Top Hepatobiliary Articles from 2022 to Inform Your Cancer Practice.

Until recently, there have been only modest therapeutic advances in the treatment of hepatobiliary malignancies. However, the introduction of immune checkpoint inhibitors in combination with targeted therapy or chemotherapy has changed the therapeutic landscape of hepatocellular carcinoma and biliary tract cancers. As such, revisions have been made to guidelines reflecting therapeutic advances for patients who can be considered for surgical options including resection and liver transplantation. This article highlights recently published studies that have impacted both the oncological and surgical approach to the treatment of patients with hepatobiliary malignancies.

Comparison of tumor response and outcomes of patients with hepatocellular carcinoma after multimodal treatment including immune checkpoint inhibitors - a systematic review and meta-analysis.

BACKGROUND: The efficacy of immune checkpoint inhibitors (ICIs) combined with tyrosine kinase inhibitors (TKIs), trans-arterial chemoembolization (TACE), and radiotherapy to treat hepatocellular carcinoma (HCC) has not been well-defined. We performed a meta-analysis to characterize tumor response and survival associated with multimodal treatment of HCC. METHODS: PubMed, Embase, Medline, Scopus, and CINAHL databases were searched (1990-2022). Random-effect meta-analysis was conducted to compare efficacy of treatment modalities. Odds ratios (OR) and standardized mean difference (SMD) were reported. RESULTS: Thirty studies (4170 patients) met inclusion criteria. Triple therapy regimen (ICI + TKI + TACE) had the highest overall disease control rate (DCR) (87%, 95% CI 83-91), while ICI + radiotherapy had the highest objective response rate (ORR) (72%, 95% CI 54%-89%). Triple therapy had a higher DCR than ICI + TACE (OR 4.49, 95% CI 2.09-9.63), ICI + TKI (OR 3.08, 95% CI 1.63-5.82), and TKI + TACE (OR 2.90, 95% CI 1.61-5.20). Triple therapy demonstrated improved overall survival versus ICI + TKI (SMD 0.72, 95% CI 0.37-1.07) and TKI + TACE (SMD 1.13, 95% CI 0.70-1.48) (both p < 0.05). Triple therapy had a greater incidence of adverse events (AEs) compared with ICI + TKI (OR 0.59, 95% CI 0.29-0.91; p = 0.02), but no difference in AEs versus ICI + TACE or TKI + TACE (both p > 0.05). CONCLUSION: The combination of ICIs, TKIs and TACE demonstrated superior tumor response and survival and should be considered for select patients with advanced HCC.

Disparities in Care Access to Liver-Directed Therapy Among Medicare Beneficiaries with Colorectal Cancer Liver Metastasis.

BACKGROUND: Liver-directed therapies (LDT) are important components of the multidisciplinary care of patients with colorectal cancer liver metastases (CRCLM) that contribute to improved long-term outcomes. Factors associated with receipt of LDT are poorly understood. PATIENTS AND METHODS: Patients > 65 years old diagnosed with CRCLM were identified within the Medicare Standard Analytic File (2013-2017). Patients with extrahepatic metastatic disease were excluded. Mixed-effects analyses were used to assess patient factors associated with the primary outcome of LDT, defined as hepatectomy, ablation, and/or hepatic artery infusion chemotherapy (HAIC), as well as the secondary outcome of hepatectomy. RESULTS: Among 23,484 patients with isolated CRCLM, only 2004 (8.5%) received LDT, although resectability status could not be determined for the entire cohort. Among patients who received LDT, 61.7% underwent hepatectomy alone, 28.1% received ablation alone, 8.5% underwent hepatectomy and ablation, and 1.8% received HAIC either alone (0.8%) or in combination with hepatectomy and/or ablation (0.9%). Patient factors independently associated with lower odds of LDT included older age, female sex, Black race, greater comorbidity burden, higher social vulnerability index, primary rectal cancer, synchronous liver metastasis, and further distance from a high-volume liver surgery center (p < 0.05). Results were similar for receipt of hepatectomy. CONCLUSIONS: Despite the well-accepted role of LDT for CRCLM, only a small proportion of Medicare beneficiaries with CRCLM receive LDT. Increasing access to specialized centers with expertise in LDT, particularly for Black patients, female patients, and those with higher levels of social vulnerability or long travel distances, may improve outcomes for patients with CRCLM.

