Cervical Screening (HRP Session) Flashcards

1
Q

12% of human cancers are caused by viruses.
Which virus is implicated?

A
  1. HBV
  2. HIV
  3. EBV
  4. HPV - we are going to focus on this one, this can result in precancer of the cervix so lens itself to cervical screening
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2
Q

How common is HPV infection?

A

peak prevalence 15-25yrs

prevalence declines with age

10% overall

~30% prevalence in young women

lifetime risk of exposure 80% from serological studies

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3
Q

High-risk HPV causes other less common cancers such as what?

A
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4
Q

HPV infection in the cervix - what is the process?

A

Early HPV infections may be accompanied by mild changes in the epithelium

An abnormal growth of squamous cells detectable on smear is called a squamous intraepithelial lesion (SIL). Such changes may be low grade (LSIL) or high grade (HSIL), depending on how much of the cervical epithelium is affected, and how abnormal the cells appear

Abnormal cells in the cervix detected by biopsy and histological examination are classified as cervical intraepithelial neoplasia (CIN). Graded 1 to 3 according to the proportion of cervix affected

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5
Q

what is the process of HPV leading to cervical cancer?

A

cervical intraepithelial neoplasia - CIN

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6
Q

how is primary prevention done?

A

UK HPV Immunisation Programme

1 Sept 2008

Girls born after 1 September 1990 - Bivalent vaccine HPV16/18

Sept 2012 - Quadrivalent vaccine HPV 16/18/6/11

Sept 2014 - 2 dose regime

Boys included 2019

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7
Q

what oercentage uptake did we need to aim for?

A

80% but we got more than that in scotland

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8
Q

what do you know about HPV?

  1. HPV infection is ____ __________
  2. Most HPV infections are cleared by the _________ _______ (little clinical input)
  3. Most _______ cancers are associated with HPV
  4. HPV very ________ causes cancer
  5. In UK, 12 year olds are immunised against HPV_____ to reduce the risk of cervical cancer
A

very common

immune system

cervical

rarely

16/18

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9
Q

Flora, 25 year old P0 is receives an invitation to book an appointment for cervical screening at her GP practice:

  1. She is lower risk as only she is only 25 years old
  2. She is lower risk as she has no symptoms
  3. She is higher risk as she smokes
  4. She is higher risk because her mother had cervical cancer at age 35 years
  5. She is higher risk as she did not have the HPV vaccine
A

3.

screening is about screening asymptomatic people

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10
Q

what is the Scottish Cervical Call Recall System (SCCRS)?

A
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11
Q

what is the community health index?

A

unique number

first 6 digits are patients date of birth

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12
Q

what is the uptake of cervical screening in scotland?

A

older women are better attending

cervical screening uptake is higher in the least deprived

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13
Q

She makes an appointment with the practice nurse for a cervical screening test

how is it taken

A

collected using plastic broom

in a liquid based cytology

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14
Q

what is the epithelium of the cervix?

A

want to sample in the transformation zone

in ouberty there is everison of the intenral os of the cervix and the columnar epithelium becomes exposed to the vaginal

white is the columnar/glandular epithelium is undergoing metaplasia and now have a new squamo-columnar junction and this is the zone that is the transformation zone

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15
Q

Flora was invited for a smear test because:

  1. Her post code and CHI identify her as female, age 25 and deprived
  2. Her CHI identifies she is female and age 25
  3. Her CHI identifies she has not had a smear test recorded yet on SCCRS
  4. Her CHI identifies that she is aged 25 and sexually active
  5. Her CHI identifies that she is a person with a cervix and age 25
A

2

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16
Q

Case continued:

Flora makes an appointment with the practice nurse for a cervical screening test

She gets a letter 2 weeks later to advise her that there are minor changes and she will be seen at colposcopy for further investigation

A
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17
Q

how is taking a screening sample done?

A

Person with a cervix* aged 25-64 years

From March 2020:

5 yearly smears

Liquid Based Cytology (LBC)

Test for high risk HPV

If hrHPV positive; triage with cytology

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18
Q

how has cervical screening changed?

