VIA and Cervical Cancer Flashcards
How common is cervical cancer?
- 4th most common cancer among women globally
- 2nd most common in Africa
Where is cervical cancer located?
85-90% located at Squamocolumnar junction
Incidence of cervial cancer in Malawi?
Incidence: 72/100,000
Mortality: 54/100,000
5-year survival rate 2.9%
(Uganda 17.7%, Zimbabwe 26.5%)
Cervical cancer accounts for almost 20% of cancers in woman in LIC, in Malawi over 40%!
Incidence of cervical cancer in the world?
Worldwide 660,000 cases/year of which 53% dies
Why is cervical cancer worse in LMIC?
- HIV-prevalence (Malawi 12% women HIV+)
- Lack of access to national HPV-vaccination, cervical screening and treatment services (Malawi 2020 only 10% screened)
- Socio-economic determinants
Describe the anatomy of the cervix?
- The endocervix is composed of a thin secretory glandular epithelium.
- The ectocervix consists of a stronger stratified squamous epithelium.
- Ectropion mainly in early adulthood
Pathophysiology of cervical cancer?
Transformation zone has high mitotic activity, so vulnerable to HPV-driven neoplastic change if persistent infection
- glandular epithelium pushed out in to ectocervix (u.i.o. estrogen) and undergoes physiological squamous metaplasia (u.i.o. low pH)
- Occurs in 80% of premenopauzal women
- Becomes endocervical in PMP women)
How HPV causes cervical cancer?
HPV-viruses suppress p53 and rBp.
1. P53: This protein acts as a tumor suppressor, which means that it regulates cell division by keeping cells from growing and dividing (proliferating) too fast or in an uncontrolled way.
2. rBp (retinoblastoma protein): prevent excessive cell growth by inhibiting cell cycle progression until a cell is ready to divide.
The 4 major steps in cervical cancer development are?
- oncogenic HPV infection of the epithelial cells at the cervical transformation zone
- persistence of the HPV infection
- progression of a clone of epithelial cells from persistent viral infection to pre cancer cells
- development of carcinoma and invasion through the basement membrane
What is cervical intraepithelial neoplasia?
- CIN will always develop prior to the cervical cancer and only arises due to oncogenic HPV-infection!
- So no cervical cancer without hrHPV.
- Untreated high grade CIN (2 or 3) leads to cervical cancer in 20-30% of women over 10 years.
Main cause of cervical cancer?
- Hr-HPV detected in 99.7% of cervical cancer cases
> HPV-16 and HPV-18 found > 70% of the cases.
> Other hr-HPV: 6, 11, 31, 33, 45, 52, 58. - Increase the risk of cancer via DNA changes: Suppress p53 & Rb1 genes
- Usually cleared asymptomatically for most people.
Risk factors for contracting HPV?
- Early onset of sexual activity
- Multiple sexual partners
- Having a high risk sexual partner
Relationship between HPV and HIV?
HIV increases the risk of contracting HPV
1. Higher prevalence of HPV infection
2. Tend to have persistent infection with HPV
3. Tend to have infection with multiple types of HPV
Note: Cervical cancer is an AIDS defining illness in HIV infected women
Risk factors for cervical cancer?
- HPV
- HIV
- History of STI
- Immunosuppression (h/o transplant)
- Early age of 1st birth (<20 years)
- Parity greater than 3
- History of vulvar/vaginal cancers (HPV related)
- Low socioeconomic status
- Oral contraceptive use
- Cigarette smoking (reduces viral clearance)
Signs and symptoms of cervical cancer?
Usually asymptomatic in the early stages → need for screening!
1. Unusual/abnormal vaginal bleeding
- post coital, intermenstrual, post menopausal
2. Abnormal vaginal discharge (AVD)
- foul-smelling, ↑ quantity, change in texture +/- blood
3. Vaginal dyscomfort
4. O/E: roughened/hard cervix, los of fornices / fixed cervix
Diagnosis?
Part of routine screening for cervical cancer:
1. HPV-DNA Testing
2. Visual Inspection with Acetic Acid
3. Papanicolaou Smear (PAP Smear) = cytology
4. Colposcopy