Cervical Screening Flashcards
What percentage of cervical cancers are HPV-related?
> 99%
What other cancers can be caused by HPV than cervical?
- Penis
- Vulva/vagina
- Anus
- Mouth
- Oropharynx
How are HPV immunisations given in the UK?
The UK HPV immunisation schedule currently involves a quadrivalent vaccine against HPV 16, 18, 6 and 11. This increased in 2012 from a bivalent vaccine against HPV 16 and 18
How are screening samples for cervical cancer taken?
- Women aged 25-64 years
- 5 yearly smears
- Liquid Based Cytology (LBC)
- Test for high risk HPV
- If positive; triage with cytology
What is abnormal cytology of the cervix known as?
Dyskaryosis
What are the cytological features of dyskaryosis?
- Increased size and nuclear:cytoplasmic ratio
- Variation in size, shape and outline
- Coarse irregular chromatin
- Nucleoli
What steps need to be taken after cervical screening testing?
- Negative- recall at routine five years
- Positive for hrHPV but normal cytology- repeat test after one year
- Dyskaryosis- refer for colposcopy
What is involved in colposcopy?
- Magnification and light to see cervix
- Exclude obvious malignancy
- Use of acetic acid =/- Iodene to identify the limits of lesion, select the biopsy site or define area to treat
What are the options for management during colposcopy?
- Punch biopsy to make a diagnosis
- Return for Treatment if CIN2/3
- “See and treat” at first visit
How does HPV infection affect the cervix?
HPV infects the basal layer of the transformation zone, utilising the host for reception. As the host cell matures, different viral genes are expressed
What are the high risk types of HPV?
16, 18, 31 and 45
How does HPV infection cause CIN?
HPV causes high risk CIN as a result of persistent infection causing the following processes:
•Viral DNA integrates into host cell genome
•Overexpression of viral E6 and E7 proteins
•Deregulation of host cell cycle
How is CIN graded?
- CIN 1: low grade dysplasia–will regress
- CIN 2: moderate dysplasia – may regress
- CIN 3: severe dysplasia – unlikely to regress
How is CIN treated?
LLETZ, thermal coagulation or laser ablation
Why should treatment of CIN be followed up?
- Confirm effectiveness of treatment
- Prevent invasive cancer
- Reassure patient
- Increased risk of cervical cancer