4. Cervical Screening

Question 1

Cervical Cancer Facts

Answer 1

9th most commonly diagnosed cancer in women
12th most common cause of in women
Average age at Dx = 46
Average age at death = 56

Question 2

How is cervical cancer prevented?

Answer 2

Primary = Vaccination

Secondary = Cervical Cytology, Cervical Check Prog

Early Dx = Down staging of cancers at Dx, agreed assessment and referral for women with symptoms.

Question 3

What virus is linked to Cervical Cancer?

Answer 3

Human Papillomavirus (HPV)

Question 4

How is HPV linked to Cervical Cancer?

Answer 4

99.7% of cervical cancers contain certain types of HPV DNA

Question 5

Describe the virology of HPV?

Answer 5

Double stranded, tightly coiled, circular virus

More than 100 types

Genetic structure
Early Late and Upper regulatory areas
E=(1,2,6,7), L=(1,2)

Infects basal cell layers of genital epithelium

Question 6

Why is HPV type important?

Answer 6

HPV 16 and 18 = 75% of cervical cancers

HPV 58, 33, 45, 31 and 32 = 20%

Question 7

What are the aims of the cervical screening? (Public Health Perspective?)

Answer 7

1. Reduce Incidence
2. Reduce Mortality
3. Detection and Treatment of High Grade Precancerous Lesions.

Question 8

What are the aims of the cervical screening? (Women’s Perspective)

Answer 8

To achieve a normal smear result

In presence of any uncertainty, to get further information .

Question 9

What must be balanced in decision making re: management of women with abnormal smears?

Answer 9

Risk of Cancer (Treatment, Diagnosis)

With

Risk of Harm (Physical, Psychological, Resources)

Question 10

What are the elements in ensuring uptake of cerv check screening?

Answer 10

1. Register Pop to be screened
2. Aim for 80% coverage
3. Reminders + Recalls

Question 11

What are the possible cervical cytology results and what do they mean?

Answer 11

1. High Grade = Abnormal Glandular, Suspected Neoplasia
2. Low Grade = ASCUS (atypical cells of undetermined significance (ASCUS). Mildly abnormal cells, unknown cause.
3. Normal = No abnormalities detected

Question 12

Follow up tests after positive screening test?

Answer 12

Colposcopy

Question 13

What features are looked for in the colposcopy?

Answer 13

1. White change on application of acetic acid
2. Vascular patterns
3. Iodine negative (neoplasm have no glycogen to uptake)

Question 14

What other test can be used to identify cerv cancer?

Answer 14

Histology

Question 15

Describe the role of HPV in the pathogenesis of CervCancer

Answer 15

Infection with HPV prompts clearance = Usual
Failure to Clear can cause progression to precancer.
Regression from precancer to HPV can occur
Alternatively precancerous cells can invade = Cancer

Question 16

What are the involved stages of HPV to cancer?

Answer 16

1. Exposure (Sex, 80% lifetime risk)
2. Infection (transient, most resolve)
3. Persistence (s detectable)
4. Malignant Transformation (virus integrates in host DNA)
5. CIN (Cervical intraepithelial neoplasia) (Loss of tumour supressor gene E2, Uncontrolled cells division)

Question 17

What is the efficacy of HPV testing?

Answer 17

HR HPV testing is 20-30% more sensitive than cytology for detection of CIN2+ and CIN3 +, respectively.

A negative HR HPV test provides a better protection against CIN3+, than a negative Pap smear.