Issues

Targeting strategies of the epidermal growth factor receptor (EGFR) with small-molecules EGFR tyrosine kinase inhibitors (TKIs) or a monoclonal antibody (cetuximab) are being developed in non-small cell lung cancer. Unlike TKIs, cetuximab potentially can provoke immunologic antitumor effects, such as antibody-dependent cellular cytotoxicity (ADCC) activity, although few studies have focused on this activity. The cover shows an immunostaining of EGFR on a cancer cell line, which express 3.51×10⁶ EGFR molecules measured by quantitative flow cytometric analysis. Using these estimation methods, the authors demonstrated that even low EGFR expression levels on lung cancer cells, which are weakly detectable by immunostaining, are sufficient for maximum ADCC activity, and further increases in EGFR expression on the target cells have no further effect on the ADCC activity. For further details, please see Kurai et al. on page 1552 in this issue.