The etiologic role of human papillomavirus in penile cancers: a study in Vietnam

BACKGROUND: We investigated the aetiologic role of human papillomavirus (HPV) in 120 penile squamous cell carcinomas (PSCCs) from Vietnam. METHODS: Human papillomavirus DNA was detected by PCR using SPF10 primers and a primer set targeting HPV-16 E6. The INNO-LiPA HPV genotyping kit was used to determine genotype. Human papillomavirus-16 viral load and physical status were determined by real-time PCR. P16(INK4A) protein expression was investigated by immunohistochemistry. RESULTS: Human papillomavirus DNA was detected in 27 of 120 (23%) PSCCs. The most frequently detected genotype was HPV-16 (24 of 27 cases, 89%). In 16 of 18 (89%) HPV-16-positive cases, the HPV DNA was considered to be integrated into the host genome. The geometric mean of the HPV-16 viral load was 0.4 copies per cell. P16(INK4A) overexpression was significantly related to PSCCs infected with high-risk HPV (P=0.018) and HPV-16 copy numbers (P<0.001). CONCLUSION: Human papillomavirus-16 DNA integration and p16(INK4A) overexpression in high-risk HPV detected PSCCs suggested an aetiologic role of high-risk HPV in the development of PSCCs.