Cervical cancer & screening Flashcards
what is CIN?
disordered growth & development of epithelial cells lining the transformation zone
aetiology of CIN?
HPV infection (16 & 18) most common cause
who is vaccination for and for what subtypes?
- >12 years old
- for subtypes 6,11, 16 & 18
what else is HPV infection linked to?
anal, vaginal, throat, mouth, penis and vulval cancer
how does HPV work?
infects cells and inhibits tumour suppressor genes p53 and pRb
how is HPV transmitted?
sexually
where is smear test taken from and why
- transition zone of cervix & squamous epithelium of ectocervix
- because this is where HPV infects
outline the screening programme
what happens during colposcopy?
- magnification w light to see cervix
- use acetic acid and iodine to stain
- cone biopsy may be taken for degree of CIN
every how often do women participate in screening?
- 25-49–> every 3 years
- 50-65–> every 5 years
what other indications are there for referral to colposcopy? (apart from dyskaryosis on smear)
- 3 consecutive inadequate smear samples
- 3 borderline smears (squamous)
describe CIN I-3
- CIN1
- Mild dysplasia, affects lower 1/3 of cervical epithelium
- CIN2
- moderate dysplasia, affects lower 2/3 of cervical epithelium
- CIN3
- severe dysplasia, affects full thickness of cervical epithelium ie carcinoma in situ
treatment options for CIN 1-3?
- CIN1
- likely to return to normal w/o treatment - conservative Mx
- CIN 2/3
- 2- likely to progress to cancer w/o treatment
- 3-will progress to cancer if untreated
- both treated w LLETZ
cervical cancer epidemiology?
- young women in peak reproductive years
- elderly women (80s)
histological types?
80% squamous cell carcinoma, 20% adenocarcinoma