A

Prior to the change to HPV-based screening in 2020, all samples had a cytology slide made which was examined under the microscope (see left of diagram) - by a human. Since the changeover, all samples now have a HPV test – done by a machine (shown on right). Only the HPV-positive ones now have a cytology test. Therefore from 2020, cervical screening is largely done by machines

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19
Q

Why did we change to HPV testing for cervical screening?

A

HPV testing is more sensitive than cytology for high grade abnormalities

As more HPV-immunised women enter the screened population, cervical disease will decrease and will be more difficult to detect by cytology. HPV will be more effective test for the future.

If the HPV test is negative, the woman’s chance of developing cervical cancer in the next 5 years is very small, allowing a 5 year screening interval for all women regardless of age.

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20
Q

The smear is taken in the ____ way, so the cervical sampling experience for women will ___ ______

Remember…..HPV vaccination doesn’t prevent all _______ and even if women have been __________, they should still attend for their smear tests!

A

same

not change

cancers

immunised

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21
Q

how do these tests differe? - HPV test and cytology

22
Q

Laboratory Processing of Cervical Samples - what is the process?

A

Cells in the vial are tested

Hr HPV test (all)

If positive (15%) reflex cytology

23
Q

What is an HPV test?

A

Molecular test on cells sampled from cervix

Identifies high risk HPV E6/7 mRNA

Targets 14 High risk HPV types (but screening test does not identify specific HPV types)

Works on LBC (liquid based cytology) samples

Technology: Hybridisation & PCR

24
Q

Cervical cytology sample:

Only if high risk ________

_________ assessment of cells scraped from the __________ zone

Look for _________ cells (dyskaryosis)

indicate that woman may have underlying _______ __________ _________ - CIN

not a ________ test, a screening test and more _______ the cytology is, the more likely there is that there is an abnormality

