8: Cancer Prevention I Flashcards
Give some examples of primary preventions against cancer
- healthy lifestyle choices: tobacco, alcohol, obesity, nutrition, sun safety
- vaccines (HPV)
- approaches to modify population level behaviour
According to CRUK, what % of cancer is preventable?
38%
Describe the WHO action plan for prevention and control of noncommunicable disease
- 25% relative reduction in risk of premature mortality from non-communicable disease by 2025
- 10% reduction in harmful alcohol use
- 30% reduction in prevalence of current tobacco use
How many people does non-communicable disease kill each year, and how many of these are premature?
- 41 million deaths/year
- 15 million premature (30-69 yrs)
Fill in the blanks.
Non-communicable disease kills ___ million pear each year. ___% of these deaths are due to cancer, and ___% of all deaths were in low and middle income countries.
- 41
- 23%
- 80%
Which cancer types have the largest NUMBER of preventable cases?
Lung, bowel, melanoma, breast
Which cancer types have the highest PROPORTION of preventable cases?
Kaposi sarcoma, cervical, mesothelioma, anal, pharyngeal, melanoma, nasopharyngeal, lung, vaginal
T of F;
- tobacco is a group 3 carcinogen
- 40% of cancers in the UK are caused by smoking
- there is a short delay between initiation of tobacco use and onset of cancer
- F: Group 1
- F: 15% not 40%
- F: there is a long delay
Fill in the blanks:
- Tobacco smoke generates both mainstream and sidestream smoke. These collectively form __1__ smoke.
- Tobbaco and smoke contains at least __2__, of which __3__ are considered carcinogenic
- NNK (__4__) and NNN (N-trosonornicotine) are of particular interest
- __5__ (principal alkaloid in tobacco) inhibits ___6___, stimulates cell growth and functions as a tumour promoter.
1: environmental
2: 8000
3: 70
4: 4-methylnitrosamino-1-3-pyridyl-butanone
5: nicotine
6: apoptosis
Describe the chemical composition of tobacco and tobacco smoke
- tobacco smoke: mainstream and sidestream smoke -> environmental smoke
- both contain >8000 chemical components, >70 are carcinogenic
- known carcinogens of interest: NNK (4-methylnitrosamine1-3pyridyl-butanone) and NNN (N-nitrosonornicotine)
What 15 cancer types are related to smoking?
- oropharnyx
- larynx
- esophagus
- trachea, bronchus, lung
- acute myeloid leukemia
- stomach
- liver
- pancreas
- kidney, ureter
- cervix
- bladder
- colorectal
What are the hazard ratios for smokers who have quit at different age groups compared to continued smokers for risk of death from smoking?
> 34 year: 1.0
35-44: 1.2
45-54: 1.5
55-64: 1.7
Continued smoking: 2.9
What factors modify risk of cancer related to smoking?
- genetic factors (ie addiction, carcinogen metabolism, DNA repair, tumour suppression)
- age at smoking initiation
- carcinogenity of cigarettes (higher in unfiltered cigs)
- interaction with asbestos, ionizing radiation, alcohol, hep B, HPV, and tuberculosis
- if parents smoke
Do hookah/waterpipes and ENDS (electronic nicotine delivery systems, vapes) increase chance of cancer?
- hookahs/waterpipes: yes
- vapes: long term effects unknown, levels of carcinogens significantly lower than tobacco smoke
Describe the 4 stages of the smoking epidemic
Stage 1: male smoking rises in sub-Saharan African countries
Stage 2: smoking rises to 60% in males, 30% in females, with both genders death % rising in china, japan, Southeast Asia, Latin America, North Africa
Stage 3: smoking incidence decreases in both genders, with deaths rising to 30% in males and <10% females. Eastern Europe, southern Europe, and Latin America
Stage 4: incidence decreases further to 30% in both genders. Male deaths begin o plateau/fall, female deaths still increase. Western Europe, UK, USA, Canada Australia
Describe some action taken in the UK that have correlated with a fall in smoking rates
- British doctors study in the 1950s
- advertisation of cigarettes banned 1965
- tax rise for tobacco products 1980s
- media campaigns and service to help people quit in the 2000s
- heath warnings on tobacco packs 2003
- tobacco displays banned and banning smoking in cars with children 2015
- tobacco packs standardized (2017) based on 2016 tobacco & related products regulations
Describe the age-standardized incidence rates of lung cancer between males and females in Europe from 1993-2017
- decrease in male incidence from 140 in 1993 to 90 in 2017 (per 100,000)
- increase in female incidence from 55 to 70 (per 100,000)
- overall plateau in person incidence at ~80/85/100,000
Globally and in the UK what % of new cancer cases in 2020 were attributable to alcohol consumption?
