Vulval squamous cell carcinoma and premalignant skin conditions : a population-based study
Incidence trends for invasive and non-invasive disease are explored. A nested case control study of those women who progress from non-invasive disease to carcinoma is performed. The incidence of vulval carcinoma in Grampian remains stable. Incidence rates of all non-invasive chronic vulval skin disorders, regardless of underlying aetiology are rising dramatically. Age specific incidence rates suggest that there may be significant ascertainment bias in rising incidence rates for each of these skin disorders. No distinction could be found between the relative risks for women with vulval litchen sclerosus or vulval intraepithelial neoplasia developing subsequent carcinoma. Vulval squamous hyperplasia appears to be of low malignant potential. The malignant risk of vulval lichen sclerosus or vulval intraepithelial neoplasia within Grampian is currently in the order of 9% over ten years of follow-up. The presence of HPV 16 DNA does not appear to confer an increased risk of subsequent malignant transformation in women with biopsy-proven chronic vulval skin disorders. Although p-53 overexpression is not associated with an increased risk of subsequent malignant transformation, there are patterns of altered expression that may identify a high risk group of women. Those women that have been identified as suffering from a chronic vulval skin disorder before they develop invasive disease appear to have more favourable prognostic factors at presentation. The primary role of viral carcinogenesis in vulval carcinoma has been overestimated in the current literature. p53 aberrations may be a unifying factors in the biology of vulval carcinoma, with HPV acting as a co-factor in some cases. Aggressive surgical management for vulval intraepithelial neoplasia solely for the purposes of anticipating a rise in invasive disease rates should be resisted. An increase in resource allocation for the purpose of close surveillance of women with vulval lichen sclerosis or vulval intraepithelial neoplasia now seems justified.