A significant subgroup of resectable gallbladder cancer patients has an HER2 positive status

HER2/ERBB2 overexpression in advanced gallbladder carcinoma: comprehensive evaluation by immunocytochemistry and fluorescence in situ hybridisation on fine-needle aspiration cytology samples

AIMS

Advanced gallbladder carcinoma (AGBC) carries a poor prognosis with dismal survival. There are no data regarding HER2/ERBB2 expression in AGBC. This study evaluated the overexpression of HER2/ERBB2 in cytological aspirates from AGBCs to identify potential patients for whom anti-HER2 targeted therapies can benefit.

METHODS

This prospective, case-control study was performed on 50 primary AGBC cases. A detailed cytomorphological assessment, followed by immunocytochemistry (ICC) for HER2/ERBB2, was performed on AGBC cell blocks. A similar number of age-matched and gender-matched resected chronic cholecystitis specimens were included as controls. Fluorescence in situ hybridisation (FISH) was performed in equivocal cases.

RESULTS

A total of 10 (20%) cases showed positive (3+), 19 (38%) equivocal (2+) expression and 21 (42%) were negative on HER2/ERBB2 ICC. None of the equivocal cases demonstrated HER2 amplification by FISH. Among the controls, none showed positive (3+) immunoexpression, 23 (46%) demonstrated equivocal expression and 27 (54%) were negative. On statistical analysis, HER2/ERBB2 overexpression was significantly associated with AGBC compared with the controls. Of all the clinical, radiological and cytomorphological parameters, the predominant papillary or acinar arrangements of the tumour cells were significantly associated with HER2/ERBB2 overexpression.

CONCLUSIONS

This is the first study to evaluate the expression of HER2/ERBB2 on cytological aspirates in AGBC using ICC and FISH. HER2/ERBB2 overexpression(20%) was significantly associated with AGBC. Furthermore, predominant papillary or acinar arrangements of tumour cells in the cytological smears were significantly associated with HER2/ERBB2 overexpression. They can serve as potential predictors of HER2/ERBB2 overexpression to select AGBC patients for anti-HER2 targeted therapies.

Expression of ER, PR, and HER-2 Neu and correlation with tumor markers in gall bladder carcinoma

Background

Females having a large proportion of gallbladder carcinoma (GBC) and a higher incidence of gallstones pointed toward the role of sex hormones in GBC development. In this study, we evaluated the expression of Estrogen receptor (ER), Progesterone receptor (PR), and Her2/neu and their correlation with tumor markers and clinicopathological parameters in the GBC.

Methods

A total of 50 patients of GBC and 42 patients in control group undergoing surgery for other conditions were taken. The patient's biopsy sample's paraffin block was tested for ER, PR, and Her2/neu expression by immunohistochemistry.

Results

ER and PR had no significant expression in GBC and control group, but Her2/neu had 16% expression in GBC, significantly associated with the degree of differentiation with 62.5% (n-5) being well-differentiated; 75% of Her2/neu positive were in stages III and IV. Her2/neu did not correlate with tumor markers despite expression.

Conclusions

Her2/neu amplification is a small step in validating that option so it could be included in the treatment and prognostication of GBC.

Discordances in expression of human epidermal growth factor receptor 2 between primary and metastatic uterine carcinosarcoma: A proposal for HER2-targeted therapy specimen selection

Uterine carcinosarcoma (UCS) frequently expresses human epidermal growth factor receptor 2 (HER2) and metastasizes. However, little is known about changes in the HER2 expression status in metastatic lesions and its impact on clinical outcomes. In 41 patients with synchronous or metachronous metastases and matched primary UCSs, we assessed the HER-2 expression using immunohistochemistry and scored it per the 2016 American Society of Clinical Oncology/College of American Pathologists guidelines, modified for UCS. We compared HER2 scores between paired primary and metastatic lesions and reviewed the association between clinicopathological characteristics and impact on overall survival. HER2 scores of 3+, 2+, 1+, and 0 were observed in 12.2 %, 34.2 %, 26.8 %, and 26.8 % of primary tumors, respectively, and 9.8 %, 19.5 %, 43.9 %, and 26.8 % of metastatic tumors, respectively. HER2 intratumoral heterogeneity occurred in 46.3 % and 19.5 % of the primary and metastatic lesions, respectively. The agreement rate of the HER2 score was 34.2 % in the four-tiered scale, while it was 70.7 % in the two-tiered scale (score 0 vs. score ≥ 1+) with fair agreement (к = 0.26). Patients with HER2 discordance showed significantly shorter overall survival (hazard ratios = 2.38, 95 % confidence interval 1.01-5.5, p = 0.049). HER2 discordance was not associated with specific clinicopathological characteristics. Discordance in HER2 status between primary and metastatic tumors in UCS was frequently observed regardless of clinicopathological characteristics and was a poor prognostic factor. Even if one tumor (primary or metastatic) is HER2 negative, HER2 testing of other tumors may be beneficial in terms of patient treatment options.

