Squamous cell carcinomas of the skin responsive to erlotinib: 5 cases

CR: complete response EGFR: epidermal growth factor receptor EGFRi: epidermal growth factor receptor inhibitors mTOR: mechanistic target of rapamycin SCCS: squamous cell cancers of skin INTRODUCTION Epidermal growth factor receptor inhibitors (EGFRi) are a class of targeted antineoplastics used for the palliative treatment of aggressive squamous cell cancers of skin (SCCS). Most reports describe the monoclonal antibody, cetuximab, or the small molecule, gefitinib. Response rates of SCCS to EGFRi are high, with complete response (CR) not uncommon. The molecular basis for susceptibility of SCCS to EGFRi remains unknown. A report found no EGFR mutations in SCCS of patients treated with gefitinib. Erlotinib is an orally available EGFRi approved for the treatment of lung and pancreatic cancer. Here we describe the courses of 5 patients with recurrent/ unresectable or metastatic SCCS who had palliative benefit from erlotinib. We also report the results of EGFR mutational analysis of their archived tumors. One of these patients was reported on previously in an abstract.