Background
In 2016, the Korean government launched a national HPV vaccination programme for 12 year old girls (bivalent and quadrivalent HPV vaccines) and approved the use of 9-valent HPV vaccine. This is expected to have a significant impact on HPV-related disease burden in Korea. The aim of this review is to examine the current burden of HPV-related cancers and disease and to estimate the relative contribution of the nine vaccine types (HPVs 16/18/31/33/45/52/58/6/11).
Methods
A comprehensive search of peer-reviewed biomedical literature was conducted to assess the burden of HPV disease in Korea by using MEDLINE, Asian Pacific Journal of Cancer Prevention , KoreaMed Synapse and Google Scholar until August 2016.
To assess the potential impact of the 9vHPV vaccine in HPV-related lesions, we used data from an international project on HPV-related lesions designed and coordinated by the Catalan Institute of Oncology (ICO) (Barcelona-Spain). Consecutive histologically confirmed paraffin-embedded cases of HPV-related anogenital cancers (cervix, vulva, vagina, anus and penis) were obtained from Korean hospital pathology archives. Cancer sites with a limited number of cases were supplemented with cases from the Asian region. HPV DNA-detection and typing was performed by using SPF10-DEIA-LiPA25 system and relative contribution was expressed as the proportion of type-specific cases among HPV positive samples.
Results
Despite a downtrend in cervical cancer rates in recent years, Korean rates still remain high in comparison to other developed countries (age-standardized rate in 2012:9.5 cases per 100.000 women). HPV-related anogenital cancers other than cervix remain rare. Preliminary results show that the combined relative contribution of the nine HPV vaccine types was 91.3% (95% CI: 89.9-92.6) in cervical cancer, 73.6% (95% CI: 51.6-89.8) in vaginal cancer, 83.3% (95% CI: 70.7-92.1) in vulvar cancer , 88.9% (95% CI: 51.6-99.7) in penile cancer and 91.3% (95% CI: 72.0-98.9) in female anal, and 88.2% (95% CI: 63.6-98.5) in male anal cancer. The most frequently detected types in cervical cancer are HPV 16 (65%), HPV 18 (9%), HPV 33 (5%), followed by HPVs 58 (4%) and 31 (4%). HPV16 was the most frequent type in all lesions.
Conclusion
HPV-related disease burden in Korea is significant. Results suggest that the HPV types in the 9vHPV vaccine contribute to more than 90% of HPV positive female cervical and anogenital lesions. Consequently, the introduction of the 9vHPV vaccine could have a significant impact on the prevention of HPV-related cancer and disease in Korea.