Comparison of the efficacy and tolerability of gefitinib with pemetrexed maintenance after first-line platinum-based doublet chemotherapy in advanced lung adenocarcinoma: single-center experience

PURPOSE Both gefitinib and pemetrexed maintenance were effective therapies for advanced lung adenocarcinoma, but which is better is unclear. For patients with advanced lung adenocarcinoma, we have no idea whether we should choose gefitinib or pemetrexed maintenance in clinical practice. Here, we assessed the efficacy and tolerability of gefitinib versus pemetrexed maintenance in these patients. PATIENTS AND METHODS A total of 101 patients were identified and divided into gefitinib (n=53) or pemetrexed (n=48) maintenance. Epidermal growth factor receptor (EGFR) status of tumors was analyzed in 67 patients. Disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were compared between the two groups. RESULTS The results showed that DCR (79.2% vs 75%, P=0.642) was similar between gefitinib and pemetrexed groups. The PFS of gefitinib was significantly longer than that of pemetrexed (8 months vs 5.4 months, hazard ratio [HR]: 0.520, 95% confidence interval [CI]: 0.341-0.791, P=0.002); however, the OS was similar (19.9 months vs 18.8 months, HR: 1.006, 95% CI: 0.664-1.525, P=0.977). In EGFR mutation-positive patients, PFS was significantly longer in gefitinib (12 months vs 5.4 months; HR: 0.158, 95% CI: 0.074-0.333, P<0.001), whereas in EGFR wild-type subgroup gefitinib had a significantly shorter PFS than that by pemetrexed (2.5 months vs 5 months; HR: 2.822, 95% CI: 1.137-7.005, P=0.025). Cox multivariate regression analysis of PFS for overall population showed that smoking status (P=0.001) and maintenance regimens (P=0.013) were independent prognostic factors for PFS. Both gefitinib and pemetrexed were well tolerated. CONCLUSION Gefitinib compared with pemetrexed as maintenance therapy had a significantly longer PFS and a similar OS with good tolerability in patients with advanced lung adenocarcinoma. Moreover, for EGFR mutation-positive patients, gefitinib maintenance had a significantly longer PFS; however, pemetrexed maintenance was considered more effective for EGFR wild-type patients.