Prevalence of Human Papillomavirus (HPV) Genotypes and Multiple Infections in Routine Cervical Cancer Screening in a Spanish Regional Population

Abstract

BackgroundCervical cancer is the second most common cancer in women worldwide and the most common cause of mortality in underdeveloped and developing countries [1,2]. Persistent infection with certain oncogenic high-risk (HR) types of Human Papillomavirus (HPV) is the required factor for the development of invasive cervical cancer and precursor lesions [3][4][5][6].Overall, the prevalence and distribution of HPV infection in cervical lesions has been determined in many geographical regions of the world, this can vary depending on several factors including epidemiological differences in the populations studied and the methodology used for molecular detection and typing of HPV DNA [7]. Over 120 types of HPV have been classified as either low (LR-HPV) or high risk (HR-HPV), according to their oncogenic potential [8,9]. Within the high-risk genotypes, HPV types 16 and HPV 18 are most often associated with cancer and squamous intraepithelial lesion [5,6,10,11,12]. Nevertheless, the risk of neoplasia for other types of HPV as well as for multiple HPV infection has not yet been established.Because current strategies for the prevention of cervical cancer and their precancerous lesions are based on the HPV genotyping [13] and prophylactic vaccines [14][15][16], it seems necessary to determine the types of HPV most commonly associated with malignant cell transformation in different geographical areas in order to establish effective preventive measures according to the epidemiology of the population. This study was to know the prevalence and distribution of cervical HPV infection in women attending routine cervical cancer screening in the Valencia region (Spain). Study designLiquid-based cytology (LBC) of cervical specimens was collected during routine screening visits, between June 20, 2011 and September 9, 2011 in the Clinical Hospital of Valencia, Spain. LBC samples were processed using the Thin Prep® 5000 processor (Madrid, Spain). For HPV detection and genotyping, we used the residual cervical sample material available from the same Thin Prep Pap test vial previously used for cytological screening. DNA was extracted from the residual materials of LBC by QIAamp® DNA mini kit (IZASA, Valencia, Spain), according to the manufacturer's instructions. HPV testing was performed by INNO-Lipa HPV genotyping Extra Reverse Hybridization Line Probe Assay kit (Innogenetics®, Barcelona, Spain), according to the manufacturer's instructions. Briefly, HPV detection and genotyping was based on PCR amplification of a 65pb fragment, within the L1 region of the HPV genome, using broad-spectrum SPF10 biotinylated primers. PCR was performed in a final AbstractBackground: Infection with human papillomavirus (HPV) has been identified as the primary cause of cervical cancer. Persistent infection with high risk-HPV is the required factor for the development of cervical cancer.