A

HPV +ve

Microscopic

transformation

abnormal

cervical intraepithelial neoplasia

diagnostic

abnormal

25
cervical cytology sample The majority of cells present are mature squamous cells scraped from the surface of the metaplastic squamous epithelium of the transformation zone. Immature squamous metaplastic cells may also be obtained from areas where the process of metaplasia is less complete e.g. adjacent to the squamocolumnar junction
26
CYTOLOGY of the CERVIX abnormal = \_\_\_\_\_\_\_\_\_\_\_\_\_\_
DYSKARYOSIS
27
CYTOLOGY of the CERVIX abnormal = DYSKARYOSIS Abnormal cells may be few what are the nuclear features?
increased size and nuclear:cytoplasmic ratio variation in size, shape and outline coarse irregular chromatin nucleoli
28
Graded low or high grade dyskaryosis - reflects degree of underlying \_\_\_ Low grade (+ borderline) High grade (this is what we are intrested in)
CIN
29
what is shown here?
KOILOCYTES - reflect HPV infection perinuclear halo apperance Koilocytes, also known as halo cells, are a type of epithelial cell that develops following a human papillomavirus (HPV) infection
30
what is shown here?
low grade dyskaryosis
31
what is shown here?
high grade dyskaryosis High grade dyskaryosis – underlying CIN3
32
what happens next weather you are positive or negative?
Negative for hrHPV – routine recall 5 years Positive for hrHPV: - Cytology normal; repeat test 1 year - Dyskaryosis: refer to colposcopy
33
Flora gets an invitation to book a colposcopy appointment at her local hospital. The reason is: 1. Her HPV test is positive 2. She has high risk HPV and low grade dyskaryosis 3. She had low grade dyskaryosis or BNA on cytology 4. Her test was unsatisfactory or failed 5. Her smear taker thought her cervix looked abnormal
2 need to have some sort of dyskaryosis to have been refered to colposcopy
34
what happens on your frist visit to colposcopy? watch again
Education and advice Colposcopy: - Magnification and light to see cervix - Exclude obvious malignancy - Use of acetic acid (causes whitening of any CIN lesions) =/- Iodene: * Identify limits of lesion * Select biopsy site * Define area to treat
35
what is shown here?
normal colposcopy image of the cervix can see the new squamous-columnar juction
36
Clinical picture - low-grade change this cervix has had acentic acid appleid to it CIN 1
Clinical picture - high-grade change capillary vessel patterns mossaic effect
37
whata re the options for management?
Punch biopsy to make a diagnosis Return for Treatment if CIN2/3 if high grade then can offer to do treatment on that first clinic visit “See and treat” at first visit
38
PATHOLOGY of the CERVIX - what are pathologiests looking for
patholgist is trying to identify the Transformation zone of cervix: HPV related pathology we ask the pathologist is it: - HPV infection - precancerous changes cervical intraepithelial neoplasia (CIN) - cervical carcinoma
39
how does HPV infect the transformation zone?
Infects basal layer cells Utilises host for replication As host cell matures, different viral genes expressed
40
HPV histology - what are Koilocytosis?
Cells with wrinkled nucleus and perinuclear halo Multinucleation
41
Human Papilloma Virus: what are low risk types and what do they cause?
Low Risk types - 6, 11, 42, 44 (et al) Genital warts and Low grade CIN Often transient and resolve
42
Human Papilloma Virus: what are high risk types and what do they cause?
High Risk types - **16, 18**, 31, 45 (et al) Persistent infection increases risk of developing High grade CIN and (more rarely) cancer
43
How does HPV cause high grade CIN?
High risk HPV type and Persistent infection: - Viral DNA integrates into host cell genome - overexpression of viral E6 and E7 proteins - deregulation of host cell cycle
44
HIstology of CIN CIN3
Neoplastic cells or undifferentiated cells fill full thickness of epith here, no normal differentiated cells seen = CIN3 When undiffer cells occupy 2/3 of thickness and only top layers show maturation to medium size cells = CIN2 If undiff cells only occupy lowest 1/3 of epith and surface cells can mature to big flat cells = CIN1
45
what is Cervical Intraepithelial Neoplasia?
Invisible to naked eye Disorganised proliferation of abnormal cells in squamous epithelium (dysplasia) - Lack of maturation, variation in cellular size and shape, nuclear enlargement, irregularity, hyperchromasia (darkly staining nuclei), cellular disarray CIN 1: low grade dysplasia – will regress CIN 2: moderate dysplasia – may regress CIN 3: severe dysplasia – unlikely to regress Precursor of invasive cancer
46
the different types of CIn affect how much oft he epithelium?
Low-grade neoplasia (CIN 1) refers to dysplasia that involves about one-third of the thickness of the epithelium CIN 2 refers to abnormal changes in about one-third to two-thirds of the epithelial layer CIN 3 (the most severe form) describes a condition that affects more than two-thirds of the epithelium
47
what age is most cases of CIN seen?
25-29
48
what is the treatment of CIN2/3
Excise TZ\* of cervix - LLETZ (loop electrosurgical excision procedure - The abnormal tissue is removed using a thin wire loop that is heated electrically) Ablate TZ of cervix - Thermal Ablation, Laser ablation \* = Transformation zone
49
what follow-up happens after the treatment of CIN?
To confirm that treatment was effective - Residual disease with in 2 years To prevent invasive cancer: - Recurrent disease 5% after 3-5 years - Detect occasional cancer To reassure the woman that her treatment has worked After treatment of CIN there is an Increased risk of cervical cancer compared with the normal population Follow-up LBC at 6 months for cytology and high risk HPV: - Both negative – return to 3 year recall - Either positive – return to colposcopy
50
What is the aim of cervical screening? 1. Detect cervical dyskaryosis 2. Reduce the risk of cervical cancer 3. Detect CIN 4. Prevent Cervical Cancer 5. Reduce high risk HPV infections
2 does this by detecting high risk HPV adn cervical dyskaryosis, aim is not to detect CIN itself
51
what to remember: \_\_\_ is single most important cause of CIN and cervical cancer Screening detects high risk ___ and ________ changes which are asymptomatic Screening allows treatment of pre-invasive changes (CIN) to prevent \_\_\_\_\_\_ HPV __________ + cervical screening to maximise protection Even if immunised, anyone with a ______ still needs to be offered cervical screening
HPV HPV pre-invasive cancer vaccination cervix
52