Herceptin and gemcitabine for metastatic pancreatic cancers that overexpress HER-2/neu

Combined KRAS-MAPK pathway inhibitors and HER2-directed drug conjugate is efficacious in pancreatic cancer

Targeting the mitogen-activated protein kinase (MAPK) cascade in pancreatic ductal adenocarcinoma (PDAC) remains clinically unsuccessful. We aim to develop a MAPK inhibitor-based therapeutic combination with strong preclinical efficacy. Utilizing a reverse-phase protein array, we observe rapid phospho-activation of human epidermal growth factor receptor 2 (HER2) in PDAC cells upon pharmacological MAPK inhibition. Mechanistically, MAPK inhibitors lead to swift proteasomal degradation of dual-specificity phosphatase 6 (DUSP6). The carboxy terminus of HER2, containing a TEY motif also present in extracellular signal-regulated kinase 1/2 (ERK1/2), facilitates binding with DUSP6, enhancing its phosphatase activity to dephosphorylate HER2. In the presence of MAPK inhibitors, DUSP6 dissociates from the protective effect of the RING E3 ligase tripartite motif containing 21, resulting in its degradation. In PDAC patient-derived xenograft (PDX) models, combining ERK and HER inhibitors slows tumour growth and requires cytotoxic chemotherapy to achieve tumour regression. Alternatively, MAPK inhibitors with trastuzumab deruxtecan, an anti-HER2 antibody conjugated with cytotoxic chemotherapy, lead to sustained tumour regression in most tested PDXs without causing noticeable toxicity. Additionally, KRAS inhibitors also activate HER2, supporting testing the combination of KRAS inhibitors and trastuzumab deruxtecan in PDAC. This study identifies a rational and promising therapeutic combination for clinical testing in PDAC patients.

ERBB2 (HER2) amplifications and co-occurring KRAS alterations in the circulating cell-free DNA of pancreatic ductal adenocarcinoma patients and response to HER2 inhibition

Purpose

Despite accumulating data regarding the genomic landscape of pancreatic ductal adenocarcinoma (PDAC), olaparib is the only biomarker-driven FDA-approved targeted therapy with a PDAC-specific approval. Treating ERBB2(HER2)-amplified PDAC with anti-HER2 therapy has been reported with mixed results. Most pancreatic adenocarcinomas have KRAS alterations, which have been shown to be a marker of resistance to HER2-targeted therapies in other malignancies, though the impact of these alterations in pancreatic cancer is unknown. We describe two cases of ERBB2-amplified pancreatic cancer patients treated with anti-HER2 therapy and provide data on the frequency of ERBB2 amplifications and KRAS alterations identified by clinical circulating cell-free DNA testing.

Methods

De-identified molecular test results for all patients with pancreatic cancer who received clinical cell-free circulating DNA analysis (Guardant360) between 06/2014 and 01/2018 were analyzed. Cell-free circulating DNA analysis included next-generation sequencing of up to 73 genes, including select small insertion/deletions, copy number amplifications, and fusions.

Results

Of 1,791 patients with pancreatic adenocarcinoma, 36 (2.0%) had an ERBB2 amplification, 26 (72.2%) of whom had a KRAS alteration. Treatment data were available for seven patients. Two were treated with anti-HER2 therapy after their cell-free circulating DNA result, with both benefiting from therapy, including one with a durable response to trastuzumab and no KRAS alteration detected until progression.

Conclusion

Our case series illustrates that certain patients with ERBB2-amplified pancreatic adenocarcinoma may respond to anti-HER2 therapy and gain several months of prolonged survival. Our data suggests KRAS mutations as a possible mechanism of primary and acquired resistance to anti-HER2 therapy in pancreatic cancer. Additional studies are needed to clarify the role of KRAS in resistance to anti-HER2 therapy.

The Role of Chemokines in Orchestrating the Immune Response to Pancreatic Ductal Adenocarcinoma

Chemokines are small molecules that function as chemotactic factors which regulate the migration, infiltration, and accumulation of immune cells. Here, we comprehensively assess the structural and functional role of chemokines, examine the effects of chemokines that are present in the pancreatic ductal adenocarcinoma (PDAC) tumor microenvironment (TME), specifically those produced by cancer cells and stromal components, and evaluate their impact on immune cell trafficking, both in promoting and suppressing anti-tumor responses. We further explore the impact of chemokines on patient outcomes in PDAC and their role in the context of immunotherapy treatments, and review clinical trials that have targeted chemokine receptors and ligands in the treatment of PDAC. Lastly, we highlight potential strategies that can be utilized to harness chemokines in order to increase cytotoxic immune cell infiltration and the anti-tumor effects of immunotherapy.

Pancreatic Cancer: Beyond Brca Mutations

Pancreatic cancer is the fourth-leading cause of cancer-related deaths worldwide. The outcomes in patients with pancreatic cancer remain unsatisfactory. In the current review, we summarize the genetic and epigenetic architecture of metastatic pancreatic cancer beyond the BRCA mutations, focusing on the genetic alterations and the molecular pathology in pancreatic cancer. This review focuses on the molecular targets for the treatment of pancreatic cancer, with a correlation to future treatments. The potential approach addressed in this review may lead to the identification of a subset of patients with specific biological behaviors and treatment responses.

HDACs/mTOR inhibitor synergizes with pyrotinib in HER2-positive pancreatic cancer through degradation of mutant P53

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), as a highly lethal malignancy with high mortality, lacks of effective treatment. Canonical therapeutic targets in PDAC demand further verification among which HER2 receptor tyrosine kinase inhibitor pyrotinib as treatment targets has not be decided.

METHODS

Anti-PDAC efficacy of pyrotinib was evaluated both in vitro and in vivo using both cell lines and patient-derived xenografts. By screening a large-scale library of 1453 compounds, we identified HDACs/mTOR inhibitor 1 as a promising candidate to synergize with pyrotinib. The combination therapy was evaluated in vitro and in vivo in multiple cell lines and animal models. Furthermore, RNA-seq analysis was performed to reveal the latent molecular mechanism of combination therapy.

RESULTS

In our study, pyrotinib monotherapy was found to be inefficient to anti-PDAC which exhibited limited anti-proliferation effect in vitro and in vivo. Through therapy combined with HDACs/mTOR inhibitor 1, pyrotinib triggered intense apoptosis in PDAC both in cell lines and animal models. Mechanistic analyses revealed that mutant P53 degradation mediated by HDAC inhibition synergized with HER2 and mTOR inhibition.

CONCLUSIONS

In conclusion, identification of HDACs/mTOR inhibitor as a synergistic inhibitor, provides a potent therapeutic strategy that targets HER2-positive pancreatic cancer.

