Shp2 Deficiency in Kupffer Cells and Hepatocytes Aggravates Hepatocarcinogenesis by Recruiting Non-Kupffer Macrophages.

BACKGROUND & AIMS: Complex communications between hepatocytes and Kupffer cells (KCs) are known to drive or suppress hepatocarcinogenesis, with controversial data in the literature. In previous experiments that aimed to decipher hepatocyte/KC interactions, we unexpectedly unveiled a tumor-suppressing effect of polyinosinic-polycytidylic acid, a widely used inducer of MX dynamin like GTPase 1 (Mx1)-cre expression, which questioned a theory of interleukin 1a/6 cytokine circuit in hepatocyte/KC communication. The goal of this study was to clarify the controversy and decipher unique functions of KCs and non-KC macrophages in liver tumorigenesis. METHODS: We used the C-type lectin domain family 4 member F (Clec4f)-cre system to delete Src-homology 2 domain-containing tyrosine phosphatase 2 (Shp2)/protein tyrosine phosphatase nonreceptor 11 (Ptpn11) in KCs, and a combination of Clec4f-cre and adeno-associated virus-cre to delete Shp2 in KCs and hepatocytes to investigate the effects on hepatocellular carcinoma development and immune cell compositions/activities. RESULTS: Ablating Shp2 in KCs generated a tumor-promoting niche, which was exacerbated further by concurrent removal of Shp2 in both KCs and hepatocytes. Shp2 deficiency induced KC apoptosis and decreased its numbers, which induced compensatory recruitment of bone marrow-derived monocytes into liver. These newly recruited monocytes differentiated into non-KC macrophages with tumor-associated macrophage function, leading to aggravated tumor progression through down-regulation of CD8 T cells. Tumor-associated macrophage blockade by anti-chemokine (C-C motif) ligand 2 (CCL2) antibody inhibited hepatocellular carcinoma progression, while depletion of all macrophages had a tumor-promoting effect by increasing myeloid-derived suppressor cells (M-MDSCs) and decreasing CD8 T cells. CONCLUSIONS: Shp2 loss in KCs or hepatocytes generated a protumorigenic microenvironment, which was exacerbated by its removal in both cell types. These results show the complexity of intercellular signaling events in liver tumorigenesis and raises caution on the use of specific Shp2 inhibitor in liver cancer therapy. Transcript profiling: RNA sequencing data are available at Gene Expression Omnibus (GSE222594).

Sarcopenia and myosteatosis are associated with survival in patients receiving immunotherapy for advanced hepatocellular carcinoma.

OBJECTIVES: To investigate the association of sarcopenia, myosteatosis, and sarcopenic obesity with survival outcomes among patients who underwent immunotherapy for advanced hepatocellular carcinoma (HCC). METHODS: In this retrospective analysis, patients who initiated immunotherapy for advanced HCC were enrolled. Sarcopenia and myosteatosis were evaluated on pretreatment CT at L3 level by skeletal muscle index and mean muscle attenuation using predefined cutoff values. Sarcopenic obesity was defined as concurrent sarcopenia and body mass index > 25 kg/m2. The log-rank test and the Cox proportional hazards model were used to compare overall survival (OS) and progression-free survival (PFS). RESULTS: A total of 138 patients was included (discovery cohort n = 111, validation cohort n = 27). In the discovery cohort, patients with sarcopenia exhibited significantly poorer PFS (p = 0.048) and OS (p = 0.002) than patients without sarcopenia. Patients with myosteatosis exhibited significantly poorer PFS (p < 0.001) and OS (p < 0.001) than patients without myosteatosis. Patients with sarcopenic obesity compared to patients without sarcopenic obesity exhibited significantly poorer OS (p = 0.006) but not PFS (p = 0.31). In multivariate analysis adjusting for patient demographics, tumor extent, and liver function reserve, myosteatosis remained an independent predictor of poor PFS (p = 0.014) and OS (p = 0.007); sarcopenia remained an independent predictor for poor OS (p = 0.007). The prediction models for survival outcomes built by the discovery cohort showed similar performance in the validation cohort. CONCLUSIONS: Sarcopenia and myosteatosis are independent prognostic factors in patients who received immunotherapy for advanced HCC. KEY POINTS: • Sarcopenia and myosteatosis can be evaluated by CT at L3 level. • Sarcopenia, myosteatosis, and sarcopenic obesity were associated with poor survival outcomes in patients who underwent immunotherapy for advanced HCC. • Myosteatosis was an independent predictor of PFS and OS, and sarcopenia was independent for OS in these patients.

