Abstract
Pulmonary enteric adenocarcinoma (PEAC) is a distinct subtype of non-small cell lung cancer (NSCLC) whose histomorphology and immunophenotype closely resemble those of metastatic colorectal adenocarcinoma; its pathogenesis and standard treatment strategies have yet to be clearly established. Here, we reported a case of PEAC harboring epidermal growth factor receptor (EGFR) exon 19 deletion mutation with high programmed cell death ligand 1 (PD-L1) expression. The patient showed no meaningful response to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), including the first-generation (Icotinib), the second-generation (Afatinib) and the third-generation (Aumolertinib). Trophoblast cell surface antigen 2-antibody-drug conjugate (TROP2-ADC) and immune checkpoint inhibitors (ICIs) combined with Bevacizumab also resulted in limited efficacy. Based on the clinical features and treatment response of this case, we reviewed the published literature about the pathological characteristics, mutational landscape, and current therapeutic approaches for PEAC, with a particular focus on the therapeutic challenges and future research directions for EGFR-mutant PEAC, aiming to provide insights for clinical practice and further studies.
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