Cervical Ca screening & prevention

Question 1

Squamocolumnar junction

Answer 1

Junction between squamous and columnar epithelium
- Plays an important role in development of the transformation zone

Question 2

Main site for development of cervical cancer

Answer 2

Transformation zone

Question 3

Development of transformation zone

Answer 3

During puberty -> increase in estrogen
Original SCJ moves outwards outwards (eversion of endocervix) -> exposes columnar epithelium to the outside acidic vaginal environment -> cervical ectropion
‘Harsh’ environment of vagina promotes squamous metaplasia (of what is the exposed columnar epithelium) -> formation of new SCJ

Transformation zone: region bound by original and new SCJ

Question 4

Human Papillomavirus (HPV)

Answer 4

Double stranded DNA virus
HPV 16 + 18 a/w cervical ca

Question 5

Important facts about HPV infection

Answer 5

1. HPV infections alone does NOT mean cancer
   - HPV infections are TRANSIENT
2. PERSISTENT infection increases risk of future cervical ca
   - takes up to 30 years from HPV infection to CIN to cancer

Question 6

What does persistent infection mean?

Answer 6

Inability of body to get rid of HPV infection leading to chronic infection that eventually develops into pre-cancer then cancer over time

Question 7

Risk factors of cervical ca

Answer 7

Increase exposure to HPV infection
- HPV infection (16/18) ++
- Multiple sexual partners
- Early age of 1st coitus < 20y/o

Reduce ability for body to eradicate HPV infection
- STI
- Smoking
- Immunosuppression

Question 8

Primary prevention of cervical ca

Answer 8

HPV vaccination
- prevent infection from high risk HPV

Question 9

Secondary prevention of cervical ca

Answer 9

Pap smear, HPV DNA test
- Detects presence of abnormal cells (pap)
- Detects presence of virus (HPV DNA test)

KIV Colposcopy (diagnostic test)
- Detects CIN and treatment to prevent from progressing to cancer

Question 10

Pap smear

Answer 10

DETECTION OF CIN
- Liquid based cytology to look for abnormal cells
- SCREENING test
- For asymptomatic women
- Cervical pre-cancers are asymptomatic
- Helps with risk stratification

Question 11

Sensitivity of Pap smear test

Answer 11

50%

Question 12

Management of Pap smear result (normal women)

Answer 12

All cytology results require refer to colposcopy except
1. Negative for intra-epithelial lesion and malignant cells
2. Atypical squamous cells of undetermined significance (ASC-US)
- Repeat PAP in 6 months and only refer to colposcopy after 2x ASCUS

Question 13

Management of HPV DNA test results

Answer 13

1. HPV negative -> 5 yearly HPV
2. HPV 16/18 +ve -> colposcopy
3. HPV NON-16/18 +ve -> Do reflex cytology (PAP smear)
   a. Cytology negative -> 1 year HPV
   i. If 1 year HPV +ve -> colposcopy
   ii. If 1 year HPV -ve -> 5 yearly HPV
   b. Cytology positive (ASCUS onwards)-> colposcopy

*For immunocompromised women -> ALL HPV positive results refer to colposcopy

Question 14

HPV DNA testing in cervical ca screening

Answer 14

DETECTION OF CIN
- Objective test
- SCREENING test
- HPV 16/ 18 via the Roche Cobas test
- Higher sensitivity (strong negative predictive value)
- Helps with risk stratification

Question 15

2 types of HPV DNA test available

Answer 15

1. Hybrid capture 2
   - Tells you either you are positive or negative for High risk HPV only
   - You will not know which type
2. Genotyping
   - Tells you whether you are positive or negative for HPV infection and which type it is

Question 16

Cervical ca screening methods

Answer 16

For all women who ever had sexual intercourse
25-29 y/o: PAP smear every 3 years
30-69 y/o: HPV test alone every 5 years

Question 17

Cervical ca screening for immunocompromised women

Answer 17

For all immunocompromised women who ever had sexual intercourse
- ALL women with history of HIV
- ALL women with history of solid organ transplant
- Women on more than 2 immunosuppressants meds

25-29 y/o: PAP smear yearly
≥30 y/o: HPV test every 3 years

Question 18

What is HPV vaccine?

Answer 18

• Viral like particle - no virus in vaccine, empty protein coat
• Offers protection from future cancer
• Prophylactic, does not treat current infection

Question 19

Types of HPV vaccine

Answer 19

1: Cervarix (protects from HPV 16, 18)
2: Gardasil (protects from HPV 16, 18, 6, 11)
3: Gardasil 9 (protects from HPV 16, 18, 6, 11 + 5 more HPV types)

Question 20

Why is there a need for HPV vaccine?

Answer 20

Highly effective in preventing cervical pre-cancer

Question 21

How good is the HPV vaccine?

Answer 21

• At least 70% protection against cervical cancer
• MUST still go for regular cervical cancer screening when you are eligible
• It does not cover all cancer causing HPV infection but the most common ones with highest risks
• MUST complete injection regime to get best protection.

Question 22

Is the HPV vaccine safe?

Answer 22

Safe
- Common S/E: pain, swelling and redness at injection site

Question 23

How is the HPV vaccine given?

Answer 23

• Can be given to girls and boys
• Approved for use in Singapore from 9 to 26 year olds
• Most effective if given BEFORE a person becomes sexually active
• Lifetime protection. No booster currently required.

Question 24

Dosing regimen for HPV vaccine

Answer 24

Age 9 to 14 years old:
2 dose regime (0 and 6 months)

Age 15 years old and above:
3 dose regime (0, 1-2 and 6 months)

Question 25

Who will benefit from the vaccine?

Answer 25

BEFORE sexually active Limited benefits observed in: – Sexually active women – Up to 45 years old – Women who had abnormal pap smear – Women who had treatment for pre-cancer cells

Question 26

Colposcopy procedure

Answer 26

Cervix examined with low power microscopy with bright illumination Purpose of colposcopy - Diagnostic procedure to confirm CIN (precancerous)**/ invasive CA - locates lesions on cervix - indicates severity of CIN - allows selection of sites of the lesion for biopsy - facilitates local ablative and excisional therapy Note: If you can already see a suspicious fungating mass on speculum exam, there is no need for colposcopy evaluation bc a punch/cone biopsy is performed instead. Colposcopy is only used for assessing margins and extent of atypical surface changes on cervix in absence of suspicious mass

Question 27

Important colposcopy solutions used

Answer 27

Saline - moistening and cleansing - does not modify appearance of cervical epithelium - evaluate abnormal blood vessels and leukoplakia before acetic acid application Acetic acid - denatures protein (in nucleus) of cervical epithelial cells - abnormal cells have bigger nucleus - the higher the dysplasia, the more dense acetowhite the lesion will appear Lugol's solution - looking for poor iodine intake - iodine stains glycogen (in cytoplasm) - abnormal calls have smaller cytoplasm

Question 28

Colposcopy features suggestive of CIN

Answer 28

Acetowhite Abnormal blood vessel patterns - Punctation - Mosaicism - Atypical blood vessels (microinvasion until proven otherwise)

Question 29

Treatment of CIN

Answer 29

CIN 1 can regress back to normal - Observation Treat CIN 2 and 3 - Ablative therapy (LEEP) vs excisional therapy (Knife cone biopsy) Followup

Question 30

Note: CIN is precancerous condition, NOT cancer Treat before it turns to cancer

Answer 30

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