LECTURES ONCOLOGY AND PUBLIC HEALTH
LECTURE 1: INTRODUCTION AND PUBLIC HEALTH
DEFINITION PUBLIC HEALTH
PUBLIC HEALTH
- “The science and art of preventing disease, prolonging life and promoting health through the
organized efforts of society.“ (Acheson, 1988)
o “The science and art of preventing disease, prolonging life and promoting health through the
organized efforts and informed choices of society, organizations, public and private,
communities and individuals.“
- WHO 1948: Health is a state of complete physical, mental and social well-being and not merely the
absence of disease or infirmity
- It refers to collective actions to improve population health
- WHO: all organized measures (whether public or private) to prevent disease, promote health, and
prolong life among the population as a whole
APPLICATION OF PUBLIC HEALTH
Three field of public health research
1. Epidemiology and community diagnosis
2. Collective prevention and health promotion
3. Health care organization and performance
- Populations: from local areas to the world population
- Causes of disease (causes of causes): from behaviors to broader environments
o Smoking is bad for your health, why are people smoking, smoking environment, taxes for
cigarettes
- Prevention of disease: from individual patients to national policies
- General health outcomes: from quality of life to healthy life expectancy
PUBLIC HEALTH FUNCTIONS
Main public health functions (WHO)
- Assessment and monitoring of the health of communities and populations at risk to identify health
problems and priorities
- The formulation of public policies designed to solve identified local and national health problems and
priorities
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, - Assure that all populations have access to appropriate and cost effective care, including health
promotion and diseases prevention services
There are also ten essential public health services
MAJOR PUBLIC HEALTH ACHIEVEMENTS
- Since 1900: vaccination, safer workplaces, control of infectious diseases
- Since 1920: safer and healthier foods, healthier mothers and babies, family planning
- Since 1965: fluoridation of drinking water, motor vehicle safety, recognition of tobacco use as a health
hazard, decline in deaths from coronary heart disease and stroke
Biggest success in public health: improved sewage disposal and clean water supply systems as most important
medical milestone, since 1840
CURRENT/FUTURE PUBLIC HEALTH ISSUES
- Examples: infectious diseases (Ebola, Covid19), chronic diseases, overweight and obesity, mental
health, environmental quality, planetary health, social issues, such as violence, drug abuse, teenage
pregnancy
GLOBAL BURDEN OF CANCER
- Cancer is leading cause of death
- 1 in 8 deaths worldwide
- 2012: cases: 14,1 million and deaths: 8,2 million
- 2030: cases: 21,7 million and deaths 13 million
- More people get it, less die from it
- Increase global population
- Increasing age
- Screening: more new cases: breast, cervix and
colon cancer
- Increase in risk factors: smoking, obesity, physical
inactivity, unhealthy diet
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,GEOGRAPHIC VARIATIONS
- Stomach cancer: 7x increased risk in Japan and Korea (consumption smoked fish)
- Breast and prostate cancer: less frequent in Asian vs Caucasian people (Asian vs Western diet)
- Melanoma: Australia + sunny parts south US
- Liver cancer: south east Asia and east Africa (hepatitis B)
- Thyroid cancer: deficiency of iodine in local food and water supplies (e.g. Swiss Alps, Rocky mountains,
Andes, Himalayas)
CANCER PREVENTION
NATIONAL INSTITUTE FOR PUBLIC HEALTH AND THE ENVIRONMENT (RIVM)
- Primary prevention: prevent the disease from occurring
o Encourage healthy lifestyles
o Legislation: increase tax on tobacco/alcohol
o HPV vaccination for prevention of cervical cancer
- Secondary: detect and treat the disease in an early phase before symptoms occur
o Screening for breast, cervical or colon cancer
- Tertiary: prevent damage and pain from the disease, slow down the disease, and prevent the disease
from causing other problems
o Survivorship care – improve HRQoL
o Prevention of cancer recurrence
Living healthy helps to prevent cancer
- 30% cancer can be reduced by living healthy
- 19.000 get cancer because of smoking
- 9500 food pattern
- 3600 overweight
- 2900 alcohol
- 2100 inactivity
FACTORS INFLUENCING CANCER RISK
Studies to explore cancer risk: longitudinal cohort, prospective
Physical activity and colon cancer
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,What increases the risk of cancer? (strong evidence)
- Overweight or obese: colorectum, breast (post-menopause), gallbladder, kidney, liver, oesophagus,
ovary, pancreas, prostate, stomach, endometrium
- Weight gain in adulthood: breast (post-menopause)
- Salt-preserved foods: stomach
- Arsenic in drinking water: bladder, lung, skin
- Alcoholic drinks: colorectum, breast, liver, mouth, pharynx, larynx, oesophagus, stomach
- Beta-carotene supplements: lung
- Mate (South American herbal tea): oesophagus
- Contonese style salted fish: nasopharynx
- Processed meat: colorectum, stomach
- Red meat: colorectum
- Glycaemic load (raise in blood sugar by diet): endometrium
- Aflotoxins (toxins produced by certain fungi): liver
- Height (being tall): colorectum, breast, kidney, ovary, pancreas, prostate→ more research is needed
before recommendations can be made
- Greater birth weight: breast→ more research is needed before recommendations can be made
Strong evidence of what decreases the risk of cancer
- Non-Starchy vegetables: mouth, pharynx, larynx
- Fruit: lung, mouth, pharynx, larynx
- Physical activity: colon, breast, endometrium
- Dietary fibre: colorectum
- Breast feeding: breast
- Coffee: liver, endometrium→ Unanswered questions →no recommendations
- Garlic: colorectum
- Greater body fatness: breast (pre-menopause)→ But strong evidence for increased risk of many
cancers
- Greater body fatness between 18-30 years: breast (post-menopause)→ But strong evidence for
increased risk of many cancers
- Diets high in calcium: colorectum→ Unanswered questions link milk/dairy and other cancers →no
recommendations
- Alcohol: kidney → strong evidence for increased risk of many other cancers
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,WCRF RECOMMENDATIONS
This overall recommendation can best be achieved
by maintaining energy balance throughout life by:
- Being physically active
- Eating a diet rich in wholegrains, vegetables, fruit
and pulses
- Limiting fast food consumption and other
processed foods high in fat, starches or sugar
- Limiting consumption of sugar sweetened drinks
Move more, sit less
Regular consumption of sugar sweetened drinks is
a cause of body weight gain, overweight and
obesity
WHY PUBLIC HEALTH POLICY?
