INTRODUCTION: CERVICAL CANCER SCREENING

1. INTRODUCTION:CERVICAL CANCER SCREENING

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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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