Cervical Screening Symposium Flashcards
What virus is associated with cervical cancer?
HPV
What is the incidence of HPV?
- Peak prevalence 15-25yrs
- Prevalence declines with age
- 10% overall
- ~30% prevalence in young women
- Lifetime risk of exposure up to 75% from serological studies
What cancers does HPV have an association with?
- Cervical
- Anus
- Penis
- Vulva/vagina
- Oropharynx
- Mouth
What is a squamous intraepithelial lesion?
An abnormal growth of squamous cells detectable on smear
What are abnormal cells in the cervix detected by biopsy and histological examination classified as?
Cervical intraepithelial neoplasia (CIN) and is graded 1-3
What types of HPV is associated with cervical cancer in Europe?
Types 16 and 18
What are the possible outcomes of CIN1?
- Regression
- Remain unchanged
- Progression to CIN2, CIN 3 or cervical cancer
What is the UK HPV immunisation programme?
- Introduced in September 2008 and developed since
- Offered to girls born after 1 September 1990
- Currently a 2 dose regime
What are the steps in the Scottish Cervical Call Recall System?
- Smear taker enters request details onto SCCRS database
- Vials sent to lab receipt logged on SCCRS
- Patient details received from SCCRS, vials processed, slides stained and screened
- Cytology lab results put on SCCRS database
- Woman and GP receive results
What is the cervical screening programme in Scotland?
- Women aged 25-64 years
- 5 yearly smears
- Liquid based cytology
- test for high risk HPV
- If positive, triage with cytology
What is an HPV test?
- Molecular test on cells sampled from cervix
- Identifies high risk type HPV viral DNA or RNA
- Any high risk type leads to type specific genotyping
- Works on LBC samples
- Technology used includes hybridisation and PCR
What is cervical cytology?
- Microscopic assessment of cells scraped from the transformation zone
- Look for abnormal cells (dyskaryosis)
- Indicate that woman has underlying cervical intraepithelial neoplasia - CIN
Currently all smear samples but from 2020 only HPV +ve
What type of epithelium is found in the endocervix?
Columnar epithelium
What type of epithelium is found in the ectocervix?
Stratified squamous epithelium
What type of epithelium is find at the transformation zone of the cervix?
Squamo-columnar junction
How are cervix cells stained?
Stained by Papinicolaou method
What is dyskaryosis?
Abnormal cells showing the earliest signs of malignancy in its nucleus whilst retaining relatively normal cytoplasm
What are the nuclear features of dyskaryosis?
- Increased size and nuclear:cytoplasmic ratio
- Variation in size, shape and outline
- Coarse irregular chromatin
- Nucleoli
How is dyskaryosis graded?
Graded low or high grade dyskaryosis - reflects degree of underlying CIN
- Low grade (+ borderline)
- High grade
What do loilocytes reflect?
HPV infection
What does HPV test identify?
HPV infection (could be transient or CIN associated)
What does cytology identify?
Cellular changes
- Low grade (persisting infection/CIN1)
- High grade (CIN2/3)
What happens if a cervical smear is hrHPV is negative?
Routine recall in 5 years
What happens if a cervical smear is hrHPV is positive?
- Cytology normal; repeat test 1 year
- Dyskaryosis: refer to colposcopy
What is colposcopy?
-Magnification and light to see cervix
-Exclude obvious malignancy
0Use of acetic acid =/- Iodene: to identify lesion limits, select biopsy site and define area to treat
What are the options for management of dyskaryosis?
- Punch biopsy to make a diagnosis and can return for Treatment if CIN2/3
- Or “See and treat” at first visit
What HPV related pathology can affect the transformation zone of the cervix?
- HPV infection
- Precancerous changes cervical intraepithelial neoplasia (CIN)
- Cervical carcinoma
How does HPV infection affect the transformation zone of the cervix?
-Infects basal layer cells
-Utilises host for replication
-As host cell matures,
different viral genes expressed
What does the E7 protein product do?
Prevents cell cycle arrest
What does the E6 protein product do?
Inhibits cell death
What is koilocytosis?
- Cells with wrinkled nucleus and perinuclear halo
- Multinucleation
What are the low risk types of HPV?
6, 11, 42, 44, others
What are the high risk types of HPV?
16, 18, 31, 45, others
How do low risk types of HPV present?
- Genital warts and low grade CIN
- Often transient and resolve
How do high risk types of HPV present?
- Persistent infection increases risk of developing
- High grade CIN and(more rarely) cancer
How does HPV cause high grade CIN?
Persistent infection
- Viral DNA integrates into host cell genome
- Overexpression of viral E6 and E7 proteins
- Deregulation of host cell cycle
How does CIN present histologically?
- Disorganised proliferation of abnormal cells in squamous epithelium (dysplasia)
- Lack of maturation, variation in cellular size and shape, nuclear enlargement, irregularity, hyperchromasia, cellular disarray
What is CIN a precursor of?
Invasive cancer
How is CIN treated?
- LLETZ
- Thermal coagulation
- Laser ablation
Why is CIN followed up after treatment?
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
- More at risk than the normal population
To reassure the woman
How is CIN followed up after treatment?
Follow-up LBC at 6 months for cytology and high risk HPV
- Both negative – return to recall
- Either positive – return to colposcopy
What is the incidence of cervical cancer?
- 2500 cases per year in UK
- 1200 deaths
- 10th commonest cancer in women in Scotland
- Good cure rate if detected early
- BUT major cause of death in in women in developing countries
What are the risk factors for cervical cancer?
- Peak age 45-55 years
- HPV relayed (16+18)
- Multiple partners
- Early age at first intercourse
- Older age of partner
- Cigarette smoking
What are the symptoms of cervical cancer?
- Abnormal vaginal bleeding
- Post coital bleeding
- Intermenstrual bleeding/PMB
- Discharge
- (Pain)
How is cervical cancer diagnosed?
- Clinical
- Screen detected
- Biopsy
What is the histology of cervical cancer?
Tumour cells from epithelium invade into underlying stroma
- Majority squamous carcinoma (80%)
- Adenocarcinoma (endocervical) rising in relative incidence
What is stage 1A cervical cancer?
Invasive cancer identified only microscopically
What is stage 1B cervical cancer?
Clinical tumours confined to the cervix
How can cervical cancer spread?
Local
- Stage 2: Vagina (upper 2/3),
- Stage 3: lower vagina, pelvis,
- Stage 4 bladder, rectum
Metastases
- Lymphatic: pelvic nodes
- Blood: liver, lungs, bone
How is cervical cancer staged?
- EUA (especially rectal)
- PET-CT
- MRI
How is stage 1a1 cervical cancer treated?
Stage 1a1:
-Type 3 Excision of the cervical TZ or hysterectomy
What is a radical hysterectomy?
Removal of
- Uterus, cervix, upper vagina
- Parametria
- Pelvic nodes
Ovaries conserved
How is stage 1b-11a cervical cancer treated?
Stage 1b - 11a:
-Radical hysterectomy or chemo-radiotherapy
How is 11b-1v cervical cancer treated?
Stage 11b - 1V:
-Chemo-Radiotherapy
What treatments are available for cervical cancer?
- Radiotherapy- External Beam x 20 fractions
- Chemotherapy- 5 cycles of cisplatin
- Caesium Insertion (24 hours)
