Cancer 3: Cancer Epidemiology

Question 1

LO:
- Summarise incidence and mortality rates of the major adult tumours as well as their spatial distribution and temporal trends

• Discuss the epidemiological evidence for cancer causation

Answer 1

uhh please focus on your lecture please and thank you

Question 2

note:

cancer = leading cause of death
2nd highest cause of death

Answer 2

-

Question 3

over 50 years :
MEDCs
–> there has been a big increase/ decrease in deaths for CVD
–> cancer death rate = relatively stable / increase / decrease

Answer 3

over 50 years :
MEDCs
–> there has been a big decrease in deaths for CVD
–> cancer death rate = relatively stable

Question 4

define incidence of cancer

Answer 4

= no. of new cases of cancer diagnosis

Question 5

note: geographical cancer distribution
- high prostate cancer incidence in MEDCs –>
- high melanoma incidence in Australia –>

Answer 5

note: geographical cancer distribution
- high prostate cancer incidence in MEDCs –> increased PSA testing
- high melanoma incidence in Australia –> increased exposure to UV

Question 6

migrants - exposed to / protected from environmental factors that contribute to development of cancer

for e.g via the adaptation of lifestyle/ diet in that particular area

Answer 6

good case study =

incidence of stomach cancer between japanese + Hawaii-Japanese + caucasians.

Question 7

what type of cancer is the most prevalent?

Answer 7

lung/ bronchus cancer

Question 8

when interpreting incidence of cancer - it is important to analyse:
(burden is increasing because…)

(2 main things)

Answer 8

• age structure of country

- size of population

Question 9

incidence of cancer is increasing / decreasing
but
mortality of cancer is increasing/ decreasing

Why is this?

how does this differ in LEDCs?

Answer 9

incidence of cancer is increasing
but
mortality of cancer is decreasing

why is this?

• due to early diagnosis / treatment
• due to increased screening

In LEDCs:
- incidence + mortality = both increasing

Question 10

highly lethal cancer –> incidence + mortality = almost identical –> LOW / HIGH survival

more clinically benign cancer –> LOW / HIGH survival

Answer 10

highly lethal cancer –> incidence + mortality = almost identical –> LOW survival rates

more clinically benign cancer –> HIGH survival rates

Question 11

increased metastasis of cancer = lower / higher survival rate

Answer 11

increased metastasis of cancer = lower survival rate

Question 12

note: there is lower survival rates in those with an african american ethnicity in terms of cancer

Answer 12

-

Question 13

what are the different causes of cancer?

Answer 13

• hereditary/genetic factors (5-10%)
• smoking (30%)
• diet (20-50%)
• alcohol (4-6%)
• infection (10-20%) –> e.g HPV / H.pylori / EBV
• occupation (2-4%)
• reproductive hormone (10-20%)
• obesity (sex hormones –> oestrogen –> increases risk of endometrial/breast cancer)

Question 14

Parkin’s estimate of preventable cancers in the UK:

predicts that 45% of cancer in m
and 40% in female could have been prevented if risk factors had been reduced / eliminated

Answer 14

–> which would also cause a decrease in renal / hepatic / cardiovascular disease

Question 15

smoking causes 90% of lung cancer in men

and 80% of long cancer in women

Answer 15

• there is synergism with alcohol + tobacco

Question 16

decrease in risk of colorectal cancer –> with increase in consumption of high fibre diet

Answer 16

-

Question 17

World cancer research guidelines

to prevent cancer:

Answer 17

• be as lean as possible –> but not underweight
• be physically active for at least 30 mins per day
• avoid sugary drinks
• avoid salty/ processed food
• limit alcohol consumption
• limit consumption of red / processed meats
• eat more variety of fruits and vegetables