Yuh Baba and Yasumasa Kato
The Epidermal Growth Factor Receptor (EGFR) is overexpressed in most Head and Neck Squamous Cell Carcinomas (HNSCCs), making EGFR an important therapeutic target. Although specific mutations in EGFR sensitize inhibitors of the EGFR tyrosine kinase, these mutations are rarely observed in HNSCCs. Early clinical trials of monotherapy with EGFR inhibitors in patients with HNSCC have therefore yielded disappointing results. Clinical response rates to EGFR inhibitors may be improved by identifying suitable biomarker(s). One such promising biomarker is PIK3CA, which encodes phosphoinositide 3-kinase catalytic subunit α isoform; mutations in this gene may predict the efficacy of EGFR inhibitors.
