Context: Women infected with human immunodeficiency virus (HIV) are at increased risk for cervical squamous intraepithelial lesions (SILs), the precursors to invasive cervical cancer. However, little is known about the causes of this association.
Objectives: To compare the incidence of SILs in HIV-infected vs uninfected women and to determine the role of risk factors in the pathogenesis of such lesions.
Design: Prospective cohort study conducted from October 1,1991, to June 30, 1996.
Setting: Urban clinics for sexually transmitted diseases, HIV infection, and methadone maintenance.
Participants: A total of 328 HIV-infected and 325 uninfected women with no evidence of SILs by Papanicolaou test or colposcopy at study entry.
Main outcome measure: Incident SILs confirmed by biopsy, compared by HIV status and risk factors.
Results: During about 30 months of follow-up, 67 (20%) HIV-infected and 16 (5%) uninfected women developed a SIL (incidence of 8.3 and 1.8 cases per 100 person-years in sociodemographically similar infected and uninfected women, respectively [P<.001]). Of incident SILs, 91% were low grade in HIV-infected women vs 75% in uninfected women. No invasive cervical cancers were identified. By multivariate analysis, significant risk factors for incident SILs were HIV infection (relative risk [RR], 3.2; 95% confidence interval [CI], 1.7-6.1), transient human papillomavirus (HPV) DNA detection (RR, 5.5; 95% CI, 1.4-21.9), persistent HPV DNA types other than 16 or 18 (RR, 7.6; 95% CI, 1.9-30.3), persistent HPV DNA types 16 and 18 (RR, 11.6; 95% CI, 2.7-50.7), and younger age (<37.5 years; RR, 2.1; 95% CI, 1.3-3.4).
Conclusions: In our study, 1 in 5 HIV-infected women with no evidence of cervical disease developed biopsy-confirmed SILs within 3 years, highlighting the importance of cervical cancer screening programs in this population.