Scar cosmesis: Imiquimod may be effective as surgical adjunct

January 1, 2008

The topical immune response modifier imiquimod 5 percent cream (Aldara, Graceway Pharmaceuticals) induces the upregulation of an array of cytokines involved in wound healing and tumor control. Based on its activity, a number of investigators have examined its efficacy and safety when used off-label to prevent keloid recurrence after surgical removal, improve surgical scar appearance and improve local tumor control and scar cosmesis following surgical treatment of basal cell carcinoma.

Key Points

Las Vegas - Results from clinical trials suggest the topical immune response modifier imiquimod 5 percent cream (Aldara, Graceway Pharmaceuticals) may be a useful adjunct in the surgical management of keloids and basal cell carcinoma (BCC), says Brian Berman, M.D., Ph.D., professor of dermatology and internal medicine, University of Miami Miller School of Medicine, Miami, Fla.

At the 26th Fall Clinical Dermatology Conference, Dr. Berman reviewed studies evaluating the efficacy and safety of imiquimod cream used off-label to prevent keloid recurrence, improve surgical scar appearance and enhance the cosmetic and oncologic outcomes after surgical treatment for BCC.

Keloid control

"According to the literature, 51 percent of earlobe keloids recur after excision, and so the results of these open-label studies provide positive support for this novel use of imiquimod cream," Dr. Berman says.

Considering that surgical excision of keloids may be impractical in some patients seen in clinical practice who present with multiple lesions, Dr. Berman and colleagues also undertook a study to evaluate use of imiquimod after shave excision. The study was primarily designed to investigate the tolerability of applying imiquimod to the freshly shaved sites.

A total of 20 earlobe keloids were shaved flat to the level of surrounding skin and then randomized to treatment with vehicle or imiquimod cream. The study agents were applied nightly for two weeks and then three times a week under Tegaderm occlusion for four weeks.

At the end of two weeks, imiquimod treatment was associated with more clinically significant pain and tenderness compared with the vehicle cream control, and throughout the study, the imiquimod group also needed more rest periods due to the occurrence of more local oozing, crusting, erythema and/or pruritus.

However, there were no systemic adverse events associated with direct application of the cream to the recently shaved lesion or any evidence of wound infection, and no differences in pain by the six-week evaluation.

"This tolerability study was not powered to critically determine recurrence rates, but at six months, we did note the recurrence rate was 50 percent lower in the imiquimod treated group compared with the controls," Dr. Berman tells Dermatology Times.

Improving scar cosmesis

Recognizing the potential activity of imiquimod cream for modulating postsurgical wound healing, Dr. Berman and colleagues also undertook a study to examine the tolerability of applying imiquimod to postsurgical excision sites in non-keloid prone patients. This prospective, double-blind clinical trial enrolled 20 patients undergoing surgical excision of two melanocytic or dysplastic nevi in a similar anatomic area. After excision, the surgical wounds were sutured and patients were instructed to treat one site with imiquimod cream and the other with vehicle at night for four weeks. At eight weeks postsurgery, there was no dehiscence at any surgical site, no evidence of infection, no pain and no clinically significant difference in tenderness between the imiquimod- and vehicle-treated sites. However, cosmesis was poorer at the imiquimod-treated sites due to greater erythema.

"The conclusion from this study was that imiquimod was well-tolerated, but the real question is whether it improves the appearance of the scar over the long term," Dr. Berman says.

That issue was investigated in a study of patients undergoing bilateral breast augmentation or reduction who, beginning two months after surgery, treated one scar with imiquimod and the contralateral site with petrolatum or nothing.

Again, inflammation was greater at the imiquimod-treated sites early during the treatment course, but at the final assessment, scar appearance rated with two different severity scales was significantly better when the topical immune response modifier was used, Dr. Berman says.

Adjunct in surgical management of BCC

Several investigators have evaluated imiquimod as an adjuvant in the surgical management of BCC based on its potential to improve scar cosmesis and reduce the risk of tumor recurrence.