principles Flashcards
epidemiology: recall the epidemiological evidence of cancer causation, recall the incidence and mortality rates of major adult tumours, recall spatial distribution and temporal trends
where is incidence for common cancer sites increasing, and why
both high-income (increase but now beginning to plateau and in some cancers even decreasing) and low-income countries (breast, protate, colorectum) due to earlier diagnosis, screening and changes in risk factors (e.g. decreasing smoking frequency)
where is mortality for common cancer sites decreasing
high-income countries (decreasing slightly but relatively stable; CVD deaths plummeting though) due to earlier diagnosis and better therapies; not low-income countries (incidence does not match mortality - e.g. most skin cancers are not lethal)
why is the total burden for common cancer sites increasing
demographic changes (ageing populations, increasing size), Westernisation of lifestyles
inherited condition that increases risk (5-10% of cases; 90% directly environmental or interaction with genetic risk based on migrant studies - Knudson’s 2 hit hypothesis) for retinoblastoma
hereditary retinoblastoma
inherited condition that increases risk for colorectal cancer
familial adenomatous polyposis
inherited condition that increases risk for bone cancer
Paget’s disease of bone
main risk factors for cancer
smoking, diet, alcohol, infection, occupation, reproductive hormone
by reducing risk factors for cancer, what other diseases would have a substantial reduction in prevalence, and why are questionnaire studies only relevant to 50% of cancers
CVD, renal disease, hepatic disease, diabetes, some neurological diseases (more complex to investigate environmental pollutants e.g. if air pollution is carcinogenic, effect of PCPs by biological samples, not just questionnaires)
smoking as a risk factor for cancer: % of cancer deaths, no. of cancers associated, % of lung cancer deaths in M and F
30% of cancer deaths, associated with >15 types of cancer, causes 90% of lung cancer deaths in M and 80% in F
8 diet guidelines to reduce risk of cancer
be as lean as possible without being underweight, have >30mins physical activity/day, avoid foods high in sugar, eat more veg, fruit, wholegrains and pulses, limit consumption of red meats, limit alcoholic drinks to 2/day, limit consumption of Na, don’t use supplements to protect vs cancer
what cancers is alcohol a risk factor for (smoking very similar)
oral cavity, pharynx, larynx, oesophagus, liver
consequences of westernised lifestyle (energy dense diet rich in fat, refined carbs and animal protein; low physical activity; smoking and drinking)
greater adult body height, early menarche, obesity, diabetes, CVD, hypertension, cancer
what infectious agent causes cancer of cervic, head and neck
HPV
what infectious agent causes cancer of stomach
H. pylori
what 3 things is cancer incidence related to
age, common environmental causes, geographical variation and secular trends
