HPV status and favourable outcome in vulvar squamous cancer.

It is universally accepted that high-risk human papillomavirus (HR-HPV) is the cause of cervical dysplasia and cancer. More recently, it has been shown that HPV is also a marker of clinical outcome in oropharyngeal cancer. However, contemporary information is lacking on both the prevalence of HPV infection in vulvar cancer (VSCC), its precursor lesion, vulvar intraepithelial neoplasia (VIN) and the influence of HPV-status on the prognosis of this malignancy. We have conducted a detailed population-based study to examine rates of progression of VIN to VSCC, type-specific HPV prevalence in vulvar disease and the influence of HPV status on clinical outcome in VSCC. We observed that the age at which women are diagnosed with VSCC is falling and there is a significant time gap between first diagnosis of VIN and progression to invasive disease. HR-HPV infection was detected in 87% (97/112) cases of VIN and 52% cases (32/62) of VSCC. The presence of HR-HPV in squamous intraepithelial lesion was associated with lower rates of progression to invasive cancer (hazard ratio, 0.22, p = 0.001). In the adjusted analysis, HR-HPV was associated with improved progression-free survival of VSCC compared to those with HPV negative tumours (hazard ratio, 0.32, p = 0.02).