Prognosis and treatment pattern of advanced hepatocellular carcinoma after failure of first-line atezolizumab and bevacizumab treatment.

BACKGROUND: The combination of atezolizumab and bevacizumab (Atezo-Bev) has become the standard first-line therapy for patients with advanced hepatocellular carcinoma (HCC), but the prognosis and treatment pattern after its treatment failure are unclear. METHODS: We reviewed the medical records of patients who failed first-line Atezo-Bev treatment for advanced HCC from January 2018 to May 2021 in four Taiwan medical centers. Post-first-line survival (PFLS) was defined as the date from the failure of Atezo-Bev treatment to the date of death or last follow-up. RESULTS: A total of 41 patients were included in the study. All patients had Child-Pugh A liver reserve before the initiation of Atezo-Bev treatment, but the liver reserve of 6 (15%) and 7 (17%) patients deteriorated to Child-Pugh B and C, respectively, after treatment failure. The median PFLS was 5.9 months. PFLS significantly differed among patients with various liver reserves after the failure of Atezo-Bev treatment (median 9.6 vs 3.8 vs 1.2 months, for Child-Pugh A, B, and C; p < 0.001). In total, 30 (73%) patients received second-line systemic therapy, and they exhibited significantly longer PFLS (median 8.0 vs 1.8 months, p = 0.033) than patients who did not. Deteriorated liver function and not receiving second-line therapy remained associated with inferior PFLS in multivariate analysis. The most common second-line therapies were sorafenib (n = 19, 63%) and lenvatinib (n = 9, 30%), with no significant differences in efficacies. CONCLUSION: Receiving second-line therapy and good liver reserve were associated with favorable PFLS after the failure of first-line Atezo-Bev treatment.

ICOS-Positive Regulatory T Cells in Hepatocellular Carcinoma: The Perspective from Digital Pathology Analysis.

INTRODUCTION: Inducible co-stimulator (ICOS), an important co-stimulatory receptor on effector T cells (Teffs), may also contribute to tumor growth due to its high expression on regulatory T cells (Tregs). This study explored the clinical significance of ICOS-expressing Tregs in hepatocellular carcinoma (HCC). METHODS: Tumor tissues from HCC patients who received curative hepatectomy were obtained at a referral center. Dual immunohistochemistry was performed to evaluate the expression of ICOS and Foxp3. The cell densities and proximities between stained cells in regions of interest were measured by digital pathology and the associations with clinical outcome were analyzed. RESULTS: A total of 142 patients (male:female = 112: 30, median age of 61.0 years) were enrolled. Among them, 87 (61.3%) had chronic hepatitis B virus infection and 33 (23.2%) had chronic hepatitis C infection. Low α-fetoprotein level (<20 ng/mL) and early-stage were significantly associated with improved overall survival (OS). The density of ICOS+Foxp3+ cells and the ratio of ICOS+Foxp3+/total Foxp3+ cells were significantly higher (p < 0.001) in the tumor center than in the peritumor area. Patients with a high density of ICOS+Foxp3+ cells or a high ratio of ICOS+Foxp3+/total Foxp3+ cells in the tumor center trended to have a shorter OS. A shorter distance between ICOS+Foxp3+ cells and ICOS+Foxp3- cells (likely Teffs) in the tumor center was significantly associated with a shorter OS (p = 0.030), suggesting active immunosuppression of ICOS+ Tregs on ICOS+ Teffs. CONCLUSION: An increased abundance of ICOS+ Tregs in the tumor center in comparison to the peritumor area indicates a strong immunosuppressive tumor microenvironment of HCC. A high proportion of ICOS+Foxp3+ cells and a shorter distance between ICOS+ Tregs and other ICOS+ cells were associated with a poor OS, suggesting that depleting ICOS+ Tregs might provide clinical benefit for patients with HCC.

Polatuzumab vedotin-based salvage immunochemotherapy as third-line or beyond treatment for patients with diffuse large B-cell lymphoma: a real-world experience.

