1.01 - Introduction to Oncology Flashcards
Modifiable risk factors for cancer.
- tobacco use
- infectious agents
- unhealthy diet
- obesity
- physical inactivity
- alcohol consumption
Which cancers is smoking associated with in particular?
- lung
- oesophagus
- oral cavity
- pancreas
Smoking is responsible for approximately 2.3 million cancer deaths globally. An additional 190,000 cancer deaths are associated with smokeless tobacco and secondhand smoke.
Infectious agents are responsible for what proportion of new cancer diagnoses worldwide?
15%
What are the main infectious agents that contribute to the following cancers?
a) stomach cancer
b) cervical cancer
c) liver cancer
a) H. pylori infection
b) HPV (also causes vulvar, vaginal, anal and penile cancer).
c) Hepatitis B virus (low SES) or Hepatitis C virus (high SES)*
*high SES have vaccination against hepatitis B
Alcohol is a risk factor for which cancers?
- pharynx
- lip and oral cavity
- larynx
- oesophagus
- colon / rectum
- liver
- breast
How can skin cancers caused by ultraviolet radiation be prevented?
Sun protection and banning sunbeds - Australia implemented UV protection campaigns in the 1980s, and rates of melanoma are now decreasing in younger generations.
Environmental risk factors for cancer.
- air pollution
- radon gas exposure
- arsenic in drinking water (ie. China, Bangladesh)
Occupational risk factors for cancer.
- UV radiation (skin and eye)
- asbestos (lung, mesothelioma, ovary)
- benzene (leukaemia, lymphoma)
- xray radiation
Non-modifiable risk factors for cancer.
- sex (M>F)
- age
- low SES*
- genetics (ie. germline mutations)
- race
- PMHx (e.g. UC, cirrhosis)
*higher rates of smoking, obesity, inactivity; poor vaccination programmes, low vaccine uptake
What are some ways of controlling tobacco use?
- tax tobacco products
- smoke-free air laws
- health warnings on tobacco packaging
- restrictions on the promotion and advertising of tobacco
Note we should focus on preventing people starting smoking, and also on helping people to stop smoking; the risk of dying from lung cancer can be substantially reduced by quitting at any age.
How can unhealthy diet and physical activity be controlled?
- tax sweetened beverages
- pedestrian and cycle lanes
- green prescriptions
What is the role of vaccination in cancer prevention?
HPV and HBV vaccination is safe and available in the UK.
What is the benefit of early cancer detection?
Less aggressive treatment required, leading to a better quality of life and reduced mortality.
What are the approaches to early detection of cancer?
- screening
- early diagnosis
What are the three cancer screening programmes in the UK?
- Bowel cancer screening
- Breast cancer screening
- Cervical screening
For screening to be useful, the tests must be:
- reliable
- sensitive and specific
- benefit > harm
- cost-effective
- something people are willing to do
Bowel cancer screening programme in England.
Bowel cancer screening kit sent in the post to men and women aged 60 to 74, once every 2 years.
The test looks for trace blood in the faeces, which may indicate cancer.
What are the benefits of the bowel cancer screening programme?
Bowel cancer screening saves lives - it aims to detect cancer at an early stage where treatment is more likely to work.
What are the risks of the bowel cancer screening programme?
False positive result - results in anxiety and further unnecessary tests.
False negative result - rarely, screening may miss cancer.
Overdiagnosis - chance that some people are diagnosed and treated for bowel growths that would not have caused harm.
How are people deemed to be at high risk of bowel cancer screened?
Colonoscopy
Which people are deemed to be at high risk of bowel cancer?
- FAP
- Lynch syndrome (HNPCC)
- SPS
- FHx bowel cancer
- UC / Crohn’s disease
- polyps
- previous history of bowel cancer
What is breast cancer screening?
Mammogram takes x-rays of the breast, aiming to detect breast cancer when it is too small to see or feel.
These cancers are usually easier to treat than large cancers.
Who has breast cancer screening?
Women aged 50 to 70 are invited for a mammogram every 3 years.
Is breast cancer screening offered to trans people?
Breast screening is offered to:
- trans men and non-binary people assigned female at birth, who have not had bilateral mastectomy
- trans women and non-binary people assigned male at birth, who have taken feminising hormones
What is cervical cancer screening?
Tests for HPV, which can cause infected cervical cells to become abnormal.
A sample of the cervical cells are taken using a smear. If HPV is found in the cells, then they are looked at under a microscope for cell changes.
Who can have cervical screening?
Women aged 25 to 64:
- invited every 3 years between 25 and 49
- invited every 5 years between 50 and 64
What happens if you test positive for HPV?
The laboratory will also test your sample for cell changes. These changes are also called dyskaryosis.
If there are cell changes, you will be invited for a colposcopy to look closely at your cervix.
You will be invited back for cervical screening earlier than normal if there are no cell changes. This is usually after 1 year.
How is cervical cancer prevented?
HPV vaccination programme rolled out in England - given to boys and girls aged 13 and 14.
It protects against cervical, mouth, throat, anal and penile cancers.
What are the most common cancers in the UK?
- breast
- prostate
- lung
- bowel
Phases of clinical trials.
Phase 1
1-2 dozen participants.
The safety and best dosage levels of a drug is determined.
Phases of clinical trials.
Phase 2
<100 participants.
The response to new treatment is recorded and analysed.
Phases of clinical trials.
Phase 3
> 100 participants.
The results are studied; submission to a regulatory agency for approval.
Phases of clinical trials.
Phase 4
> 1000 partipants.
The treatment is marketed, and allows opportunity to learn more about rare side effects and long term effects.
What proportion of cancer diagnoses are preventable in the UK?
38%
Incidence of cancer in the UK annually.
Around 1000 diagnoses per day.
375,400 per year.
What is hyperplasia?
Increase in a size of tissue by an increase in the number of cells in the tissue.
Example of physiological hyerplasia.
Endometrial hyperplasia upon stimulation of oestrogen in the menstrual cycle.
Example of pathological hyperplasia.
Unopposed oestrogen HRT after menopause for symptomatic relief can cause endometrial hyperplasia.
This pathological hyperplasia increases the risk of dysplasia, then neoplasia.
What is metaplasia?
Transformation of one cell type to another.