Gallbladder Cancer:Current Insights in Genetic Alterations and Their Possible Therapeutic Implications

SIMPLE SUMMARY: Knowledge of genetic alterations in gallbladder cancer (GBC) continues to increase. This systematic review provides an overview of frequently occurring genetic alterations in GBC and describes their possible therapeutic implications. We detected three frequently (>5%) altered genes (ATM, ERBB2 and PIK3CA) for which targeted therapies are available in other cancer types. For solid cancers with microsatellite instability or a high tumor mutational burden pembrolizumab is FDA-approved. Altogether, these five biomarkers might be used in future molecular panels to enable precision medicine for patients with GBC. We found only nine clinical trials evaluating targeted therapies in GBC directed at frequently altered genes (ERBB2, ARID1A, ATM and KRAS). This underlines the challenges to perform such clinical trials in this rare, heterogeneous cancer type and emphasizes the need for multicenter clinical trials. ABSTRACT: Due to the fast progression in molecular technologies such as next-generation sequencing, knowledge of genetic alterations in gallbladder cancer (GBC) increases. This systematic review provides an overview of frequently occurring genetic alterations occurring in GBC and their possible therapeutic implications. A literature search was performed utilizing PubMed, EMBASE, Cochrane Library, and Web of Science. Only studies reporting genetic alterations in human GBC were included. In total, data were extracted from 62 articles, describing a total of 3893 GBC samples. Frequently detected genetic alterations (>5% in >5 samples across all studies) in GBC for which targeted therapies are available in other cancer types included mutations in ATM, ERBB2, and PIK3CA, and ERBB2 amplifications. High tumor mutational burden (TMB-H) and microsatellite instability (MSI-H) were infrequently observed in GBC (1.7% and 3.5%, respectively). For solid cancers with TMB-H or MSI-H pembrolizumab is FDA-approved and shows an objective response rates of 50% for TMB-H GBC and 41% for MSI-H biliary tract cancer. Only nine clinical trials evaluated targeted therapies in GBC directed at frequently altered genes (ERBB2, ARID1A, ATM, and KRAS). This underlines the challenges to perform such clinical trials in this rare, heterogeneous cancer type and emphasizes the need for multicenter clinical trials

Trends in treatment and survival of gallbladder cancer in the Netherlands; Identifying gaps and opportunities from a nation-wide cohort

Gallbladder cancer (GBC) is rare in Western populations and data about treatment and outcomes are scarce. This study aims to analyze survival and identify opportunities for improvement using population-based data from a low-incidence country. GBC patients diagnosed between 2005 and 2016 with GBC were identified from the Netherlands Cancer Registry. Patients were grouped according to time period (2005-2009/2010-2016) and disease stage. Trends in treatment and overall survival (OS) were analyzed. In total 1834 patients were included: 661 (36%) patients with resected, 278 (15%) with non-resected non-metastatic, and 895 (49%) with metastatic GBC. Use of radical versus simple cholecystectomy (12% vs. 26%, p < 0.001) in early (pT1b/T2) GBC increased. More patients with metastatic GBC received chemotherapy (11% vs. 29%, p < 0.001). OS improved from 4.8 months (2005-2009) to 6.1 months (2010-2016) (p = 0.012). Median OS increased over time (2005-2009 vs. 2010-2016) in resected (19.4 to 26.8 months, p = 0.038) and metastatic (2.3 vs. 3.4 months, p = 0.001) GBC but not in unresected, non-metastatic GBC. In early GBC, patients with radical cholecystectomy had a median OS of 76.7 compared to 18.4 months for simple cholecystectomy (p < 0.001). Palliative chemotherapy showed superior (p < 0.001) survival in metasta

Metastasis in the gallbladder: does literature reflect reality?

Background: Metastases to the gallbladder (GBm) are rare and pose a unique diagnostic challenge because they can mimic a second primary tumor. This study aimed to gain insight into the clinicopathological and epidemiological characteristics of GBm. Methods: A comprehensive literature review was performed (literature cohort) and compared with a nationwide cohort of GBm patients diagnosed between 1999 and 2015 in the Netherlands, collected via two linked registries (population cohort). Overall survival (OS) was estimated by Kaplan–Meier. Hazard ratios were determined by a Cox proportional hazard model. Results: The literature cohort and population cohort consisted of 225 and 291 patients, respectively. In the literature cohort, melanoma was the most frequent origin (33.8%), while colorectal cancer was the most frequent origin in the population cohort (23.7%). Prognosis was poor with median OS ranging from 6.0 to 22.5 months in the literature and population cohorts, respectively. Age, timing of GBm (synchronous/metachronous) and primary tumor origin were independent prognostic factors for OS. Discussion: Metastases to the gallbladder are rare and carry a poor prognosis. Differences between both cohorts can be attributable to the biased reporting of tumor types that are more easily recognized as GBm because of distinct histological features

Clinical, Pathology, Genetic, and Molecular Features of Colorectal Tumors in Adolescents and Adults 25 Years or Younger

