The genomes of cancers deficient in mismatch repair (MMR) contain exceptionally high numbers of somatic mutations. In a proof-of-concept study, we previously showed that colorectal cancers with MMR deficiency were sensitive to immune checkpoint blockade with anti-PD-1 antibodies. We have expanded this study to now evaluate efficacy of PD-1 blockade in patients with advanced MMR-deficient cancers across 12 different tumor types. Objective radiographic responses were observed in 53% of patients and complete responses were achieved in 21% of patients. Responses were durable with median progression-free and overall survival still not reached. Functional analysis in a responding patient demonstrated rapid in vivo expansion of neoantigen-specific T cell clones that were reactive to mutant neopeptides found in the tumor. These data support the hypothesis that the large proportion of mutant neoantigens in MMR-deficient cancers make them sensitive to immune checkpoint blockade, regardless of the cancers’ tissue of origin.

Background & Aims Tremelimumab is a fully human monoclonal antibody that binds to cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) on the surface of activated T lymphocytes. Ablative therapies induce a peripheral immune response which may enhance the effect of anti-CTLA4 treatment in patients with advanced hepatocellular carcinoma (HCC). This study aimed to demonstrate whether tremelimumab could be combined safely and feasibly with ablation. Methods Thirty-two patients with HCC were enrolled: male:female: 28:4; median age: 62 (range 36–76). Patients were given tremelimumab at two dose levels (3.5 and 10 mg/kg i.v.) every 4 weeks for 6 doses, followed by 3-monthly infusions until off-treatment criteria were met. On day 36, patients underwent subtotal radiofrequency ablation or chemoablation. Staging was performed by contrast-enhanced CT or MRI scan every 8 weeks. Results No dose-limiting toxicities were encountered. The most common toxicity was pruritus. Of the 19 evaluable patients, five (26.3%; 95% CI: 9.1–51.2%) achieved a confirmed partial response. Twelve of 14 patients with quantifiable HCV experienced a marked reduction in viral load. Six-week tumor biopsies showed a clear increase in CD8+ T cells in patients showing a clinical benefit only. Six and 12-month probabilities of tumor progression free survival for this refractory HCC population were 57.1% and 33.1% respectively, with median time to tumor progression of 7.4 months (95% CI 4.7 to 19.4 months). Median overall survival was 12.3 months (95% CI 9.3 to 15.4 months). Conclusions Tremelimumab in combination with tumor ablation is a potential new treatment for patients with advanced HCC, and leads to the accumulation of intratumoral CD8+ T cells. Positive clinical activity was seen, with a possible surrogate reduction in HCV viral load. Lay summary Studies have shown that the killing of tumors by direct methods (known as ablation) can result in the immune system being activated or switched on. The immune system could potentially also recognize and kill the cancer that is left behind. There are new drugs available known as immune checkpoint inhibitors which could enhance this effect. Here, we test one of these drugs (tremelimumab) together with ablation.

A B S T R A C T PurposeThe purpose of cancer staging systems is to accurately predict patient prognosis. The outcome of advanced hepatocellular carcinoma (HCC) depends on both the cancer stage and the extent of liver dysfunction. Many staging systems that include both aspects have been developed. It remains unknown, however, which of these systems is optimal for predicting patient survival. Patients and MethodsPatients with advanced HCC treated over a 5-year period at Memorial Sloan-Kettering Cancer Center were identified from an electronic medical record database. Patients with sufficient data for utilization in all staging systems were included. TNM sixth edition, Okuda, Barcelona Clinic Liver Cancer (BCLC), Cancer of the Liver Italian Program (CLIP), Chinese University Prognostic Index (CUPI), Japan Integrated Staging (JIS), and Groupe d'Etude et de Traitement du Carcinome Hepatocellulaire (GETCH) systems were ranked on the basis of their accuracy at predicting survival by using concordance index (c-index). Other independent prognostic variables were also identified. ResultsOverall, 187 eligible patients were identified and were staged by using the seven staging systems. CLIP, CUPI, and GETCH were the three top-ranking staging systems. BCLC and TNM sixth edition lacked any meaningful prognostic discrimination. Performance status, AST, abdominal pain, and esophageal varices improved the discriminatory ability of CLIP. ConclusionIn our selected patient population, CLIP, CUPI, and GETCH were the most informative staging systems in predicting survival in patients with advanced HCC. Prospective validation is required to determine if they can be accurately used to stratify patients in clinical trials and to direct the appropriate need for systemic therapy versus best supportive care. BCLC and TNM sixth edition were not helpful in predicting survival outcome, and their use is not supported by our data.

