Human papillomavirus genotype distribution in cervical cancer cases in Spain. Implications for prevention.

OBJECTIVE: Human papillomavirus (HPV) genotype distribution in invasive cervical cancer (ICC) is critical to guide the introduction and to assess the impact of HPV prophylactic vaccines. This study aims to provide specific information for Spain.

METHODS: 1043 histological confirmed ICC cases diagnosed from 1940 to 2007 from six Spanish regions were assembled. HPV DNA detection was performed by SPF(10) broad-spectrum PCR followed by deoxyribonucleic acid enzyme immunoassay and genotyping by reverse hybridization line probe assay (LiPA(25)) (version 1).

RESULTS: Of 1043 ICC cases, 904 were HPV DNA positive (adjusted prevalence: 89.1%). The eight most common types, in decreasing order, were HPV 16, 18, 33, 31, 45, 35, 52 and 56, accounting for more than 90% of cases. HPV 16 and 18 contributed to 72.4% of all HPV positive ICC cases. In cervical adenocarcinomas, this contribution increased up to 94%. HPV 16 and 18 relative contributions showed a stable pattern over the 60 year study period. HPV 45, 18 and 16-positive ICC cases presented at younger ages than cases with other HPV types (adjusted mean age: 43.8, 45.2, 52.6 and 57.7 years, respectively).

CONCLUSIONS: HPV 16 and 18 accounted together for a 72.4% of positive cases, with no statistically significant changes in their relative contributions over the last decades. In 94% of cervical adenocarcinomas we identified at least one of the two HPV types included in the current vaccines (HPV 16/18). Results suggest a major impact of HPV vaccines on reduction of ICC burden in Spain in the HPV vaccinated cohorts.