Application of Hazard Function to Investigate Recurrence of Intrahepatic Cholangiocarcinoma After Curative-Intent Liver Resection: A Novel Approach to Characterize Recurrence.

PURPOSE: To investigate recurrence patterns after surgery for intrahepatic cholangiocarcinoma (ICC) relative to lymph node status, tumor extension, tumor burden score (TBS), and adjuvant chemotherapy. METHODS: Patients who underwent curative-intent resection for ICC from 1990 to 2020 were enrolled from a multi-institutional database. The hazard function was applied to plot the hazard rates over time, with further stratification by T and N AJCC 8th edition categories, TBS, and adjuvant chemotherapy. RESULTS: A total of 1192 patients underwent curative-intent resection for ICC and 59.9% experienced recurrence. Overall, the peak of recurrence occurred at 6.6 months. Among patients with negative lymph nodes, the T4-category had a higher peak rate of recurrence (0.1199 at 10.2 months) compared with other T-categories, while high TBS had an earlier peak of recurrence (4.2 months) compared with lower TBS. Among patients with N1 disease, T2-T4 categories had multipeak patterns of recurrence with higher hazard rates during the first 3 years after surgery in comparison with T1-category, while patients with high TBS had an earlier (4.0 months) and higher hazard peak rate compared with lower TBS groups. The administration of adjuvant chemotherapy was associated with delayed hazard rates of recurrence for N1 (4 months) and NX (6 months) categories. DISCUSSION: The novel application of the hazard function to assess hazard rates and timing patterns of recurrence following resection for ICC demonstrated that recurrence varied based on T- and N-categories, as well as TBS. Hazard function-based recurrence data may be helpful to tailor counseling, surveillance, and adjuvant therapy recommendations.

Diagnosis and management of choledochal cysts.

BACKGROUND: Choledochal cysts (CCs) are rare cystic dilatations of the intrahepatic and/or extrahepatic bile ducts. We review the pathophysiology, diagnosis, and management of CCs. METHODS: MEDLINE/PubMed and Web of Science databases were queried for "choledochal cyst", "bile duct cyst", "choledochocele", and "Caroli disease". Data were synthesized and systematically reviewed. RESULTS: Classified according to the Todani Classification, CCs are generally believed to arise secondary to reflux of pancreatic enzymes into the biliary tree due to anomalous pancreaticobiliary duct union. Complications of CCs include abdominal pain, jaundice, cystolithiasis, cholecystitis, pancreatitis, liver abscess, liver cirrhosis and malignant transformation (3-7.5%). Radiological and endoscopic imaging is the cornerstone of CC diagnosis and full delineation of cyst anatomy is imperative for proper management. Management is generally guided by cyst classification with complete cyst excision necessary for CCs with high potential of malignant transformation such as types I and IV. 5-year overall survival after choledochal cyst excision is 95.5%. CONCLUSION: Most CCs should undergo surgical intervention to mitigate the risk of cyst related complications such as cholangitis and malignant transformation.

Application of hazard functions to investigate recurrence after curative-intent resection for hepatocellular carcinoma.

