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Factors Affecting Cancer Distribution - Coggle Diagram
Factors Affecting Cancer Distribution
Dietary Components
Red Meat
International Agency for Research on Cancer (IARC) Lancet publication
States processed meat 'carcinogenic to humans' (Group 1 carcinogen) and red meat probably carcinogenic to humans (Group 2a carcinogen)
Heterocyclic amines (cook meat at high temp) and poly aromatic hydrocarbons cause increased production of NOC (n-nitroso compounds)
Whole grains
AICR report states higher intake of whole grains lowers cancer incidence esp. GIT cancers i.e. oesophageal and colorectal
Does this directly by ^ stool bulk and reduce gut transit time
Indirectly as other components of fibre-rich foods i.e. phytochemicals lowers risk of cancer
Indirectly as high fibre/wholegrain intake lowers obesity
Soy
Decrease in breast cancer occurrence in women who consumed soy before puberty and during adolesence
Asia women have low endometrial and breast cancer rate
Isoflavones, genistein and daidzein (chemicals and phytoestrogens)
Alcohol
Primary cause of liver cancer due to scarring and cirrhosis meaning liver can't function
WHS - moderate consumption increases breast cancer risk
Heredity
Some have mutations in genes which produce tumour suppressor protein (interfering with cell proliferation and increasing apoptosis)
TP53 (most common mutated cancer gene) mutations can cause Li-Fraumeni syndrome a rare inherited disorder that increases risk of developing certain cancers
PTEN mutation in this gene associated w/ Cowden syndrome inherited disorder which ^ risk breast, thyroid, endometrial and other types of cancer
70% men have this gene miscoded relates ^ risk prostate cancer
Inherited mutations in BRCA1 and BRCA2 genes associated w/ hereditary breast and ovarian cancer syndrome
Causes incontrollable cell proliferation on epithelial cells
Geographical Variations
Gibney et al
Cancer incidence in Japanese women and Hawaiian women
2nd Gen Hawaiian high incidence of breast and colon cancer compared to Japan (^ red meat consumption and obesity and decreased soy intake
High stomach cancer in Japanese women compared to Hawaii due to high consumption of H pylori in Japan
Japan reduced colon cancer due to higher fibre intake than Hawaii
Cancer Research UK 2012 world estimate of cancer incidence
Australia, EU, USA, Canada higher incidences of cancer
African countries, some South American, India lower incidence
Globally
Cancer risk factors are overall similar
Smoking (liver cancer=oxidation/free radicals) insufficient PA, alcohol (liver as reduces ability to metabolise) obesity, infections
Prevalence of diff risk factors varies as well as incidence and mortality vary by region and country
Viruses in diff countries contributing
Human papilloma virus (HPV) = cervical cancer
H pylori in underdeveloped countries w/ contaminated water = stomach cancer
Hepatitis B and C = liver cancer
USA
Some cancers i.e. lung cancer incidence varies across states
Lung cancer rate example
Utah (lowest incidence of tobacco intake) 40.3 male and 20.9 female cases per 100,000
Kentucky (high tobacco intake) 137.9 males and 47.9 female cases per 100,000
Factors contributing to variation
Risk factor prevalence
Access to utilization of early detection services
Completeness of reporting
Temporal variations
World Cancer Report 2014
Cancer death rates decreasing but incidence ^, plateu in some places due to measures put in place
Ethnicity
Incidence and death rates 40% higher in
African Americans
than white people
^ incidence breast cancer in
white Americans
reflects differences in
diagnosis
& underlying factors affecting disease occurrence
More frequent mammograms and breast tissue tests
Stomach & liver cancer: more than double incidence & death rates in
Asian American/Pacific Islanders
as in white american
Kidney cancer mortality rates highest among American Indians/Alaska natives (Hepatitis, H pylori)
Socioeconomic Status
Clegg et al 2009
Large group (200,000) found as income decreased cancer risk ^
Possibly due to lower access to medical care? unhealthier diet> etc
Education level
Jemel et al 2008
Less education more cancer (more on slides)