No abstract

Primary neuroendocrine carcinoma of the breast (NECB) as defined by the World Health Organization (WHO) in 2012 is a rare, but possibly under-diagnosed entity. It is heterogeneous as it entails a wide spectrum of diseases comprising both well-differentiated neuroendocrine tumors of the breast as well as highly aggressive small cell carcinomas. Retrospective screening of hospital charts of 612 patients (2008–2019) from our specialized outpatient unit for neuroendocrine neoplasia revealed five patients diagnosed with NECB. Given the low prevalence of these malignancies, correct diagnosis remains a challenge that requires an interdisciplinary approach. Specifically, NECB may be misclassified as carcinoma of the breast with neuroendocrine differentiation, carcinomas of the breast of no special type/invasive ductal carcinoma, or a metastasis to the breast. Therefore, this study presents multifaceted characteristics as well as the clinical course of these patients and discusses the five cases from our institution in the context of available literature.

For almost a decade, systemic therapy of advanced hepatocellular carcinoma (HCC) was limited to the tyrosine kinase inhibitor (TKI) sorafenib. Different agents including checkpoint inhibitors, TKIs and anti-VEGFR antibodies demonstrated efficacy in treatment. For the first time, the combination of atezolizumab and bevacizumab, a first-line treatment that is superior to the current standard was identified, potentially changing the way we treat HCC. In this review, we summarize current data on systemic treatment of patients with advanced HCC, focusing on combination therapies comprising immune checkpoint inhibitors, TKIs and locoregional therapies. We elucidate findings from recent trials and discuss such challenges as the lack of predictive biomarkers for identification of subgroups that will benefit from novel treatment strategies.

Background and Aims: The progression of chronic liver diseases towards liver cirrhosis is accompanied by drastic tissue changes. This study combines elaborate transcriptomic and histological methods aiming at spatially resolving the hepatic immune microenvironment in NAFLD (including NASH, primary sclerosing cholangitis, primary biliary cholangitis, and severe alcoholic hepatitis). Approach and Results: Human liver samples were subjected to RNA-sequencing (n=225) and imaging cytometry (n=99) across 3 independent patient cohorts. Liver samples from alcoholic hepatitis and primary biliary cholangitis patients were used for comparison. Myeloid populations were further characterized in corresponding mouse models. Imaging, clinical, and phenotypical data were combined for multidimensional analysis. NAFLD/NASH and primary sclerosing cholangitis disease stages were associated with loss of parenchymal areas, increased ductular cell accumulation, and infiltration of immune cells. NASH patients predominantly exhibited myeloid cell accumulation, whereas primary sclerosing cholangitis patients additionally had pronounced lymphoid cell responses. Correlating to disease stage, both etiologies displayed intense IBA1+CD16lowCD163low macrophage aggregation in nonparenchymal areas, with a distinct spatial proximity to ductular cells. Mouse models revealed that disease-associated IBA1+ hepatic macrophages originated from bone marrow–derived monocytes. Using an unbiased, machine learning–based algorithm, IBA1 in combination with hepatocyte and ductular cell immunostaining–predicted advanced cirrhosis in human NASH, primary sclerosing cholangitis, and alcoholic hepatitis. Conclusions: Loss of hepatocytes and increased ductular reaction are tightly associated with monocyte-derived macrophage accumulation and represent the most prominent common immunological feature revealing the progression of NAFLD, primary sclerosing cholangitis, primary biliary cholangitis, and alcoholic hepatitis, suggesting IBA1+CD163low macrophages are key pathogenic drivers of human liver disease progression across diverse etiologies.

The implementation of immune checkpoint inhibitors (ICI) into the clinical management of different malignancies has largely changed our understanding of cancer treatment. After having proven efficacy in different tumor entities such as malignant melanoma and lung cancer, ICI were intensively tested in the setting of hepatocellular carcinoma (HCC). Here they could achieve higher and more durable response rates compared to tyrosine-kinase inhibitors (TKI), that were sole standard of care for the last decade. Most recently, ICI treatment was approved in a first line setting of HCC, for cases not suitable for curative strategies. However, only a subset of patients benefits from ICI therapy, while others experience rapid tumor progression, worsening of liver function and poor prognosis. Efforts are being made to find immune characteristics that predict tumor responsiveness to ICI, but no reliable biomarker could be identified so far. Nevertheless, data convincingly demonstrate that combination therapies (such as dual inhibition of PD-L1 and VEGF) are more effective than the application of single agents. In this review, we will briefly recapitulate the current algorithms for systemic treatment, discuss available results from checkpoint inhibitor trials and give an outlook on future directions of immunotherapy in HCC.

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a rare, heterogeneous group of tumors that originate from the endocrine system of the gastrointestinal tract and pancreas. GEP-NENs are subdivided according to their differentiation into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). Since GEP-NENs represent rare diseases, only limited data from large prospective, randomized clinical trials are available, and recommendations for treatment of GEP-NEN are in part based on data from retrospective analyses or case series. In this context, tractable disease models that reflect the situation in humans and that allow to recapitulate the different clinical aspects and disease stages of GEP-NET or GEP-NEC are urgently needed. In this review, we highlight available data on mouse models for GEP-NEN. We discuss how these models reflect tumor biology of human disease and whether these models could serve as a tool for understanding the pathogenesis of GEP-NEN and for disease modeling and pharmacosensitivity assays, facilitating prediction of treatment response in patients. In addition, open issues applicable for future developments will be discussed.

Cholangiocarcinoma (CCA) comprises a heterogeneous group of primary liver tumors. They emerge from different hepatic (progenitor) cell populations, typically via sporadic mutations. Chronic biliary inflammation, as seen in primary sclerosing cholangitis (PSC), may trigger CCA development. Although several efforts were made in the last decade to better understand the complex processes of biliary carcinogenesis, it was only recently that new therapeutic advances have been achieved. Animal models are a crucial bridge between in vitro findings on molecular or genetic alterations, pathophysiological understanding, and new therapeutic strategies for the clinic. Nevertheless, it is inherently difficult to recapitulate simultaneously the stromal microenvironment (e.g., immune-competent cells, cholestasis, inflammation, PSC-like changes, fibrosis) and the tumor biology (e.g., mutational burden, local growth, and metastatic spread) in an animal model, so that it would reflect the full clinical reality of CCA. In this review, we highlight available data on animal models for CCA. We discuss if and how these models reflect human disease and whether they can serve as a tool for understanding the pathogenesis, or for predicting a treatment response in patients. In addition, open issues for future developments will be discussed.

In almost all cases, hepatocellular carcinoma (HCC) develops as the endpoint of a sequence that starts with chronic liver injury, progresses to liver cirrhosis, and finally, over years and decades, results in liver cancer. Recently, the role of non-coding RNA such as microRNA (miRNA) has been demonstrated in the context of chronic liver diseases and HCC. Moreover, data from a phase II trial suggested a potential role of microRNAs as therapeutics in hepatitis-C-virus infection, representing a significant risk factor for development of liver cirrhosis and HCC. Despite progress in the clinical management of chronic liver diseases, pharmacological treatment options for patients with liver cirrhosis and/or advanced HCC are still limited. With their potential to regulate whole networks of genes, miRNA might be used as novel therapeutics in these patients but could also serve as biomarkers for improved patient stratification. In this review, we discuss available data on the role of miRNA in the transition from liver cirrhosis to HCC. We highlight opportunities for clinical translation and discuss open issues applicable to future developments.