Alpha-fetoprotein Response Predicts Treatment Outcomes in Patients with Unresectable Hepatocellular Carcinoma Receiving Immune Checkpoint Inhibitors with or Without Tyrosine Kinase Inhibitors or Locoregional Therapies

Combined immune checkpoint inhibitors (ICIs) along with tyrosine kinase inhibitors (TKIs) and locoregional therapies have been used increasingly to treat hepatocellular carcinoma (HCC). Biomarkers are required to predict the treatment efficacy of ICIs with or without combination therapies in patients with unresectable HCC. This study enrolled 95 consecutive patients with unresectable HCC from May 2017 to June 2021 from two hospitals retrospectively. Of the 95 patients, 15 and 80 had Barcelona Clinic Liver Cancer stages B and C, respectively. The median ICI treatment duration was 3.43 (1.87-7.87) months, and 77 patients received combination therapies. Radiological imaging was not performed in 13 patients. Objective response and disease control rates were 27.4% and 53.7%, respectively. The duration of progression-free survival (PFS) and overall survival (OS) was 4.07 (1.59-6.54) months and 14.53 (6.93-22.14) months, respectively. Alpha-fetoprotein (AFP) response was defined as a decline of >15% in the serum AFP level within the initial 3 months of ICI therapy according to Youden's index. AFP response was determined to be a predictor of disease control (odds ratio: 11.657, 95% confidence interval [CI]: 2.834-47.941, P=.001). Macrovascular invasion (MVI), AFP response (hazard ratio [HR]: 0.488, 95% CI: 0.255-0.934, P=.030), combination therapy, and disease control were predictors of PFS, and MVI, AFP response (HR: 0.344, 95% CI: 0.160-0.737, P=.006), and disease control were predictors of OS. AFP response was a predictor of disease control, PFS, and OS. These findings indicate that AFP response can serve as a biomarker to predict treatment outcomes in patients with unresectable HCC receiving ICIs with or without TKIs or locoregional therapies.