Cervical Screening Flashcards
What will this deck cover:
The origins of cervical cancer and the process of HPV -> Cancer
The british cervical screening programme
A bit about Cervical cancer and its management
What are the risk factors for cervical cancer?
Early age of 1st intercourse Multiple partners Prolonged oral contraceptive use Smoking STIs Immunodeficiency Persistant infection Age (Peaks at 45-55yrs)
MOST IMPORTANT IS HPV types 16 & 18
What types of cancer are caused by Types 16 & 18 HPV?
Most cervical and anal cancers 40% of penile & vaginal cancers 12% oropharyngeal 3% mouth (Dont bother learning the numbers just know almost all cervical cancers are due to HPV)
How does HPV lead to cancer?
So HPV infection causes abnormal growth of squamous cells aka Squamous Intraepithelial Lesion (SIL)
Which can progress to Cervical Intraepithelial Neoplasia (CIN), an abnormal proliferation & disarray of cells in the epithelium
This can then progressive to invasive cancer
How do we grade CIN?
1-3 based on proportion of affected cervix
CIN3 only progresses to cancer in 20-30% of untreated cases
How do we prevent HPV infections?
A secondary school immunisation programme for girls.
It’s now a 2 dose regime.
What is the aim of cervical screening?
To pick up PRE-CANCEROUS disease, essentially CIN
The whole point is to get there before it becomes cancerous
Describe the process of cervical screening, from smear to results
Smear taker enters request onto Scottish Cervical Call Recall System (SCCRS)
Lab tests virals and puts
results on SCCRS database
GP & women receive results
1) If HPV negative: come back in 5 yrs
2) If HPV positive:
- Cytology normal: come back in 1 year
- Cytology abnormal:colposcopy referral
How often do you get a cervical smear?
3yrly from age 25-50, then 5yrly after that
What method do we use to test for cervical abnormality?
Liquid based Cytology (LBC)
We take smears from the “transformation zone”, i.e. where the endocervical glandular epithelium becomes squamous cells
We also test the cells for HPV
Why do we call them PAP smears?
Cos a thin layer of cells is stained on a slide used the Papnicolaeou method
The lab looks for nuclear abnormalities in the cells called “Dyskariosis”, what are these abnormalities?
- Increased size & nuclear:cytoplasmic ratio
- Varied shape, size & outline of nuclei
- Coarse irregular chromatin
- Nucleoli
What are the possible results from a PAP smear?
- Normal so come back in 3yrs
- Borderline Nuclear Abnormalities (BNA) aka low grade dyskariosis = test HPV (+ve colposcopy, -ve return to normal programme)
- High grade dyskaryosis - colposcopy
What is colposcopy?
We use magnification and a light to see the cervix Then use Acetic acid +/- iodine to: - Identify lesions - Select biopsies - Define area to treat
So Astrid’s been flagged up on smear and gone for colposcopy which showed up a lesion, how do we test it?
Punch biopsy:
If its CIN 2 or 3 we will treat
