HIV and pre-neoplastic and neoplastic lesions of the cervix in South Africa: a case-control study

Background: Cervical cancer and infection with human immunodeficiency virus ( HIV) are both major public health problems in South Africa. The aim of this study was to determine the risk of cervical pre-cancer and cancer among HIV positive women in South Africa. Methods: Data were derived from a case-control study that examined the association between hormonal contraceptives and invasive cervical cancer. The study was conducted in the Western Cape ( South Africa), from January 1998 to December 2001. There were 486 women with invasive cervical cancer, 103 control women with atypical squamous cells of undetermined significance ( ASCUS), 53 with low-grade squamous intraepithelial lesions ( LSIL), 50 with high-grade squamous intraepithelial lesions ( HSIL) and 1159 with normal cytology. Odds ratios ( OR) and 95% confidence intervals ( CI) were calculated using multiple logistic regression. Results: The adjusted odds ratios associated with HIV infection were: 4.4 [ 95% CI ( 2.3-8.4) for ASCUS, 7.4 ( 3.5-15.7) for LSIL, 5.8 ( 2.4-13.6) for HSIL and 1.17 ( 0.75-1.85) for invasive cervical cancer. HIV positive women were nearly 5 times more likely to have high-risk human papillomavirus infection ( HR-HPV) present compared to HIV negative women [ OR 4.6 ( 95 % CI 2.8-7.5)]. Women infected with both HIV and high-risk HPV had a more than 40 fold higher risk of SIL than women infected with neither of these viruses. Conclusion: HIV positive women were at an increased risk of cervical pre-cancer, but did not demonstrate an excess risk of invasive cervical cancer. An interaction between HIV and HR-HPV infection was demonstrated. Our findings underscore the importance of developing locally relevant screening and management guidelines for HIV positive women in South Africa.