Polatuzumab vedotin (PoV) has recently shown promising activity when combined with rituximab-bendamustine (BR) in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). However, few studies have described the prognostic factors predicting response. Here, we aimed to evaluate the efficacy and safety profile of PoV-based chemotherapy, including regimens other than BR, as third-line or beyond treatment for patients with R/R DLBCL and to explore prognostic factors. Overall, 40 patients, including 37 with de novo and 3 with transformed DLBCL, were enrolled. The overall response rate was 52.5%, and 25% and 27.5% of patients showed a complete response and partial response, respectively. With a median follow-up of 18.8 months, the median overall survival (OS) of the total cohort was 8.5 months, and that of those receiving subsequent hematopoietic stem cell transplantation (HSCT) was 24 months. Low/intermediate risk according to the revised International Prognostic Index score at diagnosis and before PoV treatment predicted better OS. Furthermore, a normal lactate dehydrogenase level and an absolute lymphocyte count/absolute monocyte count ratio > 1.5 were favorable OS prognostic factors. The most common adverse event was cytopenia, with 42.5% of patients developing febrile neutropenia. Grade 1-3 peripheral neuropathy associated with PoV was reported in 25% of patients and resolved in most patients after the cessation of treatment. In summary, we demonstrated that PoV combined with either BR or other intensive chemotherapy is an effective and well-tolerated salvage option for patients with R/R DLBCL. Subsequent HSCT has the potential to further improve survival outcomes in this high-risk population. Clinicaltrials.gov number: NCT05006534.

Limited Predictive or Prognostic Role of Tumor-Infiltrating Tissue-Resident Memory CD8 T Cells in Patients with Hepatocellular Carcinoma Receiving Immunotherapy.

PURPOSE: Tumor-infiltrating tissue-resident memory CD8 T cells (CD8 TRM; CD103+ CD8+) are considered tumor-specific and may correlate better with the tumor response to immune checkpoint blockade (ICB). This study evaluated the association of tumor-infiltrating CD8 TRM and their subsets with the efficacy of immunotherapy in patients with advanced hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: Consecutive HCC patients who received ICB in prospective trials were analyzed. Formalin-fixed paraffin-embedded tumor sections were stained for DAPI, CD8, CD103, CD39, programmed cell death-1 (PD-1), and programmed cell death ligand 1 (PD-L1) using a multiplex immunohistochemical method. The densities of CD8 T cells, CD8 TRM, and CD39+ or PD-L1+ subsets of CD8 TRM were correlated with tumor response and overall survival (OS). RESULTS: A total of 73 patients were identified, and 48 patients with adequate pretreatment tumor specimens and complete follow-up were analyzed. A median of 32.7% (range: 0-92.6%) of tumor-infiltrating CD8 T cells were TRM. In subset analyses, 66.6% ± 34.2%, 69.8% ± 33.4%, and 0% of CD8 TRM cells coexpressed CD39, PD-L1, and PD-1, respectively. The objective response rates for CD8 T cell-high, CD8 TRM-high, CD39+ CD8 TRM-high, and PD-L1+ CD8 TRM-high groups were 41.7%, 37.5%, 37.5%, and 29.2%, respectively. Patients with CD8 T cell-high, but not those with CD8 TRM-high, CD39+ CD8 TRM-high, or PD-L1+ CD8 TRM-high, tumors, had significantly prolonged OS (p = 0.0429). CONCLUSIONS: Compared with total tumor-infiltrating CD8 T cells, tumor-infiltrating CD8 TRM or their subsets failed to provide additional advantages in predicting the efficacy of immunotherapy for HCC.

Negative prognostic implications of splenomegaly in nivolumab-treated advanced or recurrent pancreatic adenocarcinoma.

