Cancer: A Global Perspective Flashcards
1
Q
Learning Objectives
A
- What is Cancer?
- What causes it?
- What is the global impact of Cancer?
- What can we do about it?
2
Q
Define Cancer
A
- A term for diseases in which abnormal cells divide without control and can invade nearby tissues.
- Cancer cells can also spread to other parts of the body through the blood and lymph systems
3
Q
Define Tumour
A
- An abnormal mass of tissue that results when cells divide more than they should or do not die when they should.
- Tumours may be benign (not cancer), or malignant (cancer), Also called neoplasm
4
Q
What is carcinogenesis?
A
- Cancer arises from a single cell that develops oncogenic driver mutations
- 2-8 driver mutations are required for carcinogenesis:
- Confer growth/survival advantage
- Other mutations occur as a consequence of loss of function of key DNA repair genes = passenger mutations
5
Q
List the hallmarks of cancer
A
- Sustaining proliferation signalling
- Evading growth suppressors
- Deregulating cellular energetic
- Resisting cell death
- Genome instability & mutation
- Introducing angiogenesis
- Activating invasion & metastasis
- Tumour promoting inflammation
- Enabling replication immortality
- Avoiding immune destruction
6
Q
List the different types of carcinogens
A
- Chemical
- Physical
- Viral
- Hereditary cancer predisposition syndromes
7
Q
Give examples for each type of carcinogen
A
- Chemical: Benzene, Alkylating agents (Chemotherapy)
- Physical: X-ray, UV light, Alpha particles
- Viral: Hepatitis B, Human papilloma
- Hereditary Cancer pre..: Li-Fraumeni syndrome, Down syndrome
8
Q
Give an example of a chemical carcinogen
A
- Platinum agents = Include chemotherapies like cisplatin and carboplatin
- They irreversibly bind at guanines (G) of the DNA and crosslink the two DNA strands (or intra-link them) inhibiting strand separation and preventing DNA replication.
9
Q
Give an example of physical carcinogens
A
- Ionising radiation:
- Gamma, X-rays (Photon) low linear energy transfer
- Particulate radiation (protons, neutrons, electrons) high linear energy transfer
10
Q
Give an example of a Viral Carcinogen
A
- Normal cells infected with certain viruses can be transformed into cancer cells due to expression or activation of viral oncogenes
- Transformation can result in integration of viral genes or genomes into the host genome
11
Q
Give some examples of hereditary cancer predisposition syndromes
A
- Gene mutations involving oncogenes (activation) or/and tumour suppressors (inactivation) common to other malignancies (TP53- Li-Fraumeni syndrome, NF1-Neurofibromatosis) or specific to the cancer type. Lynch syndrome.
- Chromosome aberrations: Translocations (BCR-ABL in leukaemia), Numerical disorders (trisomy 21 Down syndrome)
- Inherited immune system problems (Atxia telangiectasia, Wiskott-Aldrich syndrome)
12
Q
Describe the impact of cancer
A
- In 2022, approximately 20 million cancer cases were newly diagnosed, and 9.7 million people died from cancer worldwide.
- Global cancer statistics for 2024 indicate that there will be an estimated 35.3 million new cancer cases, representing a 76.6% increase, and 18.5 million cancer deaths, a 89.7% rise, by 2050
13
Q
How many new cases of cancer are there per year, in the UK?
A
There are around 375,000 new cancer cases in the UK every year, that’s around 1,000 every day (2016-2018)
14
Q
Give the statistics of cancer in the UK between 2016-18
A
- New cases: 375,000
- Deaths: 166,533
- Survival: 50% survived for 10 or more years
- Preventable cases: 38%
15
Q
List the 7 ways to cut down on cancer
A
- Become Smoke free
- Keep a healthy weight
- Be safe in the sun
- Drink less alcohol
- Eat a high fibre diet
- Cut down on processed meat
- Be more active
16
Q
Describe how some of these factors prevent cancer?
