HPV distribution in cervical cancer in Portugal. A retrospective study from 1928 to 2005

Abstract

Objectives: To determine human papillomavirus (HPV) types in invasive cervical cancer in Portugal. Methods: Cases diagnosed at the Institute Portugues de Oncologia de Lisboa de Francisco Gentil from the year 1928 to 2005 were selected for HPV DNA detection and genotyping using SPF10/DEIA/LiPA25 system. Results: Of the 1214 samples that were considered appropriate for HPV detection, 714 (58.8%; 95% CI: 56.0-61.6%) were positive for HPV DNA. This detection rate varied being lower in the first 3 decades (31.3%; 50.1%; 46.5%) and higher in the last decades (77.4-95.1%). This difference was due probably to the fixative used in the first three decades. The five most common types identified among HPV positive cases were HPV16 (58.2%), HPV18 (9.2%), HPV33 (6.2%), HPV45 (4.7%) and HPV31 (4.4%). Multiple infections were detected in 2.8% of the cases. HPV16 and 18 accounted for 67.4% of infections. There were no statistically significant changes of these types over the studied period. An increase at patient's age at diagnosis was observed in the last decades (p < 0.001). Conclusion: HPV16 and 18 accounts for almost 70% of cervical cancers in all 9 decades studied and support data that effective vaccination against these 2 types will reduce the cervical burden in Portuguese women.