HER2 status based on breast cancer guidelines as a useful prognostic marker of T2 gallbladder cancer

INTRODUCTION

T2 gallbladder cancer (GBC) is the only stage showing a survival benefit after complete surgical resection, but recurrence rates remain high. Although human epidermal growth factor receptor 2 (HER2) has emerged as a therapeutic target, its role in T2 GBC remains unclear. This study investigated the status and prognostic impact of HER2 expression on T2 GBC.

MATERIALS AND METHODS

HER2 expression and amplification were detected by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively, in 90 patients with T2 GBC who underwent radical cholecystectomy. We evaluated HER2 status according to the breast and gastric cancer guidelines and analyzed the effect of relevant prognostic factors on survival.

RESULTS

HER2 positive status was observed in 11.11% (10/90) and 8.89% (8/90) of cases based on gastric and breast cancer guidelines, respectively. Poor differentiation and a higher level of perineural invasion were independent prognostic factors of disease-free survival (DFS). Old age, male sex, presence of lymph node metastasis, poor differentiation, high levels of perineural invasion, and HER2 positivity based on breast cancer guidelines were identified as independent prognostic factors of overall survival (OS). Patients with HER2-positive T2 GBC according to breast cancer guidelines had worse OS.

CONCLUSIONS

HER2 positivity based on breast- but not gastric-cancer guidelines was associated with poorer survival. These results provide a criterion for the evaluation of HER2 and a rationale for therapeutic strategies targeting HER2 in T2 GBC.

Multicenter phase II trial of trastuzumab deruxtecan for HER2-positive unresectable or recurrent biliary tract cancer: HERB trial

Trastuzumab deruxtecan (DS-8201) is an antibody-drug conjugate composed of a humanized monoclonal anti-HER2 antibody, a cleavable tetrapeptide-based linker and a potent topoisomerase I inhibitor. The drug's efficacy has been proven in HER2-positive breast and gastric cancers. The rate of HER2 positivity in biliary tract cancer (BTC) has been reported to be 5-20%, and case reports and clinical trials have suggested that HER2 inhibitors might be active in HER2-positive BTC. Here we describe the rationale and design of the phase II HERB trial that will evaluate the efficacy and safety of trastuzumab deruxtecan in patients with HER2-expressing unresectable or recurrent BTC. The primary end point will be the centrally assessed objective response rate in HER2-positive patients.

HER2 Positivity Is Affected by the Papillary Structure and Has a Bidirectional Prognostic Value for Gallbladder Carcinoma

Gallbladder carcinoma (GBC) is responsible for 80%–95% of biliary tract malignancies and has a dismal prognosis. Human epidermal growth factor receptor 2 (HER2) is a promising therapeutic target of GBC. Through immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) methods, HER2 expression and gene amplification were identified on high-output tissue microarrays (TMAs) developed in 306 GBC cases to investigate its relationship with GBC and clinicopathological characteristics. Adenocarcinomas accounted for 223 (72.9%) of the cases, with 62 (27.8%) being papillary adenocarcinoma or having partial papillary structure. HER2 positivity was studied in 16.1% (36/223) of patients with adenocarcinoma and 41.9% (26/62) in adenocarcinoma with papillary structures. For 143 radically resected primary GBC cases with 24 HER2-positive tumors, survival data were valid; the median survival time was not reached, and the 5-year survival rate was 52.9%. All patients in stages 0–I survived, and the results of the HER2-positive group and the stage II HER2-negative group were similar (p = 0.354). However, in stage III, the mortality rate in the HER2-positive group was reduced (p = 0.005) and that in stage IV was higher (p = 0.005). In conclusion, HER2 positivity was significantly higher in patients with papillary GBC. The predictive value of HER2 varies by clinical stage, with no prediction in the early stages, better in stage III, and worse in stage IV.

Human epidermal growth factor receptor 2 targeted therapy in endometrial cancer: Clinical and pathological perspectives

Endometrial cancer is the most common gynecological cancer in developed countries, and its incidence has increased. The majority of patients with endometrial cancer have an early disease and favorable prognosis; however, a significant proportion of endometrial cancer, which mainly comprises high-grade or type II endometrial cancer such as serous, clear cell, and carcinosarcoma, shows advanced/recurrent disease and dismal prognosis. Novel therapeutic development is required for patients with aggressive endometrial cancers. Recent genomic and immunohistochemical analyses revealed human epidermal growth factor receptor 2 (HER2) overexpression/gene amplification in 20%-40% of patients with type II endometrial cancer. Historically, HER2 targeted therapy has been developed for various major cancers, including breast and gastric cancer. Notably, recent advances in HER2 targeted therapy for patients with type II endometrial cancer are also expected to change. Simultaneously, an optimized HER2 test for endometrial cancer as companion diagnostics should be established. In this review, we summarize the recent findings on endometrial cancer, current treatment, optimized HER2 testing, key clinical trials on HER2 targeted therapy, and future directions in aggressive endometrial cancer, including serous carcinoma and carcinosarcoma.

