Cancer 3 Flashcards
what are the most common cancers worldwide?
• Lung • Breast • Bowel • Prostate • Stomach
why is the incidence of cancer set to increase?
- 22 million cases in 2030
- greater westernization in developing countries will reduce infection based cancers and increase western cancers
what are the main anti-cancer modalities?
- Surgery
- Radiotherapy
- Chemotherapy
- Immunotherapy
what are types of genetic mutation that cause cancer?
- Chromosome translocation
- Gene amplification (copy number variation)
- Point mutations within promoter or enhancer regions of the genes
- Deletions or insertions
- Epigenetic alterations to gene expression
- Can be inherited
it might be a multitude of these factors
what are the types of systemic chemotherapy drugs :
- Cytotoxic Chemotherapy
- Targeted Therapies
what are cytotoxic chemotherapy options?
- Alkylating agents
- Antimetabolites
- Anthracyclines
- Vinca alkaloids and taxanes
- Topoisomerase inhibitors
what are targeted therapy options?
- Small molecule inhibitors
- Monoclonal antibodies
how do cytotoxic drugs work?
Cytotoxic drugs ‘select’ rapidly dividing cells by targeting their structures (mainly their DNA)
how is cytotoxic chemotherapy given?
- given IV or orally
- works systemically
- it is not targetted
at what times is cytotoxic chemotherapy used?
Post-operatively = adjuvant
Pre-operatively = neoadjuvant
As a monotherapy or in combination with curative or palliative intent
adjuvant = given after initial treatment to prevent secondary cancer formation
what do alkylating agents do?
- adds alkyl groups to guanine residues in DNA
- It then cross-links DNA strands and prevents DNA from uncoiling at replication
- this triggers apoptosis
- It encourages mispairing
Chlorambucil Cyclophosphamide Dacarbazine Temozolomide

what do psuedo- alkylating agents do?
- these add platinum to guanine residues in DNA
- it triggers the same mechanism of death as alkylating agents
Carboplatin Cisplatin Oxaliplatin

what are the side effects of pseudo - alkylating agents and alkylating agents?
- cause hair loss
- vomiting
- nausea
- tiredness
- Nephrotoxicity
- Neurotoxicity
- Ototoxicity (ear)
- Immunosuppression
how do Anti-metabolites work?
- Masquerade as purine or pyrimidine residues leading to
- inhibition of DNA synthesis
- DNA double-strand breaks
- apoptosis
they work by blocking DNA replication and DNA transcription
they can also be folate antagonists which inhibit dihydrofolate reductase preventing folic acid being made ( an important building block for nucleic acids)
Methotrexate
what are the side effects of antimetabolites?
- Hair loss
- Bone marrow suppression causing anaemia
- neutropenia and thrombocytopenia
- Increased risk of neutropenic sepsis
- Nausea and vomiting
- Mucositis and diarrhoea
- Palmar-plantar erythrodysesthesia PPE (Hand-foot syndrome, swelling of hands and feet)
- Fatigue
how do Anthracyclines work?

- Inhibit transcription and replication by intercalating (inserting between) nucleotides within the DNA/RNA strand
- Also block DNA repair
- They create DNA-damaging and cell membrane damaging oxygen free radicals
eg
Doxorubicin
Epirubicin
what are side effects of Anthracyclines?
- Cardiac toxicity (arrythmias, heart failure) – probably due to damage induced by free radicals
- Alopecia
- Neutropenia
- Nausea
- Vomiting
- Fatigue
- Skin changes
- Red urine (doxorubicin “the red devil”)
how do Vinca Alkaloids and taxanes work?
Work by inhibiting assembly or disassembly of mitotic microtubules causing dividing cells to undergo mitotic arrest

side effects of Vinca Alkaloids and taxanes?
- Nerve damage: peripheral neuropathy, autonomic neuropathy
- Hair loss
- Nausea
- Vomiting
- Bone marrow suppression (neutropenia, anaemia etc)
- Arthralgia
- Allergy
how do Topoisomerase inhibitors work?
- Topoisomerases are responsible for the uncoiling of DNA- they prevent DNA torsional strain during DNA replication and transcription
- Topoisomerase Inhibitors induce temporary single strand or double-strand breaks in the phosphodiester backbone of DNA
- drugs such as anthracyclines have anti-topoisomerase effects
- examples: Topotecan, Irinotecan , Etoposide

what are side effects of Topoisomerase inhibitors?
- (irinotecan): Acute cholinergic type syndrome – diarrhoea, abdominal cramps and diaphoresis (sweating).
Therefore given with atropine
- Hair loss
- Nausea
- vomiting
- Fatigue
- Bone marrow suppression
what is the greatest recent development in cancer treatment?
immunotherapy
what are resistant mechanisms of the DNA against treatment?
- DNA repair mechanisms upregulated
- Drug effluxed from the cell by ATP-binding cassette
- DNA adducts replaced by Base Excision repair

what are the modern non cytotoxic methods we use to manipulate cancer cells?
- these mainly revolve around the use of monoclonal antibodies and small-molecule inhibitors
- There is a lot of signaling within cancer cells and these signals can be cut in monogenic cancers
- however, for some cancers, the feedback cascades are activated
- we are in an era of dual kinase inhibitors which prevent feedback loops but increase toxicities
