Leading the way for SCC is cetuximab, which has been approved by the Food and Drug Administration as single-agent therapy for recurrent or metastatic disease and in combination with radiation therapy for locally advanced SCC of the head and neck.
But targeted therapy has its shortcomings, Dr. Hofbauer stressed. "These molecules are not as specific or targeted as we'd like them to be. That can lead to untoward outcomes," he noted.
Dr. Hofbauer cited as an example sorafenib (Nexavar), an oral inhibitor of multiple tyrosine protein kinases. Sorafenib is approved for the treatment of advanced renal cell carcinoma and advanced hepatocellular carcinoma. But in addition to its better-known dermatologic side effects, such as hand-foot syndrome, sorafenib also apparently induces SCC or inflammation of actinic keratosis in about 7% of treated patients (Clin. Genitourin. Cancer 2009;7:20-3). The likely mechanism involves impairment of skin immunosurveillance due to reduced dendritic cell function and a diminished primary immune response, he said.
Dr. Hofbauer reported having no conflicts of interest.