Open AccessTumor immunity is related to 18 F‐FDG uptake in thymic epithelial tumor
Author(s) -
Imai Hisao,
Kaira Kyoichi,
Hashimoto Kosuke,
Nitanda Hiroyuki,
Taguchi Ryo,
Yanagihara Akitoshi,
Umesaki Tetsuya,
Yamaguchi Ou,
Mouri Atsuto,
Kawasaki Tomonori,
Yasuda Masanori,
Kobayashi Kunihiko,
Sakaguchi Hirozo,
Kuji Ichiei,
Kagamu Hiroshi
Publication year - 2021
Publication title -
cancer medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 53
ISSN - 2045-7634
DOI - 10.1002/cam4.4176
Subject(s) - thymic carcinoma , positron emission tomography , medicine , immunohistochemistry , thymoma , biopsy , stage (stratigraphy) , standardized uptake value , glut1 , pathology , nuclear medicine , glucose uptake , biology , paleontology , insulin
Background 2‐deoxy‐2‐[fluorine‐18] fluoro‐d‐glucose ( 18 F‐FDG) positron emission tomography ( 18 F‐FDG‐PET) is a convenient modality to assess the metabolic activity within tumor cells. However, there is no consensus regarding the relationship between 18 F‐FDG uptake and the immune environment in thymic epithelial tumors (TETs). We conducted a clinicopathological study to elucidate the relationship between 18 F‐FDG uptake and programmed death ligands 1 and 2 (PD‐L1/PD‐L2) expression in patients with TETs. Methods: A total of 108 patients with histologically confirmed TETs classified as thymomas or thymic carcinomas who underwent surgical resection or biopsy or needle biopsy and 18 F‐FDG PET before any treatment between August 2007 and March 2020 were enrolled in this study. Tumor specimens underwent immunohistochemical staining for PD‐L1, PD‐L2, GLUT1, HIF‐1α, VEGFR2, VEGF‐C, and β2 adrenergic receptor. Results: High uptakes of SUV max , SUV mean , MTV, and TLG were identified in 28 (25.9%), 61 (56.5%), 55 (50.9%), and 55 (50.9%) of 108 patients, respectively. High uptake of SUV max significantly correlated with PS (performance status) of 1–2, thymic carcinoma, and advanced stage, and SUV max on 18 F‐FDG uptake displayed a close association with PD‐L1 and PD‐L2 expressions, but not with MTV and TLG. Our analysis revealed that SUV max was identified as being significant relationship for positive PD‐L1/PD‐L2 expression. GLUT1, HIF‐1α, and VEGFR2 were significantly associated with the expression of PD‐L1/PD‐L2 from the biological viewpoint. Conclusion 18 F‐FDG accumulation was closely associated with the expression of PD‐L1/PD‐L2, which, in turn, was correlated with glucose metabolism and hypoxia. PD‐L1/PD‐L2 could affect the glucose metabolism and hypoxia in thymic tumor cells.