Therapeutic advances in metastatic pancreatic cancer: a focus on targeted therapies

Mortality from pancreatic ductal adenocarcinoma (PDAC) is increasing worldwide and effective new treatments are urgently needed. The current treatment of metastatic PDAC in fit patients is based on two chemotherapy combinations (FOLFIRINOX and gemcitabine plus nab-paclitaxel) which were validated more than 8 years ago. Although almost all treatments targeting specific molecular alterations have failed so far when administered to unselected patients, encouraging results were observed in the small subpopulations of patients with germline BRCA 1/2 mutations, and somatic gene fusions (neurotrophic tyrosine receptor kinase, Neuregulin 1, which are enriched in KRAS wild-type PDAC), KRAS G12C mutations, or microsatellite instability. While targeted tumor metabolism therapies and immunotherapy have been disappointing, they are still under investigation in combination with other drugs. Optimizing pharmacokinetics and adapting available chemotherapies based on molecular signatures are other promising avenues of research. This review evaluates the current expectations and limits of available treatments and analyses the existing trials. A permanent search for actionable vulnerabilities in PDAC tumor cells and microenvironments will probably result in a more personalized therapeutic approach, keeping in mind that supportive care must also play a major role if real clinical efficacy is to be achieved in these patients.

Moving the Needle on Precision Medicine in Pancreatic Cancer

The management of pancreatic ductal adenocarcinoma (PDAC) has posed a considerable challenge for decades, with incidence and mortality rates almost mirroring each other. Despite this, a deeper understanding of the complex biology inherent to PDAC has provided a roadmap for a more precise approach to treatment. PDAC deficient in homologous recombination repair and mismatch repair is a subgroup that should be identified in the clinic for a targeted approach. In addition, KRAS wild-type PDAC, occurring in approximately 10% of patients, is enriched in highly actionable alterations including fusions, underscoring the importance of integrative germline and somatic sequencing. Comprehensive sequencing efforts over the past decade have documented genomic- and transcriptomic-based classifiers, with the latter emerging as two main subtypes: the classical and basal-like, which are now being evaluated in clinical trials. Together with promising, innovative strategies to target KRAS mutations and their pleotropic effects, a new era of precision medicine in PDAC is on the horizon.

Comparison of actionable events detected in cancer genomes by whole-genome sequencing, in silico whole-exome and mutation panels

Background

Next-generation sequencing is used in cancer research to identify somatic and germline mutations, which can predict sensitivity or resistance to therapies, and may be a useful tool to reveal drug repurposing opportunities between tumour types. Multigene panels are used in clinical practice for detecting targetable mutations. However, the value of clinical whole-exome sequencing (WES) and whole-genome sequencing (WGS) for cancer care is less defined, specifically as the majority of variants found using these technologies are of uncertain significance.

Patients and methods

We used the Cancer Genome Interpreter and WGS in 726 tumours spanning 10 cancer types to identify drug repurposing opportunities. We compare the ability of WGS to detect actionable variants, tumour mutation burden (TMB) and microsatellite instability (MSI) by using in silico down-sampled data to mimic WES, a comprehensive sequencing panel and a hotspot mutation panel.

Results

We reveal drug repurposing opportunities as numerous biomarkers are shared across many solid tumour types. Comprehensive panels identify the majority of approved actionable mutations, with WGS detecting more candidate actionable mutations for biomarkers currently in clinical trials. Moreover, estimated values for TMB and MSI vary when calculated from WGS, WES and panel data, and are dependent on whether all mutations or only non-synonymous mutations were used. Our results suggest that TMB and MSI thresholds should not only be tumour-dependent, but also be sequencing platform-dependent.

Conclusions

There is a large opportunity to repurpose cancer drugs, and these data suggest that comprehensive sequencing is an invaluable source of information to guide clinical decisions by facilitating precision medicine and may provide a wealth of information for future studies. Furthermore, the sequencing and analysis approach used to estimate TMB may have clinical implications if a hard threshold is used to indicate which patients may respond to immunotherapy.

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Genome analysis revealed that treatment biomarkers are shared across solid tumours, highlighting repurposing opportunities.

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Comprehensive panels detect most known biomarkers; however, WGS detects more biomarkers for treatments in clinical trials.

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TMB is well correlated between sequencing methods, but absolute values vary and are dependent on mutation types considered.

HER2-positive adenocarcinoma arising from heterotopic pancreas tissue in the duodenum: A case report

BACKGROUND

Adenocarcinoma originating from heterotopic pancreas tissue is a rare disease. Furthermore, to our knowledge, no HER2-positive cases in the duodenum have been reported in the scientific literature nor has the efficacy of trastuzumab treatment for the disease been reported.

CASE SUMMARY

A 65-year-old woman whose clinical diagnosis was unresectable advanced duodenal cancer with HER2 overexpression responded well to trastuzumab chemotherapy. The main tumor in the duodenum reduced drastically. The patient underwent pancreaticoduodenectomy and lymph node dissection. A small number of cancer cells remained in the submucosal layer of the duodenum and pancreas head. After histological and immunohistochemical examination, the patient was diagnosed with duodenal adenocarcinoma originating from heterotopic pancreas tissue.

CONCLUSION

Trastuzumab treatment is effective in HER2-positive adenocarcinoma originating from heterotopic pancreas tissue in the duodenum.

Pandey M, Plano D, Amin S, Lu J, Sharma AK. Novel Seleno-Aspirinyl Compound AS-10 Induces Apoptosis, G1 Arrest of Pancreatic Ductal Adenocarcinoma Cells, Inhibits Their NF-κB Signaling, and Synergizes with Gemcitabine Cytotoxicity

Current available therapies for pancreatic ductal adenocarcinoma (PDAC) provide minimal overall survival benefits and cause severe adverse effects. We have identified a novel molecule AS-10, a selenazolidine-bis-aspirinyl derivative, that was two to three orders of magnitude more potent than aspirin and at least one to two orders of magnitude more potent than gemcitabine in inhibiting PDAC cancer cell growth/viability against three PDAC cell lines while sparing mouse embryonic fibroblasts in the same exposure range. In Panc-1 cells, AS-10 induced apoptosis without necrosis, principally through caspase-3/7 cascade and reactive oxygen species, in addition to an induction of G1 cell cycle block. Transcriptomic profiling with RNA-seq indicated the top responses to AS-10 exposure as CDKN1A (P21Cip1), CCND1, and nuclear transcription factor-kappa B (NF-κB) complex and the top functions as cell cycle, cell death, and survival without inducing the DNA damage gene signature. AS-10 pretreatment (6 h) decreased cytokine tumor necrosis factor-alpha (TNF-α)-stimulated NF-κB nuclear translocation, DNA binding activity, and degradation of cytosolic inhibitor of κB (IκB) protein. As NF-κB activation in PDAC cells confers resistance to gemcitabine, the AS-10 combination with gemcitabine increased the in vitro cytotoxicity more than the additivity of both compounds. Overall, our results suggest AS-10 may be a promising drug lead for PDAC, both as a single agent and in combination therapy.

