Cervical screening, cancer and HPV Flashcards
(57 cards)
Which virus is commonly associated with cervical cancer?
HPV = Human papillomavirus
What is the peak prevalence of HPV in terms of age?
15-25 years old
- Prevalence declines with age however.
- Overall prevalence is 10%
- Lifetime exposure is up to 75% from serological studies
Within men which types of cancers can be caused by HPV?
> Penis = 40% cases are caused by HPV
Anus = 90% of cases are caused by HPV
Mouth = 3% cases are caused by HPV
Oropharynx = 12% cases caused by HPV
Within women which types of cancers can be caused by HPV?
> Cervix = 99% of cases caused by HPV > Vulva/Vagina = 40% cases are caused by HPV > Anus = 90% of cases are caused by HPV > Mouth = 3% cases are caused by HPV > Oropharynx = 12% cases caused by HPV
Where can abnormal growth of squamous cells be detected on smear?
The transformation zone, changes are called squamous intraepithelial lesions and can be graded low or high 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 what?
Cervical intraepithelial neoplasia (CIN). Graded 1 to 3 according to the proportion of cervix affected.
What is considered CIN I? How is this managed?
When <1/3rd of the thickness of the epithelium is involved
Mild dyskaryosis
1) Perform HPV testing (Cervical cytology)
2) If positive colposcopy within 8 weeks
3) If negative, repeat screen in 3-5 years
What is considered CIN II? How is this managed?
When <2/3rd of the thickness of the epithelium is involved
Moderate dyskaryosis
Urgent colposcopy within 2 weeks
What is considered CIN III? How is this managed?
Almost entire epithelium is involved, this is rarely reversible
Severe dyskatyosis
Urgent colposcopy with punch biopsy within 2 weeks
If after cervical screening there is changes what is the next step?
HPV serology
If there is a positive HPV serology what is the next step?
Colposcopy
- if low grade (CIN I) within 8 weeks
- if high grade CIN II within 2. weeks, CIN III requires bunch biopsy
What percentage of patients with CIN 1 will regress in patients aged 15-34 yrs old?
> 65%
What percentage of patients with CIN 1 will regress in patients aged >35 yrs old?
40%
Which forms of HPV commonly cause cervical cancer?
High risk:
> 16, 18, 31 and 33.
> With 16 and 18 causing 70% of cervical cancers in Europe
Low risk:
> 6 and 11
At CIN 2/3 at biopsy what percentage of patients will go onto develop cervical carcinoma?
40%
What is the prevention protocol now?
UK HPV Immunisation Programme:
1st 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
What is LBC?
Liquid based cytology
Hybridisation of PCR is usually used which allows identification of high risk types of HPV (16, 18, 31 and 33)
Which type of epithelium is present within the endocervix?
Columnar epithelium
Which type of epithelium is present within the ectocervix?
Squamous epithelium
How many samples show mild dyskaryosis (CIN I)?
Of satisfactory smears, around 6% will show mild dyskaryosis or borderline nuclear abnormalitiy (BNA) due to HPV features or very minor abnormalities
How many samples show moderate dyskaryosis (CIN II) or sever dyskaryosis (CIN II)?
1.5%
What forms the transition zone?
It is where the columnar epithelium of the endocervix meets the squamous epithelium of the ectocervix
What is an abnormal cytology of the cervix called? Nuclear features?
Dyskaryosis
Nuclear features: > Increased size and nuclear:cytoplasmic ratio > Variation in size, shape and outline > Coarse irregular chromatin nucleoli
What are the nuclear features in dyskaryosis?
Nuclear features: > increased size and nuclear:cytoplasmic ratio > Variation in size, shape and outline > Coarse irregular chromatin nucleoli