BACKGROUND: Defining patterns and risk of recurrence can help inform surveillance strategies and patient counselling. We sought to characterize peak hazard rates (pHR) and peak time of recurrence among patients who underwent resection of hepatocellular carcinoma (HCC). METHODS: 1434 patients who underwent curative-intent resection of HCC were identified from a multi-institutional database. Hazard, patterns, and peak rates of recurrence were characterized. RESULTS: The overall hazard of recurrence peaked at 2.4 months (pHR: 0.0384), yet varied markedly. The incidence of recurrence increased with Barcelona Clinic Liver Cancer (BCLC) stage 0 (29%), A (54%), and B (64%). While the hazard function curve for BCLC 0 patients was relatively flat (pHR: <0.0177), BCLC A patients recurred with a peak at 2.4 months (pHR: 0.0365). Patients with BCLC B had a bimodal recurrence with a peak rate at 4.2 months (pHR: 0.0565) and another at 22.8 months. The incidence of recurrence also varied according to AFP level (≤400 ng/mL: 52.6% vs. >400 ng/mL: 36.3%) and Tumor Burden Score (low: 73.7% vs. medium: 50.6% vs. high: 24.2%) (both p < 0.001). CONCLUSION: Recurrence hazard rates for HCC varied substantially relative to both time and intensity/peak rates. TBS and AFP markedly impacted patterns of hazard risk of recurrence.

Steatohepatitis Impairs T-cell-Directed Immunotherapies Against Liver Tumors in Mice.

BACKGROUND & AIMS: Nonalcoholic steatohepatitis causes loss of hepatic CD4+ T cells and promotes tumor growth. The liver is the most common site of distant metastases from a variety of malignancies, many of which respond to immunotherapy. We investigated the effects of steatohepatitis on the efficacy of immunotherapeutic agents against liver tumors in mice. METHODS: Steatohepatitis was induced by feeding C57BL/6NCrl or BALB/c AnNCr mice a methionine and choline-deficient diet or a choline-deficient l-amino acid-defined diet. Mice were given intrahepatic or subcutaneous injections of B16 melanoma and CT26 colon cancer cells, followed by intravenous injections of M30-RNA vaccine (M30) or intraperitoneal injections of an antibody against OX40 (aOX40) on days 3, 7, and 10 after injection of the tumor cells. We measured tumor growth and analyzed immune cells in tumor tissues by flow cytometry. Mice were given N-acetylcysteine to prevent loss of CD4+ T cells from liver. RESULTS: Administration of M30 and aOX40 inhibited growth of tumors from intrahepatic injections of B16 or CT26 cells in mice on regular diet. However, M30 and/or aOX40 did not slow growth of liver tumors from B16 or CT26 cells in mice with diet-induced steatohepatitis (methionine and choline-deficient diet or choline-deficient l-amino acid-defined diet). Steatohepatitis did not affect the ability of M30 to slow growth of subcutaneous B16 tumors. In mice with steatohepatitis given N-acetylcysteine, which prevents loss of CD4+ T cells, M30 and aOX40 were able slow growth of hepatic tumors. Flow cytometry analysis of liver tumors revealed reduced CD4+ T cells and effector memory cells in mice with vs without steatohepatitis. CONCLUSIONS: Steatohepatitis reduces the abilities of immunotherapeutic agents, such as M30 and aOX40, to inhibit tumor liver growth by reducing tumor infiltration by CD4+ T cells and effector memory cells. N-acetylcysteine restores T-cell numbers in tumors and increases the ability of M30 and aOX40 to slow tumor growth in mice.

Surgical resection rates after neoadjuvant therapy for localized pancreatic ductal adenocarcinoma: meta-analysis.

BACKGROUND: Neoadjuvant therapy is increasingly being used before surgery for localized pancreatic cancer. Given the importance of completing multimodal therapy, the aim of this study was to characterize surgical resection rates after neoadjuvant therapy as well as the reasons for, and long-term prognostic impact of, not undergoing resection. METHODS: A systematic review and meta-analysis of prospective trials and high-quality retrospective studies since 2010 was performed to calculate pooled resection rates using a generalized random-effects model for potentially resectable, borderline resectable, and locally advanced pancreatic cancer. Median survival times were calculated using random-effects models for patients who did and did not undergo resection. RESULTS: In 125 studies that met the inclusion criteria, neoadjuvant therapy consisted of chemotherapy (36.8 per cent), chemoradiation (15.2 per cent), or chemotherapy and radiation (48.0 per cent). Among 11 713 patients, the pooled resection rates were 77.4 (95 per cent c.i. 71.3 to 82.5), 60.6 (54.8 to 66.1), and 22.2 (16.7 to 29.0) per cent for potentially resectable, borderline resectable, and locally advanced pancreatic cancer respectively. The most common reasons for not undergoing resection were distant progression for resectable and borderline resectable cancers, and local unresectability for locally advanced disease. Among 42 studies with survival data available, achieving surgical resection after neoadjuvant therapy was associated with improved survival for patients with potentially resectable (median 38.5 versus 13.3 months), borderline resectable (32.3 versus 13.9 months), and locally advanced (30.0 versus 14.6 months) pancreatic cancer (P < 0.001 for all). CONCLUSION: Although rates of surgical resection after neoadjuvant therapy vary based on anatomical stage, surgery is associated with improved survival for all patients with localized pancreatic cancer. These pooled resection and survival rates may inform patient-provider decision-making and serve as important benchmarks for future prospective trials.

