This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Winters, U. Articles by Kitchener, H. C. PubMed PubMed Citation Articles by Winters, U. Articles by Kitchener, H. C.

Clinical and Immunologic Results of a Phase II Trial of Sequential Imiquimod and Photodynamic Therapy for Vulval Intraepithelial Neoplasia

Authors' Affiliations: ¹ School of Cancer and Imaging, University of Manchester, St. Mary's Hospital, ² Immunology Group, Paterson Institute for Cancer Research, University of Manchester, Christie Hospital National Health Service Trust, and ³ Department of Dermatology, Manchester Royal Infirmary, Manchester, United Kingdom

Requests for reprints: Peter Stern, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester, M20 4BX, United Kingdom. Phone: 161-446-3127; Fax: 161-446-3109; E-mail: pstern{at}picr.man.ac.uk.

Purpose: High-risk human papillomavirus (HPV)-associated vulval intraepithelial neoplasia (VIN) is difficult to treat by excision or ablation because of high recurrence rates. Small studies of photodynamic therapy (PDT) and imiquimod treatments have shown some success and function at least in part through stimulation of local immune responses. Indeed, there is evidence that immunosuppressed individuals have higher rates of VIN, suggesting immune control is relevant.

Experimental Design: In the study, 20 women with high-grade VIN were treated with topical imiquimod and the PDT sequentially. Vulval biopsy and blood were taken pretreatment and, after imiquimod and PDT, with follow up for 1 year. Clinical response was assessed by measuring lesion size. Biopsies were analyzed for HPV DNA and tumor-infiltrating lymphocytes including T regulatory cells.

Results: The treatment was well-tolerated. There was an overall response rate of 55% by intention treat and 64% per protocol. The 52-week symptom response was 65% asymptomatic, compared with 5% at baseline. The nonresponders showed a significantly higher level of T regulatory cells in the lesions after imiquimod treatment.

Conclusions: The response rates are clinically relevant, and the treatment regimen was feasible for the majority. Initial nonresponders to imiquimod seem to be relatively refractory, and this may derive from their unfavorable local immune environment, in particular, the increased proportions of T regulatory cells, possibly the limiting action and/or development of any HPV T-cell immunity. The potential benefit of this treatment is its ability to treat multifocal disease.