Application of the Novel Grading System of Invasive Pulmonary Adenocarcinoma in a Real Diagnostic Scenario: A Brief Report of 9353 Cases

Yunlang She; Yifan Zhong; Likun Hou; Shengnan Zhao; Liping Zhang; Dong Xie; Yuming Zhu; Chunyan Wu; Chang Chen

doi:10.1016/j.jtocrr.2023.100465

Application of the Novel Grading System of Invasive Pulmonary Adenocarcinoma in a Real Diagnostic Scenario: A Brief Report of 9353 Cases

JTO Clin Res Rep. 2023 Jan 24;4(3):100465. doi: 10.1016/j.jtocrr.2023.100465. eCollection 2023 Mar.

Authors

Yunlang She¹, Yifan Zhong¹, Likun Hou², Shengnan Zhao², Liping Zhang², Dong Xie¹, Yuming Zhu¹, Chunyan Wu², Chang Chen¹

Affiliations

¹ Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China.
² Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China.

Abstract

Introduction: The International Association for the Study of Lung Cancer proposed a novel grading system of invasive pulmonary adenocarcinoma (IPA), but the application of this grading system and its genotypic characterization in the real diagnostic scenario has never been reported.

Methods: We prospectively collected and analyzed the clinicopathological and genotypic features of a cohort of 9353 consecutive patients with resected IPA, including 7134 patients with detection of common driver mutation.

Results: In the entire cohort, 3 (0.3%) of lepidic, 1207 (19.0%) of acinar, and 126 (23.6%) of papillary predominant IPAs were diagnosed as grade 3. In chronological order, an evident downtrend of the proportion of grade 2 was observed in chronological order. Conversely, the diagnostic ratio of grade 1 (8.0%-14.5%) and grade 3 (27.9%-32.3%) experienced a gradual rise. EGFR mutation was more frequently detected in grade 2 (77.5%) and grade 1 (69.7%) IPA than grade 3 (53.7%, p < 0.001), whereas the mutation rates of KRAS, BRAF, ALK, and ROS1 were higher in grade 3 IPA. More importantly, the rate of EGFR mutation gradually fell as the proportion of high-grade components increased, to 24.3% in IPA with more than 90% high-grade components.

Conclusions: The grading system for IPA could be applied to stratify patients with different clinicopathological and genotypic features in a real diagnostic scenario.

Keywords: Complex glands; EGFR mutation; Grading system; Histological grade; Lung adenocarcinoma.