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Flashcards in Pharmacology - Cancer Deck (35)
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What is cancer?

Epigenetic disease resulting in the reprogramming of cancer cells so that they are growing in a no regulated manner and overcome physiological tissue and organ barriers (Invasive growth)


What are the main 2 causes of cancer?

1) Germline mutations/hereditary familil syndromes (5-10%)
2) Environmental factors/somatic mutations (90-95%)


What are the main risk factors of cancer?

1) Diet (35%) - (obesity (20%))
2) Smoking - 30%
3) Chronic infections (15-20%)
- Viruses 70%


What cancers have the highest and lowest 5 year relative survival for men and women?

> Testes 96%
> Hodgkin lymphoma 84%
> Pancreas 3%
> Lung 6%

> Melanoma 90%
> Hodgkin lymphoma 83%
> Pancreas 2%
> Lung 6%`


What is the major cancer treatment?

Surgical removal of the tumour if detected early enough


What is radical mastectomy and when was it first indroduced?

surgical procedure in which the breast, underlying chest muscle (including pectoralis major and pectoralis minor), and lymph nodes of the axilla (armpit area) are removed as a treatment for breast cancer.
1894 to avoid cancer spread


For how long did radical mastectomy remain a standard procedure?

>70 years


What therapy was introduced to replace radical mastectomy?

Removal of tumour mass plus chemo/radiotherapy
Equally effective but less morbidity


How does untreatable cancer kill patients?

Primary tumour and/or metastases destroy essential tissue and organs
- wasting syndrome (20%): appetite loss, weight loss, weakness, fatigue, muscle atrophy
- Only 1 in 5 patients with metastasised disease will survive >5 years


What percentage of cancer cures are achieved by which therapy?

- Systemic therapy (most common is chemotherapy) - 11%
- Local radiotherapy - 40%
- Surgery - 49%


What limits the efficacy of anti-cancer therapies?

1) Drug concordance (patients need to take their drugs)
2) The therapeutic window is very small
3) Do not fully understand the action of anti cancer drugs
4) Complicated disease
5) Cancer cell populations are highly adaptable


Why is the cancer therapeutic window so small?

Because cancer cells and normal diploid non maligant cells are so similar
- differences are in expression levels of genes but limited number of cancer specific mutations
- Result is that anti cancer drugs also have some non specific activity on normal cells


Describe some factors that contribute to cancer complexity?

Every cancer is its own unique disease:
- Genetic factors differ
- Time point of cancer formation
- Time point of diagnosis
- The therapy

Metastases may require different treatment than the primary tumour
Different cells from the same tumour may require different treatment


How are cancer cells so highly adaptable?

They undergo clonal evolution by natural selection
Selection pressures include:
- hypoxia (oxygen deficiency)
- starvation
- Anti-cancer therapy
- different microenvironments (invasion of other tissues)


What is the result of cancer cell adaptability?

Initially respond to treatment but eventually mutant resistant cells emerge and proliferate


Name 7 common anti-cancer drug types

- Alkylating agents
- Platinum drugs
- Tubulin-binding agents
- Antimetabolites
- Topoisomerase inhibitors
- Cytotoxic antibiotics (extra reading)
- Monoclonal antibiotics (ER)


What are akylating agents, how do they act and what are they used to treat? Give an example

Drugs regularly used in chemotherapy
React bases in DNA, and prevent cell division by cross linking the 2 strands on the double helix with an alkyl group
Used to treat Hodgkins lymphoma and other lymphoma laukaemias
Example drug: cyclophosphamide


What are platinum drugs, how do they act and what are they used to treat? Give examples

Platinum reacts with DNA bases (mainly guanine) resulting in intra and inter DNA strand cross linking
- Inhibits mitosis
- Induces DNA repair and subsequently cell death if the DNA damage is too severe
- Cisplatin
- Carboplatin
- Oxaliplatin


What are the 2 types of tubulin binding agents and what is their basic function?

Destabilising agents: bind to tubulin dimers and inhibit microtubule assembly
Stabilising agents: prevent microtubule disassembly , block mitosis


What are the 2 types of destabilising tubulin-binding agents and what are they used to treat?

1) Vinca domain binders
- Vinca alkaloids (e.g vincristine, vinblastine) and Eribulin
- Used in chemotherapy to treat cancers by preventing mitosis
2) Colchicine domain binders
- Colchicine
- Used to treat gout


What is the 1 type of stabilising tubulin-binding agent? Name the classes of drugs and individual examples?

Taxoid domain binders
- Drug classes: Taxanes (paclitaxel, docetaxel)
Epothilones (ixabepilone)


What do antimetabolites do broadly?

Inhibit purine and pyrimidine synthesis, affecting DNA synthesis and therefore preventing DNA replication


What is methotrexate and how does it function?

Antimetabolite - folic acid antagonist
Inhibits dihydrofolate resuctase in folate metabolism - folic acid needed for DNA synthesis


What are nucleoside analogues and how do they work?

Contain nucleotide analogue, a sugar and 3 phosphates
Faulty nucleotides incorporated into chain, causing termination
e.g deoxycytidine


What does topoisomerase I do?

Creates a single strand break during DNA replication, to relieve tension in the double stranded region to prevent supercoiling
- Also reseals the break


What do topoisomerase I inhibitors do?

Inhibit topoisomerase I function resulting in inhibition of DNA replication
e.g topotecan


What does topoisomerase II do?

Involved in reversing supercoiled DNA
- causes a double stranded break to allow another strand to pass through it, then reseals


What do topoisomerase II inhibitors do?

Inhibit topoisomerase II, resulting in double stand breakages
e.g etoposide


What are the 3 main types of targeted anti cancer drugs?

- Hormone therapy
- Kinase inhibitors
- Antibodies


What is oestrogen receptor (ER) positive breast cancer

Breast cancers that rely on oestrogen to grow