Relationship between SP142 PD-L1 Expression and <sup>18</sup>F-FDG Uptake in Non-Small-Cell Lung Cancer
Long Zhao, Jinjun Liu, Jingyun Shi, Huoqiang Wang
Abstract
Objectives . Immune checkpoint blockers constitute the first-line treatment for advanced non-small-cell lung cancer (NSCLC) with ≥50% PD-L1 expression. In NSCLC, PD-L1 positivity is correlated with high 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake. However, these studies only included patients undergoing surgical resection, almost all in their early stages. Moreover, differences in 18 F-FDG uptake between NSCLC with high (≥50%) and low (49%) PD-L1 expression remain unknown. We aimed to investigate the association between metabolic parameter 18 F-FDG uptake and PD-L1 expression status in NSCLC patients. Methods . From February 2017 to June 2018, 428 consecutive NSCLC patients who underwent 18 F-FDG positron emission tomography/computed tomography (PET/CT) and SP142 PD-L1 expression analysis were retrospectively assessed. The association between clinicopathological characteristics and PD-L1 expression was examined. Results . The frequency of PD-L1-positive tumors was 38.1% (163/428), 28.5% (91/319), and 64.2% (61/95) for NSCLC, adenocarcinoma (ADC), and squamous cell carcinoma (SCC), respectively. Maximal standard uptake (SUVmax) was significantly higher in PD-L1-positive than in PD-L1-negative NSCLC (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>p</mml:mi><mml:mo><</mml:mo><mml:mn>0.0001</mml:mn></mml:math>), ADC (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>p</mml:mi><mml:mo><</mml:mo><mml:mn>0.0001</mml:mn></mml:math>), and SCC (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.006</mml:mn></mml:math>). SUVmax was significantly higher in NSCLC (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.001</mml:mn></mml:math>) and ADC (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.003</mml:mn></mml:math>) with high rather than low PD-L1 expression. The receiver operating characteristic curve yielded area under the curve values of 0.726 (95% CI, 0.679–0.774, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mi>p</mml:mi><mml:mo><</mml:mo><mml:mn>0.0001</mml:mn></mml:math>), 0.694 (95% CI, 0.634–0.755, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mi>p</mml:mi><mml:mo><</mml:mo><mml:mn>0.0001</mml:mn></mml:math>), and 0.625 (95% CI, 0.513–0.738, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn>0.044</mml:mn></mml:math>) for NSCLC, ADC, and SCC, respectively. Conclusion . 18 F-FDG tumor uptake is strongly, positively correlated with PD-L1 expression in NSCLC and significantly differs between high and low PD-L1-expressing individuals.