GBC is commonly diagnosed incidentally (47%). Re-exploration reveals a high incidence of residual disease (74%). Median survival is better for patients who have no evidence of disease on re-exploration (72 months) compared to those with residual disease detected (P < 0.0001). Overall prognosis is poor. Although we did not observe a survival benefit for those who received adjuvant therapy, the study did not have sufficient power to address this question. In addition, the number of patients who received adjuvant therapy was small with marked heterogeneity in clinical and therapeutic details, precluding any definitive conclusions being drawn. Prospective randomized trials of adjuvant therapy are needed in this disease.

Objectives Hepatocellular carcinoma (HCC) incidence has been increasing in the United States for several decades. As the incidence of hepatitis C virus (HCV) infection declines and the prevalence of metabolic disorders rises, the proportion of HCC attributable to various risk factors may be changing. Methods Data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linkage were used to calculate population attributable fractions (PAFs) for each risk factor over time. HCC cases (n=10,708) diagnosed during the years 2000–2011 were compared to a 5% random sample of cancer-free persons (n=332,107) residing in the SEER areas. Adjusted odds ratios (ORs) and PAFs were calculated for hepatitis C virus (HCV), hepatitis B virus (HBV), metabolic disorders, alcohol-related disorders, smoking, and genetic disorders. Results Overall, the PAF was greatest for metabolic disorders (32.0%), followed by HCV (20.5%), alcohol (13.4%), smoking (9.0%), HBV (4.3%) and genetic disorders (1.5%). The PAF for all factors combined was 59.5%. PAFs differed by race/ethnicity and gender. Metabolic disorders had the largest PAF among Hispanics (39.3%, CI=31.9–46.7%) and whites (34.8%, CI=33.1–36.5%), while HCV had the largest PAF among blacks (36.1%, CI=31.8–40.4%) and Asians (29.7%, CI=25.9–33.4%). Between 2000 and 2011, the PAF of metabolic disorders increased from 25.8% (CI=22.8–28.9%) to 36.0% (CI=33.6–38.5%). In contrast, the PAFs of alcohol-related disorders and HCV remained stable. Conclusions Among U.S. Medicare recipients, metabolic disorders contribute more to the burden of HCC than any other risk factor and the fraction of HCC due to metabolic disorders has increased in the last decade.

Current systemic treatment options for patients with hepatocellular carcinoma (HCC) are limited to sorafenib. With the recent FDA approval of the second PD1-PD-L1 pathway inhibitor, immunotherapy has gained even more interest as a potential novel treatment option for patients with HCC. This is due not only because of the failure of other treatment approaches in the past, but also because immunological mechanisms have been shown to play an important role during tumor development, growth, and treatment. Here we present a review of immunological mechanisms in the liver relevant for tumor progression and treatment. We summarize our current knowledge on immune activating and immune suppressing mechanisms during tumor initiation, development, and treatment. We try to explain the paradox of how inflammatory responses in a setting of chronic infection promote tumor development, while the primary aim of immunotherapy is to activate immunity. Finally we summarize recent advances in addition to providing an outlook for the immunotherapy of HCC.

Summary Myeloid‐derived suppressor cells (MDSC) are a heterogeneous population of cells that negatively regulate the immune response during tumour progression, inflammation and infection. Only limited data are available on human MDSC because of the lack of specific markers. We have identified members of the S100 protein family – S100A8, S100A9 and S100A12 – specifically expressed in CD14+ HLA‐DR−/low MDSC. S100A9 staining in combination with anti‐CD14 could be used to identify MDSC in whole blood from patients with colon cancer. An increase in the population of CD14+ S100A9high MDSC was observed in the peripheral blood from colon cancer patients in comparison with healthy controls. Finally, nitric oxide synthase expression, a hallmark of MDSC, was induced in CD14+ S100A9high upon lipopolysaccharide/interferon‐γ stimulation. We propose S100 proteins as useful markers for the analysis and further characterization of human MDSC.

In this largest case series, fibrolamellar and HCC-NOS age- and race-specific incidence rates and time trends differed. Despite larger tumor size than HCC-NOS cases fibrolamellar cases received surgery more often and had better survival rates. Differences in co-morbidity may influence treatment. Studies of fHCC biology, including by age, are recommended.