[Durable remission under dual HER2 blockade with Trastuzumab and Pertuzumab in a patient with metastatic gallbladder cancer]

The Hallmarks of Liver Fluke Related Cholangiocarcinoma: Insight into Drug Target Possibility

Cholangiocarcinoma (CCA) is a malignant tumor of the biliary tree that is classified into three groups based on its anatomic location: intrahepatic (iCCA), perihilar (pCCA), and distal (dCCA). Perihilar CCA is the most common type and accounts for 50-60% of CCA cases. It is followed by distal CCA and then intrahepatic CCA that account for 20-30% and 10-20% of cases, respectively. This chapter discusses the hallmarks of liver fluke related CCA and explores insights into drug target possibilities.

Prolonged Response to HER2-Directed Therapy in Three Patients with HER2-Amplified Metastatic Carcinoma of the Biliary System: Case Study and Review of the Literature

HER2 amplification, which results in overexpression of the receptor tyrosine kinase HER2, has been described in a wide variety of malignancies. HER2-targeting agents have been incorporated into the treatment paradigms for HER2-overexpressing breast and gastric cancer. More recently, these agents have shown promise in other gastrointestinal malignancies, such as colon cancer and biliary tract tumors. This study discusses two patients with gallbladder carcinoma and a third with ampullary carcinoma who were able to achieve marked responses to HER2-directed therapy. These cases underscore the importance of molecular analysis for HER2 amplification/HER2 overexpression, irrespective of tumor histology, and highlight a need for further investigation of HER2-directed therapy beyond breast and gastroesophageal cancers. KEY POINTS: Current guidelines recommend molecular assessment for HER2 overexpression exclusively in breast and gastric adenocarcinoma. The focus of this report is on three cases (two biliary tract and one ampullary carcinoma) in which amplification of HER2 or overexpression of HER2 was detected and treatment with HER2-directed therapy resulted in robust responses. These cases exemplify responsiveness of non-breast/gastric histologies to HER2-directed therapies, highlighting several promising new settings for these agents. Testing for amplification of HER2 or overexpression of HER2 should be considered especially in rare diseases with limited treatment options.

Programmed Death Ligand-1 (PD-L1) Is an Independent Negative Prognosticator in Western-World Gallbladder Cancer

Inhibition of the programmed cell death protein-1/ligand-1 (PD-1/PD-L1) axis has opened a new era in the treatment of solid cancers. However, there is no data on the expression and relevance of PD-L1 in Western gallbladder cancer (GBC). We assessed PD-L1 immunohistochemically in 131 GBC patients as Tumor Proportion Score (TPS), Immune Cell Score (IC) and Combined Positivity Score (CPS). Tumor cells expressed PD-L1 in a subset of 14.7% GBC patients at a TPS cut-off of 1%. Higher PD-L1 levels above 10% and 25% TPS were reached in 4.7% and 3.1% of GBC cases, respectively. At a 10% cut-off, TPS was associated with distinct histomorphological subtypes and correlated with poor tumor differentiation. Survival analysis revealed a TPS above 10% to be a highly significant and independent negative prognosticator in GBC. PD-L1 expression was associated with increased CD4+, CD8+ and PD-1+ immune cell densities. In 14.8% of the cases, scattered immune cells expressed T-cell immunoreceptor with Ig and ITIM domains (TIGIT), which was correlated to tumoral expression of its ligand CD155. We here show that a high PD-L1 expression confers a negative prognostic value in Western-world GBC and highlight the TIGIT/CD155 immune checkpoint as a potential new target for GBC immunotherapy.

Promising Molecular Targets for the Targeted Therapy of Biliary Tract Cancers: An Overview

Biliary tract cancer (BTC) is a leading cause of cancer-related death, due to the limited benefits of current systematic therapies and the heterogeneity of the tumor itself. High heterogeneity means that the clinical and molecular features vary between different subtypes of BTC, while the underlying molecular mechanisms remain unclear. Targeted therapy, where inhibitors are developed to selectively combine with targeted molecules in order to block abnormal signaling pathways in BTC, has shown promise as an emerging form of treatment for various types of cancer. In this article, a comprehensive review is conducted to examine potential molecular targets for BTC targeted therapy and their mechanisms. Furthermore, preliminary data published from clinical trials is utilized to analyze the main drugs used to combat BTC. The collective information presented in this article has provided useful insights into the current understanding of BTC.

