Chapter 1 + 2

Question 1

Li Fraumeni is an inherited condition involving which gene?

Answer 1

p53

Question 2

In human CML patients,
This gene has been shown to have been translocated _1__, resulting in an activating mutation.
What function does this gene/protein have in the cell? (2)
This is also called the (3) chromosome
Imatinib (also called (4) ) is a specific competitive inhibitor of this protein.
What is the DLT in dogs? 5

Answer 2

1. Bcr-Abl
2. Results in consitutively activated protein kinase
3. Philadelphia chromosome
4. Gleevac
5. Hepatotoxicity

Extra: present in 95% of humans w/ CML. DT reciprocal translocation bt chromosomes 9/22. Result is that BCR is fused w/ ABL. ABL is a tyrosine kinse (can phosphorylate tyrosines to activate a protein). The BCR is a serine/threonine kinase. When BCR and ABL are fused as BCR-ABL it is constitutively active (no longer needs cell signaling to work) resulting in increased cell division.

Question 3

Bevacizumab is used to inhibit the receptor for ____. Given its target name at least one broad use for this drug in cancer treatment.

Answer 3

VEGF

Angiogenesis

Question 4

Define:

Descriptive and analytical epidemiology

Answer 4

Descriptive: provides an indication of how frequently cancer occurs in terms of rates/risks/and the # of cases

Analytical: used to study the determinants of cancer whereby comparisons of cancer risks are made bt subgroups of populations

Question 5

Define:
Incidence and prevalence
Which is affected by the outcome associated w/ a given dx and why?

Answer 5

Incidence: # of new cases in defined pop w/in specific time pd

Prevalence: # of ppl w/ a given dz in a defined population at a given time. *affected by outcome w/ a given diagnosis.

Question 6

Define:

incidence rate

Answer 6

Incidence rate: # new cases over the pd of observation/total amt of person-time ovserved

Denominator = sum of follow up times for all persons in study

Question 7

Define:

Null hypothesis

Answer 7

Null hypoth states that theres no assoc bt the factor and cancer development. Opposite of what you want to prove. Your goal is to disprove the null hypothesis.

Question 8

Define:
Cohort study
List 2 disadvantages

Answer 8

Cohort study: a population is divided into grps based on exposure to possible causative cancer agent. Subjects then followed forward in time to see how many in each group develop cancer. Relative risk based on exposure can then be calculated.

Disadvantage: cancer occurs infrequently so large #’s needed over long time pd.

Question 9

Define:
Case control study.

List example of when a case-control study might be most useful

Give 2 limitations of case control studies

Answer 9

Case control study has affected patients (cases) and non-affected patients (controls) and compares the two populations to find differences that may explain cancer risk.

Most useful for rare diseases.

Limitations: recall bias for exposure and many other biases possible in selection of patients and measurement of exposure

Question 10

Define:
Confounding

Give an example in vet med (think k9 LSA)

Answer 10

Confounding: distortion of the effect of an exposure on risk that arises dt association w/ other factors that affect risk.

Ex: hyperCa and T cell are “both” neg px factors