Expression of HER2 and Mismatch Repair Proteins in Surgically Resected Gallbladder Adenocarcinoma

Background

Gallbladder cancer (GBC) has a poor prognosis. Although complete surgical resection is the only successful approach for improving survival, additional therapeutic modalities are required for recurrent or surgically unresectable GBCs.

Materials and Methods

To determine the expression status of HER2 and the mismatch repair (MMR) proteins MLH1, MSH2, MSH6, and PMS2, immunohistochemical staining of MMR proteins and HER2 was carried out in 216 surgically resected GBCs. HER2 labeling was scored by adopting a scoring system for gastric carcinomas. Tissues scoring 0 to 2+ were defined as HER2 negative, whereas those scoring 3+ were regarded as HER2-positive. In addition, silver in situ hybridization and microsatellite instability (MSI) analysis were conducted to confirm HER2 amplification and MSI, respectively.

Results

Three of 216 GBCs (1.3%) showed MMR protein deficiency. All three observed MSI cases exhibited dual loss of MSH2 and MSH6 protein expression. However, no cases showed loss of either MLH1 or PMS2 expression. No association was observed between MMR protein deficiency and other clinicopathological factors. HER2 amplification was noted in 30 (13.9%) GBCs and associated with Crohn-like lymphoid reaction (P = 0.023). No survival difference was observed based on HER2 overexpression or HER2 amplification status.

Conclusion

MMR protein deficiency and HER2 overexpression were observed in a small subset (1.3% and 13.9%, respectively) of GBCs without simultaneous occurrence of deficient MMR protein expression and HER2 overexpression. The presence of Crohn-like lymphoid reaction may help identify cases with HER2 amplification, by using hematoxylin-stained slides. Although the proportion of MMR protein-deficient- and HER2-overexpressing GBCs was small, applying immunotherapy to MMR protein-deficient GBCs and herceptin to HER2-overexpressing GBCs may provide alternative treatment options for patients with GBC.

Role of EGFR and HER-2/NEU Expression in Gall Bladder Carcinoma (GBC)

Background  Gall bladder carcinoma (GBC) is the most common malignancy of the biliary tract. Being known for its geographical and racial variations, and compared with the global statistics, its incidence is higher in the Indian subcontinent, mainly in the northern and eastern regions, accounting for 80 to 95% of cases. Aims and Objectives  This study was conducted to evaluate the clinic-pathological spectrum and expression of EGFR and HER-2/NEU in GBCs and to understand their relation to prognosis, paving the way for targeted therapies for better treatment outcomes and patient survival. Materials and Methods  This is a prospective study performed in a tertiary care hospital in 30 resected specimens of GBC cases recorded in our Department of Pathology from November 2017 to November 2019. Clinical history including the radiological reports and demographic parameters were included in the study pro forma. Immunohistochemical (IHC) staining for EGFR and HER-2/NEU was performed on all the selected cases. Clinicopathologic parameters like age, sex, histologic type, perineural, and lymphovascular invasion were compared and correlated with EGFR and HER-2/NEU status. Results  Expression of EGFR was found in 93.33% of cases, which showed a highly significant correlation with histological tumor type ( p = 0.000). HER-2/NEU expression was found in 56.66% of cases, which also showed a significant correlation with histological tumour type ( p = 0.021). We found most of the cases with strong EGFR immunoreactivity (3+) were poorly differentiated tumors and most of the cases showing weak immunoreactivity for EGFR (1+) were well-differentiated. Conversely, in case of HER-2/NEU immunoreactivity, strong staining (3+) was seen in well-differentiated tumors and weak staining (1+) in poorly differentiated tumors. A significant correlation was also found between EGFR and HER-2/NEU expression ( p = 0.000) and between cholelithiasis and EGFR expression ( p = 0 .033). Conclusion  EGFR is expressed in most cases of GBC. Its expression is more in poorly differentiated carcinomas as compared to the well-differentiated carcinomas, whereas HER-2/NEU expression is more in well-differentiated carcinomas. Therefore, they may serve as independent prognostic factors and also as targets for molecular therapy in GBCs.