Immune checkpoint inhibitors have limited efficacy in the treatment of pancreatic ductal adenocarcinoma (PDAC). We investigated prognostic markers for nivolumab-based therapy in advanced or recurrent PDAC. Consecutive patients receiving nivolumab-based therapy at our institution between 2015 and 2020 were evaluated. Overall survival (OS) was analyzed through univariate and multivariate analyses. Spleen volume was estimated from the width, thickness, and length of the spleen. A total of 45 patients were identified. Biweekly nivolumab was administered as monotherapy (n = 5) or in combination with chemotherapy or targeted therapy (n = 40). Among 31 evaluable patients, the response and disease control rates were 7% and 36%, respectively. The baseline median spleen volume was 267 (110-674) mL. Patients with spleens ≥267 mL had significantly shorter median OS (1.9 months, 95% confidence interval [CI], 1.0-2.7) than did those with smaller spleens (8.2 months, 95% CI, 5.6-10.8; P = .003). In the multivariate analysis, spleen volume of <267 mL, ≤2 lines of prior chemotherapy, ECOG performance status of 0-2, add-on nivolumab with stable disease after prior therapy, concomitant or sequential cell therapy, high lymphocyte count, and total bilirubin <1 mg/dL were independent favorable prognostic factors for OS. In the control groups of patients receiving gemcitabine-based chemotherapy (n = 142) or FOLFIRINOX regimen (n = 24), spleen volume exhibited no prognostic significance. In heavily pretreated PDAC, a large spleen may predict poor OS following nivolumab-based immunotherapy. Studies with larger cohorts should confirm the prognostic value of spleen volume.

An Exploratory Study for the Association of Gut Microbiome with Efficacy of Immune Checkpoint Inhibitor in Patients with Hepatocellular Carcinoma.

BACKGROUND: Gut microbiome has been associated with the efficacy of immune checkpoint inhibitors (ICI) in patients with various types of cancers but not yet in hepatocellular carcinoma (HCC). AIMS: To investigate the association between gut microbiome and efficacy of ICI in patients with HCC. METHODS: Patients with HCC who were scheduled to receive ICI were prospectively enrolled. Fecal samples were collected within 7 days before initiation of ICI (baseline) and 8 weeks later. Gut microbiome was assessed using 16S rRNA sequencing and shotgun whole-genome sequencing and correlated with objective response (complete or partial response), disease control (objective response or stable disease for ≥16 weeks), and overall survival. RESULTS: Thirty-six patients with HCC were enrolled, and 20 of them provided both baseline and 8-week feces. Alpha diversity, richness, and compositions of baseline gut microbiome indicated no difference between responders and nonresponders or between disease control and nondisease control groups. For the 20 paired feces, immunotherapy did not change any of the major microbiome features. No specific taxa were enriched in patients with objective response. Three taxa-Bifidobacterium, Coprococcus, and Acidaminococcus-were enriched in patients with disease control. However, the baseline abundance of these three taxa did not predict overall survival benefit. CONCLUSIONS: In this exploratory study, we failed to disclose any overt association of gut microbiome with the efficacy of ICI in patients with HCC. A larger prospective study is warranted for definite conclusion.

Response to Immune Checkpoint Inhibitors in Recurrent or Metastatic Esophageal Squamous Cell Carcinoma May Be Affected by Tumor Sites.

INTRODUCTION: Heterogeneous tumor response has been reported in cancer patients treated with immune checkpoint inhibitors (ICIs). This study investigated whether the tumor site is associated with the response to ICIs in patients with recurrent or metastatic esophageal squamous cell carcinoma (ESCC). METHODS: Patients with ESCC who had measurable tumors in the liver, lung, or lymph node (LN) according to the response evaluation criteria in solid tumors (RECIST) 1.1 and received ICIs at 2 medical centers in Taiwan were enrolled. In addition to RECIST 1.1, tumor responses were determined per individual organ basis according to organ-specific criteria modified from RECIST 1.1. Fisher test or χ2 test was used for statistical analysis. RESULTS: In total, 37 patients were enrolled. The overall response rate per RECIST 1.1 was 13.5%. Measurable tumors in the LN, lung, and liver were observed in 26, 17, and 13 patients, respectively. The organ-specific response rates were 26.9%, 29.4%, and 15.4% for the LN, lung, and liver tumors, respectively (p = 0.05). The organ-specific disease control rates were 69.2%, 52.9%, and 21.1% for the LN, lung, and liver tumors, respectively (p = 0.024). Five (27.8%) among 18 patients harboring at least 2 involved organs had heterogeneous tumor response. CONCLUSION: The response and disease control to ICIs may differ in ESCC tumors located at different metastatic sites, with a lesser likelihood of response and disease control in metastatic liver tumors than in tumors located at the LNs and lung.

Atezolizumab plus bevacizumab combination enables an unresectable hepatocellular carcinoma resectable and links immune exclusion and tumor dedifferentiation to acquired resistance.

