Cancer

Question 1

Factors affecting distribution of cancer : Obesity

Answer 1

Strongly associated with increased risk of colon, kidney,
pancreatic, endometrial and postmenopausal breast cancer.
One hypothesis…….
 High levels of insulin and IGF-1 in obese people may promote tumour development.
 Insulin and IGF-1 stimulate cell proliferation, inhibit apoptosis and promote angiogenesis
Adult weight gain most consistent and strongest predictor of post-menopausal breast cancer risk

Question 2

Factors affecting cancer distribution : Dietary components

Answer 2

Red meat: Processed meat “carcinogenic to humans”, Red meat “probably carcinogenic to humans”
Increased production of NOC (N-nitroso compounds) in the stomach
Heterocyclic amines, PAHs (polycyclic aromatic hydrocarbons)

Wholegrains: Higher intake of whole grains, lower cancer incidence esp. GIT cancers– oesophageal, colorectal

Soy
Asia: low endometrial and breast cancer rate
Isoflavones: genistein and daidzein
Decrease in breast cancer occurrence in women who consumed soy before puberty and during
adolescence

Alcohol:
Primary cause of liver cancer
Moderate alcohol consumption increases breast cancer risk- Women’s Healthy Study

Question 3

Diet and cancer key study

Answer 3

European Prospective Investigation into Cancer and Nutrition (EPIC) study
◦ Adherence to Med. diet can improve survival in a study of 70,000 elderly
◦ 13% of total cancer incidence attributable to former and current alcohol consumption esp. when
higher than recommended upper limit

Question 4

Factors affecting cancer distribution: Heredity

Answer 4

Mutations in genes that produce tumor suppressor protein
◦ TP53 (most commonly mutated gene in all cancer). Mutations in this gene can cause Li-Fraumeni
syndrome, a rare, inherited disorder that increases risk of developing certain cancers.
◦ PTEN – mutations in this gene are associated with Cowden syndrome, an inherited disorder that
increases the risk of breast, thyroid, endometrial, and other types of cancer.
Inherited mutations in the BRCA1 and BRCA2 genes are associated with hereditary
breast and ovarian cancer syndrome

Question 5

Factors affecting cancer distribution : Ethnicity

Answer 5

Generally - cancer incidence and death rates higher in African Americans than in White
individuals
Breast cancer – higher incidence rates among White Americans reflect differences in
diagnosis and underlying factors affecting disease occurrence.
Stomach and liver cancer – more than double incidence and death rates in Asian
American/Pacific Islanders as in White American
Kidney cancer – mortality rates highest among American Indians/Alaska Natives

Question 6

Geographical variations in cancer

Answer 6

Worldwide
Cancer risk factors are overall similar worldwide.
Smoking, insufficient physical activity, alcohol, diet, overweight and obesity, and infections account for a high
proportion of cancers worldwide
Prevalence of different risk factors varies incidence and mortality vary by region and country.
Example: USA
For some cancers especially lung cancer, rates vary widely across states.
◦ E.g. Utah: 40.3 male, 20.9 female cases per 100,000 / Kentucky: 137.9 male, 47.9 female cases per 100,000
Factors contributing to variation: differences in risk factors prevalence, access to and utilization of early
detection services, completeness of reporting.

Question 7

Cancer prevention strategies

Answer 7

Tobacco control: Smoking prevalence decreased in most regions, but estimated 2.4 million tobacco-related cancer
deaths occur per year
HIC: reduced smoking prevalence has reduced lung & laryngeal cancer in men and younger
women
LMIC: about 80% of the world’s smokers live here. Disease burden from tobacco use continues
to increase as a result of population growth and the ageing of long-term, continuing smokers.

Screening

Vaccination

Question 8

Case study cancer : Australia

Answer 8

Australia – Cancer Prevention Policy (Cancer Council Australia)
Specific recommendations for national action including programs and strategies
to reduce the incidence of specific cancer types
Including
◦ Increase taxes on tobacco
◦ Develop an integrated national food and nutrition plan to improve the availability of
affordable, accessible nutritious food for all Australians
◦ Eradication/phasing out of solariums
◦ Phasing out exposure of young people to the promotion of alcohol

Question 9

Case study cancer: Ireland

Answer 9

Sunbeds: promotions ban, protective eyewear mandatory, warning signs, health claims
banned
National Cancer Strategy 2017-2026 (DOHC)
◦ Aim to make Ireland tobacco free by 2025
◦ Improve diet and exercise, reduce alcohol
◦ Reducing health inequalities is a priority
◦ Improve uptake of screening programs