Biological Basis of Cancer Therapy Flashcards
What are the five most common cancers worldwide?
Lung Breast Bowel Prostate Stomach
most common for men is lung, women is breast
What are the four main anti-cancer modalities?
Radiotherapy
Chemotherapy
Surgery
Immunotherapy
List the different types of cytotoxic chemotherapy, how they can be taken and what cells they act on.
Alkylating agents Pseudoalkylating agents Antimetabolites Anthracyclines Vinca alkaloids and taxanes Topoisomerase inhibitors
- target ALL rapidly dividing cells
- given orally or IV function systematically
What are the main types of targeted therapy for cancer?
Monoclonal antibodies
Small molecule inhibitors
hat is the term used to describe chemotherapy that is given:
a. Following surgery
b. Before surgery
Adjuvant- post operatively
Neoadjuvant- pre operatively
How do alkylating agents work?
- add an alkyl group (CnH2n+1) to the guanine residues in DNA
- this causes cross-linking of the DNA strands and prevents DNA from uncoiling at replication
- this then triggers apoptosis (via a DNA checkpoint pathway)
It encourages mis-pairing (oncogenic)
Name four alkylating agents.
Chlorambucil
Cyclophosphamide
Dacarbazine
Temozolomide
How do pseudoalkylating agents work?
They have the same mechanism as alkylating agents but use platinum instead of alkyl groups
Name three pseudoalkylating agents.
Carboplatin
Cisplatin
Oxaliplatin
What are some side effects of alkylating and pseudoalkylating agents?
Alopecia (except carboplatin) Nephrotoxicity Neurotoxicity Ototoxicity (platins) Nausea, Vomiting, Diarrhoea, Immunosuppression, Tiredness
How do anti-metabolites work?
- masquerade (are analogues) of purine or pyrimidines
- leads to inhibition of DNA replication and transcription - they can also be folate antagonists (dihydrofolate reductase inhibitors) needed to make folic acid needed to make nucleic acids
Give six examples of anti-metabolites.
Methotrexate - Folate
6-mercaptopurine, decarbazine and fludarabine (purine)
5-fluorouracil, capecitabine, gemcitabine (pyrimidine)
State some side effects of anti-metabolites.
Alopecia (not 5-fluorouracil or capecitabine)
Bone marrow suppression
Increased risk of neutropenic sepsis
Nausea, Vomiting, Mucositis, Diarrhoea, Fatigue
Palmar-plantar erythrodysesthesia (PPE)
How do anthracyclines work?
- They intercalate into DNA or RNA sequences and inhibit transcription and replication
- It also blocks DNA repair
- They create DNA damaging and cell membrane damaging oxygen free radicals
Give two examples of anthracyclines.
Doxorubicin
Epirubicin
State some side effects of anthracyclines.
Cardiac toxicity (probably due to the free radicals) Alopecia Neutropenia Nausea, Vomiting, Fatigue Red urine (doxorubicin –‘the red devil’)
How do vinca alkaloids and taxanes work?
Vinca alkaloids inhibit assembly of mitotic microtubules
Taxanes inhibit disassembly of mitotic microtubules
This forces the cells into mitotic arrest
State some side effects of these drugs.
Nerve damage (peripheral neuropathy and autonomic neuropathy)
Hair loss
Nausea, Vomiting
Bone marrow suppression
Arthralgia (severe joint pain without swelling or signs of arthritis)
Allergy