Metabolic characteristics of programmed cell death‐ligand 1‐expressing lung cancer on ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography

Abstract

Programmed cell death‐1 (PD‐1) and programmed cell death‐ligand 1 (PD‐L1) have been identified as novel targets of immunotherapy of lung cancer. In present study, we evaluated the metabolic characteristics of lung cancer by using 18F‐fluorodeoxyglucose positron emission tomography/computed tomography (18F‐FDG PET/CT) with regard to PD‐L1 protein expression. PD‐L1 protein expression was evaluated by immunohistochemistry with the antibody clone SP142 in 579 surgically resected primary lung cancer patients. Cases with less than 5% tumor membrane staining were considered negative. We examined the association between the frequency of PD‐L1 protein expression and the maximum standardized uptake value (SUVmax) in preoperative 18F‐FDG PET/CT. The cut‐off values for SUVmax were determined by receiver operating characteristic curve analyses. The SUVmax was significantly higher in nonsmall cell lung cancer (NSCLC) patients with PD‐L1 protein expression compared with those without PD‐L1 protein expression (P < 0.0001). However, there was no correlation between SUVmax and PD‐L1 protein expression in patients with neuroendocrine tumors (P = 0.6545). Multivariate analysis revealed that smoking, the presence of pleural invasion, and high SUVmax were independent predictors of PD‐L1 positivity. PD‐L1‐expressing NSCLC had a high glucose metabolism. The SUVmax in preoperative 18F‐FDG PET/CT was a predictor of PD‐L1 protein expression in patients with NSCLC.

FDG PET/CT for assessing tumour response to immunotherapy

“…Indeed, in patients with NSCLC, there is a statistically significant association between tumour metabolic parameters on PET and PD1/PD-L1 expression, along with the presence of CD8+ tumour infiltrating lymphocytes (TILs), in resected tumour specimens [31, 32]. The presence of immune infiltrate is already known as a good predictor of response to immunotherapy.…”

Radiological Features of Programmed Cell Death-Ligand 2-positive Lung Adenocarcinoma: A Single-institution Retrospective Study

“…Three thoracic oncologists (KT, GT, and ST) evaluated all of the CT images, and disagreements were resolved by consensus. 18 F-FDG PET/CT. 18 F-FDG PET/CT scanning was performed using SECAT EXACT HR+, Biograph mCT (both Siemens), and Discovery STElite16 (GE) scanners.…”

“…18 F-FDG PET/CT. 18 F-FDG PET/CT scanning was performed using SECAT EXACT HR+, Biograph mCT (both Siemens), and Discovery STElite16 (GE) scanners. The maximum standardized uptake value (SUVmax) of the tumor was calculated.…”

“…PD-L1 and PD-L2 expression in formalin-fixed, paraffin-embedded tumor sections was performed by IHC using primary antibodies against PD-L1 (1:100 dilution, rabbit monoclonal, clone SP142; Spring Bioscience, Ventana, Tucson, AZ, USA) and PD-L2 (1:200 dilution, mouse monoclonal, clone 176611; R&D Systems, Minneapolis, MN, USA). For PD-L1, staining was performed as previously described (16)(17)(18)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31). For PD-L2, 4-μm-thick sections were mounted on glass slides and stained using a B Bond-III autostainer (Leica Microsystems, Bannockburn, IL, USA).…”

“…Recently, we identified several associations between PD-L1 expression and clinical features in 394 patients with primary lung adenocarcinomas; these included radiological characteristics on computed tomography (CT) (16) and metabolic characteristics by 18 F-fluorodeoxyglucose positron-emission tomography/CT ( 18 F-FDG PET/CT) (17,18). In the present study, we analyzed the same features for the same patient cohort in the context of tumor PD-L2 expression.…”