Impact of smoking on imiquimod response in patients with vulval intraepithelial neoplasia

Background Vulval intraepithelial neoplasia (VIN) is a precancerous condition that may progress to invasive malignancy. VIN is associated with human papillomavirus (HPV) infection in most cases, and with inflammatory skin disorders in a smaller proportion of patients. Treatment of VIN has traditionally been surgical excision; however, topical treatments, including imiquimod cream, are becoming increasingly used. Patient factors influencing response to imiquimod therapy, in particular smoking, have not yet been published. Aim To assess the impact of smoking and other patient characteristics that may influence the treatment response to topical imiquimod for VIN. Methods This was a retrospective cohort study of 46 women treated with topical imiquimod for VIN in a single centre dermatology unit from January 2011 to July 2017. Results Complete clinical resolution of VIN was observed in 28 of 46 patients (61%), but was significantly reduced in the smoking cohort. Conclusions Smoking may impair response to imiquimod for VIN, and should be considered when discussing VIN treatment options with patients.