- Much of behaviour passive reflection of ‘upstream’ factors rather than active choice environmental,
economic and social factors (outside most people’s control)
- Thus effectiveness of behavioural change relies on policies that influence upstream factors and social
norms that determine people’s behaviours (“causes of causes”)
➔ Public health policy (i.e. laws, regulations, guidelines) therefore is an important and sometimes
even critical determinant of population health
Example
WCRF recommendation: be a healthy weight Policy is needed to enable people to achieve and maintain a
healthy weight by influencing food environment, food system, built environment and behavioural change
communication
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,LECTURE 2: INTRODUCTION IN ONCOLOGY
Case
- 55-year old male, Heavy smoker, lives in IJmuiden
- Presents with shortness of breath, weight loss and pain near his left hip
- First a CT scan and to confirm it’s cancer you take a biopsy
o How far has it spread → PET CT scan (contains glucose: radioactive label)
▪ Brain and bladder always light up, everything else is abnormal
▪ In left hipbone → lung cancer with a bone metastasis (in left ilium)
Environmental toxins (smoking, diet) and human diseases (hepatitis, obesity) are important risk factors for the
development of cancer
Genomic alterations can cause malignant tumor formation
- Overactive positive cell cycle regulators (oncogenes) promote unlimited proliferation
- Inactive negative regulators (tumor suppressor genes) promote malignant transformation
WHAT IS CANCER
- Our bodies consist of about 30 trillion cells
- Cells group together to form tissues and organs
- Organs work together
- Cancer can arise in any of these cells
Cancer comprises a large group of disease characterized by
abnormal cells, which:
1. Continuously proliferate
2. Invade local tissues
3. Can spread to other organs (primary cancer can
spread → metastasis)
- The additional cells may form a mass of tissue
called a tumor
WHAT IS THE DIFFERENCE BETWEEN BENIGN AND MALIGNANT TUMOR
- Benign: relatively normal cells, capsule that doesn’t break, respects normal border, never metastasis
- Malignant irregularly shaped, can invade tissues and blood vessels around it
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,A lot of cells are already there when you see the cancer→ 1 trillion
TUMOR SIZE
- 1 million: head of a pin
- 1 trillion: small grape
- A patient usually has had cancer for several year before it is detected or caused symptoms
- Every 2-6 weeks → multiplies
TYPES OF CANCER
- Carcinoma (85%)
o Esophageal cancer→ more causes
▪ Malignant (cancerous) cells arise in esophagus
▪ Squamous cell carcinoma: from squamous epithelium
▪ Adenocarcinoma: gland, columnar glandular epithelium
- Sarcoma: originates in bone or soft tissue
- Glioma: originates in glial cells of the central nervous systems
- Melanoma: originates in melanocytes in the skin
- Leukemia: originates in the blood forming tissues of the bone marrow
- Lymphoma and myeloma: originates in cells of the immune system
HOW DOES CANCER ARISE
Normally, human cells grow and multiply to regenerate tissues
1. DNA is exposed
2. DNA is replicated
3. This results in two exact copies in DNA
4. The cells divide
5. Each cells contains the same DNA
- The process of DNA replication is complex and vulnerable to
o Damage by toxins (e.g. cigarette smoke, asbestos)
o Introduction of errors
- Damage by toxins → frequent division → increased risk of introduction of errors
- Introduction of errors → mistakes in DNA can normally be repaired or cells undergo apoptosis
- However, some cells survive with an abnormal change in their DNA→ a genomic alteration
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, TYPES OF GENOMIC ALTERATIONS
- Point mutation: two bases switched → may alter function of protein
- Deletion: results in smaller protein
- Insertion: bigger piece of protein
- Translocation: chromosome parts swap over
CONSEQUENCE OF GENOMIC ALTERATIONS
- The type and location of the genomic alteration is very important
o Proto oncogene: is accelerator → can become oncogene
o Tumor suppressor gene: brake systems: put brake on certain processes
Mutation of a proto-oncogene → oncogene
- Under normal circumstances, the proto oncogene codes for a protein that is involved in cell
growth/division (positive cell cycle regulator)
- Mutation => more (or more active protein) => increase cell growth/division
- Example: a growth factor receptor may send signals even when growth factors are not there
RAS most known oncogene
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