Chronic Disease - Cancer

Question 1

what are the most common cancers

Answer 1

breast, lung, prostate, bowel
recent increase in incidence of cancers linked to lifestyle - kidney, liver, skin, oral

Question 2

what age is cancer most common in

Answer 2

1/3 of cancers are in those aged 75+

Question 3

incidence of cancer on SES

Answer 3

higher incidence in those living in more deprived areas - especially smoking-related cancers

Question 4

outline geographical variation of cancer

Answer 4

due to ethnic differences - genetic factors
environmental exposures - infections
lifestyle - diet, smoking, alcohol
demographic factors - age, sex, SES

Question 5

what is cancer?

Answer 5

clonal disease with ability to metastasize
solid tumours or leukemias

Question 6

why is cancer screening important

Answer 6

breast, colon, prostate and cervical cancer screening
for public health, detectability, early intervention

Question 7

what is the risk of cancer at age 14 and 24

Answer 7

14 = 1 in 600
24 = 1 in 300

Question 8

what are the main cancers in childhood

Answer 8

leukemia/lymphoma
brain

Question 9

what are the main cancers in men

Answer 9

big groups are lung cancer, prostate and colorectal

Question 10

does childhood cancer affect more boys or girls

Answer 10

more boys

Question 11

what % of childhood cancer can be attributed to genetic factors

Answer 11

5%

Question 12

what are congenital conditions associated with childhood cancer

Answer 12

downs syndrome
neurofibromatosis
fanconis anaemia

Question 13

what does the greater incidence of childhood cancer suggest

Answer 13

something to do with better detection but there is still an increase, so suggests a change in environment

Question 14

what is an example for an environmental cause of leukemia

Answer 14

clustering in seascale village and new towns on leukemia and brain tumours

Question 15

what were aetiological candidates of the seascale environment in causing leukemia

Answer 15

it is located near a nuclear plant so radiation, population mobility, occupation exposures and EMF (power lines)

Question 16

outline how X rays affect pregnancy

Answer 16

increased risk of leukaemia and solid tumours by 30%
X ray therapy increases risk of malignancy - 4 fold increase

Question 17

what case control study tried to get to the bottom of the seascale cluster

Answer 17

Gardner et al - paternal preconceptional occupational radiation
107 cases but the case study was flawed - did not select controls well
court case found no sufficient evidence for the association and there was no biological plausibility given the amount of radiation

Question 18

what was other evidence for paternal exposure in the seascale cluster

Answer 18

consistent findings of increased risk for leukeamias in children of men employed in radiation industry and petrochemical industry

Question 19

what did the exposure of fathers not explain in seascale?

Answer 19

commuters
evacuees
which all were shown to have high rates of leukemia
special population movements

Question 20

what was the population mixing hypothesis for the seascale cluster and leukeamia

Answer 20

linekd increased risk with population movement
more incomers = more risk

Question 21

what was Kinlens hypothesis in regard to population mixing for seascale cluster

Answer 21

when populations mix for first time there is an exchange of infectious agents for which the previously isolated (susceptible) populations do not have herd immunity
results in childhood infection which can manifest as leukeamia

Question 22

what was Kinlens hypothesis based on and why is this problematic

Answer 22

communities where mixing occurred like new towns, commuter towns and places used for war time evacuation
but ww2 evacuation was based on mortality data not incidence data so not a good measure BUT there was less treatments at the time so maybe mortality was best analyses back then

Question 23

outline population mixing and childhood leukemia in Cumbria

Answer 23

evidence shows higher rates of childhood leukaemia for children of non-Cumbrian parents, especially in early childhood, age 1-6
demonstrated population mixing could explain the higher rates

Question 24

what did the study conclude about population mixing in Cumbria

Answer 24

it increases risk of childhood leukaemia by a factor of 2.5 in children of non-Cumbrian parents and accounts for 58% of cases

Question 25

what did the Cumbria leukaemia study summarise

Answer 25

children of radiation workers have higher rate of leukeamia - 2/3 due to population mixing and 1/3 due to fathers radiation exposure
there is a dose-response relationship not accounted for by population
risk is higher for seascale children but dose response not the same

Question 26

what was the Greaves hypothesis of infection and childhood leukaemia

Answer 26

it is normal for children to encounter many infections in early first year - but this is for immune protection or dose limitation from mothers antibodies/breast milk
so said it was due to a reduction in breastfeeding

Question 27

Greaves : in what 3 ways do lifestyles compromise evolutionary adaptation of the immune system?

Answer 27

pregnant mothers not being exposed
reduction in breastfeeding
reduction and delay of infection

Question 28

what infections did evidence show in solid tumours

Answer 28

space-time clustering of brain tumours
EBV, measles and influenza
but this is not consistent

Question 29

what are some dietary requirements factors of potentially greater risk to childhood leukaemia

Answer 29

flavonoids - fruits and veg
catechins - tea, cocoa, wine

Question 30

what does evidence show about alcohol consumption and leukaemia

Answer 30

higher number of drinks in pregnancy conferred greater risk of AML leukaemia

Question 31

outline herbicides/pesticides as risk for leukaemia

Answer 31

gene-environment interaction
indoor use of insectisides and pesticide use in garden is a risk
mothers with CYP1A1m1 mutation during pregnancy or child exposed -> risk

Question 32

outline prenatal exposure to EMF causing leukaemia

Answer 32

maternal occupational exposure to extremely low frequency magnetic fields during pregnancy increased risk of leukaemia MODERATELY
highest odds ratio was 1.2-5.0

Question 33

how could we minimise childhood ALL leukaemia?

Answer 33

encourage protracted breastfeeding
avoid known leukemogens in pregnancy
encourage early social contact - play groups
identify at-risk individuals