Imiquimod Cream Effective for Vulvar Intraepithelial Neoplasia

NEW YORK MAR 07, 2006 (Reuters Health) - Imiquimod cream is well tolerated and results in histologic regression of high-grade vulvar intraepithelial neoplasia (VIN) lesions, according to researchers in Canada.

"VIN lesions are increasingly being diagnosed in younger women," Dr. Tien Le and colleagues from the University of Ottawa, Ontario, write in the February issue of the American Journal of Obstetrics and Gynecology.  "This is classified as a premalignant condition," they note.  "High-grade lesions (grade 2/3) are often treated even if asymptomatic because of increased risks of malignant transformation."

The researchers examined the tolerability and efficacy of 5% imiquimod cream for the primary treatment of VIN 2/3 in patients recruited from regional colposcopy units. Twenty-three patients with a mean age of 55.2 years were included in the study.  Twenty patients (87%) had VIN grade 3 and nine (39%) had multifocal disease distribution. 

The women were instructed to apply imiquimod cream over the abnormal area using an escalating dose regimen.  Total treatment duration was 16 weeks.

The team assessed response at the end of the study with repeat colposcopy and biopsy of the target lesion.  They defined complete response as a complete disappearance of all visible VIN lesions and a histologic confirmation of VIN 1 or less.  Partial response was defined as a decrease in the target lesion of at least 50% from baseline measurements with no new observed lesions.

The therapy was generally well tolerated, and the most common side effect was irritation at the application site.  Seventeen patients were evaluable for response.  Of these, nine patients (53%) were classified as complete responders and five (29%) as partial responders, for a total response rate of 82%. 

Partial responders had a median percentage reduction of target lesions of 56%.  The median time to response was 7 weeks.

"A comparative study between laser ablation/surgical excision and imiquimod treatment in VIN grade 2/3 patients will be needed to establish the role of local immunostimulant in the management of this morbid condition," Dr. Le"s team suggests.

"The use of imiquimod as maintenance therapy after standard treatment to prevent recurrences should be explored," they add. 

SOURCE:

• Am J Obstet Gynecol 2006;194:377-380.