Mechanisms of drug resistance of pancreatic ductal adenocarcinoma at different levels

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death worldwide, and the mortality of patients with PDAC has not significantly decreased over the last few decades. Novel strategies exhibiting promising effects in preclinical or phase I/II clinical trials are often situated in an embarrassing condition owing to the disappointing results in phase III trials. The efficacy of the current therapeutic regimens is consistently compromised by the mechanisms of drug resistance at different levels, distinctly more intractable than several other solid tumours. In this review, the main mechanisms of drug resistance clinicians and investigators are dealing with during the exploitation and exploration of the anti-tumour effects of drugs in PDAC treatment are summarized. Corresponding measures to overcome these limitations are also discussed.

Advances in Targeted Therapy and Immunotherapy for Pancreatic Cancer

Pancreatic cancer is a highly aggressive malignancy with an overall 5-year survival rate of <6% due to therapeutic resistance and late-stage diagnosis. These statistics have not changed despite 50 years of research and therapeutic development. Pancreatic cancer is predicted to become the second leading cause of cancer mortality by the year 2030. Currently, the treatment options for pancreatic cancer are limited. This disease is usually diagnosed at a late stage, which prevents curative surgical resection. Chemotherapy is the most frequently used approach for pancreatic cancer treatment and has limited effects. In many other cancer types, targeted therapy and immunotherapy have made great progress and have been shown to be very promising prospects; these treatments also provide hope for pancreatic cancer. The need for research on targeted therapy and immunotherapy is pressing due to the poor prognosis of pancreatic cancer, and in recent years, there have been some breakthroughs for targeted therapy and immunotherapy in pancreatic cancer. This review summarizes the current preclinical and clinical studies of targeted therapy and immunotherapy for pancreatic cancer and ends by describing the challenges and outlook.

Invadopodia: A potential target for pancreatic cancer therapy

Dissemination of cancer cells is an intricate multistep process that represents the most deadly aspect of cancer. Cancer cells form F-actin-rich protrusions known as invadopodia to invade surrounding tissues, blood vessels and lymphatics. A number of studies have demonstrated the significant roles of invadopodia in cancer. Therefore, the specific cells and molecules involved in invadopodia activity can provide as therapeutic targets. In this review, we included a thorough overview of studies in invadopodia and discussed their functions in cancer metastasis. We then presented the specific cells and molecules involved in invadopodia activity in pancreatic cancer and analyzed their suitability to be effective therapeutic targets. Currently, drugs targeting invadopodia and relevant clinical trials are negligible. Here, we highlighted the significance of potential drugs and discussed future obstacles in implementing clinical trials. This review presents a new perspective on invadopodia-induced pancreatic cancer metastasis and may prosper the development of targeted therapeutics against pancreatic cancer.

Molecular Subtyping and Precision Medicine for Pancreatic Cancer

Substantial progress in recent years has dramatically increased our knowledge of the molecular basis of cancer, revealing new potential therapeutic targets and paving the way for effective personalised medicine for the treatment of many tumour types. However, pancreatic cancer has been lagging behind in this success and continues to be one of the most lethal solid malignancies. Its molecular heterogeneity and the unselected design of the majority of clinical trials to date can in part explain the reason for our failure to make a significant change in the survival outcomes for patients with pancreatic cancer. A changing paradigm in drug development is required to validate the new molecular taxonomy and to rapidly translate preclinical discovery into clinical trials. Here, we review the molecular subtyping of pancreatic cancer, the challenges in identifying effective treatment regimens according to defined low-prevalence molecular subgroups and we illustrate a new model of translational therapeutic development that was established in the U.K. (Precision-Panc) as a potentially effective solution to improve outcomes for patients with pancreatic cancer.

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.

Phase II study evaluating the association of gemcitabine, trastuzumab and erlotinib as first-line treatment in patients with metastatic pancreatic adenocarcinoma (GATE 1)

In a previous phase II study (THERAPY), cetuximab and trastuzumab combination, as second-line after progression with gemcitabine, showed disease stabilization in 27% of 33 patients with pancreatic carcinoma. In the present phase II multicenter study, we assessed the efficacy and tolerance of gemcitabine, trastuzumab plus erlotinib as first-line treatment of metastatic pancreatic cancer. The primary endpoint was disease control rate (DCR, RECIST v.1); secondary endpoints were progression-free (PFS), overall (OS) survival and toxicity (NCI-CTCAE v3.0). Ancillary study addressed the predictive value of both EGFR/HER2 expression and KRAS mutational status. Sixty-three patients from four centers were included (62 evaluable for toxicity, 59 for efficacy), median age was 62 years (35-77), 59.7% men. The median treatment duration was 16.1 weeks (2.1-61). Eleven patients (19%) reported a partial tumor response, and 33 (56%) disease stabilization. DCR was 74.6% (95%CI: 61.8-85.0; 44/59 patients). After a median follow-up of 23.3 months (0.6-23.6), median PFS was 3.5 months (95%CI: 2.4-3.8) and median OS 7.9 months (95%CI: 5.1-10.2). PFS was significantly longer in patients with grade ≥ 2 cutaneous toxicities vs patients with grade 0-1 toxicities (HR = 0.55, 95%CI: 0.33-0.92, P = .020). Expression of EGFR and HER2 was correlated with PFS and OS in multivariate analysis; HER2 expression was correlated with the tumor response. Main severe toxicities were neutropenia (32%), cutaneous rash (37%) and thrombosis/embolisms (35.5%). This triplet combination is effective in terms of disease control, PFS and OS, and acceptable for safety. A larger study to investigate this combination compared to the standard regimen should be discussed.

A survival guide to HER2 testing in gastric/gastroesophageal junction carcinoma

Human epidermal growth factor receptor 2 (HER2) status determines gastric/gastroesophageal junction (GEJ) adenocarcinomas that benefit from targeted therapy; hence, HER2 testing has become a routine practice. Accurate HER2 testing is fundamental to select eligible patients who will benefit from HER2-targeted treatment. The reported HER2-positive rate in gastric/GEJ cancers ranges from 4.4% to 53.4%, and HER2-positive tumors are considered to have more-aggressive biologic behavior and tumor recurrence. Main modalities of HER2 testing in clinical practice include immunohistochemistry (IHC) for protein expression and in situ hybridization (ISH) for gene amplification. Many technical pitfalls affect the accuracy of HER2 result. Additionally, several issues in HER2 testing are related to the tumor biology, sample selection, interpretation of IHC and ISH results, and confirming HER2 status. Therefore, gastric/GEJ adenocarcinoma-specific HER2 testing protocols have been developed and standardized to minimize the impact of these preanalytical and analytical factors and to enhance reproducibility of HER2 testing results. This review provides up-to-date practical guidance to clinicians on accurate HER2 testing and interpretation of results in gastric/GEJ adenocarcinoma.