A
- Smoking: The most important preventable cause of cancer in the world
- Obesity: Small changes you can stick with help keep weight off for good
- Physicality: keeping fit can prevent 3,400 cases in the UK each year
- Alcohol: The less you drink, the lower the risk of cancer
- Diet: Earing a healthy balanced diet can play an important role in reducing cancer risk
- Sun and UV: Overexposure to ultraviolet light form the sun or sunbeds is the main cause of skin cancer
17
Q
Describe how some of these factors prevent cancer
A
- Hormones: Changes in our hormone levels can affect cancer risk
- Some jobs can affect people’s cancer risk, or may have done previously
- Infections: You can’t catch cancer but some infections such as human papilloma virus can increase risk
- Air pollution: Although exposure to air pollution can be linked to cancer, it’s low for a UK person
- Inheritance: Some inherited faulty genes can increase your risk of cancer
18
Q
Describe the affect of cancer in LMIC’s
A
- LMIC have 5% of global radiotherapy resources but >50% of new cancers!
- Nigeria has 4 radiotherapy centres serving over 200 million people!
- Kenya has 1 Oncologist for 500000 people and 1 radiotherapy machine!
- Ghana’s first radiotherapy centre opened in 2016.
19
Q
What’s the issue of cancer in LMICs?
A
- Low literacy and cancer awareness campaigns
- Myths and misconceptions e.g. Cancer is contagious, has a spiritual cause, cured by faith healing or herbal remedies
- Erroneous risk perceptions, stigma and fatalism
- No early intervention
20
Q
List another problem with cancer in LMICs
A
- Limited health spending impacts workforce, facilities and equipment, and access to affordable medicine.
- Total health expenditure is <5% GDP in most LMIC (Nigeria 2.7%; India 3.5%)
- Oncology medicines lag behind infectious disease
21
Q
How is the scarcity of the oncology workforce a problem?
A
- Many centres lack tools for surgery, chemotherapy and palliative care
- Patients face long distances to travel to oncology celtres
- Shortages of key drugs eg morphine
- LMICs have <5% optimal number of radiation oncologists for their populations (Uganda has 2 for 45 million!)
- Across Africa 34 countries have NONE
- Brain Drain to HICs!
22
Q
How is the limited access to screening a problem?
A
- Only 5% of women in India and Sub-Saharan Africa access cervical cancer screening in their lifetimes
- Shortage of pathological services for diagnostic confirmation is a major bottleneck
- Visual inspection screening in cervical cancer is showing success but still an issue for other cancers
- Diagnostic delays due to lack of staff and equipment
23
Q
Give reasons to why treatment abandonment occurs
A
- High out of pocket costs, long distances to travel and lack of social support leads to incomplete therapy.
- Particularly in poor and rural communities
- Lack of access to basic pain relief
24
Q
So what can we do about treatment abandonment?
A
- Prioritize High Impact, Cost effective approaches: HPV vaccination, Tobacco control, cervical and oral cancer inspection
- Increase public awareness: an Ethiopian radio drama featured cervical cancer increased screening
- Task sharing, nurses undertaking screening
- Education and money
25
How is immunotherapy used?
Through vaccination and providing cheaper drugs
26
What can we do to stop cancer?
- Checkpoint inhibition
- Releasing the brakes of the immune system
- Through the use of different drugs
- E.g. Checkpoint inhibitors
27
Give an example of a checkpoint inhibitor that blocks PD-1
- nivolumab (Opdivo)
- pembrolizumab (Keytruda)
- cemiplimab (Libtayo)
28
What cancer types can also be treated by Nivolumab and pembrolizumab?
- melanoma skin cancer
•Hodgkin lymphoma
•non small cell lung cancer (NSCLC)
•kidney cancer
•head and neck cancers
•bowel cancer
•stomach cancer
•bile duct cancer
Pembrolizumab is also a treatment for people with cancer of the:
•breast
•cervix
•womb
29
What is the problem with some of these treatments?
- The estimated cost of therapy for ipilimumab was $101,290—the highest of the 3 treatment regimens.
- The estimated costs of therapy for nivolumab and pembrolizumab were $30,078 and $58,008, respectively.
30
What is a killer to cure?
Expression and production costs calculation of tobacco plant-made cancer-immune checkpoint inhibitors.
