Abstract B15: Distribution of HPV genotypes in cervical intraepithelial lesions and cervical cancer in Tanzanian women

Abstract

Abstract Context: Cervical cancer incidence is four times higher in eastern and southern Africa than in North America and Europe. Infection with human papillomavirus (HPV) is associated with low-grade (LGSIL) and high-grade (HGSIL) intraepithelial lesions of the uterine cervix, and high-risk (HR) HPV DNA is detected in almost all invasive cervical cancers (ICC). Although vaccine development will rely on knowledge of HPV genotypes characteristic in HSIL, LSIL and cancer in different populations, these genotypes remain uncharacterized in African populations. Objective: To describe HPV genotype distribution in women living in Northeastern Tanzania. Methods: 215 study participants were recruited from the Reproductive Health Clinic at Kilimanjaro Christian Medical Center (KCMC). Cervical scrapes were used to grade cervical intraepithelial neoplasia (CIN). These specimens were used to detect HPV infection for 60 genotypes. Proportions were determined and ranked. Results: Of 215 women identified from the KCMC, 79 (36.7%) were HPV-positive (20 had no evidence of cytological abnormality, 12 had CIN1, 14 had CIN2–3, and 33 had cervical cancer). Overall, 31 HPV genotypes were detected, and multiple HPV infections were more common than single infections in CIN and ICC. The prevalence of HPV infection increased with lesion grade (14% in controls, 66% in CIN1 cases, 87% in CIN2/3 and 89% in ICC). Whereas in ICC, the three most common genotypes were HPV16, 35/45/6, and 18/73, the most common genotypes in CIN2–3 were HPV53, 58 and 84/83, and in CIN1 they were HPV35, 45, 53/58/59. Among controls, the most prevalent genotype was HPV58 with HPV 16, 35, 52, 66 and 73 occurring equally. Restricting analyses to HIV-negative women revealed that HR-HPV genotypes are most frequent in ICC. Conclusions: While small sample size limits interpretation, these findings suggest HPV genotypes other than 16 and 18 may drive cervical cancer risk in this region. The low frequency or absence of HPV 16 and 18 in CIN1 or CIN2–3 has implications for current cytology and HPV-based screening as well as for vaccine development for this region. Larger studies are required. Citation Information: Cancer Prev Res 2011;4(10 Suppl):B15.