ABSTRACT
Background: Anaplastic lymphoma kinase (ALK)?rearranged nonsmall cell lung cancer (NSCLC) represents a molecular subgroup with high sensitivity to ALK inhibitors. Tyrosine kinase inhibitor crizotinib, an anticancer drug acting as an ALK inhibitor, has shown remarkable response in ALK?positive NSCLC. The aim of our study is to explore the adverse events (AEs) of patients on crizotinib therapy and analyze the predictability of AEs for better survival or response on NSCLC patients. Methods: The medical records of our ALK?positive metastatic NSCLC patients who applied between years 2013 and 2018 had been reviewed retrospectively. ALK positivity of all patients had been detected by fluorescence in situ hybridization and no other driver mutations were present. Patient demographics, performance status, smoking history, previous treatments, metastatic sites, and AEs were recorded for further analyses. Results: Thirty?six ALK?positive metastatic NSCLC patients were included in the study. Median follow?up was 30.1 months. Median progression?free survival (PFS) for patients who developed hepatic, cardiac, or endocrine toxicities was similar when compared to patients who did not develop. Although there was a numeric median PFS difference between patients who did develop visual disorders (18.4 months) and did not develop visual disorders (15.5 month), this was not regarded as statistically significant. However, median PFS of the patients who developed neutropenia upon crizotinib treatment (31.9 months) was found to be more favorable than the patients with normal neutrophil counts (12.8 months) (P = 0.026). Conclusion: Neutropenia under crizotinib treatment was found to be associated with improved PFS suggesting that neutropenia might be an important determinant in treatment and survival strategies.