Dr Lesley Anderson talks to ecancertv at the UK's National Cancer Research Institute ( NCRI ) 2013 meeting about a study looking at the changing profile of HPV infection and resultant disease now that the UK has introduced an HPV vaccine.

This study aimed to determine the prevalence of HPV infection among screening age women prior to vaccination and determine HPV types associated with cervix disease.

HPV positivity was investigated using the Roche Cobas 4800 in 5557 eligible Liquid Based Cytology (LBC) samples from women of screening age in Northern Ireland and 2048 samples of cervical pathology collected prospectively.

LBC samples revealed a crude age standardised prevalence of high risk HPV of 17.4% in screening age women in Northern Ireland. The highest rate (42.5%) was in those aged 20-24. HPV prevalence by main subtypes were: HPV 16 (5.3%) 31 (2.5%) 51 (2.2%) 18 (1.7%). For cervical pathology prevalence of HPV was 64.7% overall, increasing from 48.1% of CINI, 65.7% of CINII, 81.3% of CINIII to 89.1% of cervical squamous cell carcinomas (SCC). The majority of SCC's tested positive for HPV16 or 18 (91.2% of HPV positive samples). HPV positivity was found in 92.9% microinvasive SCC, 50% of adenocarcinomas, 66.7% adenosquamous carcinomas, 88.2% cervical glandular intraepithelial neoplasia and 29.1% koilocytosis. The number of genotypes detected varied across pathology grade, On average 2.5 genotypes where detected per positive sample. A trend was identified that CIN I had the lowest percentage (66.0%) of single genotypes. On average 91.8% of all cancerous samples containing only one HPV genotype. The most frequent single genotypes found in cancerous samples were HPV16, HPV18, HPV45, HPV31, HPV39 and HPV52.

For SCC samples not testing positive for HPV16 or HPV 18, five samples tested positive for a single HPV 31, HPV 39, HPV 45 or HPV 52 genotype, which may have implications for vaccine cross protection of non-target genotypes as these types are common in women with normal cervical pathology.