The Prognostic Value of Baseline Clinical and Radiologic Imaging Features in Patients with Unresectable Hepatocellular Carcinoma Treated with Atezolizumab Plus Bevacizumab

Purpose: To identify prognostic clinical and radiologic features in patients with unresectable hepatocellular carcinoma (HCC) treated with atezolizumab plus bevacizumab. Patients and Methods: Clinical and imaging records of patients with unresectable HCC were retrospectively reviewed, and baseline features were recorded. Patients' records and imaging studies were used to determine the patients' overall survival (OS) and progression-free survival (PFS). Univariate and multivariate analyses were performed to determine prognostic features. Subanalyses of treatment-naive patients (who never received local or systemic therapy) and previously treated patients were also performed. Results: Fifty-five patients were included in the final analysis, 23 (41.8%) of whom were treatment naive. The median PFS and OS for the entire cohort were 3.0 months and 7.9 months. The 3-, 6- and 12-month OS rates were 85.5%, 79.8% and 45.7%, respectively. The 3-, 6- and 12-month PFS rates were 50.1%, 41.2% and 20.1%, respectively. On multivariate analysis, independent prognostic features for poor PFS of the entire cohort were pleural effusions (p = 0.047, HR: 6.3; CI: 1.03-38.90) and hepatic vein tumor thrombus (p = 0.005; HR: 23.37; CI: 2.63-207.67); independent prognostic features for poor OS were ascites (p = 0.008; HR: 37.37; CI: 2.53-467.64), pleural effusion (p = 0.003; HR: 110.17; CI: 5.00-2426.54), and low (< 40HU) pre-contrast attenuation on CT images (p = 0.007; HR: 0.09; CI: 0.02-0.53). On subanalysis of treatment-naive patients, the median OS and PFS were 7.4 months and 2.8 months, respectively. The 3-, 6and 12-month PFS rates were 43.5%, 38.6% and 24.8%, respectively. Pleural effusion was the only independent poor prognostic feature (p = 0.036; HR: 206.34; CI: 1.41-30,167.58). Conclusion: Independent prognostic features for survival outcomes include the presence of ascites, pleural effusions, hepatic vein tumor thrombus, and HCC with low attenuation (< 40 HU) on unenhanced CT images. Although several biochemical variables were significant on univariate analysis, none were independent predictors of OS or PFS.