Histopathological features of HER2 overexpression in uterine carcinosarcoma: proposal for requirements in HER2 testing for targeted therapy

Uterine carcinosarcoma (UCS) is an uncommon and highly aggressive tumor. There is no HER2 testing protocol for UCS despite the development of HER2 antibody conjugates. We aimed to elucidate histopathological HER2 expression details in UCS, to compare HER2 scores between ASCO/CAP criteria for gastric and breast cancer, and to propose requirements for HER2 testing for UCS. Eighty-nine specimens from 84 patients with metastatic/recurrent UCS were prospectively collected from May 2018 to July 2020. We performed HER2 immunohistochemistry (IHC) for 89 specimens and FISH for 44 specimens. HER2 expression details and HER2 score were evaluated according to the latest ASCO/CAP criteria for gastric (2016) and breast cancer (2018). HER2 IHC scores according to the gastric cancer criteria were 0 in 31 cases (35%), 1+ in 26 (29%), 2+ in 22 (25%), and 3+ in 10 cases (11%) of the 89 specimens. A lateral/basolateral membranous staining pattern was observed in 28/32 (88%) specimens with HER2 scores of 2+/3+. HER2 intratumoral heterogeneity was identified in 28/32 (88%) of the specimens with HER2 scores of 2+/3+. The overall concordance rate of HER2 score was 70% between the gastric and breast criteria. FISH revealed HER2 gene amplification in 10/44 (23%) specimens containing only lateral/basolateral membranous staining pattern. Based on the histopathological features of HER2 expression in UCS, a scoring system that accepts lateral/basolateral staining patterns should be applied. Furthermore, we proposed specific requirements for UCS testing, including specimen selection, scoring system, and calculating the proportion of HER2-positive cells.

[ISH-based HER2 diagnostics]

A prerequisite for all HER2 directed therapies is the demonstration of HER2 receptor protein overexpression and/or gene amplification by in situ hybridization (ISH). ASCO and CAP have published several HER2 test guidelines over the past 15 years for both breast and gastric cancer. The latest version for breast cancer (2018) focuses on special issues of ISH related to the definitions of special diagnostic groups (1-5). The guidelines for gastroesophageal adenocarcinoma (2017), essentially based on ToGA trial data, are now also being used for other tumors such as pancreas, gallbladder, and non-small-cell lung cancer. For colorectal cancer, a modified testing procedure has been proposed. Recently, besides overexpression and amplification, a third type of HER gene alteration, namely mutation, has gained much interest. Next-generation sequencing (NGS) allows detection of both amplification and mutation of the HER2 gene providing new options of therapy especially in the case of activating mutations.

Role of Her-2 in Gastrointestinal Tumours beyond Gastric Cancer: A Tool for Precision Medicine

Gastrointestinal (GI) tumors account for a quarter of all the cancer burden and a third of the global cancer-related mortality. Among them, some cancers retain a dismal prognosis; therefore, newer and innovative therapies are urgently needed in priority disease areas of high-unmet medical need. In this context, HER2 could be a relevant prognostic and predictive biomarker acting as a target for specific drugs. However, if the role of HER2 has been object of investigation for several years in gastric cancer, it is not well established in other GI malignancies. The aim of this narrative review was to portray the current landscape of the potential role of HER2 as a predictive biomarker for GI tumors beyond gastric cancer. In colon cancer, the benefit from anti-HER2 therapies is less clear than in gastric neoplasms for the lack of controlled studies. Pancreatic, biliary tract adenocarcinomas and hepatocarcinoma may derive a less clear clinical benefit by using anti-HER2 agents in HER2 positive tumors. Overall, the results are promising and seem to suggest that the integration of multiple modalities of therapies can optimize the cancer care. However, further prospective trials are needed to validate the use of personalized targeted therapies in this field.

ISH-based HER2 diagnostics

A prerequisite for all HER2 directed therapies is the demonstration of HER2 receptor protein overexpression and/or gene amplification by in situ hybridization (ISH). ASCO and CAP have published several HER2 test guidelines over the past 15 years for both breast and gastric cancer. The latest version for breast cancer (2018) focuses on special issues of ISH related to the definitions of special diagnostic groups (1-5). The guidelines for gastroesophageal adenocarcinoma (2017), essentially based on ToGA trial data, are now also being used for other tumors such as pancreas, gallbladder, and non-small-cell lung cancer. For colorectal cancer, a modified testing procedure has been proposed. Recently, besides overexpression and amplification, a third type of HER gene alteration, namely mutation, has gained much interest. Next-generation sequencing (NGS) allows detection of both amplification and mutation of the HER2 gene providing new options of therapy especially in the case of activating mutations.

Current and New Biomarkers for Early Detection, Prognostic Stratification, and Management of Gallbladder Cancer Patients

Gallbladder cancer (GBC) is an aggressive disease that shows evident geographic variation and is characterized by a poor prognosis, mainly due to the late diagnosis and ineffective treatment. Genetic variants associated with GBC susceptibility, including polymorphisms within the toll-like receptors TLR2 and TLR4, the cytochrome P450 1A1 (CYP1A1), and the ATP-binding cassette (ABC) transporter ABCG8 genes, represent promising biomarkers for the stratification of patients at higher risk of GBC; thus, showing potential to prioritize cholecystectomy, particularly considering that early diagnosis is difficult due to the absence of specific signs and symptoms. Similarly, our better understanding of the gallbladder carcinogenic processes has led to identify several cellular and molecular events that may influence patient management, including HER2 aberrations, high tumor mutational burden, microsatellite instability, among others. Despite these reports on interesting and promising markers for risk assessment, diagnosis, and prognosis; there is an unmet need for reliable and validated biomarkers that can improve the management of GBC patients and support clinical decision-making. This review article examines the most potentially significant biomarkers of susceptibility, diagnosis, prognosis, and therapy selection for GBC patients, highlighting the need to find and validate existing and new molecular biomarkers to improve patient outcomes.

