Targeted therapy for orbital and periocular basal cell carcinoma and squamous cell carcinoma.

PURPOSE: To review the literature on targeted therapy for orbital and periocular basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (SCC) and provide examples of patients recently treated with such therapy.
METHODS: The authors reviewed the literature on clinical results of targeted therapy and the molecular basis for targeted therapy in orbital and periocular BCC and cutaneous SCC. The authors also present representative cases from their practice.
RESULTS: Mutation in the patched 1 gene (PTCH1) has been implicated in BCC, and overexpression of epidermal growth factor receptor (EGFR) has been shown in SCC. Vismodegib, an inhibitor of smoothened, which is activated upon binding of hedgehog to Ptc, has been shown to significantly decrease BCC tumor size or even produce complete resolution, especially in cases of basal cell nevus syndrome. Similarly, EGFR inhibitors have been shown to significantly decrease SCC tumor size in cases of locally advanced and metastatic disease. The authors describe successful outcomes after vismodegib treatment in a patient with basal cell nevus syndrome with numerous bulky lesions of the eyelid and periocular region and erlotinib (EGFR inhibitor) treatment in a patient with SCC who was deemed not to be a good surgical candidate because of advanced SCC of the orbit with metastasis to the regional lymph nodes, advanced age, and multiple medical comorbidities.
CONCLUSIONS: Targeted therapy using hedgehog pathway and EGFR inhibitors shows significant promise in treatment of orbital and periocular BCC and cutaneous SCC, respectively. Such targeted therapy may be appropriate for patients who are not good candidates for surgery.