Author(s): Andrea Piana 1, Giovanni Sotgiu 1, Clementina Cocuzza 2, Rosario Musumeci 2, Vincenzo Marras 3, Stefania Pischedda 1, Silvia Deidda 1, Elena Muresu 1, Paolo Castiglia 1,*
Cervical cancer is deemed the third most frequent neoplasia in women worldwide; in particular, it is the second most prevalent cancer among women aged 15-44 years. Recently, it was estimated an annual number of 529,828 new cases of cervical carcinoma and of 275,128 deaths from cervical carcinoma .
Human Papilloma viruses (HPVs) have been shown to be associated with cervical cancers since 1976 , as a consequence of a persistent infection which occurs in less than 10% of the infected women . The majority of sexually active people (~75%) is infected by HPV types at some point during their lifetime course , . The overall estimated female prevalence of HPV infection is 11.4% . More than 70% of global cervical neoplasias have been described to be associated with HPV genotypes -16 and -18 .
On this basis, two prophylactic vaccines containing type -16 and -18 specific antigens were recently developed; to date, they have showed a 7-9 year clinical efficacy of about 100% against cervical cytological abnormalities caused by HPV-16 and -18 genotypes, with a variable cross-protective efficacy against cervical lesions associated with other high-risk oncogenic types , .
A prevalence study showed that other high-risk HPV genotypes than -16 and -18 (i.e. , HPV types -45, -33, -31, -52, -35, -39, -58, -51, -59, -56, and -66) were associated with more than 20% of cervical carcinomas globally , .
The epidemiology of circulating HPV genotypes was proved to be heterogeneous and the impact of the vaccines could vary depending on the regional distribution of HPV types .
Recently, our group performed a cross-sectional investigation, which described a high overall prevalence of HPV genotype -16 (20.5%) and -51 (14.3%) in Northern Sardinia, Italy. Their presence, as single or coinfecting agents, was detected in all kind of cytological lesions; in particular, HPV types -16 and -51 DNA were detected in 12.5 and 6.3% of atypical sqamous cells of undetermined significance; 24.0% and 16.0% of low-grade squamous intraepithelial lesions; 50.0% and 50.0% of high-grade squamous intraepithelial lesions, respectively . A similar epidemiological pattern was also described by other previous studies , , , .
Since an unexpected proportion of some genotypes could be due to random variability in limited geographical areas, in order to evaluate the epidemiological dynamics of HPV-51, particularly in invasive cervical lesions, we investigated the presence of HPV DNA in embedded tissues samples of cervical lesions collected in the same area of Northern Sardinia, Italy, before and during the above-mentioned prevalence study.
Ethical approval and informed consent for this study was unnecessary, according to the Italian legislation concerning the guidelines for the performance of observational studies (G.U. n. 76. 31-3-2008). However, a formal approval of the study protocol was requested in 2007 to the Ethical Committee of the Azienda Sanitaria Locale n°1 of Sassari, Italy (PN-132, 2007)....