Details of human epidermal growth factor receptor 2 status in 454 cases of biliary tract cancer

Human epidermal growth factor receptor 2 (HER2)-targeted therapy has improved clinical outcomes in patients with HER2-positive breast and gastric cancers, although ineffective or recurrent cases are present. One reason for this is the heterogeneity of HER2 expression in cancer cells. The aim of this study was to investigate the clinicopathological characteristics and HER2 status of patients with biliary tract cancers (BTCs). We examined HER2 protein expression by immunohistochemistry, HER2 gene amplification by fluorescence in situ hybridization, and both HER2 protein and gene levels simultaneously by gene-protein assay. Samples were collected from 454 patients who underwent surgical resection for BTCs (110 intrahepatic cholangiocarcinomas [ICC], 67 perihilar extrahepatic cholangiocarcinomas [ECC-Bp], 119 distal extrahepatic cholangiocarcinomas [ECC-Bd], 80 gallbladder carcinomas [GBC], and 79 ampullary carcinomas [AVC]). HER2 status was assessed according to the guidelines for HER2 testing in gastroesophageal adenocarcinoma. HER2-positive status was detected in 14.5% of BTCs (3.7% of ICC, 3.0% of ECC-Bp, 18.5% of ECC-Bd, 31.3% of GBC, and 16.4% of AVC). Furthermore, HER2-positivity tended to correlate with low histological grade, tumor histology, and macroscopic features in certain tumors. HER2 heterogeneity was common and highly frequent (83%) in BTC cases. Reduced HER2 protein expression in the deeper invasive areas with simultaneous dedifferentiation was frequently observed in HER2-positive cancer cells. The findings of this study suggest that a large subgroup of HER2-positive BTC cases can be considered for HER2-targeted therapy. Moreover, the HER2 status in BTCs should be determined carefully using a sensitive approach toward larger cancer tissues.

Genetic analysis in the clinical management of biliary tract cancer

Biliary tract cancer (BTC) is clinically and pathologically heterogeneous and responds inadequately to treatment. A small section of patients develop resectable disease, although the relapse rates are high; the benefits of adjuvant capecitabine chemotherapy for BTC are now understood, and gemcitabine-based combination chemotherapy is the first line of therapeutic strategy for BTC; however, alternative therapy for BTC is not known. Genomic profiling can provide detailed information regarding the carcinogenesis, identification, and therapy for BTC. Currently, confirmed restorative targets for BTC are lacking. In this review, we aimed to analyze the preclinical and clinical implications of a spectrum of genomic alterations associated with new potentially remedial targets. We focused on eight draggable genes for BTC, which were described as having evidence of therapeutic impact (evidence level 2A-3B) based on the clinical practice guidance for next-generation sequencing in cancer diagnosis and treatment; these include ERBB2, NTRK1, RNF43, CDK6, CDKN2B, FGFR2, IDH1, and IDH2. Moreover, some of the BTC present microsatellite instability, hypermutation, and germline variants, which we also reviewed. Finally, we discussed the therapeutic options based on the next-generation sequencing findings in BTC. Studies have demonstrated that BTC includes subgroups with individually distinct driver mutations, most of which will be targeted with new treatment plans.

Testing for ROS1, ALK, MET, and HER2 rearrangements and amplifications in a large series of biliary tract adenocarcinomas

Biliary tract carcinomas are divided into intrahepatic, perihilar, distal extrahepatic cholangiocarcinomas, and gallbladder adenocarcinomas. Therapies targeting ROS1, ALK, MET, and HER2 alterations are currently evaluated in clinical trials. We assessed ROS1 and ALK translocations/amplifications as well as MET and HER2 amplifications for each tumor subtype by fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) in 73 intrahepatic, 40 perihilar bile duct, 36 distal extrahepatic cholangiocarcinomas, and 45 gallbladder adenocarcinomas (n = 194). By FISH, we detected targetable alterations in 5.2% of cases (n = 10): HER2 and MET amplifications were found in 4.1% (n = 8) and 1.0% (n = 2), respectively. The HER2-amplified cases were mostly gallbladder adenocarcinomas (n = 5). The MET- and HER2-amplified cases were all positive by IHC. Fourteen cases without MET amplification were positive by IHC, whereas HER2 over-expression was detected by IHC only in HER2-amplified cases. We detected no ALK or ROS1 translocation or amplification. Several alterations were consistent with aneuploidy: 24 cases showed only one copy of ROS1 gene, 4 cases displayed a profile of chromosomal instability, and an over-representation of centromeric alpha-satellite sequences was found in five cases. We confirm a relatively high rate of HER2 amplifications in gallbladder adenocarcinomas and the efficacy of IHC to screen these cases. Our results also suggest the value of IHC to screen MET amplification. Contrary to initial publications, ROS1 rearrangements seem to be very rare in biliary tract adenocarcinomas. We confirm a relatively high frequency of aneuploidy and chromosomal instability and reveal the over-representation of centromeric alpha-satellite sequences in intrahepatic cholangiocarcinomas.

