Comparison of Effectiveness of Gefitinib, Erlotinib, and Afatinib in Advanced Non-small Cell Lung Cancer Patients with EGFR Mutation Positive in Indonesian Population

Background and objective EGFR-tyrosine kinase inhibitors(EGFR-TKIs) were used to treat non-small cell lung cancer(NSCLC) patients with EGFR mutation positive. This study aims to compare the effectiveness of first line TKIs; gefitinib, erlotinib, and afatinib in the treatment of advanced stage NSCLC patients with EGFR mutation positive in the Indonesian population.Methods A retrospective cohort study of 88 NSCLC patients with EGFR mutation positive treated with gefitinib(n=59), erlotinib(n=22), and afatinib(n=7) was performed in national cancer hospital in Indonesia.Inclusion criteria were stage IIIb or IV NSCLC with adenocarcinoma subtype. Subjects less than 18 years or with a history of other malignancy were excluded. Outcomes were treatment response, progression-free survival(PFS), and mortality rate. Results Complete response, partial response, and stable disease were shown in 1.1%, 35.2%, and 31.8% of subjects, respectively. There were 31.8% of subjects developed progressive disease during treatment. Regarding EGFR mutation positive profile, a total of 56.8% subjects had deletion in exon 19, 42% subjects had mutation in exon 21, and rare mutation in exon 18 was found in 3.4% of total subjects. Demography and clinical characteristics had no significant association with the risk of progressive disease. The median PFS of subjects was 11 months(95%CI: 6.8-15.2 months). There was no statistical difference of PFS between treatment groups.Conclusion Gefitinib, erlotinib, and afatinib have similar effectiveness in advanced stage NSCLC with EGFR mutation positive. Afatinib tends to be associated with longer PFS but further investigation is required.