Induction Hedgehog pathway inhibition followed by combined‐modality radiotherapy for basal cell carcinoma

Summary Basal cell carcinoma (BCC), the most common cancer in the U.S.A., is treated primarily with local excision. In some cases, lesion size, location or extent prevent complete resection. Locally advanced BCC responds to systemic therapy with the Hedgehog pathway inhibitor vismodegib, but withdrawal of treatment may result in disease relapse. Here we present a case of locally advanced auricular BCC treated with induction vismodegib and radiation, resulting in durable local control and an acceptable level of acute toxicity. What's already known about this topic? Basal cell carcinoma (BCC) is dependent on misactivation of the Hedgehog signalling network. The Hedgehog pathway inhibitor vismodegib is an effective treatment for relapsed and disseminated BCC. Clinical responses to vismodegib are often partial, especially in cases of advanced local disease, and are not always durable. Many patients discontinue systemic treatment due to toxicity. What does this study add? Although radiation can be used in combination with Hedgehog pathway inhibition to achieve durable local control of BCCs, the optimal sequence and timing of therapy is not yet known. This case demonstrates that induction therapy with vismodegib facilitates re‐epithelialization as tumours regress, potentially sparing selected patients from nonhealing resulting from radiotherapy to open wounds.