The ImplementatioN of perSonalized medicine In NSCLC in Central Europe: EGFR testing, Histopathology, and clinical feaTures (INSIGHT) observational study assessed both implementation of epidermal growth factor receptor (EGFR) mutation testing and treatment of patients with advanced EGFR mutation-positive non-small-cell lung cancer (NSCLC) in a real-world setting in Central Europe. A total of 1785 patients from 14 cancer centers of six Central European countries were enrolled. EGFR mutations were detected in tumors of 13.8% of the patients. More than 70% of patients with advanced EGFR mutation-positive NSCLC received EGFR tyrosine kinase inhibitors as first-line therapy. The INSIGHT study demonstrated the establishment of EGFR mutation testing, a mutation rate consistent with other Caucasian patients populations, and adherence to current guidelines regarding treatment of patients with EGFR mutation-positive tumors in Central Europe.