Cervical cancer screening and prevention

1. INTRODUCTION:
CERVICAL CANCER SCREENING

2. 2
Magnitude of the Problem
 Third most common cancer in women
 Affects 1.4 million women worldwide
 Each year, 460,000 new cases occur
 Each year, 231,000 women die of the disease
 About 80% of new cases are in developing
countries

3. 3
Background
 99.7% of cervical cancers directly linked to previous
infection with human papillomavirus (HPV)
 Of more than 50 types of HPV that infect genital
tract, 15–20 types linked to cervical cancer
 Four of these types are most often detected in
cervical cancer
 HPV infections often cause no symptoms
 Most common signs of infection are small pink or
red warts, itching and burning in genital area

4. 4
Background (cont.)
After woman becomes infected with HPV:
 Infection may remain stable
 Infection may regress spontaneously
 If cervix infected, may develop into low-grade
squamous intraepithelial lesions (LGSILs), also
called mild cervical intraepithelial neoplasia (CIN
I) or early dysplasia

5. 5
Background (cont.)
For every 1 million women affected, 10% (100,000) will
develop precancerous changes in cervical tissue:
 These changes are usually in women ages 30–40
 About 8% of these women will develop precancer
limited to outer layers of cervix (carcinoma in situ)
(CIS)
 About 1.6% will develop invasive cancer unless CIS
detected and treated

6. 6
Background (cont.)
 Progression to cervical cancer from high-grade
squamous intraepithelial lesions (HGSILs)
usually occurs over 10–20 years
 Although rare, some precancer lesions become
cancerous within a year or two

7. 7
HIV/AIDS, HPV Infection, and
Cervical Cancer
 39.5 million people living with HIV/AIDS in
2006; almost half women
 Heterosexual contact main mode of
transmission in new cases
 In HIV-infected women:
 HPV detected more frequently; resolves more
slowly
 HPV-associated diseases more difficult to treat
 Progression of precancer accelerated

8. 8
HIV/AIDS, HPV Infection, and
Cervical Cancer (cont.)
 Cervical cancer screening important in this
population
 Where HIV endemic, 15–20% women positive
for precancer
 Cervical squamous cell cancer now an
“AIDS-defining illness”
 Antiretroviral drugs improve quality of life;
effect on progression of precancer not known

9. 9
Risk Factors for HPV and
Cervical Cancer
 Sexual activity before age 20
 Multiple sexual partners
 Exposure to sexually transmitted infections (STIs)
 Mother or sister with cervical cancer
 Previous abnormal Pap smear
 Smoking
 Immunosuppression
 HIV/AIDS
 Chronic corticosteroid use

10. 10
Age-Related Changes
in the T-Zone: Puberty
Columnar cells (red
in appearance) are
gradually replaced
by squamous
cells (pink in
appearance). This is
a slow process and
continues
throughout the
reproductive years.

11. 11
Preventing Cervical Cancer
 Preventing HPV infection will prevent cervical
cancer
 No conclusive evidence that condoms reduce
the risk of HPV infection, although they may
provide some protection against HPV-associated
diseases

12. 12
Primary Prevention:
Development of a Vaccine
 A vaccine would be the most effective way to
prevent cervical cancer
 Vaccine would protect woman against only some
types of HPV
 Vaccine would need to contain mixture of virus
types
 At least two vaccines currently being tested

13. 13
Secondary Prevention
 Women already infected should be
screened to determine whether they have
early, easily treatable precancerous lesions
 Pap smear is most well-established
screening method
 Other screening methods:
 Visual screening
 HPV tests
 Automated cytology screening
 Pap smear, with its many steps, is
problematic in low-resource settings

14. 14
Screening: Visual Inspection with Acetic
Acid (VIA)
 VIA is at least as effective as Pap smear in
detecting disease
 VIA has fewer logistic and technical constraints
 Studies in South Africa, India and Zimbabwe in
1990s showed VIA as a good alternative to Pap
smear
 Later studies confirmed that VIA is viable option
for screening in low-resource settings

15. 15
Value of VIA in Low-Resource Settings
 Can effectively identify most precancerous lesions
 Is non-invasive, easy to perform and inexpensive
 Can be performed by all levels of health care
workers in almost any setting
 Provides immediate results that can be used to
inform decisions and actions regarding treatment
 Requires supplies and equipment that are readily
available locally

16. 16
Links to Other Reproductive Health Services
 Linking cervical cancer screening and treatment
to other services is essential and logical
 These services are usually separate, leaving
women without access to care and contributing
to women’s poor health status
 Cervical cancer prevention must be integrated
with existing reproductive health care services

17. 17
Links to Other Reproductive Health Services
(cont.)
 District-based implementation of interventions
will ensure that health services are available
close to where people live
 Nurse or midwife who works in the community is
usually the best person to provide community-
based, appropriate, safe and cost-effective care