Non-small Cell Lung Cancer Patients with EML4-ALK Fusion Gene Are Insensitive to Cytotoxic Chemotherapy

Background: Although patients with the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase gene (EML4-ALK) re-arrangement and epidermal growth factor gene EGFR mutations have proven sensitive to specific inhibitors, there is currently no consensus regarding the sensitivity of non-small cell lung cancer (NSCLC) patients with such mutations to cytotoxic chemotherapy. Patients and Methods: The responses to first-line cytotoxic chemotherapy were retrospectively compared between advanced or postoperative recurrent patients with non-squamous NSCLC who harbor the EML4-ALK fusion gene (ALK(+)), EGFR mutation (EGFR(+)), or neither abnormality (wild-type). Results: Data for 22 ALK(+), 30 EGFR(+), and 60 wild-type patients were analyzed. The ALK(+) group had a significantly lower response rate than the other two groups. Progression-free survival was significantly shorter in the ALK(+) cohort compared to the EGFR(+) (p<0.001) and wild-type cohorts (p=0.0121). Conclusion: NSCLC patients with the EML4-ALK fusion gene might be relatively insensitivite to cytotoxic chemotherapy.