Background: Targeted therapy with tyrosine kinase inhibitors (TKIs) were used to treat lung adenocarcinoma patients with EGFR mutation positive. EGFR mutations at exon 19 and exon 21 are classified as classical/common mutations, while mutations other than those exons are classified as rare/uncommon mutations. This study aims to compare the therapy responses of lung adenocarcinoma patients received TKI generation I (gefitinib and erlotinib) and TKI generation II (afatinib) in Makassar, as well as analyzed factors such as age, sex, tumor stage, type of EGFR mutation and comorbidity to therapy responses.

Methods: This study is a retrospective observational using secondary data from Lung Adenocarcinoma patient medical records at Wahidin Sudirohusodo Hospital Makassar in 2016 - 2020, involved 84 patients aged 28-83 years who received targeted therapy. The subjective response was determined by the Eastern Cooperative Oncology Group (ECOG) score, while the objective response was determined by the Response Evaluation Criteria In Solid Tumor (RECIST) guidelines version 1.0. The statistical test used were Pearson’s Chi-Square. The results were considered significant if p-value <0.05.

Results: Subjective response from PS2 to PS1 and from PS2 to PS0 were significantly higher in common mutations than in uncommon mutations (p<0.05). While subjective response was shown higher in TKI generation II than in TKI generation I but not statistically significant (p=0.464). The objective response of Progressive Disease (PD) was shown significantly higher in TKI generation I than in TKI generation II (p<0.05), and the objective response of PD was obtained significantly higher in uncommon mutations than in common mutations (p<0.05). Factors such as age, gender, tumor stage and comorbidities did not have a significant correlation to objective and subjective responses.

Conclusions: Targeted therapy with TKI generation II provided a significantly better objective response than TKI generation I. The type of EGFR mutation "common/classical mutation" provides a better therapeutic response regardless of the type of TKI targeted therapy received.