have two reactive groups:
One group acts within one strand of DNA to inhibit transcription
The other group acts across two strands fo DNA to prevent strand separation in DNA replication

Question 11

Give examples of alkylating agents used in chemotherapy

Answer 11

Cisplatin
Temoxolomaide
Lomustine
Bisulphan
Melphalan
Cyclophosphoamide

Question 12

Which alkylating agents is used particularly in the treatment of brain tumours?

Answer 12

Lomustine

Question 13

Melphalan is a chemotherapy agent used in the treatment of multiple myeloma, ovarian and breast cancers. What is melphalan composed of?

Answer 13

Mechlorethamine infused with phenylalanine

Question 14

Melphalan is a chemotherapy agent. What cancers is it particularly used to combat?

Answer 14

Multiple myelomas
Ovarian cancer
Breast cancer

Question 15

How do antimetabolites work to treat cancer?

Answer 15

These interfere with nucleotide synthesis and DNA synthesis

Question 16

Antifolates are chemotherapy agents which inhibit nucleotide synthesis. Give examples of antifolates.

Answer 16

Methotrexate
Relitrexed
Pemetrexed

Question 17

Nucleotide analogues inhibit DNA polymerases and so are used as chemotherapy agents. Give examples of these drugs.

Answer 17

5-fluorouracil
cytarabine
gemcitabine
fludarabine
capecitabine

Question 18

Folate antagonists inhibit dihydrofolate formation to prevent to synthesis of which nucleotides?

Answer 18

Purine / pyrimidine

Question 19

Pyrimidine analogues are chemotherapy agents which prevent the formation of which nucleotide?

Answer 19

Thymidine

Question 20

Purine analogues are chemotherapy agents. How do purine analogues disrupt DNA?

Answer 20

Converted to false nucleotides which disrupts purine synthesis

Question 21

Dactinomycin is a cytotoxic antibiotic which is used as a chemotherapy agent. What is its mechanism of action?

Answer 21

Inserts itself into the minor grove in the DNA helix to disrupt RNA polymerase

Question 22

Doxorubcin is a cytotoxic antibiotic which is used as a chemotherapy agent. What is its mechanism of action

Answer 22

Inserts itself between base pairs, binding to the sugar-phosphate backbone of DNA to cause local uncoiling and impair DNA and RNA synthesis

Question 23

Microtubule inhibitors are chemotherapy agents which block tubular polymerisation to disrupt cell division. T/F?

Answer 23

True

Question 24

Give an example of an anti-cancer drug which is an antagonist of the oestrogen receptor?

Answer 24

Tamoxifen

Question 25

Give an example of an anti-cancer drug which is an antagonist of the testosterone receptor?

Answer 25

Flutamide

Question 26

Prostate is a hormone antagonist which can be used in the treatment of prostate cancers. How does this drug work?

Answer 26

It is an LHRH agonist which inhibits the release of LH from the pituitary to cause a decrease in testosterone. Testosterone normally drives prostate tumours