Impact of care fragmentation on the outcomes of patients receiving neoadjuvant and adjuvant therapy for pancreatic adenocarcinoma.

INTRODUCTION: Neoadjuvant therapy (NT) is increasingly used for localized pancreatic ductal adenocarcinoma (PDAC). The impact of care fragmentation during NT on the outcomes of patients with PDAC is unknown. METHODS: Adult patients with Stage I-III PDAC who received NT and patients who underwent surgery first followed by adjuvant therapy (AT) between 2004 and 2016 were queried from the National Cancer Database. Short- and long-term outcomes were compared between patients who received fragmented care (FC; care provided at >1 hospital) versus integrated care (IC; care at a single institution). RESULTS: Among 6522 patients who underwent NT before pancreatectomy, 3755 (57.6%) received FC and 2767 (42.4%) received IC. While patients who received FC had a longer time to initiation of treatment (33.2 vs. 29.7 days, p < 0.001), there was no difference in median overall survival (OS) (26.7 vs. 26.5 months, p = 0.6). Among patients who underwent upfront surgery followed by AT (n = 15 291), patients who received FC had a longer time from diagnosis to undergoing surgery but less time from surgery to AT and no difference in OS (24.0 vs. 24.0 months, p = 0.910). CONCLUSION: Although care fragmentation was associated with slightly longer times to initiate and complete treatment among patients with localized PDAC, long-term survival outcomes were similar.

Regulatory T-cell and neutrophil extracellular trap interaction contributes to carcinogenesis in non-alcoholic steatohepatitis.

BACKGROUND & AIMS: Regulatory T-cells (Tregs) impair cancer immunosurveillance by creating an immunosuppressive environment that fosters tumor cell survival. Our previous findings demonstrated that neutrophil extracellular traps (NETs), which are involved both in innate and adaptive immunity, are abundant in livers affected by non-alcoholic steatohepatitis (NASH). However, how NETs interact with Tregs in the development of NASH-associated hepatocellular carcinoma (NASH-HCC) is not known. METHODS: A choline-deficient, high-fat diet+diethylnitrosamine mouse model and the stelic animal model were utilized for NASH-HCC and a western diet mouse model was used for NASH development. Treg depletion was achieved using FoxP3-DTR mice. RNA sequencing was used to explore the mechanism by which NETs could regulate Treg differentiation. Bioenergetic analyses of naïve CD4+ T-cells were assessed by Seahorse. RESULTS: Although the absolute number of CD4+ T-cells is lower in NASH livers, the Treg subpopulation is selectively increased. Depleting Tregs dramatically inhibits HCC initiation and progression in NASH. There is a positive correlation between increased NET and hepatic Treg levels. RNA sequencing data reveals that NETs impact gene expression profiles in naïve CD4+ T-cells, with the most differentially expressed genes being those involved in mitochondrial oxidative phosphorylation. By facilitating mitochondrial respiration, NETs can promote Treg differentiation. Metabolic reprogramming of naïve CD4+ T-cells by NETs requires toll-like receptor 4. Blockade of NETs in vivo using Pad4-/- mice or DNase I treatment reduces the activity of Tregs. CONCLUSIONS: Tregs can suppress immunosurveillance in the premalignant stages of NASH. NETs facilitate the crosstalk between innate and adaptive immunity in NASH by promoting Treg activity through metabolic reprogramming. Therapies targeting NETs and Treg interactions could offer a potential strategy for preventing HCC in patients with NASH. LAY SUMMARY: Regulatory T-cells (Tregs) can promote tumor development by suppressing cancer immunosurveillance, but their role in carcinogenesis during non-alcoholic steatohepatitis (NASH) progression is unknown. Herein, we discovered that selectively increased intrahepatic Tregs can promote an immunosuppressive environment in NASH livers. Neutrophil extracellular traps (NETs) link innate and adaptive immunity by promoting Treg differentiation via metabolic reprogramming of naïve CD4+ T-cells. This mechanism could be targeted to prevent liver cancer in patients with NASH.