Functional and genomic characterization of three novel cell lines derived from a metastatic gallbladder cancer tumor

Background

Gallbladder cancer (GBC) is the most common tumor of the biliary tract. The incidence of GBC shows a large geographic variability, being particularly frequent in Native American populations. In Chile, GBC represents the second cause of cancer-related death among women. We describe here the establishment of three novel cell lines derived from the ascitic fluid of a Chilean GBC patient, who presented 46% European, 36% Mapuche, 12% Aymara and 6% African ancestry.

Results

After immunocytochemical staining of the primary cell culture, we isolated and comprehensively characterized three independent clones (PUC-GBC1, PUC-GBC2 and PUC-GBC3) by short tandem repeat DNA profiling and RNA sequencing as well as karyotype, doubling time, chemosensitivity, in vitro migration capability and in vivo tumorigenicity assay. Primary culture cells showed high expression of CK7, CK19, CA 19-9, MUC1 and MUC16, and negative expression of mesothelial markers. The three isolated clones displayed an epithelial phenotype and an abnormal structure and number of chromosomes. RNA sequencing confirmed the increased expression of cytokeratin and mucin genes, and also of TP53 and ERBB2 with some differences among the three cells lines, and revealed a novel exonic mutation in NF1. The PUC-GBC3 clone was the most aggressive according to histopathological features and the tumorigenic capacity in NSG mice.

Conclusions

The first cell lines established from a Chilean GBC patient represent a new model for studying GBC in patients of Native American descent.

Human epidermal growth factor receptor 2-positive digestive tumors

PURPOSE OF REVIEW

This manuscript aims at providing an update and overview on the role of Human epidermal growth factor receptor 2 (HER2) testing and HER2-directed therapies in digestive tumors.

RECENT FINDINGS

Phase 3 trial data demonstrating a survival benefit of HER2-targeting treatments are limited to gastric cancer. However, HER2 positivity is also found in 5-6% of colorectal, 7% of pancreatic, and 16% of extrahepatic biliary cancers. Although phase 2 trial data support the use of the combination of trastuzumab and lapatinib with chemotherapy in HER2-positive colorectal cancer, the patient's benefit from targeted treatment of HER2-positive biliary or pancreatic neoplasms is currently unclear, and further clinical trials are necessary.

SUMMARY

With the exception of gastric cancer, there are currently no defined guidelines for HER2 testing in other digestive tumors. Various HER2-targeting therapies, which are standard of care in HER2-positive breast cancer, failed in HER2-positive gastric cancers. Thus, the predictive value of HER2 overexpression depends on the tumor type, and results of breast cancer trials cannot a priori be extrapolated to digestive cancers. Next-generation sequencing panel diagnostics may furthermore identify targetable activating mutations in gastric, extrahepatic biliary, and colorectal cancer, particularly if traditional testing (immunohistochemistry/in-situ hybridization) is negative. However, their clinical relevance needs to be determined.

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.

HER2-targeted therapies - a role beyond breast cancer

HER2 is an established therapeutic target in a large subset of women with breast cancer; a variety of agents including trastuzumab, pertuzumab, lapatinib, neratinib and trastuzumab emtansine (T-DM1) have been approved for the treatment of HER2-positive breast cancer. HER2 is also overexpressed in subsets of patients with other solid tumours. Notably, the addition of trastuzumab to first-line chemotherapy has improved the overall survival of patients with HER2-positive gastric cancer, and has become the standard-of-care treatment for this group of patients. However, trials involving pertuzumab, lapatinib and T-DM1 have failed to provide significant improvements in the outcomes of patients with HER2-positive gastric cancer. HER2-targeted therapies are also being tested in patients with other solid tumours harbouring HER2 overexpression, and/or amplifications or other mutations of the gene encoding HER2 (ERBB2), including biliary tract, colorectal, non-small-cell lung and bladder cancers. The experience with gastric cancer suggests that the successes observed in HER2-positive breast cancer might not be replicated in these other tumour types, owing to differences in the level of HER2 overexpression and other aspects of disease biology. In this Review, we describe the current role of HER2-targeted therapies beyond breast cancer and also highlight the potential of novel HER2-targeted agents that are currently in clinical development.

