Epidemiology and Incidence of Cancer Flashcards
Define: Genetic aberration
Abnormal/irregular portion of chromosomal DNA
What are the function of oncogenes?
Signal proliferation of cell cycles
Their over expression is associated with uncontrolled cell growth
What are the function of TSGs?
They code for inhibitory proteins.
Loss of function causes uncontrolled tumour growth
p53 (TSG) known as the “guardian of the genome”
Which UV light spectrum are we less concerned with?
UV-C because its blocked out by the ozone layer
[280 – 100 nm]
Causes of UV-B [320 – 280 nm] ?
- Sunburn :/
- Directly damages DNA bases: causes formation of
cyclobutane pyrimidine dimer (CPD)
CPD contains 2 thymine bases linked by strong covalent bonds. This disrupts the DNA strand and makes it difficult to read by DNA polymerase –> SKIN CANCER
This mutation causes:
- 8% malignant melanoma
- Mostly produces melanin (causes a TAN)
Causes of UV-A [400 – 320 nm] ?
Contributes to skin cancer through free radical formation - does not cause sunburn
What do UV-A and UV-B light produce?
Free radicals !
Free radicals are:
- Linked with ageing
- Cause indirect DNA damage (92% malignant melanoma)
Which type of cancer is radon gas associated with?
Lung cancer.
uranium miners most at risk because radon gas is a daughter product of radioactive decay of uranium in Earth’s crust
Three types of ionising radiation that causes cancer
- Excessive background radiation
- Excessive diagnostic radiology exposure
- Therapeutic radiation
Define: Ionisation
When an atom or molecule gains a positive or negative charge by gaining or losing electrons
Radiation-induced cancer Mechanisms
Energy deposited in biological material can produce ionisations in:
- Target molecules e.g. DNA
- interaction with water molecules to produce free radicals. These free radicals cause damage to DNA
DNA damage includes: Base damage, single-strand breaks (SSBs), double-strand breaks (DSBs)
Genomic instability
Identify the 2 modifiers to risk of radiation-induced cancer
Age: increased risk associated with exposure during childhood
Genetic susceptibility: Those with specified hereditable gene mutations
Name at least 2 cancers that can develop from this virus: Epstein-Barr Virus [EBV]
Burkitt lymphoma
Hodgkin lymphoma
Post-transplant lymphoma
Nasopharyngeal carcinoma
Human Papilloma Virus [HPV] can lead to what type of cancer?
Cervical cancer
What type of virus is HPV?
DNA virus affecting the epidermis or mucous membranes of humans
Which types of HPV cause cervical cancer ?
HPV-16 and HPV-18
Which types of HPV cause genital warts?
HPV-6 and HPV-11
Which types of HPV cause common warts?
HPV-1 and HPV-2
What is a consequence of overstimulation of hormone receptors (by endogenous or exogenous receptors)?
Excessive cell proliferation because:
- Altered hormone sensitivity is associated with development of cancer and chemo-resistance
- Hormonal intervention significant in cancer prevention and treatment
E.g. prostate, breast, cervical, gynaecological cancers
What is the correlation between Immunosuppression and cancer
T cell mediated response to tumour cells
Immunosuppression increases incidence of some cancers
- 40% of patients with AIDS develop cancer
- transplant patients increased risk of Hodgkins lymphoma
What are the dietary risk factors for cancer?
Bodyweight
- Obesity/overweight patients
Alcohol
- classed as a carcinogen
- increased risk of numerous cancers
Dietary fat
- animal fats contribute to cancer risk
- red meat in excess contribute to colon cancer and ER+ breast cancer
Dietary pevention of cancer
- Increased Vitamin D intake
- Physical activity (primary prevention) but also useful during treatment and after (survivors)
How can pharmacy help ?
- Smoking cessation
- Community pharmacy-based education and screening interventions are in development
