Prevalence of pre-cancerous lesions and cervical cancer in South Africa--a multicentre study

Abstract

Objectives: To describe the age-specific prevalence rates of cancer of the cervix in South African women presenting for screening.

Design: A multicentre prevalence survey in 10 geographically defined areas following a common core protocol. Services were located in existing service sites, with the exception of KwaZulu-Natal which used a mobile service. Women aged 20 years and above were eligible for inclusion.

Outcome measures: Age-specific cervical cytologically diagnosed abnormality rates according to the Bethesda classification.

Results: During the study 20,603 women participated. Eighty per cent of the sample had never had a Pap smear before and just over 91% had not had a Pap smear in the last 5 years. In this study population 468 women screened (2.42%) were found to have low-grade squamous intra-epithelial lesions (LSIL) and the average age of these women was 33.1 years; 366 (1.8%) had high-grade SIL (HSIL) and these women were statistically significantly older at 37.97 years of age; and 92 women (0.47%) were found to have cytologically diagnosed invasive cancer. These women were significantly older, with an average age of 51.3 years. A clear relationship was found between age and LSIL, with younger women having a high rate of LSIL which decreases with increasing age. A similar but inverse relationship between age and invasive cancer is described, with the rate being low in young women and increasing with increasing age. A clear relationship between HSIL and age is not described in these data. The adequacy rate (satisfactory and satisfactory but limited) of the slides was 95%, and just under 92% of the study sample received their results. Not all women were appropriately referred and it was not possible to assess if women referred for treatment received it.

Conclusions: These data indicate that cancer of the cervix is a common disease and that, similar to other countries, it is a disease of older women. These data give some positive indicators for future screening--older women will present for screening and the majority of women received their results. However, improvements in health system functioning are needed. A uniform national cytology reporting system is required as well as clear guidelines for providers on what action to take based on cytology reports. Linkage between the site of screening and treatment centre is inadequate and requires urgent attention in order to decrease cervical cancer mortality.