First- or second-line gefitinib therapy in unknown epidermal growth factor receptor mutants of non-small-cell lung cancer patients treated in Taiwan.

Gefitinib is effective in treating patients with non-small-cell lung cancer (NSCLC). The response rate and improvement in survival are related to several aspects, including race, gender, smoking status, and histology; however, little is known about the relationship between survival and length of gefitinib treatment. We conducted this retrospective study to examine this relationship and identify the predictive factors influencing survival and tumor response in chemonaive and chemotherapy patients who had stage IIIb or IV NSCLC with unknown epidermal growth factor receptor mutants. This analysis was aimed to clarify the difference between first- and second-line gefitinib therapy. Among the 918 newly diagnosed, inoperable NSCLC patients from March 2003 to December 2006, 437 (47.6%) had ever received gefitinib therapy. One hundred forty-nine patients (34.0%) who selected gefitinib as first- or second-line therapy were included in the analysis. The overall survival rates of first- and second-line gefitinib therapy were 12.8 months and 20.7 months, respectively (P = .110). The shorter overall survival may be caused by the omission of platinum-based doublet chemotherapy in 37 patients from the first-line group (39.4%). There was also no significant difference in progression-free survival (6.8 months versus 4.9 months; P = .415), and the objective tumor response and disease control rates were similar. Better prognosis and tumor response was associated with female gender, adenocarcinoma, nonsmokers, and good performance status. The difference in overall survival between patients undergoing second-line treatment compared with those undergoing first-line treatment preceding chemotherapy was significant (P = .041). The overall survival, progression-free survival, and tumor response rates were similar in the patients who received gefitinib as initial therapy or after conventional chemotherapy.