High-grade tumor classified by new system is a prognostic predictor in resected lung adenocarcinoma

• Published in: General thoracic and cardiovascular surgery Vol. 70; no. 5; pp. 455 - 462
• Main Authors: Yoshida, Chihiro, Yokomise, Hiroyasu, Ibuki, Emi, Go, Tetsuhiko, Haba, Reiji, Kadota, Kyuichi
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01-05-2022; Springer Nature B.V
• Subjects: Adenocarcinoma - pathology; Adenocarcinoma of Lung - pathology; Adenocarcinoma of Lung - surgery; Cardiac Surgery; Cardiology; Classification; Humans; Internet resources; Lung cancer; Lung Neoplasms - surgery; Medical prognosis; Medicine; Medicine & Public Health; Neoplasm Staging; Original Article; Patients; Prognosis; Retrospective Studies; Review boards; Surgical Oncology; Thoracic Surgery; Tumors; Adenocarcinoma; Prognosis; Tumor grading; Histologic subtype; Lung
• ISSN: 1863-6705; 1863-6713
• DOI: 10.1007/s11748-021-01758-3

Objectives
A grading system for pulmonary adenocarcinoma has not been established; hence, the International Association for the Study of Lung Cancer (IASLC) pathology panel developed a new grading system for invasive adenocarcinoma. We aimed to evaluate the prognostic significance of the IASLC grading system for invasive pulmonary adenocarcinoma.
Methods
We conducted a retrospective analysis of 471 Japanese patients with resected lung adenocarcinoma. Tumors were classified in accordance with the IASLC grading system and 2015 World Health Organization classification. We analyzed recurrence-free probability (RFP) and overall survival (OS) using the log-rank test and compared the two grading systems using the Cox proportional hazards model.
Results
Grade 3 tumors of the IASLC system and high-grade tumors of the 2015 World Health Organization classification were present in 38% and 17% of patients, respectively. The 5-year RFP was lower in patients with IASLC Grade 3 tumors (45%) than in patients with IASLC Grade 1 and 2 tumors (91% and 83%, respectively). The 5-year RFP of patients with IASLC Grade 2 tumors (83%) was higher than of those with 2015 World Health Organization intermediate tumors (69%). On multivariate analysis for recurrence, IASLC Grade 3 was an independent prognostic factor of worse RFP. We showed similar results on analysis for the OS.
Conclusions
The prognostic significance of IASLC Grade 3 tumors on recurrence-free probability was confirmed through both univariate and multivariate analyses. Thus, the IASLC Grade 3 tumor is an independent factor of poor prognosis in patients with resected lung adenocarcinoma.