A common treatment for vulvar pre-malignant conditions is surgery, which can be disfiguring and painful. Alternatives to surgery have long been sought but none have been effective and easy to use. Investigators at several Netherlands institutions, reporting in this week's New England Journal of Medicine, looked at the effectiveness of imiquimod 5% cream, a topical immune-response modulator, for the treatment of this condition.

Fifty-two patients with grade 2 or 3 vulvar intraepithelial neoplasia were randomly assigned to receive either imiquimod or placebo, applied twice weekly for 16 weeks. The size of affected areas was reduced by more than 25% at 20 weeks in 21 of the 26 patients (81%) treated with imiquimod and in none of those treated with placebo (P<0.001). 

At baseline, 50 patients (96%) tested positive for HPV DNA. HPV cleared from the lesion in 15 patients in the imiquimod group (58%), as compared with 2 in the placebo group (8%) (P<0.001). The number of immune epidermal cells increased significantly and the number of immune dermal cells decreased significantly with imiquimod as compared with placebo. Imiquimod reduced pruritus and pain at 20 weeks (P=0.008 and P=0.004, respectively) and at 12 months (P=0.04 and P=0.02, respectively).

The lesion progressed to invasion (to a depth of <1 mm) in 3 of 49 patients (6%) followed for 12 months (2 in the placebo group and 1 in the imiquimod group). Nine patients, all treated with imiquimod, had a complete response at 20 weeks and remained free from disease at 12 months.

So the conclusions is: Imiquimod is effective in the treatment of vulvar intraepithelial neoplasia.