Characteristics of vulvar squamous cell carcinoma in Japanese women.

Although the presence of racial differences in vulvar squamous cell carcinomas has been suggested, fully analyzed data concerning such tumors in Japanese women have not been reported. A total of 21 vulvar squamous cell carcinomas of Japanese women who lived in north-east Japan, were studied with respect to histological subtype, HPV, p53 and p16(INK4a). The majority of tumors consisted of keratinizing and non-keratinizing types (16/21, 76%), all of which were negative for HPV. The remaining five tumors of basaloid, warty or verrucous types were positive for HPV. HPV-negative tumors showed a trend of greater accumulation of gene abnormalities, including p53 gene mutation, than HPV-positive ones. p16(INK4a) overexpression was shown to not always be a marker for vulvar squamous cell carcinoma in Japanese women with activated high-risk HPV.