Molecular Features and Targeted Therapies in Extrahepatic Cholangiocarcinoma: Promises and Failures

Biliary tract cancers (BTCs) include a heterogenous group of aggressive malignancies with limited therapeutic options. According to their anatomical location, these hepatobiliary tumors are usually classified into intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma (eCCA), and gallbladder cancer (GBC). Unfortunately, BTCs are often diagnosed when already metastatic, and although the advent of genomic sequencing has led to a deeper understanding of iCCA pathogenesis, very little data are currently available about the molecular landscape of eCCA. Moreover, despite novel systemic treatments emerging in BTC, the grim prognosis of eCCA patients has not changed in the past decade, and no targeted therapies have been approved so far. The aim of the current review is to provide an overview regarding molecular features and potential targeted therapies in eCCA, together with novel therapeutic approaches and future directions of translational and clinical research on this highly aggressive disease that poses many unanswered questions.

New and Emerging Systemic Therapeutic Options for Advanced Cholangiocarcinoma

Cholangiocarcinoma (CCA) represents a disease entity that comprises a heterogeneous group of biliary malignant neoplasms, with variable clinical presentation and severity. It may be classified according to its anatomical location and distinguished in intrahepatic (iCCA), perihilar (pCCA), or distal (dCCA), each subtype implying distinct epidemiology, biology, prognosis, and strategy for clinical management. Its incidence has increased globally over the past few decades, and its mortality rate remains high due to both its biological aggressiveness and resistance to medical therapy. Surgery is the only potentially curative treatment and is the standard approach for resectable CCA; however, more than half of the patients have locally advanced or metastatic disease at presentation. For patients with unresectable CCA, the available systemic therapies are of limited effectiveness. However, the advances of the comprehension of the complex molecular landscape of CCA and its tumor microenvironment could provide new keys to better understand the pathogenesis, the mechanisms of resistance and ultimately to identify promising new therapeutic targets. Recently, clinical trials targeting isocitrate dehydrogenase (IDH)-1 mutations and fibroblast growth factor receptor (FGFR)-2 fusions, as well as immunotherapy showed promising results. All these new and emerging therapeutic options are herein discussed.

The choice for the optimal therapy in advanced biliary tract cancers: Chemotherapy, targeted therapies or immunotherapy

Biliary tract cancers (BTCs) represent a heterogeneous group that includes intrahepatic cholangiocarcinomas (CCAs), perihilar-CCAs or Klatskin tumors, extrahepatic-CCAs, and gallbladder adenocarcinoma. These entities have distinct demographics, risk factors, clinical presentation, and molecular characteristics. In advanced BTCs, the recommendations are mainly supporting a doublet chemotherapy regimen using cisplatin/gemcitabine (CisGem) with a 5-year overall survival rate close to 5% and median overall survival (mOS) of less than a year. The lack of overall efficacy stresses the need for personalized therapies. Recently, whole-genome and transcriptome sequencing highlighted the diversity of BTCs' subtypes. Distinct genetic alterations were retrieved according to the localization, with a high rate of potentially actionable alterations. Targeted therapies and immunotherapy have since then been tested for BTCs, trying to propose a more personalized treatment. This review describes the different therapeutic options, validated and in development, for patients with advanced BTCs.

