L28 Cervical Cancer Flashcards
Two parts of cervix and cell type
Endocervix - columnar epithelium
Ectocervix - stratified squamous epithelium
Where do the two parts of the cervix meet
transformation zone
continually regenerated
squamous epithelium
most common site of neoplastic changes
Most common cause of cervical cancer
HPV viruses 16 and 18
Characteristics of HPV
retrovirus (reverses usual pattern of genome by producing own DNA)
single strand of RNA
host treats virus as its own
spread through direct sexual contact
What do HPV E6 genes do
inactivate p53 (tumour suppressor gene)
What do HPV E7 genes do
binds and inactivates Rb = DNA replication
Pathogenesis of cervical cancer
HPV infection
viral persistence
progression to dysplastic changes
development of invasive cervical cancer
Risks
early age of first intercourse
multiple sexual partners or partners of high risk
smoking
oral contraceptives
Symptoms
early: undetected
late: abnormal vaginal bleeding, bleeding after intercourse, dysuria
progression
can spread to surrounding tissue
primary prevention
Gardasil vaccine
against types 16 and 18
three doses before age of first intercourse
secondary prevention
pap smear
detects dysplasia or neoplasia
What is low grade squamous intraepithelial lesion
likely to regress without treatment
What is high grade squamous intraepithelial lesion
more likely to have cervical cancer
