Outcomes and Prognostic Factors in Patients with EGFR Mutant Metastatic Non-Small Cell Lung Cancer Who Treated with Erlotinib

The study's goal is to evaluate the effectiveness of erlotinib in patients with EGFR mutant metastatic non-small cell lung cancer (mNSCLC). The patient's medical data were analyzed retrospectively. Erlotinib's effectiveness was assessed by the radiological response. Survival analyzes were done for prognostic factors. Eighty-five patients were included in the study. 49 (57.6%) of the patients were female, and the average age was 60 (range, 33-85). Exon 19, exon, 21, and other mutations were detected in 62.4%, 24.7%, and 12.9%, respectively. Brain metastases were present in 25.9% and liver metastases in 17.6% of patients. Before erlotinib treatment, 25.9% of the patients received chemotherapy, and 43.5% received radiotherapy. With erlotinib treatment, complete response was found in 15.3%, partial response in 51.8%, and stable response in 10.6% of patients. Median PFS was 22.3 (95% CI, 11.0-33.5) months. Grade 1-2 side effects were observed in 29.1% of the patients, and grade 3-4 side effects in 7.1%. The median OS was found as 37.5 (95% CI, 22.6-52.4) months. The 5-years overall survival rate was found to be 32.2%. In this study, we showed outcomes of erlotinib therapy in patients with EGFR mutant mNSCLC. Erlotinib has been well-tolerated and effective in disease control. Age, number of metastases, and EGFR mutation type predict treatment-related prognosis.