HER2 gene (ERBB2) amplification is a low-frequency driver with potential predictive value in gallbladder carcinoma

Gallbladder carcinoma (GBC) is an aggressive type of cancer with a dismal prognosis. Recent case reports have highlighted the human epidermal growth factor receptor 2 (HER2) as a promising target for individualized therapy in biliary tract cancer; however, current data on HER2 positivity in GBC is contradictory. This study aimed to assess the proportion of HER2 positivity and its clinical implications in a large and well-characterized European GBC cohort. HER2 status was determined in 186 cases of surgically resected gallbladder adenocarcinoma and a subset of coexistent high-grade biliary intraepithelial neoplasia (BilIN, n = 74) in accordance with the up-to-date consensus for HER2 testing in gastric cancer by immunohistochemistry and dual-color chromogenic in situ hybridization. Positivity for HER2 was observed in 5.4% of all cases (n = 10). In those patients with concomitant high-grade BilIN, two of four positive samples also showed amplification in the precursor lesion, while in the two remaining cases, positivity was either confined to invasive tumor or high-grade BilIN, exclusively. Equivocal staining found in eleven cases was not accompanied by gene amplification. Staging of the HER2-positive group was significantly different from the HER2-negative group with most cases presenting at stage IV, paralleled by a trend towards decreased survival. One patient who received dual HER2 inhibition almost went into full clinical remission despite treatment initiation in a metastasized state. Our results reveal a low prevalence of HER2 positivity and highlight HER2 gene amplification as an early, potentially driving event in gallbladder carcinogenesis. Prospective standardized HER2 testing and randomized control studies are needed to prove clinical efficacy of targeted HER2 inhibition in GBC.

Somatic genetic aberrations in gallbladder cancer: comparison between Chinese and US patients

Background

Gallbladder cancer (GBC) is often diagnosed at an advanced stage with limited therapeutic options and poor prognosis. The five-year survival rate of this cancer when diagnosed at an advanced stage is below 5%, and the median survival time is less than a year with standard gemcitabine-based chemotherapy. Survival benefit with second-line treatment is unknown. Thus, there is an urgent need for novel treatment strategies and targeted therapy based on next generation sequencing (NGS) may be of value.

Methods

Comprehensive genomic profiling (CGP) was performed with NGS panel on paraffin-embedded tumors from a cohort of 108 Chinese and 107 US GBC patients. Clinical data were collected using an IRB approved protocol from a single-center in US and from China.

Results

In Chinese and US GBC cohorts, an average of 6.4 vs. 3.8 genomic alterations (GAs) were identified per patient. The most frequent alterations were TP53 (69.4%), CDKN2A/B (26%), ERBB2 (18.5%), PIK3CA (17%) and CCNE1 (13%) in Chinese cohort, TP53 (57.9%), CDKN2A/B (25%), SMAD4 (17%), ARID1A (14%), PIK3CA (14%) and ERBB2 (13.1%) in US patients. NFE2L2 mutations were present in 6.5% of Chinese patients and not observed in the US cohort. Interestingly, ERBB2 genetic aberrations were significantly associated with better pathological tumor differentiation and tended to co-occurrence with CDKN2A/B mutations in both the Chinese and US GBC cases. Out of the top 9 dysregulated genetic pathways in cancer, Chinese patients harbored more frequent mutations in ERBB genes (30.6% vs. 19.0%, P=0.04). High frequency of PI3K/mTOR pathway variations was observed in both Chinese (37%) and US cohort (33%) (P=0.5). Additionally, both Chinese and US GBC patients exhibited a relatively high tumor mutational burden (TMB) (17.6% and 17.0%, respectively). In the Chinese cohort, a significant association was seen between direct repair gene alterations and TMB ≥10 muts/Mb (P=0.004).

Conclusions

In our study, over 83% Chinese and 68% US GBC patients had actionable alterations that could potentially guide and influence personalized treatment options. The identification of high TMB, ERBB2, CDKN2A/B, PI3K/mTOR pathway and DNA repair mutations indicated that both Chinese and US GBC patients may benefit from targeted or immune checkpoint inhibitors.

[Personalized oncology]

CLINICAL ISSUE

Innovative next generation sequencing (NGS) technologies and comprehensive sequencing investigations in large patient cohorts have paved the way for very promising personalized treatment strategies based on the molecular characteristics of individual tumors.

STANDARD TREATMENT

Targeted therapies, such as tyrosine kinase inhibitors, antibodies and modern immunotherapeutic approaches are well established as monotherapy and combination therapy for many hematological and oncological malignancies.

