Treatment of bowenoid and basaloid vulvar intraepithelial neoplasia 2/3 with imiquimod 5% cream.

Objective: To evaluate the effectiveness and safety of imiquimod 5% for the treatment of bowenoid and basaloid vulvar intraepithelial neoplasia (VIN) and to evaluate recurrences following treatment.

Study Design: Eight patients <55 years old (range, 32-51; mean, 39.7), with bowenoid or basaloid VIN 2/3 diagnosed by biopsy were treated with imiquimod 5%. Women with other types of intraepithelial neoplasia of the lower genital tract, immunosuppressed women, pregnant women and women with other types of vulvar pathology were excluded. Two patients previously treated for VIN 3 (surgical resection, resection by loop electrosurgical excision procedure) had recurrences. Patients applied imiquimod cream 3 times a week until total clearance of the lesions or up to a maximum of 16 weeks. Responses were categorized as total when there was no colposcopic evidence of a lesion, partial when the lesion area diminished >50% and progressive when there was an increase in the lesion area. A biopsy was performed at the end of treatment. Follow-up was carried out monthly (10-30 months).

Results: Total clearance of lesions was observed in 6 patients after 10-16 weeks. Two patients had a partial response (1 with 75% and the other with 50% reduction of the lesions). Posttreatment histopathology showed the absence of precancerous lesions in 7 patients (87.5%). Biopsy was positive for VIN 3 (12.5%) only in the patient showing a clinical response of 50%. Of the 7 patients with biopsies negative for VIN, 2 (25%) were positive for viral infection; 1 gave a negative reading after 2 months after treatment, and the other 1 remained positive for human papillomavirus. The patient with persistent VIN received surgical treatment. The side effects were as follows: erythema in 8 patients (100%), erosions in 1 patient (12.5%) and edema in 1 patient (12.5%). No relapses occurred after treatment during 10-30 months of follow-up.

Conclusion: In this initial series, imiquimod proved to be effective for the treatment of bowenoid and basaloid VIN 2/3 in a group of young women and was less aggressive treatment than surgical ones. The treatment was well tolerated, causing local reactions that enabled the therapy to be completed.