Characterization of squamous cell cancers of the vulvar anterior fourchette by human papillomavirus, p16INK4a, and p53

OBJECTIVE The incidence of vulvar squamous cell carcinomas located between the clitoris and urethra in young women is rising in distinct geographic regions, but characteristics of the tumors indicating certain carcinogenic mechanisms are unknown. The present study aimed at characterizing these vulvar cancers for their human papillomavirus (HPV), p16(INK4a), and p53 status, revealing potential pathways of carcinogenesis. MATERIALS AND METHODS Squamous cell vulvar cancers of the anterior fourchette were retrospectively collected from 8 German hospitals, with additional squamous cell cancers located at other sites of the vulva from 2 of the hospitals. All tumors were analyzed for HPV DNA by polymerase chain reaction and for p16(INK4a) and p53 expression by immunohistochemistry. RESULTS Potentially HPV-associated tumors (HPV and p16(INK4a) positive, 21.4% [27/126] of the anterior fourchette and 27.7% [13/47] from other locations), p53-overexpressing tumors (35.7% [45/126] and 29.8% [14/47]), and a third group (HPV/p16(INK4a) negative/p53 not overexpressed, 42.9% [54/126] and 42.6% [20/47]) were observed among tumors from the anterior fourchette as well as among vulvar cancers from other locations. Women with vulvar cancers of the anterior fourchette were of young age irrespective of the HPV/p16(INK4a)/p53 status. CONCLUSIONS Different types of vulvar cancers can be found in squamous cell tumors of the anterior fourchette, similar to the finding in vulvar cancers from other locations and to what has previously been reported for vulvar squamous cell carcinomas in general.