Gefitinib, an effective treatment option for patients with pulmonary enteric adenocarcinoma harboring compound EGFR L858R and A871G mutation.

Pulmonary enteric adenocarcinoma (PEAC) is a rare lung adenocarcinoma with morphological and immunohistochemical similarities to colorectal adenocarcinoma and intestinal differentiation. PEAC belongs to the group of non-small-cell lung carcinoma (NSCLC) and is defined as having a more than 50% intestinal differentiation component. We report a postoperative (T4N2M0 stage IIIb) PEAC patient with EGFR L858R + A871G combined mutation. Following surgery, the patient underwent treatment with the first-generation EGFR-TKI, gefitinib, and achieved an impressive 5-year progression-free survival (PFS). This suggests that gefitinib may serve as an effective treatment option for PEAC patients with EGFR L858R + A871G compound mutations.