Principles of Cancer Detection and Management

Question 1

Screening may involve (4 things)

Answer 1

Imaging
Lab tests
Procedures
Physical examination

Question 2

2 main requirements for a cancer screening test

Answer 2

Preclinical stage of the cancer must be detectable and have a long history
Evidence that early detection improves outcomes through effective treatment

Question 3

Sensitivity

Answer 3

What proportion of the cancers are detected with my test?
True positives/total cases with cancer
The total includes people with cancer who didnt screen positive

Question 4

Specificity

Answer 4

What proportion with a negative test DON’T have cancer?

True negative/total negative

Question 5

Positive predictive value

Answer 5

What proportions of positive cases have cancer?
Positive cases with cancer/total positive cases
Just looking at the people who screen positive
Depends on the prevalence of cancer in the population

Question 6

3 strategies to make screening worthwhile

Answer 6

Select accurate tests
Test in populations with high prevalence
Dont test in populations with short life expectancy

Question 7

3 cons of screening

Answer 7

Exposing people to the risk of the further testing and anxiety
Overdiagnosis
Financial costs

Question 8

ctDNA

Answer 8

Circulating tumor DNA
Shed into the bloodstream by tumors
Potential screening tool

Question 9

Before treatment, you want to confirm cancer with what?

Answer 9

A tissue diagnosis!

Question 10

TNM system to stage solid cancers

Answer 10

T: primary tumor characteristics (size and depth)
N: nodal status (involved or not, number, size)
M: metastasis (present or absent, extent)

Question 11

Why is lymph node involvement significant?

Answer 11

Indicates potential widespread disease despite normal staging investigations
Used to determine the need for additional post-op treatment

Question 12

Palliative intent

Answer 12

Means that the treatment is not being given with curative intent

Question 13

3 types of treatment for cancer

Answer 13

Surgery
Radiotherapy
Systemic therapy

Question 14

Radiotherapy

Answer 14

Damages DNA in tumor and normal cells

But there are better repair mechanisms in normal cells so it differentially kills tumor cells

Question 15

3 types of systemic therapy

Answer 15

Chemotherapy (kills rapidly dividing cells)
Targeted therapy (disruption of tumor cell proliferation and/or survival factors
Immunotherapy (marking tumor cells for destruction, or removing signals that are suppressing the immune response)

Question 16

Adjuvant treatment

Answer 16

Given after the primary therapy (usually surgery) to maximize effectiveness
Aim is to eradicate undetected microscopic disease

Question 17

Neoadjuvant treatmetn

Answer 17

Treatment given prior to the primary therapy (usually surgery)
Shrinks the tumor to allow safe removal

Question 18

Side effects from radiotherapy

Answer 18

Local effects

Skin irritation, organ hypofunction