Smoking history and prior surgical resection predict sensitivity to gefitinib in advanced non-small-cell lung cancer

Gefitinib is an inhibitor of epidermal growth factor receptor tyrosine kinase, and induces radiographic regression and symptomatic improvement in patients with non-small cell lung cancer (NSCLC). Phase II trials suggested female sex and adenocarcinoma were associated with response, never smoking history and adenocarcinoma were associated with survival. We attempted to identify additional clinical features associated with response and survival.

We reviewed medical records and imaging studies of all 68 NSCLC patients treated by gefitinib monotherapy in our institution. We identified patients experiencing disease control and compared their clinical features with those of other patients. We considered partial response, stable disease or incomplete response and stable disease to be evidence of disease control. Univariate and multivariate analysis were performed to determine predictive and prognostic factors associated with disease control and survival.

Of 68 patients, 20 (29.4%) experienced disease control. Variables identified as significant for disease control with gefitinib included never smoking history (p=0.0128) and history of curative surgical resection (p=0.0007) on multivariate analysis. Variables identified as significant for overall survival included never smoking history (p=0.0128), history of curative surgical resection (p=0.0007), and performance status (PS) of 0 and 1 (p=0.0001) on multivariate analysis.

Our findings suggest that never smoking history and history of curative surgical resection are key factors for disease control and prognostic factors in patients with NSCLC treated with gefitinib.