Pretreatment Positron Emission Tomography with <sup>18</sup>F-Fluorodeoxyglucose May Be a Useful New Predictor of Early Progressive Disease following Atezolizumab plus Bevacizumab in Patients with Unresectable Hepatocellular Carcinoma
Yusuke Kawamura, Masahiro Kobayashi, Junichi Shindoh, Masaru Matsumura, Satoshi Okubo, Nozomu Muraishi, Shunichiro Fujiyama, Tetsuya Hosaka, Satoshi Saitoh, Hitomi Sezaki, Norio Akuta, Fumitaka Suzuki, Yoshiyuki Suzuki, Kenji Ikeda, Yasuji Arase, Masaji Hashimoto, Hiromitsu Kumada
Abstract
BACKGROUND AND AIMS: The aim of this study was to identify the utility of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) as a predictor of early progressive disease (e-PD) in patients with hepatocellular carcinoma (HCC) treated with atezolizumab plus bevacizumab (Atezo/Bev). METHODS: Twenty consecutive patients with measurable intrahepatic target nodules who received Atezo/Bev treatment were reviewed. The oncological aggressiveness of tumors estimated by 18F-FDG-PET/CT was analyzed using the rate of e-PD within 12 weeks and early progression-free survival (e-PFS) and overall survival (OS). Multivariate analysis was used to identify potential confounders for PD during Atezo/Bev therapy. RESULTS: Using the Response Evaluation Criteria in Solid Tumors version 1.1, a tumor-to-normal liver ratio (TLR) ≥2, indicating higher oncological aggressiveness in HCCs, was associated with lower objective response rates compared with TLR values <2 (18% vs. 33%, respectively). Moreover, TLR values ≥2 were significantly associated with higher e-PD rates compared with TLR values <2 (64% vs. 11%, respectively) and worse e-PFS (p = 0.021). In multivariate analysis, TLR ≥2 showed marginal significance as a predictor of e-PD (p = 0.053), and utility as a predictor for worse e-PFS (hazard ratio, 7.153; 95% confidence interval, 1.258-40.689; p = 0.027). In contrast, no significant differences in OS with/without e-PD were observed during the treatment course. In this study, 8 patients experienced e-PD and almost 40% of patients experienced acceptable disease control following subsequent lenvatinib treatment. CONCLUSION: Pretreatment 18F-FDG-PET/CT may be a useful new predictor of e-PD and may enable early decision-making based on early treatment changes following Atezo/Bev treatment of HCC.