Long-Term Follow-Up Results of Topical Imiquimod Treatment in Basal Cell Carcinoma

Abstract

Although imiquimod is only approved for superficial BCC, treatment success was high among the study patients with various histological subtypes, with good long-term cosmetic results.

Mediators of Inflammation in Topical Therapy of Skin Cancers

“…BCC is caused by aberrant activation of the hedgehog/glioma-associated oncogene pathway, mostly due to genetic inactivation of the protein patched homolog (PTCH) gene or activation of “smoothened.” Recent studies have shown that IMQ mechanisms of action include the stimulation of adenosine receptor/protein kinase A-mediated GLI phosphorylation, resulting in the inhibition of hedgehog signaling [68].…”

“…However, for nasal localization of the BCC, the results were not as satisfactory, with a long-term response of only 63%. Therefore, the authors suggest IMQ treatment of nasal BCCs only if the patient cannot tolerate other types of treatment [68]. After a mean follow-up of 70 months, only 2 relapses were observed among 21 patients with complete response.…”

“…The authors suggested that IMQ treatment should be avoided in metatypical carcinoma, due to its aggressive biology. Usually, the prognosis for this type of carcinoma is worse than for the classical BCC, and the recurrence rate is higher [68]. The vast majority of recurrences of the BCC occurred within the first 12-24 months [46].…”

“…Moreover, development of SCC on 3 BCC lesions treated with vismodegib, a hedgehog pathway inhibitor, has been reported. The most probable theory is that either the initial lesion was a metatypical BCC or the hedgehog pathway inhibitor may have induced squamous differentiation in some stem cells, located in the deep epidermal layer or near the follicular bulge [68].…”

Successful treatment of multifocal pigmented basal cell carcinomas with the application of topical 5% imiquimod cream

“…The recommended dosage schema of the topical imiquimod therapy is not standardized and it varies among the different studies. The application is generally once daily, three to five times per week (Sterry et al, 2002) and the recommended duration of therapy lies between 6 and 8 weeks (Jansen et al, 2018;Schulze et al, 2005;Geisse et al, 2004), with success rate of up to 77%-79% (Bostanci, Kocyigit, Vural, Heper, & Botsali, 2018;Schulze et al, 2005). Occlusion does not seem to have a statistically significant effect on the efficacy of the treatment (Sterry et al, 2002).…”