HER1-4 expression status correlates with the efficacy of gefitinib treatment and tumor cell proliferative activity in non-small cell lung cancer.

The expression of human epidermal growth factor receptor (HER) family proteins was examined in specimens of 52 non-small cell lung cancers to evaluate their significance in tumor cell proliferation and their response to gefitinib. Epidermal growth factor receptor (EGFR; HER1) protein was expressed most frequently (43/52 cases). HER2 and HER3 were detected in 13 and 18 cases, respectively.