Abstract
Objective. We investigated the clinical effect of gastric acid-suppressing drugs (ASs) on the efficacy and safety of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC) patients with EGFR mutations. Methods. The clinical characteristics, efficacy, and toxicity of gefitinib and erlotinib were retrospectively evaluated in 98 patients with EGFR mutation-positive adenocarcinoma who had been treated with gefitinib or erlotinib at our center between August 2008 and December 2014. Results. Among the 56 patients receiving gefitinib, ASs were coadministered in 25 (44.6%): 17 received a proton pump inhibitor, and 8 received a histamine 2 receptor antagonist. Among the 42 patients receiving erlotinib, ASs were coadministered in 33 (78.6%): 21 received a proton pump inhibitor, and 12 received a histamine 2 receptor antagonist. Among the patients receiving gefitinib and erlotinib, the objective response rate, disease control rate, and median progression-free survival were not significantly different between those who did and did not receive ASs. Regarding toxicity, in the erlotinib group, the incidence of Grade 3/4 AST or ALT elevation was significantly lower among patients receiving ASs than among those not receiving ASs (3% vs. 22%; p=0.023). There were no other significant differences in adverse events among the treatment subgroups. Conclusions. These findings suggest that the co-administration of ASs had no effect on the efficacy or toxicity of EGFR-TKIs in patients with EGFR mutation-positive NSCLC.
