Imiquimod in the treatment of penile intraepithelial neoplasia: an update

Penile intraepithelial neoplasia (PIN), or penile squamous cell carcinoma in situ, is a rare disease and may be associated with high morbidity and mortality. In an attempt to avoid surgical intervention, which may result in poor cosmetic and functional outcomes for patients, many non-invasive treatments have been trialled with variable success rates. This review summarises the available literature describing the use of topical imiquimod for PIN. While the results of our review are limited by the heterogeneity of the methods and follow ups of the included case series and case reports, they highlight the fact that patients with PIN have variable responses to imiquimod which seem less effective than previously reported. Therefore, if imiquimod treatment is instituted in PIN, clinicians should counsel their patients about the effects associated with treatment, the potential for a partial or no response to treatment, and the risk of recurrence. A strict follow-up plan is also necessary to monitor both patient adherence and PIN recurrence after treatment completion, in case surgical options need to be considered