Predictors of Outcomes in Patients with EGFR-Mutated Non-Small Cell Lung Cancer Receiving EGFR Tyrosine Kinase Inhibitors: A Systematic Review and Meta-Analysis

Some commonly available patient or disease characteristics may be associated with progression-free survival (PFS) and overall survival (OS) in EGFR-mutant non-small cell lung cancer (NSCLC) patients receiving EGFR-TKIs (epidermal growth factor receptor - tyrosine kinase inhibitors). We performed a systematic review and meta-analysis of randomized control trials (RCTs) to explore differences in outcomes associated with EGFR-TKIs among subgroups of EGFR-mutant NSCLC patients. Pooled HRs for progression or death (PFS-HRs) and pooled HRs for death (OS-HRs) were compared among sub-groups defined according to baseline clinical and demographic variables as well as type of EGFR mutation. In the entire assessable population of 4465 EGFR-mutant NSCLC patients, significant interactions with PFS were found for gender (males vs. females; pooled ratio of the PFS-HRs = 1.2; 95% CI 1.12-1.56), smoking history (smokers vs. non-smokers; pooled ratio of the PFS-HRs = 1.26; 95% CI 1.05-1.51), and type of EGFR mutation (patients with exon 21 L858R mutation vs. exon 19 deletion; pooled ratio of the PFS-HRs = 1.39; 95% CI 1.18-1.63). Male patients, smokers and patients with EGFR exon 21 L858R mutation may derive less benefit from EGFR-TKIs compared to female patients, non-smokers and patients with EGFR exon 19 deletion.