An auristatin-based antibody-drug conjugate targeting HER3 enhances the radiation response in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer characterized by poor response to chemotherapy and radiotherapy due to the lack of efficient therapeutic tools and early diagnostic markers. We previously generated the nonligand competing anti-HER3 antibody 9F7-F11 that binds to pancreatic tumor cells and induces tumor regression in vivo in experimental models. Here, we asked whether coupling 9F7-F11 with a radiosensitizer, such as monomethylauristatin E (MMAE), by using the antibody-drug conjugate (ADC) technology could improve radiation therapy efficacy in PDAC. We found that the MMAE-based HER3 antibody-drug conjugate (HER3-ADC) was efficiently internalized in tumor cells, increased the fraction of cells arrested in G2/M, which is the most radiosensitive phase of the cell cycle, and promoted programmed cell death of irradiated HER3-positive pancreatic cancer cells (BxPC3 and HPAC cell lines). HER3-ADC decreased the clonogenic survival of irradiated cells by increasing DNA double-strand break formation (based on γH2AX level), and by modulating DNA damage repair. Tumor radiosensitization with HER3-ADC favored the inhibition of the AKT-induced survival pathway, together with more efficient caspase 3/PARP-mediated apoptosis. Incubation with HER3-ADC before irradiation synergistically reduced the phosphorylation of STAT3, which is involved in chemoradiation resistance. In vivo, the combination of HER3-ADC with radiation therapy increased the overall survival of mice harboring BxPC3, HPAC cell xenografts or patient-derived xenografts, and reduced proliferation (KI67-positive cells). Combining auristatin radiosensitizer delivery via an HER3-ADC with radiotherapy is a new promising therapeutic strategy in PDAC.

Combating pancreatic cancer with PI3K pathway inhibitors in the era of personalised medicine

Pancreatic ductal adenocarcinoma (PDAC) is among the most deadly solid tumours. This is due to a generally late-stage diagnosis of a primarily treatment-refractory disease. Several large-scale sequencing and mass spectrometry approaches have identified key drivers of this disease and in doing so highlighted the vast heterogeneity of lower frequency mutations that make clinical trials of targeted agents in unselected patients increasingly futile. There is a clear need for improved biomarkers to guide effective targeted therapies, with biomarker-driven clinical trials for personalised medicine becoming increasingly common in several cancers. Interestingly, many of the aberrant signalling pathways in PDAC rely on downstream signal transduction through the mitogen-activated protein kinase and phosphoinositide 3-kinase (PI3K) pathways, which has led to the development of several approaches to target these key regulators, primarily as combination therapies. The following review discusses the trend of PDAC therapy towards molecular subtyping for biomarker-driven personalised therapies, highlighting the key pathways under investigation and their relationship to the PI3K pathway.

Targeted therapies in pancreatic cancer: Promises and failures

Pancreatic ductal adenocarcinoma (PDAC) is an incidence rate nearly equal to its mortality rate. The poor prognosis of the disease can be explained by the absence of effective biomarkers for screening and early detection, together with the aggressive behavior and resistance to the currently available chemotherapy. The therapeutic failure can also be attributed to the inter-/intratumor genetic heterogeneity and the abundance of tumor stroma that occupies the majority of the tumor mass. Gemcitabine is used in the treatment of PDAC; however, the response rate is less than 12%. A recent phase III trial revealed that the combination of oxaliplatin, irinotecan, fluorouracil, and leucovorin could be an option for the treatment of metastatic PDAC patients with good performance status, although these approaches can result in high toxicity level. Further investigations are required to develop innovative anticancer agents that either improve gemcitabine activity, within novel combinatorial approaches or acts with a better efficacy than gemcitabine. The aim of the current review is to give an overview of preclinical and clinical studies targeting key dysregulated signaling pathways in PDAC.

NRG1 Fusions in KRAS Wild-Type Pancreatic Cancer

We used whole-genome and transcriptome sequencing to identify clinically actionable genomic alterations in young adults with pancreatic ductal adenocarcinoma (PDAC). Molecular characterization of 17 patients with PDAC enrolled in a precision oncology program revealed gene fusions amenable to pharmacologic inhibition by small-molecule tyrosine kinase inhibitors in all patients with KRAS wild-type (KRAS^WT) tumors (4 of 17). These alterations included recurrent NRG1 rearrangements predicted to drive PDAC development through aberrant ERBB receptor-mediated signaling, and pharmacologic ERBB inhibition resulted in clinical improvement and remission of liver metastases in 2 patients with NRG1-rearranged tumors that had proved resistant to standard treatment. Our findings demonstrate that systematic screening of KRAS^WT tumors for oncogenic fusion genes will substantially improve the therapeutic prospects for a sizeable fraction of patients with PDAC.Significance: Advanced PDAC is a malignancy with few treatment options that lacks molecular mechanism-based therapies. Our study uncovers recurrent gene rearrangements such as NRG1 fusions as disease-driving events in KRAS^wt tumors, thereby providing novel insights into oncogenic signaling and new therapeutic options in this entity. Cancer Discov; 8(9); 1087-95. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 1047.

The evolution into personalized therapies in pancreatic ductal adenocarcinoma: challenges and opportunities

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is projected to be the second leading cause of cancer related mortality in the United States in 2030, with a 5-year overall survival of less than 10% despite decades of extensive research. Pancreatic cancer is marked by the accumulation of complex molecular changes, complex tumor-stroma interaction, and an immunosuppressive tumor microenvironment. PDAC has proven to be resistant to many cytotoxic, targeted and immunologic treatment approaches. Areas covered: In this paper, we review the major areas of research in PDAC, with highlights on the challenges and areas of opportunity for personalized treatment approaches. Expert commentary: The focus of research in pancreatic cancer has moved away from developing conventional cytotoxic combinations. The marked advances in understanding the molecular biology of this disease especially in the areas of the microenvironment, metabolism, and DNA repair have opened new opportunities for developing novel treatment strategies. Improved understanding of molecular abnormalities allows the development of personalized treatment approaches.

Pharmacotherapeutic Management of Pancreatic Ductal Adenocarcinoma: Current and Emerging Concepts

Pancreatic ductal adenocarcinoma is a devastating malignancy, which is the result of late diagnosis, aggressive disease, and a lack of effective treatment options. Thus, pancreatic ductal adenocarcinoma is projected to become the second leading cause of cancer-related death by 2030. This review summarizes recent developments of oncological therapy in the palliative setting of metastatic pancreatic ductal adenocarcinoma. It further compiles novel targets and therapeutic approaches as well as promising treatment combinations, which are presently in preclinical evaluation, covering several aspects of the hallmarks of cancer. Finally, challenges to the implementation of an individualized therapy approach in the context of precision medicine are discussed.