Full Abstract to Published Manuscript: Evaluation of the Scientific Impact of the American Society of Breast Surgeons Conference.

BACKGROUND: The scientific rigor of the abstracts presented at the American Society of Breast Surgeons (ASBrS) annual meeting has not been recently evaluated. In this study, we sought to determine the rate at which abstracts presented at the 2017 and 2018 ASBrS meetings were published in peer-reviewed journals, and compared the rates with breast abstracts presented at the 2018 Society of Surgical Oncology (SSO) meeting. METHODS: Abstracts from the 2017 and 2018 ASBrS and 2018 SSO conferences were searched in PubMed for published manuscripts using the abstract title and/or first or last author. RESULTS: In 2017, 21.6% of the 268 abstracts presented at the ASBrS conference resulted in full publication, compared with 36.6% of the 273 abstracts presented at the 2018 ASBrS conference, resulting in a significant difference in the publication rate (p < 0.001). Of the 158 abstracts published from the 2017 and 2018 meetings, 75 (47.8%) were published in Annals of Surgical Oncology (ASO). There was no correlation between impact factor and time to publication. Oral presentations and quick shots were more likely to be published than poster presentations, and oral presentations were more likely to be published in higher-impact journals. The 2018 SSO meetings resulted in 54 of 111 (48.6%) breast abstracts leading to full publication. CONCLUSION: Approximately 29.2% of the abstracts presented at the ASBrS 2017 and 2018 conferences resulted in a published manuscript. A higher publication rate in higher impact journals for oral presentations indicates that the abstract review process properly stratifies the research.

Trends in the utilization of neoadjuvant therapy for pancreatic ductal adenocarcinoma.

For patients with localized pancreatic cancer, neoadjuvant therapy (NT) is increasingly delivered before surgery to maximize the receipt of multimodality therapy and the odds of a margin-negative resection. Three decades of refining the use of NT have led to its acceptance as a valid treatment approach for pancreatic adenocarcinoma. In this review, we discuss the rationale for and recent global trends in the utilization of NT for patients with pancreatic cancer.

Adjuvant Treatment of Hepatocellular Carcinoma: Prospect of Immunotherapy.

Although patients undergo procedures with curative intent for early-stage hepatocellular carcinoma (HCC), up to 70% of patients may have disease recurrence in the liver at 5 years. Thus far, no therapy has proven to be effective in the adjuvant setting. Here, we discuss the application of immune-based therapies in the adjuvant setting for HCC, focusing on the underlying rationale for immunotherapies, which patients may benefit from an immune-based therapy, and what type of immune therapy should be implemented.

Staging Laparoscopy is Underutilized in the Management of Gastric Adenocarcinoma.

