Liver Function Test Profile in Non-Small Cell Lung Cancer Patients Receiving Gefitinib or Erlotinib Therapy at Dharmais Cancer Hospital

Comparative safety profiles regarding drug-induced liver transaminase elevations between first-generation EGFR-TKIs in Indonesian settings remain underreported. This retrospective cohort study aimed to evaluate differences in post-treatment alanine aminotransferase (ALT) and aspartate aminotransferase (AST) elevations between erlotinib (150 mg daily) and gefitinib (250 mg daily) in patients with non-small cell lung cancer (NSCLC) at Dharmais Cancer Hospital from 2022 to 2024. Methods: A total of 114 patients with normal baseline transaminase levels (≤ 1.0 × ULN) were evaluated, comprising 35 patients receiving erlotinib and 79 patients receiving gefitinib. Intra-group paired transaminase changes were evaluated using the Wilcoxon signed-rank test, and inter-group differences in delta values were analyzed using the Mann–Whitney U test. Binary logistic regression was performed to estimate odds ratios (ORs) for developing any-grade (CTCAE v5.0 Grade 1–3) ALT and AST elevations. Post-treatment evaluations revealed statistically significant ALT and AST increases from baseline in both groups. The median ALT increase was greater in the gefitinib cohort compared to the erlotinib cohort (26 U/L vs. 6 U/L, p = 0.039), whereas median AST changes showed no significant difference (8 U/L vs. 9 U/L, p = 0.297). Patients receiving gefitinib demonstrated higher odds of developing any-grade ALT elevation compared to erlotinib; however, this association did not reach statistical significance at α = 0.05 (OR = 2.18; p = 0.0594). The odds of AST elevation were comparable between groups (OR = 0.65; p ≥ 0.05). Observed elevations were predominantly mild and subclinical (CTCAE Grade 1–2). Gefitinib was associated with a significantly greater magnitude of ALT increase than erlotinib, though the higher odds of experiencing any-grade ALT elevation showed a non-significant trend. Evidence for differential definitive hepatotoxicity between the two agents remains inconclusive. Routine hepatic monitoring remains essential. Study interpretation is mainly limited by an underpowered sample size and an imbalanced cohort ratio.