New therapeutic directions for advanced pancreatic cancer: cell cycle inhibitors, stromal modifiers and conjugated therapies

INTRODUCTION

Pancreatic adenocarcinoma is a devastating malignancy with an extremely poor prognosis. These tumors progress rapidly and somewhat silently with few specific symptoms and are relatively resistant to chemotherapeutic agents. Many agents, including cell cycle inhibitors, are under development for the treatment of this cancer for which there are disappointingly few treatment options. Areas covered: Here we outline the existing approved treatments for advanced pancreatic disease and discuss a range of novel therapies currently under development including cell cycle inhibitors, stromal modifiers and conjugated therapies. We also describe the current state of the pancreatic cancer therapeutics market both past and future. Expert opinion: Despite the recent explosion of novel therapies with an array of unique targets, the core treatment of pancreatic cancer still with traditional cytotoxic agents with a few exceptions. However, as these novel treatments move through the pipeline, we are hopeful that there will soon be a number of effective options for patients with advanced pancreatic cancer.

Bioinformatory-assisted analysis of next-generation sequencing data for precision medicine in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a tumor with an extremely poor prognosis, predominantly as a result of chemotherapy resistance and numerous somatic mutations. Consequently, PDAC is a prime candidate for the use of sequencing to identify causative mutations, facilitating subsequent administration of targeted therapy. In a feasibility study, we retrospectively assessed the therapeutic recommendations of a novel, evidence-based software that analyzes next-generation sequencing (NGS) data using a large panel of pharmacogenomic biomarkers for efficacy and toxicity. Tissue from 14 patients with PDAC was sequenced using NGS with a 620 gene panel. FASTQ files were fed into treatmentmap. The results were compared with chemotherapy in the patients, including all side effects. No changes in therapy were made. Known driver mutations for PDAC were confirmed (e.g. KRAS, TP53). Software analysis revealed positive biomarkers for predicted effective and ineffective treatments in all patients. At least one biomarker associated with increased toxicity could be detected in all patients. Patients had been receiving one of the currently approved chemotherapy agents. In two patients, toxicity could have been correctly predicted by the software analysis. The results suggest that NGS, in combination with an evidence-based software, could be conducted within a 2-week period, thus being feasible for clinical routine. Therapy recommendations were principally off-label use. Based on the predominant KRAS mutations, other drugs were predicted to be ineffective. The pharmacogenomic biomarkers indicative of increased toxicity could be retrospectively linked to reported negative side effects in the respective patients. Finally, the occurrence of somatic and germline mutations in cancer syndrome-associated genes is noteworthy, despite a high frequency of these particular variants in the background population. These results suggest software-analysis of NGS data provides evidence-based information on effective, ineffective and toxic drugs, potentially forming the basis for precision cancer medicine in PDAC.

Pancreatic Cancer from Molecular Pathways to Treatment Opinion

Pancreatic cancer is considered one of the most lethal malignances. It has been observed that the five year survival rate is less than 5%. Early diagnosis, understanding the risk factors and investigation of the molecular pathways with targeted therapy are the keys for efficient treatment. Moreover; there are several local treatments for patients with unresectable pancreatic cancer. There are several combined therapies with chemotherapy and radiotherapy, however; a local therapy approach for many patients with poor performance status are in need. For those patients with good performance status new polychemotherapy regimens are used with success and increased survival improvement. Polychemotherapy has been observed to increase the rate of radical resections in some cases. Second line therapy is used for patients with good performance status and metastatic disease. Oxaliplatin-based regimens are mostly used, however; there are several other drugs that are being developed. Unfortunately, targeted therapy has not presented the expected efficiency. Moreover; immunotherapy; another treatment approach for several cancers types has again failed to present positive results for pancreatic cancer. In the current mini review, we will present information from the diagnosis to molecular pathways and targeted treatment.

Pancreatic cancer from bench to bedside: molecular pathways and treatment options

In the last forty years the pancreatic cancer treatment has made advances, however; still novel drugs are needed. It is known that the five year survival rate remains around 5%. The best treatment option still remains surgery, if patients are diagnosed early. In the last decade the biology of pancreatic cancer has been vastly explored and novel agents such as; tyrosine kinase agents, or vaccines have been added as a treatment perspective. The big challenge is now to translate this knowledge in better outcomes for patients. In this current review we will present information from pancreatic cancer diagnosis to molecular pathways and treatment options; current and future.

Expression and Prognostic Significance of Human Epidermal Growth Factor Receptors 1, 2 and 3 in Periampullary Adenocarcinoma

Periampullary adenocarcinoma, including pancreatic cancer, is a heterogeneous group of tumours with dismal prognosis, for which there is an urgent need to identify novel treatment strategies. The human epithelial growth factor receptors EGFR, HER2 and HER3 have been studied in several tumour types, and HER-targeting drugs have a beneficial effect on survival in selected types of cancer. However, these effects have not been evident in pancreatic cancer, and remain unexplored in other types of periampullary cancer. The prognostic impact of HER-expression in these cancers also remains unclear. The aim of this study was therefore to examine the expression and prognostic value of EGFR, HER2 and HER3 in periampullary cancer, with particular reference to histological subtype. To this end, protein expression of EGFR, HER2 and HER3, and HER2 gene amplification was assessed by immunohistochemistry and silver in situ hybridization, respectively, on tissue microarrays with tumours from 175 periampullary adenocarcinomas, with follow-up data on recurrence-free survival (RFS) and overall survival (OS) for up to 5 years. EGFR expression was similar in pancreatobiliary (PB) and intestinal (I) type tumours, but high HER2 and HER3 expression was significantly more common in I-type tumours. In PB-type cases receiving adjuvant gemcitabine, but not in untreated cases, high EGFR expression was significantly associated with a shorter OS and RFS, with a significant treatment interaction in relation to OS (p_{interaction =} 0.042). In I-type cases, high EGFR expression was associated with a shorter OS and RFS in univariable, but not in multivariable, analysis. High HER3 expression was associated with a prolonged RFS in univariable, but not in multivariable, analysis. Neither HER2 protein expression nor gene amplification was prognostic. The finding of a potential interaction between the expression of EGFR and response to adjuvant chemotherapy in PB-type tumours needs validation, and merits further study.

Dual targeting of HER1/EGFR and HER2 with cetuximab and trastuzumab in patients with metastatic pancreatic cancer after gemcitabine failure: results of the "THERAPY"phase 1-2 trial

To improve treatment efficacy, we decided to simultaneously target HER1 and HER2 with trastuzumab and cetuximab. Following promising preclinical results, we conducted a phase 1-2 trial in advanced pancreatic cancer patients after first-line gemcitabine-based chemotherapy failure. In this single-arm, non-randomized, multicenter trial, patients received weekly cetuximab (400mg/m², then 250mg/m²). They were sequentially included in two trastuzumab dose levels: 3.0 or 4.0mg/kg, then 1.5 or 2.0mg/kg/weekly. Endpoints were the objective response rate, safety, progression-free (PFS) and overall survival (OS). During phase 1 (n=10 patients), toxicities were evenly distributed except for skin toxicities that frequently caused compliance issues. The higher dose level was defined as the trastuzumab recommended dose. During phase 2 (n=39 patients), toxicities were mainly cutaneous reactions and asthenia. No objective response was observed. Nine patients were stabilized but arrested treatment due to toxicity. Median PFS was 1.8 months (95%CI: 1.7-2.0 months) and median OS was 4.6 months (95%CI: 2.7–6.6 months). Both were positively correlated with skin toxicity severity (P=0.027 and P=0.001, respectively). Conventional phase 1 dose-escalation schedules are unsuitable for targeted therapies because most cutaneous toxicities are not considered dose-limiting toxicities. The compliance issues caused by skin toxicities were particularly detrimental because of the toxicity-response correlation.