Background & Aims: Colorectal cancers (CRCs) are rare in adolescents and adults ages 25 years or younger. We analyzed clinical, pathology, and molecular features of colorectal tumors from adolescents and young adults in an effort to improve genetic counseling, surveillance, and, ultimately, treatment and outcomes. Methods: We analyzed clinical data and molecular and genetic features of colorectal tumor tissues from 139 adolescents or young adults (age, ≤25 y; median age, 23 y; 58% male), collected from 2000 through 2017; tumor tissues and clinical data were obtained from the nationwide network and registry of histopathology and cytopathology and The Netherlands Cancer Registry, respectively. DNA samples from tumors were analyzed for microsatellite instability, mutations in 56 genes, and genome-wide somatic copy number aberrations. Results: Mucinous and/or signet ring cell components were observed in 33% of tumor samples. A genetic tumor risk syndrome was confirmed for 39% of cases. Factors associated with shorter survival time included younger age at diagnosis, signet ring cell carcinoma, the absence of a genetic tumor risk syndrome, and diagnosis at an advanced stage of disease. Compared with colorectal tumors from patients ages 60 years or older in the Cancer Genome Atlas, higher proportions of tumors from adolescents or young adults were microsatellite stable with nearly diploid genomes, or contained somatic mutations in TP53 and POLE, whereas lower proportions contained mutations in APC. Conclusions: We found clinical, molecular, and genetic features of CRCs in adolescents or young adults to differ from those of patients older than age 60 years. In 39% of patients a genetic tumor risk syndrome was identified. These findings provide insight into the pathogenesis of CRC in young patients and suggest new strategies for clinical management. Performing genetic and molecular analyses for every individual diagnosed with CRC at age 25 years or younger would aid in this optimization

Immunological and Genomic Analysis Reveals Clinically Relevant Distinctions between Angiosarcoma Subgroups

Angiosarcomas (AS) are extremely rare and aggressive vascular malignancies subdivided in de novo primary AS (pAS) and secondary AS (sAS). We hypothesize that the combination of immunological and genomic profiles significantly differs between primary and secondary AS, with potential impact on treatment strategies and a role for immunotherapy. Tumor-infiltrating lymphocytes were analyzed using multiplex immunohistochemistry from 79 pAS and 178 sAS. Median cell density was significantly higher in sAS for CD3+ T-cells (p + cytotoxic T-cells (p = 0.033), CD4+ T-helper cells (p + T-regulatory cells (p + B-cell density was comparable (p = 0.417). Comprehensive genomic profiling was performed in 25 pAS and 25 sAS. A (likely) pathogenic mutation was detected in 80% of pAS vs. 88% of sAS (p = 0.702). Amplifications were found in 15% of pAS vs. 84% of sAS (p p = 0.021) and MYC amplifications (p < 0.001) were predominantly seen in sAS. In conclusion we observed a clear and clinical relevant distinction in immune infiltration and genomic profiles between pAS and sAS. The T-cell infiltrated tumor microenvironment and frequent DDR gene mutations, especially in sAS, warrant clinical trials with immunotherapy

Colorectal metastasis to the gallbladder mimicking a primary gallbladder malignancy: histopathological and molecular characteristics

Aims: Outcomes of colorectal cancer (CRC) treatment and survival have steadily improved during the past decades, accompanied by an increased risk of developing second primary tumours and metastatic tumours at unusual sites. Metastatic CRC can show mucosal colonisation, thereby mimicking a second primary tumour. This potential confusion could lead to incorrect diagnosis and consequently inadequate treatment of the patient. The aim of this study was to differentiate between metastatic CRC and a second primary (gallbladder cancer, GBC) using a combination of standard histopathology and molecular techniques. Methods and results: Ten consecutive patients with both CRC and GBC were identified in our region using the Dutch National Pathology Archive (PALGA). Two patients served as negative controls. Histology of GBC was reviewed by nine pathologists. A combination of immunohistochemistry, microsatellite analysis, genomewide DNA copy number analysis and targeted somatic mutation analysis was used to aid in differential diagnosis. In two patients, CRC and GBC were clonally related, as confirmed by somatic mutation analysis. For one case, this was confirmed by genomewide DNA copy number analysis. However, in both cases, pathologists initially considered the GBC as a second primary tumour. Conclusions: Metastatic CRC displaying mucosal colonisation is often misinterpreted as a second primary tumour. A combination of traditional histopathology and molecular techniques improves this interpretation, and lowers the risk of inadequate treatment

Isocitrate dehydrogenase 1-mutated human gliomas depend on lactate and glutamate to alleviate metabolic stress

Diffuse gliomas often carry point mutations in isocitrate dehydrogenase (IDH1mut), resulting in metabolic stress. Although IDHmut gliomas are difficult to culture in vitro, they thrive in the brain via diffuse infiltration, suggesting brain-specific tumor-stroma interactions that can compensate for IDH-1 deficits. To elucidate the metabolic adjustments in clinical IDHmut gliomas that contribute to their malignancy, we applied a recently developed method of targeted quantitativeRNA next-generation sequencingto 66 clinical gliomas and relevant orthotopicglioma xenografts, with andwithoutthe endogenous IDH-1R132Hmutation.Datasetswere analyzedinRusingManhattanplotsto calculate distancebetween expressionprofiles,Ward'smethodtoperformunsupervised agglomerative clustering, andtheMann Whitney U test and Fisher's exact tests for supervised group analyses. The significance of transcriptome data was investigated by protein analysis, in situ enzymatic activity mapping, and in vivo magnetic resonance spectroscopy of orthotopic IDH1mut-and IDHwt-glioma xenografts. Gene set enrichment analyses of clinical IDH1mut gliomas strongly suggest a role for catabolism of lactate and the neurotransmitter glutamate, whereas, in IDHwt gliomas, processing of glucose and glutamine are the predominant metabolic pathways. Further evidence of the differential metabolic activity in these cancers comes fromin situenzymaticmapping studies and preclinicalin vivomagnetic resonance spectroscopy imaging. Our data support an evolutionary model in which IDHmut glioma cells exist in symbiosis with supportive neuronal cells and astrocytes as suppliers of glutamate and lactate, possibly explaining the diffuse nature of these cancers. The dependency on glutamate and lactate opens the way for novel approaches in the treatment of IDHmut gliomas