Midterm 1

Question 1

What is cancer?

Answer 1

• ancient
• chronic degenerative disease
• results in genetic changes in a cell/failure of body’s defences
• unregulated growth

Question 2

The cancer process

Answer 2

Initiation –> Promotion –> Progression

Question 3

What are the 5 most common types of cancer in Canada?

Answer 3

prostate
lung
breast
colorectal
pancreatic

Question 4

What is the goal of cancer prevention?

Answer 4

to preserve genetic integrity and to reduce the risk of cancer initiation and promotion

Question 5

What percent of cancers result from gene defects directly inherited from a parent? (e.g. mutations)

Answer 5

5-10%

Question 6

gene-environment interaction

Answer 6

most cancers are believe to result from the interaction between genes and the environment

Question 7

What is dose response?

Answer 7

pharmacological term

graded response - shows that higher exposure to something can lead to either an increase or decrease in risk

Question 8

What are the 2 types of dietary intervention?

Answer 8

controlled feeding studies (nutrient, food or whole dietary pattern)
behavioural counselling studies (always in free living conditions, can also target nutrient, food or dietary patterns)

Question 9

What are the strengths and limitations of food diaries?

Answer 9

strengths

• intake is quantified
• doesn’t rely on memory
• can include weekends
• could be relatively accurate if subjects are trained
• data is rich in detail

limitations

• recording can influence dietary choices
• expensive
• high respondent burden
• underreporting is an issue (especially with overweight participants)

Question 10

What are the strengths and limitations of food frequency questionnaires?

Answer 10

strengths

• high response rate
• can assess numerous people at once
• relatively low subject burden
• lower cost
• generally does not affect eating behaviour

limitations

• lacks detail
• requires literacy
• different FFQ’s can behave differently
• different populations respond differently
• problem with assessing foods that are in recipes

Question 11

What are the strengths and limitations of 24h recalls?

Answer 11

strengths

• suitable for illiterate subjects
• low subject burden
• high compliance
• unlikely to interfere with dietary behaviour
• standardized protocol can be used
• can be detailed

limitations

• relies on memory
• relies on getting a portion size estimate
• only a “snapshot”
• costly for face to face
• underreporting is typical

Question 12

What is negative and positive bias with dietary assessment?

Answer 12

negative bias - intakes are underestimated

positive bias - intakes are overestimated

Question 13

What is the precision-measurement error?

Answer 13

ability of a measurement to be reproduced (the degree of reproducibility)