The comparison of outcomes from tyrosine kinase inhibitor monotherapy in second- or third-line for advanced non-small-cell lung cancer patients with wild-type or unknown EGFR status

Background: Second-line treatment for advanced non-small-cell lung cancer (NSCLC) patients includes monotherapy with a third-generation cytotoxic drug (CT) or a tyrosine kinase inhibitor (TKI). These options are the actual standard for EGFR wild-type (WT) status, as patients with EGFR mutations achieve greater benefit by the use of TKI in first-line treatment. Some clinical trials and meta-analyses investigated the comparison between CT and TKI in second-line, but data are conflicting.
Methods: We designed a retrospective trial to gather information about TKI sensitivity in comparison with CT. We selected from clinical records patients treated with at least 1 line of CT and at least 1 line of TKI. We collected data about age, sex, performance status, comorbidity, smoking status, histotype, metastatic sites, EGFR status, treatment schedule, better response and time-to-progression (TTP) for each line of treatment and overall survival (OS).
Results: 93 patients met selection criteria. Mean age 66,7 (range: 46-84). M/F ratio is 3: 1. 39 EGFR-WT and 54 EGFR-UK. All patients received erlotinib or gefitinib as second-line treatment or erlotinib as third-line treatment. No TTP differences were observed for both second-line (HR: 0,91; p = 0,6333) and third-line (HR: 1.1; p = 0,6951) treatment (TKI vs CT). A trend of a benefit in OS in favor of 3rd-line TKI (HR: 0,68; p = 0,11).
Conclusions: This study explores the role of TKIs in EGFR non-mutated NSCLC patients. OS analysis highlights a trend to a benefit in patients who received TKI in third-line, even if this result is statistically non-significant. Further analysis are needed to find an explanation for this observation.