We reported a patient with unresectable hepatocellular carcinoma (HCC) who initially received 15 cycles of atezolizumab plus bevacizumab combination and had best tumor response of partial response, but later experienced disease progression. After subsequent surgical resection, the patient enjoyed long-term disease-free status at the last follow-up 19 months after surgery. By investigating paired tumor tissues (pretreatment and post-progression samples) with immunohistochemistry, multiplex immunofluorescence, RNA sequencing, and DNA sequencing, we explored the dynamic changes in the tumor microenvironment (TME) and potential mechanisms underlying acquired resistance to the combination. In the post-progression HCC tissue compared with the baseline tissue, the expression of PD-L1 in tumor-infiltrating immune cells and the abundance of CD8+ T cells in the tumor area had decreased, and an immune-excluded TME had emerged. Transcriptomic analysis revealed a gene expression signature representing progenitor/hepatoblast features in the post-progression tumor tissue, with an increased expression of imprinted genes and decreased expression of cytochrome P450 family genes. Finally, tumor mutational burden and MHC class I expression in tumor cells were both increased in the post-progression tissue, suggesting that neoantigen depletion or loss-of-antigen presentation were unlikely causes of acquired resistance in this patient. Atezolizumab plus bevacizumab combination therapy enabled our patient to receive hepatectomy and achieve long-term remission. A comparison of paired tumor tissues suggested that immune-excluded TME and tumor dedifferentiation may have contributed to acquired resistance to the combination.

Solving the deficit of cancer pain management skills by education programs.

BACKGROUND: Suboptimal cancer pain management is a worldwide problem. We examined whether an educational program on cancer pain management implemented during training could benefit primary care physicians. METHODS: We enrolled all the primary care physicians who visited the oncology ward at a medical center for the first time. Educational classes on cancer pain management were conducted. The participants' abilities in cancer pain management were measured in a pretest before the classes and approximately 2 weeks later in the first posttest. The second posttest was conducted on participants who visited the oncology ward again. All 3 tests had the same set of questions and were scored on a scale of 0 to 100. RESULTS: In total, 247 participants were enrolled. Less than 10% of them considered their previous education on cancer pain management adequate. The test scores increased significantly from the pretest to the first posttest (mean 65.6 vs. 89.7, p < 0.001). The participants' self-reported cancer pain management abilities, on a scale of 0 to 100, also improved significantly (mean 57.8 vs. 75.5, p < 0.001). The pretest scores were not associated with the participants' self-reported abilities or their perceptions about the adequacy of previous training on cancer pain management. The mean score on the second posttest, conducted 234.5 days after the program, on an average, remained similar to that of the first posttest (p = 0.254). CONCLUSION: A specific educational program on cancer pain management provided to primary care physicians improved their pain management skills substantially, with persistent effects.

Differential Organ-Specific Tumor Response to Immune Checkpoint Inhibitors in Hepatocellular Carcinoma.

BACKGROUND AND AIMS: Immune checkpoint inhibitors (ICIs) exhibit significant clinical activity in patients with advanced hepatocellular carcinoma (HCC). This study explored whether tumor response to ICIs in HCC varies among different organs. METHODS: We reviewed the data of patients with advanced HCC who had received ICIs. Patients with measurable diseases were enrolled. Organ-specific response criteria, adapted from RECIST 1.1 and immune-related RECIST, were used to evaluate the objective response to ICIs in tumors located in the liver, lung, lymph node, and other intra-abdominal sites. RESULTS: Of the 75 enrolled patients with advanced HCC, 51 and 11 patients had chronic hepatitis B virus and chronic hepatitis C virus infection, respectively. Regarding ICI treatment, 58, 1, and 16 patients had undergone anti-PD-1/anti-PD-L1 monoclonal antibody (mAb) alone, anti-CTLA4 mAb alone, and anti-PD-1 mAb plus anti-CTLA4 mAb, respectively; 20 and 55 patients had received ICIs as first-line or ≥second-line therapy. The overall objective response rate (ORR) was 28.0%. In total, 58, 34, 19, and 18 patients had measurable hepatic tumors and lung, lymph node, and other intra-abdominal metastases, and the corresponding organ-specific ORRs were 22.4, 41.2, 26.3, and 38.9%, respectively. Of the 39 patients who had both hepatic and extrahepatic tumors, 12 had disease control in extrahepatic tumors while progressive disease (PD) in hepatic tumors, whereas only 4 exhibited disease control in hepatic tumors while PD in extrahepatic tumors (p = 0.046, McNemar test). Of the 16 patients with only evaluable tumors in the liver and lungs at baseline, 8 had disease control in the lungs while PD in the liver, and none experienced disease control in the liver while PD in the lungs (p = 0.005). CONCLUSIONS: The hepatic tumors of HCC may be less responsive to ICIs than extrahepatic lesions. Lung metastases responded most favorably to ICIs. The mechanisms underlying this differential response to ICIs warrant further investigation.

