Preliminary Study on Human Papillomavirus Frequency and pecific Type-distribution in Vulva Cancer from Thai Women

Vulva cancer is rare among all gynecological cancer worldwide, including Thailand, and mainly affectsolder women. Persistent high risk type infection of human papillomavirus (HPV) is the one important factorfor developing cancer. In this study, we focused on HPV DNA investigation and type-specific distribution ofHPV in 25 formalin-fixed paraffin-embedded (FFPE) samples collected from Thai women with vulva cancerhistologically confirmed by the National Cancer Institute, Thailand, during 2003-2011. HPV DNA detectionand genotyping were undertaken with polymerase-chain reaction and enzyme-immunoassay using GP5+/bio6+consensus specific primers and digoxigenin-labeled specific oligoprobes, respectively. Human β-globin genes wasused as the internal control. Our results showed that 44% (11/25) of all vulva cancer samples were HPV-positive.All of them are high risk HPV type infection, detected as single (63.64%, 7/11) and/or double infections (4/11,36.36%). HPV 16 was the most common type identified in vulva cancer, followed by HPV 35, 33, 18 and 58.In conclusion, this study presented that HPV-16 is observed at the highest frequency in this cancer, similar tocervical cancer, with HPV 18 being less frequent. Although the sample size was small and could not representoverall incidence and prevalence in Thai women, these preliminary data for vulva cancer are of interest sincethey reinforce the necessity for HPV screening or vaccination in Thailand.