Topical Imiquimod Therapy for Basal and Squamous Cell Carcinomas: A Clinical Experience

Basal cell carcinomas (BCCs) and cutaneous squamous cell carcinomas (SCCs) are the most common malignancies in humans. Together, they constitute approximately 95% of nonmelanoma skin cancers (NMSCs). Surgical excision remains the mainstay of therapy of low-risk NMSC, though Mohs micrographic surgery is the gold standard for high-risk NMSC. Both methods produce high cure rates, but they may not be appropriate treatments for elderly patients who are either not surgical candidates or refuse to undergo surgery for their skin cancers. Imiquimod cream 5% is a topical immune response modifier that targets the toll-like receptors 7 and 8 and up-regulates inflammatory pathways targeting diseased tissue. This noninvasive topical therapy may be more appropriate for some patients. Herein, we describe our 5-month clinical experience in mostly elderly subjects with BCC (n=21) or SCC (n=19) who were not candidates for surgical excision and were treated with topical imiquimod. Most subjects had a history of skin cancer, and the median age of the subjects was 78 years and 79 years in the BCC and SCC groups, respectively. After biopsy alone or biopsy followed by curettage, subjects received imiquimod cream 5% once daily 5 times weekly for 6 weeks. Twenty-three BCC lesions and 22 SCC lesions were included in the analysis. Most of the 45 lesions treated were located on the head and most were in high-risk areas. Approximately 3 months after imiquimod therapy, repeat biopsies showed that only 3 (2 BCCs and 1 SCC) lesion sites had residual tumor. After a median follow-up of 26 months, there was only one additional SCC recurrence. We also present a selection of representative case studies. Imiquimod cream 5% as adjunctive therapy to curettage was safe and well-tolerated in this mostly elderly population. The improved residual tumor and recurrence rates compared with historical rates for electrodesiccation and curettage (ED&C) alone suggest that adjunctive imiquimod therapy may be an appropriate treatment option for patients who desire or require less invasive treatment for NMSCs.