We report a covalent chemistry-based hepatocellular carcinoma (HCC)-specific extracellular vesicle (EV) purification system for early detection of HCC by performing digital scoring on the purified EVs. Earlier detection of HCC creates more opportunities for curative therapeutic interventions. EVs are present in circulation at relatively early stages of disease, providing potential opportunities for HCC early detection. We develop an HCC EV purification system (i.e., EV Click Chips) by synergistically integrating covalent chemistry-mediated EV capture/release, multimarker antibody cocktails, nanostructured substrates, and microfluidic chaotic mixers. We then explore the translational potential of EV Click Chips using 158 plasma samples of HCC patients and control cohorts. The purified HCC EVs are subjected to reverse-transcription droplet digital PCR for quantification of 10 HCC-specific mRNA markers and computation of digital scoring. The HCC EV-derived molecular signatures exhibit great potential for noninvasive early detection of HCC from at-risk cirrhotic patients with an area under receiver operator characteristic curve of 0.93 (95% CI, 0.86 to 1.00; sensitivity = 94.4%, specificity = 88.5%).

Hepatocellular carcinoma (HCC) is a leading cause of mortality. Checkpoint inhibitors of programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PD-L1) have shown great efficacy, but lack biomarkers that predict response. Circulating tumor cells (CTCs) have promise as a liquid-biopsy biomarker; however, data on HCC CTCs expressing PD-L1 have not been reported. We sought to detect PD-L1-expressing HCC-CTCs and investigated their role as a prognostic and predictive biomarker. Using an antibody-based platform, CTCs were enumerated/phenotyped from a prospective cohort of 87 patients with HCC (49 early-stage, 22 locally advanced, and 16 metastatic), 7 patients with cirrhosis, and 8 healthy controls. Immunocytochemistry identified total HCC CTCs (4′,6-diamidino-2-phenylindolepositive [DAPI+]/cytokeratin-positive [CK+]/clusters of differentiation 45-negative [CD45−]) and a subpopulation expressing PD-L1 (DAPI+/CK+/PD-L1+/CD45−). PD-L1+ CTCs were identified in 4 of 49 (8.2%) early-stage patients, but 12 of 22 (54.5%) locally advanced and 15 of 16 (93.8%) metastatic patients, accurately discriminating early from locally advanced/metastatic HCC (sensitivity = 71.1%, specificity = 91.8%, area under the receiver operating characteristic curve = 0.807; P < 0.001). Compared to patients without PD-L1+ CTCs, patients with PD-L1+ CTCs had significantly inferior overall survival (OS) (median OS = 14.0 months vs. not reached, hazard ratio [HR] = 4.0, P = 0.001). PD-L1+ CTCs remained an independent predictor of OS (HR = 3.22, P = 0.010) even after controlling for Model for End-Stage Liver Disease score (HR = 1.14, P < 0.001), alpha-fetoprotein (HR = 1.55, P < 0.001), and overall stage/tumor burden (beyond University of California, San Francisco, HR = 7.19, P < 0.001). In the subset of 10 patients with HCC receiving PD-1 blockade, all 5 responders demonstrated PD-L1+ CTCs at baseline, compared with only 1 of 5 nonresponders, all of whom progressed within 4 months of starting treatment. Conclusion: We report a CTC assay for the phenotypic profiling of HCC CTCs expressing PD-L1. PD-L1+ CTCs are predominantly found in advanced-stage HCC, and independently prognosticate OS after controlling for Model for End-Stage Liver Disease, alpha-fetoprotein, and tumor stage. In patients with HCC receiving anti-PD-1 therapy, there was a strong association with the presence of PD-L1+ CTCs and favorable treatment response. Prospective validation in a larger cohort will better define the utility of PD-L1+ CTCs as a prognostic and predictive biomarker in HCC. (Hepatology Communications 2020;4:1527-1540). H epatocellular carcinoma (HCC) is the fourth leading cause of cancer mortality worldwide and remains an important global health burden, with an estimated one million deaths attributable to HCC by 2030. (1) In the United States, the age-adjusted incidence of HCC has increased

Background Recent trends of hepatocellular carcinoma (HCC) mortality and outcome remain unknown in the United States (US). We investigated the recent trends of primary liver cancer (excluding intrahepatic cholangiocarcinoma) mortality and HCC stage, treatment, and overall survival (OS) in the US. Methods US Cancer Mortality database was analyzed to investigate the trend of primary liver cancer mortality. We analyzed the SEER 18 database to assess the temporal trend of tumor size, stage, treatment, and OS of HCC. Cox regression analysis investigated the association between HCC diagnosis year and OS. All statistical tests were 2-sided. Results During 2000-2018, liver cancer mortality rates increased until 2013, plateaued during 2013-2016 (annual percent change [APC] = 0.1%/yr, 95% confidence interval [CI] = -2.1% to 2.4%; P=0.92), and started to decline during 2016-2018 (APC = -1.5%/yr, 95% CI= -3.2% to 0.2%; P=0.08). However, mortality continues to increase in American Indians/Alaska Natives, individuals aged 65 or older, and in 33 states. There was a 0.61% (95% CI = 0.53% to 0.69%; P&lt;0.001) increase in localized stage HCC and 0.86 mm (95% CI= -1.10 to -0.62; P&lt;0.001) decrease in median tumor size per year. One-year OS rate increased from 36.3% (95% CI = 34.3% to 38.3%) to 58.1% (95% CI = 56.9% to 59.4%) during 2000-2015, and five-year OS rate almost doubled from 11.7% (95% CI = 10.4% to 13.1%) to 21.3% (95% CI = 20.2% to 22.4%) during 2000-2011. Diagnosis year (per year) (adjusted hazard ratio = 0.96; 95% CI = 0.96 to 0.97) was independently associated with OS in multivariable analysis. Conclusions Primary liver cancer mortality rates have started to decline in the US with demographic and state-level variation. With an increasing detection of localized HCC, the OS of HCC has improved over the past decades.