Pretreatment with Gemcitabine/5-Fluorouracil Enhances the Cytotoxicity of Trastuzumab to HER2-Negative Human Gallbladder Cancer Cells In Vitro and In Vivo

The effects of standard clinical therapies including surgery and chemotherapy are poor in advanced gallbladder cancer (GBC). There are a few reported cases of human epidermal growth factor receptor 2 (HER2)-positive GBC that responded well to trastuzumab. But trastuzumab has not yet been used to treat HER2-negative GBC. In this study, we investigated the cytotoxic effects of different combined therapies with trastuzumab and gemcitabine and/or 5-fluorouracil on HER2-negative GBC cell lines in vitro and in vivo. Trastuzumab alone showed almost no cytotoxicity to GBC cells with originally low HER2 gene amplification. Sequential therapy with chemotherapy followed by trastuzumab showed superiority over reverse sequential chemotherapy (P<0.05), concurrent combined chemotherapy (P<0.05), chemotherapy alone (P<0.05), and trastuzumab alone (P<0.05) in terms of cytotoxicity. Sequential therapy with chemotherapy followed by trastuzumab nearly completely inhibited cell viability in HER2-negative GBC cells. Similar results were observed with regard to apoptosis. Western blot analysis showed that gemcitabine/5-fluorouracil increased the expressions of total and phosphorylated forms of HER2, thus enhancing the cytotoxicity of trastuzumab. In vivo study verified the results of in vitro study by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay and immunohistochemical analysis. Moreover, not only the lightest tumor bearing but also the best survival state was detected in sequential therapy with chemotherapy followed by trastuzumab group compared with other groups. Our in vivo and in vitro data suggest that sequential therapy with gemcitabine/5-fluorouracil followed by trastuzumab represents a novel and promising therapeutic strategy against HER2-negative GBC. The upregulation of phosphorylated HER2 and phosphorylated-AKT induced by gemcitabine/5-fluorouracil treatment shows that HER2/AKT pathway is triggered.

The HER3 pathway as a potential target for inhibition in patients with biliary tract cancers

INTRODUCTION

Expression of human epidermal growth factor receptor (HER)2 and HER3 have been investigated in small BTC studies using variable scoring systems.

METHODS

HER2 and HER3 overexpression/amplification were explored following internationally agreed guidelines using immunohistochemistry (IHC) and fluorescent in-situ hybridisation (FISH), respectively. Logistic regression and survival analysis (Kaplan Meier, Log rank test and Cox Regression) were used for statistical analysis.

RESULTS

Sixty-seven eligible patients with Stage I/II (31.3%) or III/IV (68.7%) disease at diagnosis were included. Membrane HER2 overexpression/amplification was identified in 1 patient (1%). HER3 overexpression was predominantly cytoplasmic; the rate of overexpression/amplification of HER3 in membrane and cytoplasm was 16% [ampullary cancer (AMP) (1/13; 8%), gallbladder cancer (GBC) (1/10; 10%), intra-hepatic cholangiocarcinoma (ICC) (6/26; 23%), extra-hepatic cholangiocarcinoma (ECC) (3/18; 17%)] and 24% [AMP (1/13; 8%), GBC (1/10; 10%), ICC (10/26; 38%), ECC (4/18; 22%)], respectively.

CONCLUSIONS

A significant subset of patients with BTC expressed HER3. Inhibition of HER3 warrants further investigation. A better understanding of the downstream effects of HER3 in BTC requires further mechanistic investigations to identify new biomarkers and improve patient selection for future clinical trials.

Investigation of targetable predictive and prognostic markers in gallbladder carcinoma

Background

Gallbladder carcinoma, uncommon in most of the world, is frequent in South East Asia. It presents in advanced stages with limited therapeutic options. We investigated targetable predictive and prognostic Markers in 268 cases including 233 primary site lesions and 35 metastatic gallbladder carcinoma.

Methods

EGFR, VEGF, HER2/Neu and p53 were assessed using immunohistochemistry. HER2/Neu was validated in a subset by fluorescent in situ hybridization (FISH) using tissue microarray (TMA). Broader spectrum of gene variation was screened in NGS in representative FFPE tissue using the Ion AmpliSeq cancer hotspot panel V2.

Results

Mean age was 49.5 years with female predominance (77.6%). Histological types included 221 cases of adenocarcinoma not otherwise specified (NOS), 23 invasive papillary carcinoma, 11 mucinous adenocarcinoma, 8 adenosquamous, 1 signet ring, 3 neuroendocrine and 1 undifferentiated carcinoma. Majority (76.1%) presented with stage 3/4 disease. Overall positive expression of p53 was 44.8%, VEGF 79.4%, HER2/Neu 27.3% and EGFR 34.6%. Intratumoral heterogeneity was evident in HER2/Neu. Marker expression was not significantly associated with stage, grade, type and metastasis except VEGF which correlated with histological type (P=0.018) and tumor grade (P=0.027). NGS using Ion AmpliSeq cancer hotspot panel V2 revealed multiple non synonymous mutations, most frequent being TP53 and CDKN2A mutations and mutations in MET, KDR, PIK3CA, VHL, MPL, HER2 and SMARCB1 genes.

