AUTHOR=Liu Ying , Huo Yanlei , Ma Chao , Lv Zhongwei 

TITLE=Relationship between standardized uptake value on 18F-FDG PET and PD-L1 expression in clear cell renal cell carcinoma

JOURNAL=Frontiers in Oncology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.1012561

DOI=10.3389/fonc.2022.1012561

ISSN=2234-943X

ABSTRACT=Purpose: Recent evidence suggests that partial CCRCC may be susceptible to treatment with immune checkpoint inhibitors that target the PD-1/PD-L1 pathway. Evaluation of PD-L1 expression by non-invasive imaging is useful for the selection of immunotherapy-sensitive patients. It is currently unknown whether there is a relationship between 18F-FDG uptake and expression of PD-L1 in CCRCC. The purpose of the present study was to evaluate the utility of FDG-PET imaging to infer PD-L1 expression in CCRCC.
Methods: PD-L1 expression was evaluated by immunohistochemistry (IHC) in tumor samples from a retrospective cohort of 58 patients with CCRCC who also underwent 18F-FDG PET/CT imaging. PD-L1 IHC scores were compared with FDG SUVmax, and SUVmean values, with CCRCC clinical characteristics and with IHC scores for glucose metabolism-related enzymes, GLUT1, HK2, LDHA and tumor suppressor gene VHL.
Results: Higher PD-L1 expression significantly correlated with increased SUVmax, SUVmean, Tumor size, Lymph node metastasis and renal venous invasion (P <0.05). PD-L1 IHC scores positively correlated with LDHA and VHL expression IHC scores (P = 0.035, P = 0.011, respectively). Multivariate analysis revealed that the SUVmean and the lymph node metastasis correlated significantly with PD-L1 expression. Combined SUVmean and lymph node metastasis to predict low, medium, and high expressing tumors of PD-L1 was 20.59%, 29.41%, and 71.43%, respectively.
Conclusion: The status of lymph node metastasis and SUVmean of the primary lesion were correlated with the expression of PD-L1 in CCRCC. Combined lymph node metastasis status and SUVmax can be used to predict PD-L1 expression and will be useful to monitor tumor response to immunotherapy.