Evaluation of Progression-Free Survival and Overall Survival of Epidermal Growth Factor Receptor-Positive Metastatic Lung Adenocarcinoma Patients Treated with Erlotinib

Background: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as erlotinib and gefitinib have shown promising efficacy and tolerability in patients with advanced NSCLC. Identifying subgroups of patients who benefit from EGFR-TKI treatment may help achieve better treatment responses. Therefore, this study was performed to evaluate the indicators of response to treatment, including progression-free survival (PFS) and overall survival (OS) of patients. Methods: The study was performed as a prospective cohort in patients referred to Hazrat Rasoul Akram Hospital in Tehran for two years (April 2019-April 2021). Erlotinib was administered to patients at 100-150 mg daily. After completion or discontinuation of erlotinib, patients were followed up every three months to evaluate clinical outcomes. Independent t-test or Man-Whitney test was used to compare quantitative variables, chi-square or Fisher exact test was used to compare qualitative variables, and correlation test was used to determine the relationship between quantitative data. Analysis of overall survival and progression-free survival was performed using the Kaplan-Meier test. Significant levels less than 0.05 were considered. Results: Thirty-two patients participated in the final analysis. Out of 32patients, 21 (65.6%) were female, and 11 (34.4%) were male. The mean age was 59.12±14.17years (32–89years). The mean PFS was 11.44±9.35months and, the OS of patients was 21.78±14.35months. Of the 32 patients, 4 (12.5%) had a history of smoking and, the rest had no history of smoking. Conclusion: Finally, according to the findings of the present study, the use of erlotinib can be considered as an effective first-line treatment option with controllable toxicity in patients with advanced or metastatic NSCLC with positive EGFR. In addition, metastatic progression asymptomatic disease has been identified as the predominant pattern of disease progression. It can be stated that smoking history can play a risk factor in reducing PFS time.