New developments in the management of VIN

Abstract

Vulvar intraepithelial neoplasia (VIN) is a precancerous skin disorder of the vulva. It is currently classified on the basis of histological findings as VIN1, −2, or −3. Clinically useful tumour markers do not yet exist. Up to 90% of cases of VIN3 are associated with human papillomavirus (HPV). Even with appropriate treatment, approximately 5% of women with VIN3 will develop cancer of the vulva, necessitating appropriate long-term follow-up. The two main aims of management of VIN are to prevent cancer and to resolve symptoms. Research into VIN has been limited by the rarity of the disease. Most data come from published case series focusing on VIN3.

Surgical local excision is a common treatment for VIN2/3. Rotational skin flap procedures are increasingly used when a large area of vulval tissue requires excision. The carbon dioxide laser is also employed for either ablation or excision of high-grade VIN, especially in non-hairy vulval skin. Ablative therapies do not allow histological assessment and unrecognised malignancy may be missed. Medical treatments, such as topical 5% imiquimod cream, or photodynamic therapy with topical 5-aminolaevulinic acid, result in comparatively poor clearance rates of VIN2/3 and long-term outcomes have not been reported. The importance of treatment-related morbidity on sexuality should not be overlooked. HPV vaccines offer an alternative approach. Early work on therapeutic HPV vaccination for high-grade VIN shows that vaccines can stimulate an immune response but not significant clinical improvement. Prophylactic vaccination may be an exciting way to prevent HPV-related diseases, including VIN.