BACKGROUND: Staging laparoscopy (SL) with peritoneal lavage is usually performed on a separate day from the planned resection and is recommended in patients with gastric adenocarcinoma as it can identify radiographically occult metastases and malignant cytology, thus altering prognosis and treatment. SL can be done on the same day as planned resection (SLSR) or with delayed resection (SLDR). The purpose of this study was to determine utilization of SL and factors associated with SLSR and SLDR, among patients diagnosed with gastric adenocarcinoma. METHODS: SEER-Medicare linked data were used to identify patients diagnosed with gastric adenocarcinoma from 2004 through 2013. SL were defined as a laparoscopy that occurred up to 3 months postdiagnosis. Multivariate logistic regression was used to identify factors associated with the utilization of SLSR and SLDR. RESULTS: Of the 5610 patients with gastric adenocarcinoma who underwent a surgical procedure, 733 (13%) had a SL. Utilization of SL increased annually from 6.4% to 22.2% (p < 0.01). Receipt of SL was associated with patient demographics, tumor location, and treatment at a National Cancer Institute (NCI) Designated Cancer Center (CC). Of the 733 patients who underwent SL, 475 (65%) received further surgical procedures; 367 (77%) underwent SLSR, while 108 patients (23%) underwent SLDR. Compared with SLSR, SLDR was more common among patients who were younger, treated at an NCI-Designated CC and had proximal tumors. CONCLUSIONS: SL for optimal preoperative staging remains underutilized in the management of gastric adenocarcinoma. Expanded use of laparoscopy as a distinct procedure could minimize unnecessary interventions.

Targeting the crosstalk between cytokine-induced killer cells and myeloid-derived suppressor cells in hepatocellular carcinoma.

BACKGROUND & AIMS: Cytokine-induced killer (CIK) cell-based immunotherapy is effective as an adjuvant therapy in early stage hepatocellular carcinoma (HCC) but lacks efficacy in advanced HCC. We aimed to investigate immune suppressor mechanisms in HCC, focusing on the role of myeloid-derived suppressor cells (MDSCs) in response to CIK therapy. METHODS: MDSCs were quantified by flow cytometry and quantitative real-time PCR. Cytokines were detected by cytokine array. A lactate dehydrogenase cytotoxicity assay was performed in the presence or absence of MDSCs to study CIK function against HCC cells in vitro. An FDA-approved PDE5 inhibitor, tadalafil, was used to target MDSCs in vitro and in vivo. Two different murine HCC cell lines were tested in subcutaneous and orthotopic tumor models in C57BL/6 and BALB/c mice. The antitumor effects of human CIKs and MDSCs were also tested in vitro. RESULTS: Adoptive cell transfer of CIKs into tumor-bearing mice induced inflammatory mediators (e.g., CX3CL1, IL-13) in the tumor microenvironment and an increase of tumor-infiltrating MDSCs, leading to impaired antitumor activity in 2 different HCC models. MDSCs efficiently suppressed the cytotoxic activity of CIKs in vitro. In contrast, treatment with a PDE5 inhibitor reversed the MDSC suppressor function via ARG1 and iNOS blockade and systemic treatment with a PDE5 inhibitor prevented MDSC accumulation in the tumor microenvironment upon CIK cell therapy and increased its antitumor efficacy. Similar results were observed when human CIKs were tested in vitro in the presence of CD14+HLA-DR-/low MDSCs. Treatment of MDSCs with a PDE5 inhibitor suppressed MDSC suppressor function and enhanced CIK activity against human HCC cell lines in vitro. CONCLUSION: Our results suggest that targeting MDSCs is an efficient strategy to enhance the antitumor efficacy of CIKs for the treatment of patients with HCC. LAY SUMMARY: Cytokine-induced killer cells are a mixture of immune cells given to eliminate cancer cells. However, not all patients respond to this treatment. Herein, we show in 2 different liver cancer models that myeloid-derived suppressor cells are increased in response to cytokine-induced killer cell therapy. Targeting these myeloid-derived suppressor cells may provide an additional therapeutic benefit alongside cytokine-induced killer cell therapy.

Laparoscopic Approach to Intrahepatic Cholangiocarcinoma is Associated with an Exacerbation of Inadequate Nodal Staging.

