A survey on the prevalence of high-risk subtypes of human papilloma virus among women with cervical neoplasia in Isfahan University of Medical Science

Abstract

Given the importance of epidemiological studies on the prevalence of human papilloma virus (HPV) and its subtypes to plan more effective strategies for cervical cancer prevention, the aim of this study was to determine the prevalence of HPV in women with cervical intraepithelial neoplasia and cancer in Isfahan. In this descriptive cross-sectional study, women referred to oncology clinic of Shahid Beheshti Hospital because of abnormal cytology of their cervices within the last year were studied. The 2001 Bethesda system was used for histologic classification. The distribution of different pathologies was as follows: squamous cell carcinoma (SCC) 34.7%, low-grade squamous intraepithelial lesions (LSIL) 30.5%, high-grade squamous intraepithelial lesions (HSIL) 22.8%, atypical squamous cell of undetermined significance (ASCUS) 8.4%, and adenocarcinoma (AC) 3.3%. There was no case of atypical glandular of undetermined significance or cases of adenocarcinoma associated with an early lesion. The presence of HPV infection and its subtypes including HPV 16, 18, 6 and 11 was assessed in different cytological categories of cervical neoplasia, by using polymerase chain reaction method. During this study, 130 patients were studied. Their median age was 52 years (range 29-73 years). HPV was detected in 118/130 patients (90.8%) with abnormal cervical cytology. The prevalence of positive HPV samples was 97.6, 80, 93.1, 92.3, and 66.6% in cases with SCC, AC, HSIL, LSIL, and ASCUS, respectively (P < 0.05 between SCC and ASCUS, HSIL and ASCUS, and LSIL and ASCUS). Out of 118 cases with positive HPV, 98 (83.1%) were positive for multiple HPV types 16, 18, and 11 or 6. The distribution of studied HPV subtypes among women with positive HPV was as follows: 49.1% for both types 16 and 18, 10.1% for type 16, 1.69% for type 18 and 22% for type 11 or 6. The prevalence of HPV type 16 was not significantly different in various cytological categories of cervical neoplasia (P > 0.05). The prevalence of HPV type 16 and 18 was significantly higher than the HPV type 11 or 6 in cervical neoplastic lesions (P < 0.05). The results of this research indicated the high prevalence of HPV infection in all categories of cervical neoplasia. This emphasizes the importance of HPV screening and vaccination programs. In order to assess more effective screening programs in Isfahan and evaluate the cost-effectiveness of vaccination programs, further population-based prospective studies are required.