Early alpha-foetoprotein response associated with treatment efficacy of immune checkpoint inhibitors for advanced hepatocellular carcinoma.

BACKGROUND: Post-treatment decline in serum alpha-foetoprotein (AFP) levels has been shown to predict the treatment efficacy of antiangiogenic therapy for advanced hepatocellular carcinoma (HCC). We explored whether a decline in AFP levels was also associated with treatment outcomes of immune checkpoint inhibitors (ICIs) in patients with advanced HCC. METHODS: We reviewed all patients who received ICI therapy for advanced HCC. AFP response was evaluated in patients with the pretreatment AFP level of >20 ng/mL. We defined early AFP response as a >20% decline in serum AFP levels within the first 4 weeks of treatment initiation relative to pretreatment levels. We then studied whether early AFP response was associated with treatment outcomes. RESULTS: Sixty patients were enrolled in this study; 43 of them were evaluable for early AFP response. The objective response rate of early AFP responders was significantly higher than that of early AFP nonresponders (73% vs. 14%, P < .001). Early AFP responders, compared with early AFP nonresponders, exhibited significantly longer overall survival (OS) (median, 28.0 vs 11.2 months, P = .048) and progression-free survival (PFS) (median, 15.2 vs 2.7 months, P = .002). After adjusting for other clinicopathological variables and treatments, early AFP response remained an independent predictor for longer OS (hazard ratio [HR] = 0.089, 95% confidence interval [CI] = 0.018-0.441; P = .003) and PFS (HR = 0.128, 95% CI = 0.041-0.399; P < .001). CONCLUSION: Early AFP response was associated with higher treatment efficacy of ICIs for advanced HCC. Additional validation studies are nonetheless warranted.

Targeting myeloid-derived suppressor cells in the treatment of hepatocellular carcinoma: current state and future perspectives.

Systemic therapy for advanced hepatocellular carcinoma (HCC) has been focusing on overcoming tumor angiogenesis and immunosuppression. Myeloid-derived suppressor cells (MDSCs) promote both angiogenesis and immunosuppression in the tumor microenvironment (TME). Multiple clinical studies have demonstrated the prognostic implications of and suggested the translational significance of MDSCs in patients with HCC. In preclinical HCC models, targeting MDSCs has been shown to enhance antitumor efficacy of sorafenib or immune checkpoint inhibitors. Reversing the protumor effects of MDSCs could be achieved by depleting MDSCs, blocking MDSC trafficking and migration into TME, and inhibiting the immunosuppressive functions of MDSCs. To date, these strategies have not yet been validated to be clinically useful in patients with malignancy including HCC. Future studies should focus on identifying specific markers for human MDSCs and developing combination approaches incorporating MDSC-targeting therapy in the treatment of HCC.

Considerations of heterogeneity in clinical trials for hepatocellular carcinoma.

Introduction: Clinical trials in hepatocellular carcinoma (HCC) exhibit a high degree of heterogeneity. These heterogeneities may lead to unexpected results among clinical trials. Area covered: In this review, we address the heterogeneity noted in early phase HCC trials, trials involving transarterial chemoembolization, and advanced HCC trials. Furthermore, we discuss possible methods to attenuate the detrimental effects of heterogeneity when conducting clinical trials. Expert opinion: Clinical trials in HCC exhibit an inherently high degree of heterogeneity because of various reasons: tumor heterogeneity, different cirrhotic backgrounds, various etiologies of cirrhosis, and geographical differences in practice and expertise. Such heterogeneity may cause imbalance among the enrolled patient population, premature withdrawal from the clinical trial, and variable response to the treatment. In addition, methodological heterogeneity also exists in designing trial protocol and response evaluation. All these factors may eventually lead to conflicting results among clinical trials. Accounting for these heterogeneities is important to foster the success of future trials. In recent years, significant progress with molecular targeted agents and immune checkpoint inhibitors was made in advanced HCC. These new agents are also being tested in clinical trials involving earlier stage HCC and will also face the challenge of these issues.

