Cervix Flashcards
What is the transformation zone of the cervix?
At the opening of the cervix (os), squamous lining transitions to glandular lining.
ACidic environment of vagina causes glandular cells to be replaced by squamous cells through metaplasia.
What is the main cause of cervical canecer and why?
HPV - transformation zone is at high risk of HPV infection.
Which HPV subtypes are clinically important?
Type 16 and 18 = high risk of cervical cancer
Type 6 and 11 = most common low risk tpyes of HPV
What is the pathogenesis of HPV?
Integration of HPV into cell DNA: Expression of viral E6 and E7 genes
These genes cause degradation of p53 pathway.
What subtypes are associated with genital warts?
HPV subtypes 6 and 11
3 grades of dysplasia?
CIN1 - Atypia and low grade dysplasia involving basal third of epithelium
CIN2 - Atypia and expansion of dysplasia into middle third of epithelium
CIN3 - Diffuse atypia, expansion of dysplasia through to epithelial surface
What types of cervical cancer and their prevalence?
Squamous cell carcinoma - 80%
Adenocarcinoa - 15%
Two classifications of cervical squamous cell cancer
LSIL - Low grade squamous intraepithelial lesion: CIn1
HSIL - High grade squamous intraepithelial lesion: CIN2 or CIN3
Treatment options for cervical dyplastic lesions or cancer?
- Surgically remove lesion with hot loop of wire: LLETZ or cone
- Hysterectomy
- Chemo/radiotherapy
What is the HPV vaccine?
Is it directly protective against cervical cancer?
Gardasil 9: Covers type 6, 11, 16 and 18.
Not directly protective against cervical cancer - just prevents major risk factor: HPV
What is the screening program for cerivcal cancer?
Why is cervical screening so effective?
Cervical screening test - CST
- Every 5 years
- Ages 25 - 74
- Safe to do so far apart, as most cervical cancers are caused by HPV and it takes 10-15 years for it to result in cancer