Conclusions

Predictive targetable markers like HER2/Neu, VEGF and EGFR are expressed in high proportion of gallbladder carcinoma. Significant expression of RAS pathway molecules suggests that interactions take place among the different members of the ErbB family during tumor development.

HER2/HER3 pathway in biliary tract malignancies; systematic review and meta-analysis: a potential therapeutic target?

Human epidermal growth factor receptor 2 (HER2) overexpression and amplification have been reported as predictive markers for HER2-targeted therapy in breast and gastric cancer, whereas human epidermal growth factor receptor 3 (HER3) is emerging as a potential resistance factor. The aim of this study was to perform a systematic review and meta-analysis of the HER2 and HER3 overexpression and amplification in biliary tract cancers (BTCs). An electronic search of MEDLINE, American Society of Clinical Oncology (ASCO), European Society of Medical Oncology Congress (ESMO), and American Association for Cancer Research (AACR) was performed to identify studies reporting HER2 and/or HER3 membrane protein expression by immunohistochemistry (IHC) and/or gene amplification by in situ hybridization (ISH) in BTCs. Studies were classified as "high quality" (HQ) if IHC overexpression was defined as presence of moderate/strong staining or "low quality" (LQ) where "any" expression was considered positive. Of 440 studies screened, 40 met the inclusion criteria. Globally, HER2 expression rate was 26.5 % (95 % CI 18.9-34.1 %). When HQ studies were analyzed (n = 27 studies), extrahepatic BTCs showed a higher HER2 overexpression rate compared to intrahepatic cholangiocarcinoma: 19.9 % (95 % CI 12.8-27.1 %) vs. 4.8 % (95 % CI 0-14.5 %), respectively, p value 0.0049. HER2 amplification rate was higher in patients selected by HER2 overexpression compared to "unselected" patients: 57.6 % (95 % CI 16.2-99 %) vs. 17.9 % (95 % CI 0.1-35.4 %), respectively, p value 0.0072. HER3 overexpression (4/4 HQ studies) and amplification rates were 27.9 % (95 % CI 9.7-46.1 %) and 26.5 % (one study), respectively. Up to 20 % of extrahepatic BTCs appear to be HER2 overexpressed; of these, close to 60 % appear to be HER2 amplified, while HER3 is overexpressed or amplified in about 25 % of patients. Clinical relevance for targeted therapy should be tested in prospective clinical trials.

Prognostic Significance of HER-2 and p53 Expression in Gallbladder Carcinoma in North Indian Patients

BACKGROUND/OBJECTIVE

Proto-oncogenes (HER-2) and tumor suppressor genes (p53) are commonly deregulated in gallbladder cancer (GBC). Available literature discloses skewed data from endemic Asian countries, especially north India. This study evaluates the prognostic significance of HER-2 and p53 in GBC patients from two major hospitals.

METHODS

Sixty resectable tumor and control specimens were prospectively collected from December 2012 to January 2016. Immunohistochemical staining was done using monoclonal antibodies to semiquantitatively evaluate HER-2 and p53 protein expression. The criterion for HER-2 positivity was set at >30% tumor cells showing complete, membranous staining while p53 positivity was established at <50% tumor cells showing complete nuclear staining. Clinicopathological correlations were drawn with major clinical outcomes.

RESULTS

It was observed that 36.67% (22/60) tumor cases and 5% (3/60) control cases showed strong HER-2 overexpression significantly correlating with sex, T-stage, nodal spread and distant metastasis (p < 0.05), while 33.3% (20/60) positivity was observed for p53 in tumor cases and 1.7% (1/60) in control cases. Multivariate analysis showed HER-2 (p = 0.04; hazard ratio: 2.36; 95% confidence interval: 1.04-5.33) and p53 (p = 0.03; hazard ratio: 5.63; 95% confidence interval: 1.21-26.26) expression to be independent prognostic factors.

CONCLUSION

Our study thus suggests the plausible role of HER-2 and p53 expression in worse prognosis of GBC in a north Indian population.

HER2 aberrations and heterogeneity in cancers of the digestive system: Implications for pathologists and gastroenterologists

Management of cancers of the digestive system has progressed rapidly into the molecular era. Despite the significant recent achievements in the diagnosis and treatment of these patients, the number of deaths for these tumors has currently plateaued. Many investigations have assessed the role of HER2 in tumors of the digestive system in both prognostic and therapeutic settings, with heterogeneous results. Novel testing and treatment guidelines are emerging, in particular in gastric and colorectal cancers. However, further advances are needed. In this review we provide a comprehensive overview of the current state-of-knowledge of HER2 alterations in the most common tumors of the digestive system and discuss the operational implications of HER2 testing.