Increased Expression of Programmed Death-Ligand 1 in Infiltrating Immune Cells in Hepatocellular Carcinoma Tissues after Sorafenib Treatment.

OBJECTIVE: Programmed death-ligand 1 (PD-L1) expression in the tumor microenvironment (TME) has been reported to be related to prognosis in patients with hepatocellular carcinoma (HCC) after hepatectomy. The impact of sorafenib on PD-L1 expression in the TME of advanced HCC is unclear. PATIENTS AND METHODS: Patients with HCC who received sorafenib for advanced disease at National Taiwan University Hospital, Taipei, Taiwan, and who had paired HCC tissues obtained before and after sorafenib treatment were included in the study group. HCC patients not treated with sorafenib who had paired primary and recurrent or metastatic tissues were identified as the reference group. The membrane PD-L1 staining, detected by immunohistochemistry (IHC) using SP142 antibody, was semiquantitatively scored in tumor cells (TCs) or tumor-infiltrating immune cells (ICs). Additional IHC assays were employed to characterize the PD-L1-expressing ICs. RESULTS: Twenty-three advanced HCC patients with pre- and post-sorafenib paired HCC tissues were included in the study group. The median duration of sorafenib treatment was 4.3 months (range: 1.3-18.7). PD-L1 expression in ICs was significantly higher in post-sorafenib HCC tissues than in pre-sorafenib HCC tissues (pre-sorafenib vs. post-sorafenib IHC 0/1/2/3: 11/5/5/2 vs. 5/5/2/11, p = 0.016). However, PD-L1 expression in TCs was not significantly different between pre- and post-sorafenib tissues (IHC 0/1/2/3: 19/2/0/2 vs. 14/5/0/4, p = 0.094). In the reference group of 44 patients not treated with sorafenib, PD-L1 expression in ICs and TCs was not significantly different between the paired primary and metastatic HCC tissues. By performing IHC double staining with PD-L1 and CD68, we found the PD-L1-expressing ICs were mainly CD68-positive macrophages. PD-L1 expression levels of pre- and post-sorafenib tissues were not associated with patients' overall survival or duration of sorafenib treatment. CONCLUSIONS: PD-L1 expression in ICs was significantly increased in post-sorafenib HCC tissues. The mechanisms and clinical significance of this observation warrants further investigation.

Targeting tumor-infiltrating Ly6G+ myeloid cells improves sorafenib efficacy in mouse orthotopic hepatocellular carcinoma.

Sorafenib, a multikinase inhibitor with antiangiogenic activity, is an approved therapy for hepatocellular carcinoma (HCC). It is unclear whether the proinflammatory and immunosuppressive mechanisms may limit the therapeutic efficacy of sorafenib in HCC. We used a syngeneic mouse liver cancer cell line to establish orthotopic liver or subcutaneous tumors to study how proinflammatory and immunosuppressive mechanisms impact on the efficacy of sorafenib. We found sorafenib exhibited a potent therapeutic effect in subcutaneous tumors, but a less potent effect in orthotopic liver tumors. The protein levels of interleukin-6 (IL-6) and vascular endothelial growth factor A (VEGF-A) were persistently elevated in orthotopic liver tumors, but not in subcutaneous tumors, treated with sorafenib. Likewise, the tumor-infiltrating Ly6G+ myeloid-derived suppressor cells (MDSCs) and immune suppressors were increased in orthotopic liver tumors, not in subcutaneous tumors, treated with sorafenib. The tumor-infiltrating Ly6G+ MDSCs of sorafenib-treated orthotopic liver tumors significantly induced IL-10 and TGF-ß expressing CD4+ T cells, and downregulated the cytotoxic activity of CD8+ T cells. IL-6, but not VEGF-A, protected Ly6G+ MDSCs from sorafenib-induced cell death in vitro. The combination of anti-Ly6G antibody or anti-IL-6 antibody with sorafenib significantly reduced the cell proportion of Ly6G+ MDSCs in orthotopic liver tumors, enhanced the T cells proliferation and improved the therapeutic effect of sorafenib synergistically. Modulating tumor microenvironment through targeting tumor-infiltrating Ly6G+ MDSCs represents a potential strategy to improve the anti-HCC efficacy of sorafenib.

