368P - A special Imaging pattern of bilateral diffuse metastases in advanced lung adenocarcinoma harboring EGFR mutations was associated with a favorable prognosis to EGFR-TKIs

Background

Bilateral diffuse metastatic lung adenocarcinoma (BLDM-LUAD) is a special imaging pattern of lung adenocarcinoma (LUAD), characterized by diffuse, innumerable, small metastatic lesions evenly distributed in bilateral lungs. We retrospectively assessed survival outcomes and co-mutation characteristics of BLDM-LUAD patients harboring EGFR mutations who were treated with EGFR-TKIs.

Methods

From May 2016 to May 2021, 1125 patients with NSCLC were admitted to the Second Affiliated Hospital of Nanchang University. Among 458 patients who submitted samples for NGS detection, 44 patients were diagnosed as BLDM-LUAD, and 129 patients were included in control group. 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 1:1 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.

Results

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; HR: 2.58(95%CI: 1.38−4.84); P=0.002) and longer median OS than control group (mOS: 45 vs. 25 months; HR: 2.64(95%CI: 0.96−7.24); P=0.052). 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 KRAS (9.4%), ATM (7.4%), MET (3.1%), MTOR (3.7%), SMAD4 (3.7%) only appeared in the control group, while he co-mutation genes APC (8.3%), BRCA2 (8.3%), ERBB2 (6.7%), BRAF (3.3%) only appeared in the BLDM-LUAD group after PSM.

Conclusions

The special bilateral diffuse metastases pattern in advanced lung adenocarcinoma harboring EGFR mutations was associated with a favorable prognosis to EGFR-TKIs.

Clinical trial identification

Editorial acknowledgement

We thank Yu Zhong from Berry Oncology, Co., Ltd. for editorial assistance in the writing of the abstract.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.