Circulating CD8 lymphocytes predict response to atezolizumab-bevacizumab in hepatocellular carcinoma.

Due to the lack of biomarkers predictive of response to atezolizumab-bevacizumab, the standard of care for advanced HCC, we analyzed baseline and early on-treatment variation of peripheral lymphocyte populations of 37 prospective patients treated by atezolizumab-bevacizumab and in 15 prospective patients treated by sorafenib or lenvatinib (TKIs). RNAseq analysis followed by RT-PCR validation on patients-derived PBMC was also performed. At first imaging, re-evaluation 13 patients receiving atezolizumab-bevacizumab, showed an objective response, 17 stable disease, while 7 were nonresponders. Baseline CD8+ and CD8+PD-L1+ peripheral lymphocytes were lower in responders versus nonresponders (T-test, p = 0.012 and 0.004, respectively). At 3 weeks, 28 of 30 responders displayed a rise of CD8+PD1+ lymphocytes with a positive mean fold change of 4.35 (±5.6 SD), whereas 6 of 7 nonresponders displayed a negative fold change of 0.89 (±0.84 SD). These changes were not observed in patients treated by TKIs. TRIM56, TRIM16, TRIM64, and Ki67 mRNAs were validated as upregulated in responders versus nonresponders after 3 weeks after treatment start, providing possible evidence of immune activation. Baseline CD8+ and CD8+PD-L1+ peripheral lymphocytes and early changes in CD8+PD1+ lymphocytes predict response to atezolizumab-bevacizumab providing noninvasive markers to complement clinical practice in the very early phases of treatment of HCC patients.

Low-Baseline PD1+ Granulocytes Predict Responses to Atezolizumab-Bevacizumab in Hepatocellular Carcinoma.

INTRODUCTION: Immune check point inhibitors have recently entered the armamentarium of advanced hepatocellular carcinoma (HCC) treatment. Among them, the combination of atezolizumab plus bevacizumab has pushed it a step forward; however, a number of patients still present primary non-responses without any biomarker to predict responses to different options. Here, we aimed to identify a putative baseline biomarker to predict the response to atezolizumab-bevacizumab, by investigating whether baseline PD1+ and PD-L1+ peripheral granulocyte percentages might offer a non-invasive, cheap, and easily feasible assay. METHODS: A prospective Italian cohort of 34 patients treated by atezolizumab-bevacizumab was tested to assay the baseline percentage of peripheral granulocytes and their PD1 and PD-L1 expression. The neutrophil to lymphocyte ratio (NLR) was also considered, and all data were compared with the clinical course of patients. RESULTS: A low-baseline PD1+ peripheral granulocyte percentage turned out to predict responder patients (mean ±SD of PD1+ granulocyte percentage in responders versus non-responders: 9.9 ± 9.1 vs. 29.2 ± 17.6; student's t-test, p < 0.01). In line, patients identified by a low PD1+ granulocyte percentage displayed a longer TTP (log-rank test, p < 0.0001). A lower granulocyte percentage on total white blood cells, irrespective of PD1 or PD-L1 expression, is also associated with responses to atezolizumab-bevacizumab (log-rank test, p < 0.05). No predictive value was observed for either the PD-L1+ granulocyte percentage or NLR. CONCLUSIONS: A low-baseline PD1+ peripheral granulocyte percentage is associated with responses to atezolizumab-bevacizumab treatment in advanced HCC. These findings encourage evaluating this minimally invasive, cheap, and easy test in further independent cohorts and outlining the relevance of innate immunity in the response to immune-checkpoint inhibitors.

Aflatoxin B1 DNA-Adducts in Hepatocellular Carcinoma from a Low Exposure Area.

Aflatoxin B1 (AFB1) is a class 1 carcinogen with an ascertained role in the development of hepatocellular carcinoma (HCC) in high exposure areas. Instead, this study aimed to assay whether chronic/intermittent, low-dose AFB1 consumption might occur in low-exposure geographical areas, ultimately accumulating in the liver and possibly contributing to liver cancer. AFB1-DNA adducts were assayed by immunostaining in liver tissues from three Italian series of twenty cirrhosis without HCC, 131 HCC, and 45 cholangiocarcinoma, and in an AFB1-induced HCC rat model. CD68, TP53 immunostaining, and TP53 RFLP analysis of R249S transversion were used to characterize cell populations displaying AFB1-DNA adducts. Twenty-five HCCs displayed AFB1-adducts both in neoplastic hepatocytes and in cells infiltrating the tumor and non-tumor tissues. Nuclear immunostaining was observed in a few cases, while most cases showed cytoplasmic immunostaining, especially in CD68-positive tumor-infiltrating cells, suggestive for phagocytosis of dead hepatocytes. Similar patterns were observed in AFB1-induced rat HCC, though with higher intensity. Cholangiocarcinoma and cirrhosis without HCC did not displayAFB1-adducts, except for one case. Despite not providing a causal relationship with HCC, these findings still suggest paying attention to detection and control measures for aflatoxins to ensure food safety in low exposure areas.

Hepatic Cancer Stem Cells: Molecular Mechanisms, Therapeutic Implications, and Circulating Biomarkers.

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. HCC is associated with multiple risk factors and is characterized by a marked tumor heterogeneity that makes its molecular classification difficult to apply in the clinics. The lack of circulating biomarkers for the diagnosis, prognosis, and prediction of response to treatments further undermines the possibility of developing personalized therapies. Accumulating evidence affirms the involvement of cancer stem cells (CSCs) in tumor heterogeneity, recurrence, and drug resistance. Owing to the contribution of CSCs to treatment failure, there is an urgent need to develop novel therapeutic strategies targeting, not only the tumor bulk, but also the CSC subpopulation. Clarification of the molecular mechanisms influencing CSC properties, and the identification of their functional roles in tumor progression, may facilitate the discovery of novel CSC-based therapeutic targets to be used alone, or in combination with current anticancer agents, for the treatment of HCC. Here, we review the driving forces behind the regulation of liver CSCs and their therapeutic implications. Additionally, we provide data on their possible exploitation as prognostic and predictive biomarkers in patients with HCC.