TREATMENT INNOVATIONS

A plethora of innovative therapies targeting various components of intracellular signaling cascades and effective mechanisms against oncogenes as well as the availability of NGS technologies enable personalized cancer treatment based on the molecular profiles of individual tumors and genetic stratification, within clinical trials.

DIAGNOSTIC WORK-UP

Comprehensive genetic approaches including cancer gene panel sequencing, whole exome, whole genome and transcriptome sequencing are carried out to a varying extent and particularly in the academic setting.

PERFORMANCE

Principally, a comprehensive characterization of tumors in addition to DNA and RNA sequencing that also incorporates epigenetic, metabolomic, and proteomic alterations would be desirable. A comprehensive clinical implementation of integrative, multidimensional genetic typing is, however, currently not possible.

ACHIEVEMENTS

It remains to be demonstrated whether these approaches will translate into significantly better outcomes for patients and whether they can be increasingly implemented in the routine diagnostic work-up.

PRACTICAL RECOMMENDATIONS

The selection of diagnostic tools in individual cases and the extent of genomic analyses in the clinical context, need to take the availability of methods as well as the present clinical situation into account.

Validating Comprehensive Next-Generation Sequencing Results for Precision Oncology: The NCT/DKTK Molecularly Aided Stratification for Tumor Eradication Research Experience

Purpose

Rapidly evolving genomics technologies, in particular comprehensive next-generation sequencing (NGS), have led to exponential growth in the understanding of cancer biology, shifting oncology toward personalized treatment strategies. However, comprehensive NGS approaches, such as whole-exome sequencing, have limitations that are related to the technology itself as well as to the input source. Hence, clinical implementation of comprehensive NGS in a quality-controlled diagnostic workflow requires both the standardization of sequencing procedures and continuous validation of sequencing results by orthogonal methods in an ongoing program to enable the determination of key test parameters and continuous improvement of NGS and bioinformatics pipelines.

Patients and Methods

We present validation data on 220 patients who were enrolled between 2013 and 2016 in a multi-institutional, genomics-guided precision oncology program (Molecularly Aided Stratification for Tumor Eradication Research) of the National Center for Tumor Diseases Heidelberg and the German Cancer Consortium.

Results

More than 90% of clinically actionable genomic alterations identified by combined whole-exome sequencing and transcriptome sequencing were successfully validated, with varying frequencies of discordant results across different types of alterations (fusions, 3.7%; single-nucleotide variants, 2.6%; amplifications, 1.1%; overexpression, 0.9%; deletions, 0.6%). The implementation of new computational methods for NGS data analysis led to a substantial improvement of gene fusion calling over time.

Conclusion

Collectively, these data demonstrate the value of a rigorous validation program that partners with comprehensive NGS to successfully implement and continuously improve cancer precision medicine in a clinical setting.

Immunotherapeutic Approaches to Biliary Cancer

OPINION STATEMENT

Biliary tract cancers (BTCs) are rare aggressive neoplasms with a poor prognosis and a median survival of less than 1 year in the locally advanced or metastatic setting. Among the few patients who undergo curative resection the recurrence rates are high. About 90% of patients are detected at advanced stages, and systemic chemotherapy is the mainstay of their treatment. The treatment options for these patients are limited and multiple modalities of therapy from targeted therapy to immunotherapy and combination therapies (immunotherapy, targeted therapy, and chemotherapy) have been tested in this disease. Targeted therapies have failed to show a survival benefit. The deregulation of the immune system plays a significant role in the pathogenesis of BTCs. Therefore, immunotherapy, especially, immune checkpoint inhibitors hold great promise for this group of cancers. Numerous trials of immunotherapy in BTC are currently ongoing. In this review, we will discuss the available data and evidence for immunotherapy in BTC.

