Incidence and Risk Factors for Recurrence and Progression of HPV-Independent Vulvar Intraepithelial Neoplasia.

Objectives: Human papillomavirus (HPV)-independent vulvar intraepithelial neoplasia (VIN) is a rare yet aggressive precursor lesion of vulvar cancer. Our objectives were to estimate its long-term incidence, the risk of recurrent disease and progression to vulvar cancer, and risk factors thereof.
Materials and Methods: Patients with HPV-independent VIN between 1991 and 2019 in a selected region were identified from the Dutch Nationwide Pathology Databank (Palga). Data were collected from the pathology reports. Crude and European age-standardized incidence rates were calculated for 10-year periods. Kaplan-Meier analyses were performed to determine the cumulative recurrence and cancer incidence, followed by Cox regression analyses to identify associated risk factors.
Results: A total of 114 patients were diagnosed with solitary HPV-independent VIN without prior or concurrent vulvar cancer. The European age-standardized incidence rate increased from 0.09 to 0.69 per 100,000 women-years between 1991-2010 and 2011-2019. A cumulative recurrence and cancer incidence of 29% and 46% were found after 8 and 13 years of follow-up, respectively. Nonradical surgery was identified as the only independent risk factor for recurrent HPV-independent VIN. Risk factors associated with progression to cancer were increasing age and a mutant p53 immunohistochemical staining pattern.
Conclusions: The incidence of detected HPV-independent VIN has substantially increased the last decade and the subsequent recurrence and vulvar cancer risks are high. Although HPV-independent VIN may present as a wide morphologic spectrum, surgical treatment should aim for negative resection margins followed by close surveillance, especially for p53 mutant lesions.
Competing Interests: R.D.M.S. is a minority shareholder of Self-screen B.V., a spin-off company of Amsterdam UMC, location VUmc. Self-screen B.V. develops, manufactures, and licenses high-risk HPV and methylation marker assays and holds patents on these tests. The other authors have declared they have no conflicts of interest.
(Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the ASCCP.)