INTRODUCTION: Laparoscopic approach to liver resection is feasible and safe, though its utilization with intrahepatic cholangiocarcinoma (ICC) remains poorly documented. We sought to evaluate the use laparoscopy for ICC, and to examine adherence to oncologic standards. METHODS: The National Cancer Database was queried for patients who underwent resection for ICC. Patients were stratified by laparoscopic (LLR) versus open liver resection (OLR). Clinicopathologic parameters and hospital volumes were recorded. RESULTS: In total, 2309 patients with ICC underwent hepatic resection (1997 OLR, 312 LLR) between 2010 and 2015. LLR increased from 12 to 16% during the study period and was utilized more commonly than OLR for wedge and segmental resections (56% vs. 33%, p < 0.001). Nodal evaluation was performed in 58% of all patients with ICC and was significantly more common in patients undergoing OLR (61%, n = 1210) versus LLR (39%, n = 120), p < 0.001. Of the 120 patients undergoing LLR with any nodal evaluation, 31% (n = 37) had a single node evaluated. Patients who underwent LLR were less likely to have ≥ 6 lymph nodes evaluated compared with those who underwent OLR (9% vs. 15%, respectively, p < 0.001). CONCLUSIONS: The use of laparoscopy for ICC is associated with an exacerbation of inadequate nodal evaluation compared with open resections.

Tumor grade and sex should influence the utilization of portal lymphadenectomy for early stage intrahepatic cholangiocarcinoma.

BACKGROUND: Portal lymphadenectomy for intrahepatic cholangiocarcinoma (ICC) is encouraged for staging purposes, though it is under-utilized for clinically early-stage tumors. We sought to determine if any factor knowable prior to resection influences rates of portal lymph node metastases. METHODS: The Surveillance, Epidemiology, and End Results (SEER) Program (1973-2014) database was queried to identify patients with T1/T2 ICC undergoing resection. Patients were stratified by lymph node (LN) status. Patients deemed LN negative required examination of six or more LNs (AJCC guidelines). RESULTS: One-hundred and fifty-two patients were included in the analysis (LN negative: 38, LN positive: 114). Patients with LN negative cancers experienced prolonged overall survival as compared to patients with positive LNs (median 77 months vs 19 months, respectively p < 0.001). Twelve patients had well-differentiated tumors (G1), 92 patients had moderately-differentiated tumors (G2) and 58 patients had poorly-differentiated tumors (G3). Tumor grade (OR 3.9, CI 1.1-13.7, p = 0.031) and male sex (OR 2.6, CI 1.1-6.1, p = 0.022) were associated with positive LNs on multivariable logistic regression analysis. CONCLUSION: Intermediate/High grade and male sex are associated with high rates of lymph node metastasis for patients with early-stage ICC, which portends abbreviated overall survival.

Indoleamine 2,3-dioxygenase provides adaptive resistance to immune checkpoint inhibitors in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Immune checkpoint blockade with anti-CTLA-4 and anti-PD-1 antibodies has shown promising results in the treatment of patients with advanced HCC. The anti-PD-1 antibody, nivolumab, is now approved for patients who have had progressive disease on the current standard of care. However, a subset of patients with advanced HCC treated with immune checkpoint inhibitors failed to respond to therapy. Here, we provide evidence of adaptive resistance to immune checkpoint inhibitors through upregulation of indoleamine 2,3-dioxygenase (IDO) in HCC. Anti-CTLA-4 treatment promoted an induction of IDO1 in resistant HCC tumors but not in tumors sensitive to immune checkpoint blockade. Using both subcutaneous and hepatic orthotopic models, we found that the addition of an IDO inhibitor increases the efficacy of treatment in HCC resistant tumors with high IDO induction. Furthermore, in vivo neutralizing studies demonstrated that the IDO induction by immune checkpoint blockade was dependent on IFN-γ. Similar findings were observed with anti-PD-1 therapy. These results provide evidence that IDO may play a role in adaptive resistance to immune checkpoint inhibitors in patients with HCC. Therefore, inhibiting IDO in combination with immune checkpoint inhibitors may add therapeutic benefit in tumors which overexpress IDO and should be considered for clinical evaluation in HCC.