Precision oncology based on omics data: The NCT Heidelberg experience

Precision oncology implies the ability to predict which patients will likely respond to specific cancer therapies based on increasingly accurate, high-resolution molecular diagnostics as well as the functional and mechanistic understanding of individual tumors. While molecular stratification of patients can be achieved through different means, a promising approach is next-generation sequencing of tumor DNA and RNA, which can reveal genomic alterations that have immediate clinical implications. Furthermore, certain genetic alterations are shared across multiple histologic entities, raising the fundamental question of whether tumors should be treated by molecular profile and not tissue of origin. We here describe MASTER (Molecularly Aided Stratification for Tumor Eradication Research), a clinically applicable platform for prospective, biology-driven stratification of younger adults with advanced-stage cancer across all histologies and patients with rare tumors. We illustrate how a standardized workflow for selection and consenting of patients, sample processing, whole-exome/genome and RNA sequencing, bioinformatic analysis, rigorous validation of potentially actionable findings, and data evaluation by a dedicated molecular tumor board enables categorization of patients into different intervention baskets and formulation of evidence-based recommendations for clinical management. Critical next steps will be to increase the number of patients that can be offered comprehensive molecular analysis through collaborations and partnering, to explore ways in which additional technologies can aid in patient stratification and individualization of treatment, to stimulate clinically guided exploratory research projects, and to gradually move away from assessing the therapeutic activity of targeted interventions on a case-by-case basis toward controlled clinical trials of genomics-guided treatments.

Personalisierte Medizin: Strukturen, Tumorboards, Visionen

Die zunehmende Berücksichtigung molekularer Charakteristika in der Therapieauswahl hat bei etlichen histologisch nicht weiter zu differenzierenden Tumorentitäten zu einer relevanten Prognoseverbesserung geführt. Beispiele wie das EGFR-mutierte Bronchialkarzinom oder das BRAF-mutierte maligne Melanom, die effektiv durch Kinaseinhibitoren behandelt werden können, ebenso wie neue Einblicke in genetische Determinanten des Ansprechens auf eine Immuncheckpointblockade lassen darauf hoffen, dass diese Ansätze auch bei anderen Tumorentitäten, Proteinfamilien und Medikamentenklassen Anwendung finden werden. Moderne Hochdurchsatzverfahren zur Sequenzierung von DNA und RNA können detaillierte Informationen über alle somatischen Alterationen in Krebsgenomen liefern und werden zunehmend bezahlbar. Die Integration dieser Analytik in klinische Abläufe stellt aber eine große Herausforderung dar. Innerhalb des NCT MASTER-Programms wurde ein standardisierter Arbeitsablauf etabliert, der ein interdisziplinäres Molekulares Tumorboard beinhaltet und eine umfassende Tumorgenomsequenzierung im klinischen Kontext ermöglicht. Im Rahmen molekular stratifizierter Studienkonzepte gilt es nun, die Umsetzung individueller Therapieempfehlungen und die Evaluation der Therapieresultate zu optimieren.

Integrating next-generation sequencing into clinical oncology: strategies, promises and pitfalls

We live in an era of genomic medicine. The past five years brought about many significant achievements in the field of cancer genetics, driven by rapidly evolving technologies and plummeting costs of next-generation sequencing (NGS). The official completion of the Cancer Genome Project in 2014 led many to envision the clinical implementation of cancer genomic data as the next logical step in cancer therapy. Stemming from this vision, the term 'precision oncology' was coined to illustrate the novelty of this individualised approach. The basic assumption of precision oncology is that molecular markers detected by NGS will predict response to targeted therapies independently from tumour histology. However, along with a ubiquitous availability of NGS, the complexity and heterogeneity at the individual patient level had to be acknowledged. Not only does the latter present challenges to clinical decision-making based on sequencing data, it is also an obstacle to the rational design of clinical trials. Novel tissue-agnostic trial designs were quickly developed to overcome these challenges. Results from some of these trials have recently demonstrated the feasibility and efficacy of this approach. On the other hand, there is an increasing amount of whole-exome and whole-genome NGS data which allows us to assess ever smaller differences between individual patients with cancer. In this review, we highlight different tumour sequencing strategies currently used for precision oncology, describe their individual strengths and weaknesses, and emphasise their feasibility in different clinical settings. Further, we evaluate the possibility of NGS implementation in current and future clinical trials, and point to the significance of NGS for translational research.