Environmental Factors And Cancer Flashcards
The population difference in cancer means?
The environment, lifestyle and cultural differences contribute to the development of cancer. If it was a random process and not induced by anything there would not be such differences between populations.
What happens to migrants?
When migrants move to a different country with different environment and lifestyle they begin to develop the cancers associated with their new country rather than their old. Indicating the importance of external factors.
How are carcinogens classified using the current IARC system?
Definite carcinogen: association has been established between exposure and outcome and chance, bias and confounders can be ruled out with reasonable confidence
Probable carcinogen: when an association has been established but bias, chance and confounders cannot be ruled out with reasonable confidence
Possible carcinogen: when available studies are of insufficient quality, consistency or statistical power to permit a conclusion of a probable or definite association between the exposure and outcome
Factors included in cancer risk assessment
Potency: potential of a given amount of a compound to cause cancer
Type of exposure: acute, chronic, avoidable exposure or non-avoidable exposure
Dose response: relationship between dose and incidence of effects in humans
What can be included in the concept of environmental factors affecting human health ?
Diet, lifestyle, infectious disease, outdoor and indoor air pollution, soil and drinking water contaminants
Nitrates and carcinogens in drinking water inc cancer in some populations
What makes up outdoor air pollution ?
Particulate matter (PM) - PM10 and PM2.5 Nitrogen dioxide Sulphur dioxide Ozone gas Carbon monoxide Polycyclic aromatic hydrocarbons (PAHs)
Sources of air pollution
Transport Industry Fossil fuel power stations Farming Fuels people use to cook and heat their homes Natural pollutants
How does exposure to environmental tobacco smoke (ETS) relate to cancer?
Women who smoke highest no of death rates per 100000 a year (32)
Non smokers (wives) of husbands who are non-smokers 8.7/100000 a year.
Non smokers wives of husbands who are smokers
15.5/100000 a year
Diet and cancer effects of what you eat?
Direct effect of particular components added to the diet that are responsible for increased and decreased risk
Indirect effect involves the balance of the diet
Conniving and probable links between particular dietary components and cancer risk
Carcinogenic classification of processed meats - sausage, bacon, salami ?
Carcinogenic classification of red meat - pork, beef, lamb
Processed meat - class 1 - causes cancer Red meat - class 2a - probably causes cancer
Tobacco vs meat which attributed to more cancers and relative percentages of each
Tobacco causes more cancers 19% of all cancers and 86% of lung cancers
Red meat 3% of all cancers and 21% of bowel cancers
Tobacco
Food that fight cancer?
Fibre- non starch polysaccharide (NSP)
Fruit and veg - fibre, folate, vitamin C, vitamin E, flavonoids
Epidemiological and observational agents that might prevent cancer
Tea and coffee Berries grapes nuts and wine Fibre and whole grains Spices Vitamins and minerals Antioxidants, polyphenols, and isoflavanoids Cruciferous vegetables
Obesity increases risk of cancers how?
Not fully understood
Inc no of adipocytes leads to inc inflammatory cytokines p, signalling lipids, adipokines, fatty acids, insulin GF
Could contribute to an inc cancer risk
Obesity related mechanism - inflammation?
Inflammation and a parallel increase in the levels aromatase expression or activity can inc hormone levels
Increased activity of NF-kB transcription factor
