6. Oncological characteristics of EGFR gene mutated clinical-stage IA lung adenocarcinoma stratified by radiological findings based on a ground-glass opacity component

Objectives: In early-stage lung adenocarcinoma, distinct clinicopathological and oncological outcomes have been widely reported based on the presence or absence of a ground-glass opacity (GGO) component, which was confirmed in a nationwide study conducted in JCOG0201 supplemental analysis. Meanwhile, a specific correlation between EGFR gene mutation positive lung adenocarcinoma and the presence of a radiologically GGO component is well-known. However, clinicopthological and oncological features have not been clarified in cases where tumors show a radiologically pure-solid appearances even in EGFR mutated early-stage lung adenocarcinoma. Hence, we aimed to evaluate the oncologic characteristics and survival outcomes of EGFR gene mutated clinical-stage IA lung adenocarcinoma stratified by radiological findings based on a presence of GGO component.
Methods: Between 2008 and 2020, the data from 1014 surgically resected clinical-stage 0-IA EGFR-mutated lung adenocarcinomas were evaluated. The consolidation tumor ratio (CTR) is defined as the ratio of the maximum consolidation size to the maximum tumor size on a thin-section CT scan. In this study, all patients were classified into 2 groups based on the presence of GGO component; With GGO arm (0 ≤ CTR < 1.0) and Pure-solid arm (CTR =1.0). Oncological characteristics were compared between the 2 study arms. Multivariable analyses were performed using the Cox proportional hazard model. Overall survival (OS) was estimated using Kaplan-Meier analysis and log-rank test. Cumulative incidence function was used to evaluate the risk of postoperative cancer recurrence by the method of Gray.
Results: Of all, 233 (23%) were Pure-solid arm. Compared to With GGO arm (n=781, 77%), the proportion of nodal metastasis (23.6% vs. 2.4%, p<0.001), micropapillary component (4.3% vs. 0.8%, p<0.001), spread through alveolar space (18.9% vs. 4.6%, p<0.001) were significantly high, and the Ex19 subtype was more common (53% vs. 37%, p<0.001) in Pure-solid arm. This trend was similarly demonstrated in 623 radiological solid-predominant lesions (i.e., 0.5 Conclusions: Among the EGFR mutated stage IA lung adenocarcinoma, oncologic behavior and prognosis of radiologically pure-solid tumor was significantly poor compared to the tumors with a GGO component. These findings imply the distinct tumor genesis according to the GGO presence among the early-stage lung adenocarcinoma with EGFR gene mutation.

Aritoshi Hattori (1), Takeshi Matsunaga (1), Mariko Fukui (1), Kazuya Takamochi (1), Kenji Suzuki (1), (1) Juntendo University Hospital, Tokyo, Tokyo

Haiquan Chen

Invited Discussant

Dr. Chen holds the position of chairman and professor in the Department of Thoracic Surgery at the Fudan University Shanghai Cancer Center. Additionally, he serves as the director of the Institute of Thoracic Oncology and the Lung Cancer Center. He holds the role of vice chief editor for the Journal of Cancer Research and Clinical Oncology and JTO Clinical and Research Reports. He is a member of the editorial board for several SCI journals, including the Journal of Thoracic and Cardiovascular Surgery. Dr. Chen is the leading principal investigator for more than 10 research programs, including two major programs funded by the National Natural Science Foundation of China. He has published over 250 papers in academic journals, including Cancer Cell, JCO, and CCR. Notably, his innovative discoveries in 33 of his papers have been referenced in 17 international guidelines for 41 times, such as guidelines from ASCO, ESMO, ACCP, and IASLC.

Aritoshi Hattori

Abstract Presenter

Name:      Aritoshi Hattori, M.D.     Age:    44 years old  

Position Title:    Associate professor, Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo

Education:     National Defense Medical Collage, Saitama, Japan, graduated in 2005

Professional Training and Clinical Experience:

Assistant professor, Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, 2016-2018

General Thoracic Ward director, Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, 2018-

Associate professor, Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, 2019-

Representative committee of JCOG Lung Cancer Study Group, Japan, 2022-

Awards:

Award of the Japanese Association of the Chest Surgery, 2017

Research fields:

Thoracic Surgery and Oncology

Small-sized lung cancer, especially in the fields of the approptiate operative mode, prognosticator, radiological findings (CT or PET), and clinical Tstaging

Radiological findings of early-stage NSCLC based on the presence of a Ground-glass opacity (GGO) component on thin-section CT scan

Published papers:

40 paper, in the field of small-sized or early stage NSCLC