A Novel Biomarker Panel Examining Response to Gemcitabine with or without Erlotinib for Pancreatic Cancer Therapy in NCIC Clinical Trials Group PA.3

Purpose

NCIC Clinical Trials Group PA.3 was a randomized control trial that demonstrated improved overall survival (OS) in patients receiving erlotinib in addition to gemcitabine for locally advanced or metastatic pancreatic cancer. Prior to therapy, patients had plasma samples drawn for future study. We sought to identify biomarkers within these samples.

Experimental Design

Using the proximity ligation assay (PLA), a probe panel was built from commercially available antibodies for 35 key proteins selected from a global genetic analysis of pancreatic cancers, and used to quantify protein levels in 20 uL of patient plasma. To determine if any of these proteins levels independently associated with OS, univariate and mulitbaraible Cox models were used. In addition, we examined the associations between biomarker expression and disease stage at diagnosis using Fisher's exact test. The correlation between Erlotinib sensitivity and each biomarkers was assessed using a test of interaction between treatment and biomarker.

Results and Conclusion

Of the 569 eligible patients, 480 had samples available for study. Samples were randomly allocated into training (251) and validation sets (229). Among all patients, elevated levels of interleukin-8 (IL-8), carcinoembryonic antigen (CEA), hypoxia-inducible factor 1-alpha (HIF-1 alpha), and interleukin-6 were independently associated with lower OS, while IL-8, CEA, platelet-derived growth factor receptor alpha and mucin-1 were associated with metastatic disease. Patients with elevated levels of receptor tyrosine-protein kinase erbB-2 (HER2) expression had improved OS when treated with erlotinib compared to placebo. In conclusion, PLA is a powerful tool for identifying biomarkers from archived, small volume serum samples. These data may be useful to stratify patient outcomes regardless of therapeutic intervention.

Trial Registration

ClinicalTrials.gov NCT00040183

Molecular targets for the treatment of pancreatic cancer: Clinical and experimental studies

Pancreatic cancer is the fourth most common cause of cancer deaths worldwide. Although recent therapeutic developments for patients with pancreatic cancer have provided survival benefits, the outcomes for patients with pancreatic cancer remain unsatisfactory. Molecularly targeted cancer therapy has advanced in the past decade with the use of a number of pathways as candidates of therapeutic targets. This review summarizes the molecular features of this refractory disease while focusing on the recent clinical and experimental findings on pancreatic cancer. It also discusses the data supporting current standard clinical outcomes, and offers conclusions that may improve the management of pancreatic cancer in the future.

SOX9 regulates ERBB signalling in pancreatic cancer development

OBJECTIVE

The transcription factor SOX9 was recently shown to stimulate ductal gene expression in pancreatic acinar-to-ductal metaplasia and to accelerate development of premalignant lesions preceding pancreatic ductal adenocarcinoma (PDAC). Here, we investigate how SOX9 operates in pancreatic tumourigenesis.

DESIGN

We analysed genomic and transcriptomic data from surgically resected PDAC and extended the expression analysis to xenografts from PDAC samples and to PDAC cell lines. SOX9 expression was manipulated in human cell lines and mouse models developing PDAC.

RESULTS

We found genetic aberrations in the SOX9 gene in about 15% of patient tumours. Most PDAC samples strongly express SOX9 protein, and SOX9 levels are higher in classical PDAC. This tumour subtype is associated with better patient outcome, and cell lines of this subtype respond to therapy targeting epidermal growth factor receptor (EGFR/ERBB1) signalling, a pathway essential for pancreatic tumourigenesis. In human PDAC, high expression of SOX9 correlates with expression of genes belonging to the ERBB pathway. In particular, ERBB2 expression in PDAC cell lines is stimulated by SOX9. Inactivating Sox9 expression in mice confirmed its role in PDAC initiation; it demonstrated that Sox9 stimulates expression of several members of the ERBB pathway and is required for ERBB signalling activity.

CONCLUSIONS

By integrating data from patient samples and mouse models, we found that SOX9 regulates the ERBB pathway throughout pancreatic tumourigenesis. Our work opens perspectives for therapy targeting tumourigenic mechanisms.

Up-regulation of HER2 by gemcitabine enhances the antitumor effect of combined gemcitabine and trastuzumab emtansine treatment on pancreatic ductal adenocarcinoma cells

Background

Although pancreatic ductal adenocarcinomas (PDAs) widely express HER2, the expression level is generally low. If HER2 expression in PDA cells could be enhanced by treatment with a given agent, then combination therapy with that agent and trastuzumab emtansine (T-DM1), a chemotherapeutic agent that is a conjugate of trastuzumab, might lead to significant antitumor effects against PDA.

Methods

Cell proliferation was examined by spectrophotometry. HER2 expression was examined by flow cytometry, immunoblot and quantitative reverse transcription polymerase chain reaction. T-DM1 binding to cells was examined by flow cytometry and enzyme-linked immunosorbent assay.

Results

Out of 5 tested human PDA cell lines, including MIA PaCa-2, three showed increases in HER2 expression after gemcitabine (GEM) treatment. The binding of T-DM1 to GEM-treated MIA PaCa-2 cells was higher than to untreated MIA PaCa-2 cells. Treatment with GEM and T-DM1 showed synergic cytotoxic effects on MIA PaCa-2 cells in vitro. Cells in the G2M phase of the cell cycle were retained after GEM treatment and showed higher levels of HER2 expression, possibly contributing to the synergic effect of GEM and T-DM1.

Conclusions

Combined treatment with GEM and T-DM1 might confer a potent therapeutic modality against PDA as a result of GEM-mediated HER2 up-regulation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1772-1) contains supplementary material, which is available to authorized users.

Cancer Genetics and Implications for Clinical Management

There is now compelling evidence that the molecular heterogeneity of cancer is associated with disparate phenotypes with variable outcomes and therapeutic responsiveness to therapy in histologically indistinguishable cancers. This diversity may explain why conventional clinical trial designs have mostly failed to show efficacy when patients are enrolled in an unselected fashion. Knowledge of the molecular phenotype has the potential to improve therapeutic selection and hence the early delivery of the optimal therapeutic regimen. Resolution of the challenges associated with a more stratified approach to health care will ensure more precise diagnostics and enhance therapeutic selection, which will improve overall outcomes.

