Prognostic value of E-cadherin expression in non-small cell lung cancer treated with gefitinib

E-cadherin expression has been suggested to be related with response to EGFR-TK inhibitors. To evaluate the prognostic value of E-cadherin expression in lung cancer treated with gefitinib, we retrospectively reviewed patients with inoperable stage IIIb or IV non-small cell lung cancer treated with gefitinib and compared immunohistochemical staining for E-cadherin on biopsied specimens. The association between gefitinib sensitivity and E-cadherin expression by Western blot and immunocytochemistry was also examined in 10 lung cancer cell lines. Of 52 eligible patients, 15 (28.8%) showed a partial response, and the disease control rate was 42.3%. Median progression-free survival (PFS) and overall survival (OS) in responders were 8 and 20 months, respectively. Response rates (RR), PFS, and disease control rates were higher in never-smokers and patients showing adenocarcinoma histology, and improved OS was observed in patients with adenocarcinoma. E-cadherin expression did not impact any parameters (RR, PFS, or OS). Although there was a tendency for cell lines with lower IC50 to have E-cadherin expression, H2009 cells were the least sensitive to gefitinib, with an IC50 of 30 microM, and H1650 cells had an intermediate sensitivity despite high E-cadherin expression. E-cadherin expression was not a useful indicator of response and survival after treatment with gefitinib.