Cancer Treatment: Chemotherapy

Question 1

systematic anti-cancer therapies (SACT) include

Answer 1

• chemotherapy
• hormonal therapy
• targeted therapy
• immunotherapy

Question 2

chemotherapy

Answer 2

• anti-cancer
• cytotoxic drugs
• targeting DNA

Question 3

history of chemotherapy

Answer 3

• mustard gas
• basis for first chemotherapy for lymphoma

Question 4

how are chemotherapies classified

Answer 4

• type of chemical drug
• mode of action (interfering with other damaging dna)

Question 5

classes of chemo

Answer 5

• alkylating agents
• anti-metabolites
• microtubule inhibitors
• topo-isomerase inhibitors
• anthracyclins

Question 6

mode of action of antimetabolites

Answer 6

• affect purine synthesis
• affect deoxyribonucleases

Question 7

mode of acion of alkylating agents

Answer 7

alter structure and function of dna by cross-linkage or fragmenting dna through alkylation

Question 8

cell cycle- depended chemo

Answer 8

• anti-metabolites (S phase)
• vinca-alkaloids (mitosis)
• taxanes (mitosis)

Question 9

cell cycle independent chemo

Answer 9

alkylating agents

Question 10

alkylating agents

Answer 10

• binds to DNA causing cross-links
• stop replication
• causing cancer cell death

Question 10

microtubules inhibitors

Answer 10

• stop degradation of microtubules: paclitaxel, docetaxel [taxanes]
• stop polymerisation of microtubules: colchicine, vinblastine [vinca-alkaloids]

Question 11

what determines chemo efficacy

Answer 11

-proportion of cancer cells killed
- growth rate of cancer
- amount of treatment deliverable
- inherent chemosensitivity of the tumour (lymphomas, germ cancers often very responsive BUT melanoma, glioblastomas very resistant)
- higher doses kill more cells
- BUT non-selective so kill both cancer cells and healthy cells
- kill cancer cells more because they are more rapidly dividing
- given in cycles to allow recovery of normal tissues

Question 12

log kill model

Answer 12

• with every cycle a proportion of cells are killed
• in curative treatment, reduction over time until none

Question 13

aims of chemo

Answer 13

• cure the cancer
• reduce the cancer load (kill some cells, improve symptoms and increase life expectancy)
• reduce tumour size sufficiently for surgery

Question 14

chemo curative cancer examples

Answer 14

• germ cell cancers
• hodgkins
• non-hodgkins lymphoma
• gestational choriocarcinoma
• paeds tumours
• tends to be more aggressive treatment

Question 15

chemo palliative examples

Answer 15

• considerable prolonged survival
• breast and ovarian cancer
• CRC
• lung cancer
• blood cancers

Question 16

adjuvant chemo

Answer 16

reduce risk of recurrance after surgery
kill microscopic cancer cells
used in breast, ovarian, CRC and lung cancers

Question 17

neo-adjuvant chemo

Answer 17

reduce size of primary cancer before surgery
kill microscopic cells prior to surgery
- used in breast, ovarian and upper GI cancers

Question 18

how is chemo given

Answer 18

• intravenous
• oral
• local (intra-arterial, intra-thecal, intra-peritoneal)
• single agent OR combination

Question 19

combination therapies

Answer 19

• use drugs active as a singular agent
• use drugs with different mechanisms of action
• use drugs with different mechanisms of resistance
• use drugs either different side effects
• be aware of drug-drug interactions

Question 20

examples of combination therapies

Answer 20

• FEC: breast cancer

Question 21

toxicities of chemo

Answer 21

• drug specific
• most reversible and reducible
• usually dose dependent
• major ones: bone marrow suppression, nausea, alopecia, cardiotoxicity

Question 22

neutropenia

Answer 22

drop in neutrophils caused by most chemos
can cause severe overwhelming infections (immunosuppression)
must give IV antibiotics within 1 hr

Question 23

nausea-vomiting

Answer 23

most chemos
treat with anti-emetics, ondansetron

Question 24

alopecia

Answer 24

alkylating agents, taxanes, cell-cycle drugs scalp cooling techniques

Question 25

cardiotoxicity

Answer 25

anthracyclines need close monitoring and dexrazoxane treatment

Question 26

gonadal damage

Answer 26

alkylating agents need sperm preservation treatment

Question 27

RECIST (response rate)

Answer 27

PD- >20% increase in diameter of tumour, new lesions or progression of non-target lesions SD- no PD or PR PR- >30% decrease in diameter of tumour CR- disappearance of all lesions