4.1 Cervical Pathology and Cervical Screening

Question 1

What is a colposcopy?

Answer 1

procedure to closely examine the cervix, vagina and vulva for signs of disease - may be done is results of pap test were abnormal

Question 2

What strains of HPV are most commonly associated with cervical cancer?

Answer 2

16 and 18

Question 3

Why is HPV16 so potent?

Answer 3

occurs earlier and after shorter incubation period

HPV 16 CIN2 will not regress at all

Question 4

What are the classifications of HPV

Answer 4

Low grade squamous intraepithelial lesion (LSIL) = CIN1

High grade squamous intraepithelial lesion (HSIL) = CIN2 and 3

Question 5

What are the 10 principles of screening

Answer 5

1. Condition should be important
2. There should be an accepted treatment
3. facilities for diagnosis and treatment should be available
4. there should be a recognisable latent or early symptomatic stage
5. There should be a suitable examination
6. The test should be acceptable to the population
7. Natural history of the condition ,including development from latent to declared disease should be adequately understood
8. There should be an agreed policy on who to treat
9. The cost of case finding should be economically balanced in relation to expenditure on medical care as a whole
10. Case finding should be a continuing process not a one off project

Question 6

What are the four key components of cervical screening?

Answer 6

1. Population coverage
2. Screening interval
3. Test sensitivity
4. Age of commencement

Question 7

What is the screening age of cervical cancer in Australia?

Answer 7

20-69

Question 8

What is the recommended screening interval for cervical cancer in Australia?

Answer 8

2 years

Question 9

Define sensitivity

Answer 9

True positives/ (true positives + false negatives)

Question 10

Define specificity

Answer 10

True negatives / (true negatives + false positives)

Question 11

What is the impact on testing with a high sensitivity?

Answer 11

The higher the sensitivity the more chance there is of identifying the precursors
- The more sensitive the test the lower the proportion of false negatives

Question 12

Define negative predictive value

Answer 12

True negatives/ (true negatives + False positives)

Question 13

Define positive predictive value

Answer 13

True positives/ (true positives + False positives)

Question 14

What is the impact on NPV with a higher sensitivity?

Answer 14

It will be higher

Question 15

What is the alternative testing to Pap smear?

Answer 15

HR-HPV testing

Question 16

What is the sensitivity and specificity of HR-HPV testing compared with pap smear?

Answer 16

More sensitive less specific

Question 17

What happens if there is a negative/positive HR-HPV test?

Answer 17

Negative - sent away for 5 years as there is a high NPV

Positive - further testing (cytology/genotyping)