Globally: 4.1%
UK: 3%
T or F:
- the link between alcohol and cancer is more difficult to determine
- any amount of alcohol increases the risk of cancer
- under 14 units/week keeps risk of cancer due to alcohol consumption low
- T
- T
- T
Drinking 1.25 units per day increases the risk by what % of:
- mouth & upper throat
- oesophagus
- breast
- liver
- bowel
- mouth & upper throat: 15%
- oesophagus: 25%
- breast: 7%
- liver: 4%
- bowel: 2%
What cancers can alcohol affect the risk of?
- mouth & upper throat
- larynx
- oesophagus
- breast
- liver
- bowel
Explain how alcohol consumption leads to cancer
- acetaldehyde is a carcinogen that is mutagenus and affects apoptosis
- ethanol affects induction of P450 cytochromes, inhibiting carcinogenic clearance
- Hormone changes (eg to oestrogen and insulin) affects hormone-sensitive tumours
- increased absorption impacts tissues (eg GI tract) and nutrient absorption
- can cause cirrhosis (long term damage to liver)
T or F:
- 1 in 25 cancers are caused by excess weight
- maintaining a healthy weight reduces the risk of 13 different types of cancer
- risk of cancer in adults due to obesity is linked to other factors such as age and genetics
- there is a link between obesity and cancer in children
- F: 1 in 20
- T
- T
- F: there is no link between obesity and cancer in children
What cancers are associated with obesity?
- meningioma (brain & spinal cord tissue)
- oesophagus
- multiple myeloma
- kidney
- endometrium
- ovary
- thyroid
- breast (postmenopausal)
- liver
- gallbladder
- upper stomach
- pancreas
- colon & rectum
How can overweight and obesity cause cancer?
- fat cells increase inflammation and make extra hormones and GFs
- causes division of cells and increase risk of cancer
Fill in the blanks
Healthier diets could prevent around 1 in __1__ cancers in the UK (CRUK). Processed meats increase the risk of __2__ cancer (IARC group 1)
Red meats are a probable cause of cancer (IARC group (__3__).
Fruits, veg, and __4__ may help to reduce the risk of some cancers.
There is an increased risk of cancer for every __5__g of processed meat a person eats every day, with a relative risk of __6__%
1: 20
2: bowel
3: 2A
4: fibre
5: 25
6: 17
Which chemicals found in red and processed meats can cause cell damage?
- haem
- nitrates and nitrites
- heterocyclic amines (HCAs)
- polycyclic amines (PCAs)
1 - what % of lung/bowel cancers are attributable to tobacco/meat
2 - what % of all cancers are attributable to tobacco/meat
3 - how many cases per year could be prevented by not smoking/cutting down on processed meat?
1: 72% (lung) 13% (bowel)
2: 15% (tobacco) 1.5% (processed meat)
3: 54,300 (not smoking), 5,400 (processed meat)
On average how many cases and deaths per year for melanoma are there in the UK?
What % are preventable?
- 16,000+ cases, 2400 deaths
- 86% preventable
Fill in the blanks
PM__1__ and PM__2__ are linked to lung cancer. Levels in the UK tend to be __3__ compared to other countries around the world.
1 & 2: 10 & 2.5
3: low
As a population, how can outdoor air pollution be reduced?
- burning less fossil fuels
- clean air zone initiatives
- active travel networks
- reduced vehicle emissions
- indoor cooking (particulate matter)
List countries that have exposures above the WHO’s highest target guideline of 35ug/m^3
China
Bangladesh
India
Pakistan
Nigeria
What is the HPV vaccination coverage:
- in England
- in the UK
- England: 71%
- Global: 21%
What cancers s HPV linked to?
Cervical, vaginal, vulval, penile.
Mouth & throat
What types of HPV does the vaccination protect against?
HPV 16 and 18 (high-risk)
HPV 6 and 11 (genital warts)
