AUTHOR=Li Yongjiang , Zhang Wenbiao , Zhang Hu , Hu Junfeng , Zhou Chao , Zhang Xu , Fan Wei 

TITLE=Prognostic Significance of Regional/Systemic Metabolic Parameters on 18F-FDG PET in Pulmonary Lymphoepithelioma-Like Carcinoma

JOURNAL=Frontiers in Oncology

VOLUME=Volume 11 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2021.675961

DOI=10.3389/fonc.2021.675961

ISSN=2234-943X

ABSTRACT=Background:  Pulmonary lymphoepithelioma-like carcinoma (LELC) is a rare subtype of lung cancer with less than 700 cases been reported in the literature and no specialized treatment guidelines been established. The prognostic significance of metabolic parameters on 18F-FDG PET in pulmonary LELC still remains unknown.  

Methods:  From July 2011 to September 2020, 76 pulmonary LELC patients undergoing pre-treatment 18F-FDG PET imaging were enrolled, and PET parameters including maximum standard uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were calculated. In addition, whole-body tumor burdens were categorized into primary tumor lesion (PRL), thoracic lymph-node lesion (TRLN) and distant metastasis (DM) for respective metabolic parameters acquisition. ROC curves were generated to evaluate the predictive performance of the PET parameters, and correlations between tumor burdens of the different regional lesions were analyzed using linear correlation analysis. The prognostic significance for progression-free survival (PFS) and overall survival (OS) was assessed using univariate and multivariate survival analysis.  

Results:  Tumor stage, pre-/post-treatment serum EBV-DNA copies, SUVmax, MTV and TLG were significantly associated with PFS and OS in univariate analysis. MTV and TLG (AUC=0.862 and 0.857, respectively) showed significantly higher predictive value than SUVmax (AUC=0.754), and remained independent prognostic indicators for PFS in multivariate analysis (P=0.026 and 0.019, respectively). Besides, non-colinearity was detected between metabolic burdens of the different regional lesions. MTV-PRL, MTV-DM , TLG-PRL and TLG-DM were identified to be independent prognostic factors for PFS and OS, whereas MTV-TRLN and TLG-TRLN were not.  

Conclusion:  The study demonstrated that MTV and TLG had independent prognostic significance for pulmonary LELC, which supported the incorporation of 18F-FDG PET imaging into clinical treatment protocols for pulmonary LELC, and implied multi-disciplinary cooperation for primary and distant metastatic lesions to further improve prognosis.