Pancreatic cancer: optimizing treatment options, new, and emerging targeted therapies

Pancreatic cancer is the fourth leading cause of cancer death in the US and is expected to become the second leading cause of cancer-related deaths in the next decade. Despite 5-fluorouracil/leucovorin with irinotecan and oxaliplatin (FOLFIRINOX) and gemcitabine/nab-paclitaxel significantly improving outcomes for metastatic cancer, refractory disease still poses significant challenges. Difficulties with early detection and the inherent chemo- and radio-resistant nature of this malignancy led to attempts to define the sequential biology of pancreatic cancer in order to improve survival outcomes. Pancreatic adenocarcinoma is characterized by several germline or acquired genetic mutations, the most common being KRAS (90%), CDK2NA (90%), TP53 (75%-90%), DPC4/SMAD4 (50%). In addition, the tumor microenvironment, chemoresistant cancer stem cells, and the desmoplastic stroma have been the target of some promising clinical investigations. Among the core pathways reproducibly shown to lead the development and progression of this disease, DNA repair, apoptosis, G1/S cell cycle transition, KRAS, Wnt, Notch, Hedgehog, TGF-beta, and other cell invasion pathways, have been the target of "precision therapeutics". No single molecularly targeted therapeutic though has been uniformly successful, probably due to the tumor heterogeneity, but biomarker research is evolving and it hopes to select more patients likely to benefit. Recent reports note activity with immunotherapies such as CD40 agonists, CCR2 inhibitors, cancer vaccines, and novel combinations against the immunosuppressive tumor milieu are ongoing. While many obstacles still exist, clearly we are making progress in deciphering the heterogeneity within pancreatic cancers. Integrating conventional and immunological targeting will be the key to effective treatment of this deadly disease.

New targeted therapies in pancreatic cancer

Patients with pancreatic cancer have a poor prognosis with a median survival of 4-6 mo and a 5-year survival of less than 5%. Despite therapy with gemcitabine, patient survival does not exceed 6 mo, likely due to natural resistance to gemcitabine. Therefore, it is hoped that more favorable results can be obtained by using guided immunotherapy against molecular targets. This review summarizes the new leading targeted therapies in pancreatic cancers, focusing on passive and specific immunotherapies. Passive immunotherapy may have a role for treatment in combination with radiochemotherapy, which otherwise destroys the immune system along with tumor cells. It includes mainly therapies targeting against kinases, including epidermal growth factor receptor, Ras/Raf/mitogen-activated protein kinase cascade, human epidermal growth factor receptor 2, insulin growth factor-1 receptor, phosphoinositide 3-kinase/Akt/mTOR and hepatocyte growth factor receptor. Therapies against DNA repair genes, histone deacetylases, microRNA, and pancreatic tumor tissue stromal elements (stromal extracellular matric and stromal pathways) are also discussed. Specific immunotherapies, such as vaccines (whole cell recombinant, peptide, and dendritic cell vaccines), adoptive cell therapy and immunotherapy targeting tumor stem cells, have the role of activating antitumor immune responses. In the future, treatments will likely include personalized medicine, tailored for numerous molecular therapeutic targets of multiple pathogenetic pathways.

Novel approaches in the management of pancreatic ductal adenocarcinoma: potential promises for the future

Despite a few breakthroughs in therapy for advanced disease in the recent years, pancreatic ductal adenocarcinoma continues to remain one of the most challenging human malignancies to treat. The overall prognosis for the majority of patients with pancreatic cancer is rather dismal, and therefore, more effective treatment options are being desperately sought. The practical goals of management are to improve the cure rates for patients with resectable disease, achieve a higher conversion rate of locally advanced tumor into potentially resectable disease, and finally, prolong the overall survival for those who develop metastatic disease. Our understanding of the complex genetic alterations, the implicated molecular pathways, and the role of desmoplastic stroma in pancreatic cancer tumorigenesis has increased several folds in the recent years. This has facilitated the development of novel therapeutic strategies against pancreatic cancer, some of which are currently under evaluation in ongoing preclinical and clinical studies. This review will summarize the existing treatment approaches for this devastating disease and also discuss the promising therapeutic approaches that are currently in different stages of clinical development.

Pancreatic cancer: from state-of-the-art treatments to promising novel therapies

Pancreatic cancer is expected to be the second deadliest malignancy in the USA by 2020. The survival rates for patients with other gastrointestinal malignancies have increased consistently during the past 30 years; unfortunately, however, the outcomes of patients with pancreatic cancer have not changed significantly. Although surgery remains the only curative treatment for pancreatic cancer, therapeutic strategies based on initial resection have not substantially improved the survival of patients with resectable disease over the past 25 years; presently, more than 80% of patients suffer disease relapse after resection. Preclinical evidence that pancreatic cancer is a systemic disease suggests a possible benefit for early administration of systemic therapy in these patients. In locally advanced disease, the role of chemoradiotherapy is increasingly being questioned, particularly considering the results of the LAP-07 trial. Novel biomarkers are clearly needed to identify subsets of patients likely to benefit from chemoradiotherapy. In the metastatic setting, FOLFIRINOX (folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin), and nab-paclitaxel plus gemcitabine have yielded only modest improvements in survival. Thus, new treatments are urgently needed for patients with pancreatic cancer. Herein, we review the state-of-the-art of pancreatic cancer treatment, and the upcoming novel therapeutics that hold promise in this disease are also discussed.

A phase I trial of combination trastuzumab, lapatinib, and bevacizumab in patients with advanced cancer

PURPOSE

Preclinical data indicate that combination HER2-directed and anti-VEGF therapy may bypass resistance to trastuzumab. A phase I trial was performed to assess safety, activity, and correlates.

EXPERIMENTAL DESIGN

Patients with advanced, refractory malignancy were enrolled (modified 3 + 3 design with expansions for responding tumor types). Patients received lapatinib daily for 21 days, and bevacizumab and trastuzumab every 3 weeks. Correlates included HER2 extracellular domain levels (ECD) and single nucleotide polymorphisms (SNPs).

RESULTS

Ninety-four patients were treated (median = four prior systemic therapies). The most common related adverse events ≥ grade 2 were diarrhea (n = 33, 35 %) and hypertension (n = 10, 11 %). The recommended phase 2 dose was trastuzumab 6 mg/m(2) (loading = 8 mg/m(2)) and bevacizumab 15 mg/kg every 3 weeks, with lapatinib 1,250 mg daily (full FDA-approved dose of each drug). One patient (1 %) achieved a complete response (CR); eight (9 %), a partial response (PR) (includes breast (n = 7, one of which was HER2 2+ by IHC) and salivary ductal carcinoma (n = 1); and 14 (15 %), stable disease (SD) ≥6 months (total SD ≥ 6 months/PR/CR =23 (25 %). All patients with PR/CR received prior trastuzumab +/- lapatinib. SD ≥ 6 months/PR/CR rate and time to treatment failure (TTF) correlated with elevated baseline HER2 ECD (N = 75 patients tested) but not with HER2 SNPs.

CONCLUSIONS

Combination trastuzumab, lapatinib, and bevacizumab was well-tolerated and demonstrated antitumor activity in heavily pretreated patients with advanced malignancy.

