Prevalence of Human Papillomavirus (HPV) types in cervical cancer 2003-2008 in Stockholm, Sweden, before public HPV vaccination

Background. Human papillomavirus (HPV) infection is the major cause of cervical cancer, but the prevalence of different HPV types varies depending on geographical location and may change dramatically after introduction of HPV vaccination. Here, we aimed to gain some information regarding the recent prevalence of different HPV types, in cancer of the uterine cervix in the Stockholm region, before the introduction of public HPV vaccination in Sweden. Material and methods. From 215 diagnosed cervical cancer patients 2003-2008 at the Karolinska University Hospital, 160 pretreatment cervical cancer samples, including both squamous cell carcinomas (SCC) and adenocarcinomas (ADC) could be obtained. DNA was extracted from 154/160 of the SCC and ADC samples and assayed by Luminex Multiplex for 24 different HPV types, including 15 high-risk (HR), three putative HR and six low-risk types (LR). Results. We successfully analysed 154/215 (71.6%) of the locally diagnosed cases and found a high prevalence of HPV with 92.9% in all uterine cervix cancer cases, and 93.3% and 91.4% in SCC and ADC, respectively. All HPV positive cases harboured HR types, either alone or as multiple infections. In SCC HPV16 dominated and together with HPV18 accounted for 69.7% of the cases, followed in prevalence by HPV33, 31 and 45. In ADC, HPV18 was more common than HPV16, and they were observed in all except one of the HPV positive samples. Conclusion. The prevalence of HPV16 and 18, followed by HPV33, 31 and 45 is high in SCC and ADC in the Stockholm region. Public HPV vaccination could potentially inhibit a large proportion of such tumours underlining the urgency to initiate HPV vaccination.