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Although surgical resection is available as a potentially curative therapy for hepatocellular carcinoma (HCC), high recurrence of HCC after surgery remains a serious obstacle for long-term patient survival. Therefore, the discovery of valuable prognostic biomarkers for HCC recurrence is urgently needed. Pre-S2 mutant is a mutant form of hepatitis B virus (HBV) large surface protein which is expressed from the HBV surface gene harboring deletion mutations spanning the pre-S2 gene segment. Pre-S2 mutant-positive HCC patients have been regarded as a high-risk population of HCC recurrence after resection surgery and display increased immune checkpoint programmed death ligand 1 (PD-L1) expression and pro-tumor regulatory T cells (Tregs) infiltration in tumor tissues. In this study, the association of higher levels of PD-L1 expression and Tregs infiltration in tumor tissues with post-operative HCC recurrence in pre-S2 mutant-positive HCC patients was evaluated. We found that patients with pre-S2 mutant in combination with higher levels of PD-L1 expression and Tregs infiltration in tumor tissues were independently associated with a higher risk of HCC recurrence (hazard ratio, 4.109; p value = 0.0011) and poorer recurrence-free survival (median, 8.2 versus 18.0 months; p value = 0.0004) than those of patients with either one or two of these three biomarkers. Furthermore, a combination of pre-S2 mutant, intra-tumoral PD-L1 expression, and tumor-infiltrating Tregs exhibited superior performance in identifying patients at a higher risk of HCC recurrence (area under the receiver operating characteristic curve, 0.8400). Collectively, this study suggests that higher levels of PD-L1 expression and Tregs infiltration in tumor tissues predicted a higher risk of HCC recurrence in pre-S2 mutant-positive HCC patients after curative surgical resection. [ABSTRACT FROM AUTHOR]

Chiao-Fang Teng,1– 3 Tsai-Chung Li,4,5 Ting Wang,2 Tzu-Hua Wu,2 John Wang,6 Han-Chieh Wu,7 Woei-Cherng Shyu,1,8– 10 Ih-Jen Su,11 Long-Bin Jeng2 1Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan; 2Organ Transplantation Center, China Medical University Hospital, Taichung, Taiwan; 3Research Center for Cancer Biology, China Medical University, Taichung, Taiwan; 4Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan; 5Department of Healthcare Administration, College of Medical and Health Science, Asia University, Taichung, Taiwan; 6Department of Pathology, China Medical University Hospital, Taichung, Taiwan; 7National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan, Taiwan; 8Department of Occupational Therapy, Asia University, Taichung, Taiwan; 9Department of Neurology, China Medical University Hospital, Taichung, Taiwan; 10Translational Medicine Research Center, China Medical University Hospital, Taichung, Taiwan; 11Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, TaiwanCorrespondence: Chiao-Fang TengGraduate Institute of Biomedical Sciences, China Medical University, No. 91, Hsueh-Shih Road, Northern Dist., Taichung City 404, TaiwanTel + 886-4-2205-2121Fax + 886-4-2202-9083Email chiaofangteng@gmail.comLong-Bin JengOrgan Transplantation Center, China Medical University Hospital, No. 2, Yude Road, Northern Dist., Taichung City 404, TaiwanTel + 886-4-2205-2121Fax + 886-4-2202-9083Email longbin.cmuh@gmail.comPurpose: Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC), a leading cause of cancer-related death worldwide. The HCC patients who harbor HBV pre-S2 mutant, an oncoprotein that plays key roles in HCC development, have been closely associated with a worse prognosis after curative surgical resection, suggesting an urgent need for alternative therapeutic options to improve their survival. In this study, we aimed to evaluate the expression profiles of programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1), two of the most well-studied immune checkpoint molecules that promote tumor immune evasion, in tumor of the pre-S2 mutant-positive/high HCC patients.Methods: We classified 40 HBV-related HCC patients into the pre-S2-positive/high and -negative/low groups by a next-generation sequencing-based approach. The fluorescent immunohistochemistry staining was performed to detect the expression of PD-1 and PD-L1 in HCC tissues of patients.Results: We showed that patients with either deletion spanning pre-S2 gene segment or high percentage of pre-S2 plus pre-S1+pre-S2 deletion (the pre-S2 mutant-positive/high group) exhibited a significantly higher density of PD-L1-positive cells in HCC tissues than those without. Moreover, the percentage of pre-S2 plus pre-S1+pre-S2 deletion displayed a high positive correlation with the density of PD-L1-positive cells in HCC tissues.Conclusion: The increased expression of PD-L1 in tumor tissues of the pre-S2 mutant-positive HCC patients suggest that pre-S2 mutant may play a potential role in dysregulation of tumor immune microenvironment in the progression of HBV-related HCC, implicating for the development of future therapeutic strategies.Keywords: hepatitis B virus, hepatocellular carcinoma, pre-S2 mutant, programmed death 1, programmed death ligand 1

Hepatocellular carcinoma (HCC) is, globally, one of the most prevalent and deadly human cancers; despite curative surgical resection, its high recurrence rate after surgery remains a large threat, resulting in poor patient survival. The hepatitis B virus (HBV) pre-S2 mutant that harbors deletions spanning the pre-S2 gene segment has emerged as an important oncoprotein for HCC development and a valuable prognostic biomarker for HCC recurrence; however, its relationship with clinicopathological factors is largely unexplored. In this study, the correlation of the deletion spanning the pre-S2 gene segment with clinicopathological factors and the association of such correlation with HCC recurrence after curative surgical resection were examined in HBV-related HCC patients. Inverse correlation between serum albumin level and the deletion spanning the pre-S2 gene segment was identified. HCC patients with the presence of the deletion spanning the pre-S2 gene segment and a low serum albumin level were associated with higher HCC recurrence than patients with either factor alone or neither factor were. Moreover, a combination of the serum albumin level and the deletion spanning the pre-S2 gene segment exhibited better performance than that of either factor alone in predicting HCC recurrence. Collectively, this study shows an association of low serum albumin level with pre-S2 mutant-positive HCC patients, and validates the prognostic value of this association in identifying patients with higher HCC recurrence after curative surgical resection. [ABSTRACT FROM AUTHOR]