Advanced pancreatic cancer: flourishing novel approaches in the era of biological therapy

The progress in the development of systemic treatment for advanced pancreatic cancer (APC) has been slow. The mainstream treatment remains using chemotherapy including gemcitabine, FOLFIRINOX, and nab-paclitaxel. Erlotinib is the only approved biological therapy with marginal benefit. Studies of agents targeting epidermal growth factor receptor, angiogenesis, and RAS signaling have not been satisfying, and the usefulness of targeted therapy in APC is uncertain. Understanding in molecular processes and tumor biology has opened the door for new treatment strategies such as targeting insulin-like growth factor 1 receptor, transforming growth factor β, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin pathway, and Notch pathway. New directions also include the upcoming immunotherapy and many novel agents that act on the microenvironment. The practice of personalized medicine using predictive biomarkers and pharmacogenomics signatures may also enhance the effectiveness of existing treatment. Future treatment approaches may involve comprehensive genomic assessment of tumor and integrated combinations of multiple agents to overcome treatment resistance.

Dual targeting of ErbB-2/ErbB-3 results in enhanced antitumor activity in preclinical models of pancreatic cancer

ErbB-3 and its ligand NRG-1β are key players in driving oncogenic signaling and resistance to therapy through the activation of the PI3K/Akt pathway. We have recently reported that EV20, a humanized anti-ErbB3 antibody, possesses a marked antitumor activity in a variety of human tumor models, including pancreatic cancer (PC). Here, we report that despite epidermal growth factor receptor overexpression, PC cells are more sensitive to NRG-1β than EGF in terms of Akt activation and cell proliferation. Using stable ErbB-3-knocked down cells and EV20 in combination with trastuzumab, we showed that dual targeting of ErbB-2 and ErbB-3 was necessary to completely abrogate ErbB-3 signaling and to impair cell proliferation. Similarly, enhanced therapeutic efficacy of the antibody combination was seen in xenografts originating from K-Ras-mutated HPAF-II and SW1990 cells, without increasing the toxicity. These results indicate that dual targeting of ErbB-2 and ErbB-3 could represent a new therapeutic approach in PC.Oncogenesis (2014) 3, e117; doi:10.1038/oncsis.2014.31; published online 18 August 2014.

Adjuvant chemoradiation for pancreatic cancer: what does the evidence tell us?

The role of adjuvant chemoradiation (CRT) for pancreas cancer remains unclear. A handful of randomized trials conducted decades of ago ignited a debate that continues today about whether CRT improves survival after surgery. The many flaws in these trials are well described in the literature, which include the use of antiquated radiation delivery techniques and suboptimal doses. Recent prospective randomized data is lacking, and we eagerly await the results the ongoing Radiation Therapy Oncology Group (RTOG) 0848 trial that is evaluating the utility of high quality adjuvant CRT in resected pancreas cancer patients. Until the results of RTOG 0848 are available we should look to other studies from the modern era to guide adjuvant treatment recommendations. Here we review the current state of the art for adjuvant pancreas CRT with respect to patient selection, radiation techniques, radiation dose, and integration with novel systemic agents.

Homozygous deletion of the activin A receptor, type IB gene is associated with an aggressive cancer phenotype in pancreatic cancer

Background

Transforming growth factor, beta (TGFB) signal is considered to be a tumor suppressive pathway based on the frequent genomic deletion of the SMAD4 gene in pancreatic cancer (PC); however; the role of the activin signal, which also belongs to the TGFB superfamily, remains largely unclear.

Methods and results

We found a homozygous deletion of the activin A receptor, type IB (ACVR1B) gene in 2 out of 8 PC cell lines using array-comparative genomic hybridization, and the absence of ACVR1B mRNA and protein expression was confirmed in these 2 cell lines. Activin A stimulation inhibited cellular growth and increased the phosphorylation level of SMAD2 and the expression level of p21^CIP1/WAF1 in the Sui66 cell line (wild-type ACVR1B and SMAD4 genes) but not in the Sui68 cell line (homozygous deletion of ACVR1B gene). Stable ACVR1B-knockdown using short hairpin RNA cancelled the effects of activin A on the cellular growth of the PC cell lines. In addition, ACVR1B-knockdown significantly enhanced the cellular growth and colony formation abilities, compared with controls. In a xenograft study, ACVR1B-knockdown resulted in a significantly elevated level of tumorigenesis and a larger tumor volume, compared with the control. Furthermore, in clinical samples, 6 of the 29 PC samples (20.7%) carried a deletion of the ACVR1B gene, while 10 of the 29 samples (34.5%) carried a deletion of the SMAD4 gene. Of note, 5 of the 6 samples with a deletion of the ACVR1B gene also had a deletion of the SMAD4 gene.

Conclusion

We identified a homozygous deletion of the ACVR1B gene in PC cell lines and clinical samples and proposed that the deletion of the ACVR1B gene may mediate an aggressive cancer phenotype in PC. Our findings provide novel insight into the role of the activin signal in PC.

Frequency of HER2/neu overexpression in adenocarcinoma of the gastrointestinal system

AIM: To determine the frequency of HER2/neu protein overexpression in gastric (group A), small intestine (group B), and colorectal (group C) adenocarcinoma.

METHODS: A descriptive, cross-sectional study was performed on 50 cases of gastrointestinal adenocarcinoma (stomach, small intestine, and colorectal); 11 from group A, 8 from group B, and 31 from group C. The samples were grossed and processed in the pathology department, and sections were stained with HE (hematoxylin and eosin stain) for histopathological confirmation of malignancy (well-differentiated, moderately-differentiated, and poorly-differentiated). The confirmed samples were processed for immunomarker study of HER2/neu.

RESULTS: HER2/neu protein overexpression was found in 33 (66%) patients overall (P = 0.000). Out of 33 HER2/neu positive subjects, 23 (69.6%) were from group C, while the remaining 10 (30%) were from group A. None of the patients from group B had positive HER2/neu protein overexpression. No protein overexpression or membrane staining in < 10% tumor cells was observed in 17 (34%) patients, which were labeled as score “0” and considered negative for HER2/neu protein overexpression. Faint/weak staining (in ≥ 10% of tumors cells) were observed in 8 (16%) patients and given the “1+” score. Similarly 13 (26%) patients reported moderate staining (in ≥ 10% tumor cells) and were thus labeled as “2+”, and strong staining (in ≥ 10% tumors cells), labeled as “3+”, was observed in 12 (24%) patients. Out of 50 patients, 26 (52%) were suffering from grade-II malignancy, 16 (32%) from grade-I, and 8 (16%) from grade-III. There was highly significant association between tumor grades and HER2/neu protein overexpression (P = 0.0000).

CONCLUSION: HER2/neu protein is credibly overexpressed in colon and gastric adenocarcinomas in immunohistochemistry. There is significant association between grade of tumor and HER2/neu protein overexpression.