Prescription Patterns of Sorafenib and Outcomes of Patients with Advanced Hepatocellular Carcinoma: A National Population Study.

BACKGROUND: Sorafenib is the current standard treatment for advanced hepatocellular carcinoma (HCC). We analyzed national prescription patterns and treatment outcomes of patients who received sorafenib for advanced HCC. PATIENTS AND METHODS: We established a nation-wide cohort of patients who started receiving treatment with sorafenib for advanced HCC between August 2012 and July 2013 from the National Health Insurance Research Database of Taiwan and also retrieved demographic and prescription data. The databases of National Death Registry and Taiwan Cancer Registry were used for survival outcomes and cancer diagnosis information, respectively. RESULTS: A total of 3,293 patients were enrolled. The median overall survival (OS) and time to treatment discontinuation (TTD) of all patients were 6.8 and 2.6 months, respectively. Upon the first prescription of sorafenib, 58.4% of patients received the standard dose (800 mg/day). Among them, 61.9% had subsequent dose reduction. A total of 41.6% of patients initially received lower than standard doses; 36.1% of them had subsequent dose escalation to 800 mg/day. Being male (odds ratio=1.41; p<0.001) and treatment year of 2012 (odds ratio=1.28; p=0.002) were associated with the standard initial dose. Patients who received standard initial dose of sorafenib, compared to patients who received lower initial doses, exhibited longer OS (median of 7.8 vs. 6.6 months, p<0.001) but similar TTD (median of 2.6 vs. 2.9 months, p=0.840). CONCLUSION: A considerable number of patients with advanced HCC received less than the standard dose of sorafenib. The treatment outcomes in the general population were consistent with those reported in clinical trials.

Tumor Heterogeneity in Hepatocellular Carcinoma: Facing the Challenges.

Tumor heterogeneity in hepatocellular carcinoma (HCC), such as that found in second primary tumors after curative treatment, synchronous multifocal tumors of different clonality, or intratumor heterogeneity, poses severe challenges for the development and administration of systemic molecular targeted therapies. Various methodologies, including historical DNA ploidy analysis, integrated hepatitis B virus DNA analysis, DNA fingerprinting, and next-generation sequencing technologies, are used to explore tumor heterogeneity in HCC. It is estimated that 30%-60% of recurrent or metastatic tumors harbor clones different from the primary tumor, 22%-79% of synchronous tumors vary clonally, and 12%-66% of single tumors contain intratumor heterogeneity. Substantial intertumor and intratumor heterogeneity renders biomarker identification, which is critical for the development and administration of molecular targeted therapy, challenging when applied to a single tumor biopsy specimen. The use of circulating tumor cells or circulating tumor DNA to evaluate overall tumor heterogeneity may help resolve this problem. This article reviews previous studies of tumor heterogeneity and discusses the implications and future opportunities regarding tumor heterogeneity in HCC.

Inhibition of the Wnt/ß-catenin signaling pathway improves the anti-tumor effects of sorafenib against hepatocellular carcinoma.

Sorafenib, a multikinase inhibitor, is currently the only approved drug for advanced hepatocellular carcinoma (HCC). The current study tested the hypothesis whether inhibition of the Wnt/ß-catenin signaling pathway could improve the anti-tumor effects of sorafenib in HCC. ICG-001, a small molecule which blocks the interaction of ß-catenin with its transcriptional coactivator CBP, dose-dependently enhanced the growth-suppressive and apoptosis-induction effects of sorafenib in multiple HCC cell lines. Downregulation of ß-catenin by RNA interference increased sorafenib sensitivity, whereas overexpression of ß-catenin reduced sorafenib sensitivity in Huh7 cells. The sorafenib-sensitization effect of short hairpin RNA (shRNA)-mediated ß-catenin downregulation in Huh7 cells was attenuated by ß-catenin overexpression. Mechanistically, sorafenib combined with ICG-001 or shRNA-mediated ß-catenin downregulation augmented the induction of apoptosis, and resulted in a significant downregulation of Mcl-1 in HCC cells. In Huh7 cell mouse xenograft model, the combination of ICG-001 and sorafenib showed a more significant growth-retarding effect than single agent treatment of sorafenib or ICG-001. Our data indicate that inhibition of the Wnt/ß-catenin signaling pathway improves the antitumor effects of sorafenib against HCC in vitro and in vivo.