Bilateral diffuse metastases in advanced lung adenocarcinoma harboring EGFR mutations was associated with a favorable prognosis to EGFR-TKIs.

Bilateral diffuse metastatic lung adenocarcinoma (BLDM-LUAD) is a special imaging pattern of lung adenocarcinoma (LUAD). We retrospectively assessed survival outcomes and co-mutation characteristics of BLDM-LUAD patients harboring epidermal growth factor receptor (EGFR) mutations who were treated with EGFR-yrosine kinase inhibitors (TKIs). From May 2016 to May 2021, among 458 patients who submitted samples for next generation sequencing (NGS) detection in 1125 patients with non-small-cell lung cancer (NSCLC), and 44 patients were diagnosed as BLDM-LUAD. In order to analyze the survival outcomes of BLDM-LUAD patients harboring EGFR mutations who were treated with EGFR-TKIs, the factors age, gender, smoking history, hydrothorax, site of EGFR mutations and EGFR-TKIs treatment were adjusted using propensity score-matching (PSM). The Kaplan-Meier survival curves and log-rank test were used to analyze progression-free survival (PFS) and overall survival (OS). The co-mutation characteristics of BLDM-LUAD patients harboring EGFR mutations were analyzed by NGS panels. 64 patients with advanced lung adenocarcinoma harboring EGFR mutations and first-line treatment of EGFR-TKIs were successfully matched. BLDM-LUAD (n = 32) have significantly longer median PFS than control group (n = 32) (mPFS: 14 vs 6.2 months; p = .002) and insignificantly longer median OS than control group (mOS: 45 vs 25 months; p = .052). The patients with BLDM-LUAD have the higher frequency of EGFR mutation than control group (84.1% vs 62.0%) before PSM. The co-mutation genes kirsten rat sarcoma viral oncogene homolog (KRAS) (9.4%), ataxia telangiectasia-mutated (ATM) (7.4%) and mesenchymal-epithelial transition (MET) (3.1%) only appeared in the control group after PSM. The BLDM-LUAD harboring EGFR mutations was associated with a favorable prognosis to EGFR-TKI.