A multicenter phase II trial of single-agent cetuximab in advanced esophageal and gastric adenocarcinoma

Drug Delivery Opportunities in Esophageal Cancer: Current Treatments and Future Prospects

With one of the highest mortality rates of all malignancies, the 5-year survival rate for esophageal cancer is under 20%. Depending on the stage and extent of the disease, the current standard of care treatment paradigm includes chemotherapy or chemoradiotherapy followed by surgical esophagogastrectomy, with consideration for adjuvant immunotherapy for residual disease. This regimen has high morbidity, due to anatomic changes inherent in surgery, the acuity of surgical complications, and off-target effects of systemic chemotherapy and immunotherapy. We begin with a review of current treatments, then discuss new and emerging targets for therapies and advanced drug delivery systems. Recent and ongoing preclinical and early clinical studies are evaluating traditional tumor targets (e.g., human epidermal growth factor receptor 2), as well as promising new targets such as Yes-associated protein 1 or mammalian target of rapamycin to develop new treatments for this disease. Due the function and location of the esophagus, opportunities also exist to pair these treatments with a drug delivery strategy to increase tumor targeting, bioavailability, and intratumor concentrations, with the two most common delivery platforms being stents and nanoparticles. Finally, early results with antibody drug conjugates and chimeric antigenic receptor T cells show promise as upcoming therapies. This review discusses these innovations in therapeutics and drug delivery in the context of their successes and failures, with the goal of identifying those solutions that demonstrate the most promise to shift the paradigm in treating this deadly disease.

DR30318, a novel tri-specific T cell engager for Claudin 18.2 positive cancers immunotherapy

BACKGROUND

Claudin 18.2 (CLDN18.2) is a highly anticipated target for solid tumor therapy, especially in advanced gastric carcinoma and pancreatic carcinoma. The T cell engager targeting CLDN18.2 represents a compelling strategy for enhancing anti-cancer efficacy.

METHODS

Based on the in-house screened anti-CLDN18.2 VHH, we have developed a novel tri-specific T cell engager targeting CLDN18.2 for gastric and pancreatic cancer immunotherapy. This tri-specific antibody was designed with binding to CLDN18.2, human serum albumin (HSA) and CD3 on T cells.

RESULTS

The DR30318 demonstrated binding affinity to CLDN18.2, HSA and CD3, and exhibited T cell-dependent cellular cytotoxicity (TDCC) activity in vitro. Pharmacokinetic analysis revealed a half-life of 22.2-28.6 h in rodents and 41.8 h in cynomolgus monkeys, respectively. The administration of DR30318 resulted in a slight increase in the levels of IL-6 and C-reactive protein (CRP) in cynomolgus monkeys. Furthermore, after incubation with human PBMCs and CLDN18.2 expressing cells, DR30318 induced TDCC activity and the production of interleukin-6 (IL-6) and interferon-gamma (IFN-γ). Notably, DR30318 demonstrated significant tumor suppression effects on gastric cancer xenograft models NUGC4/hCLDN18.2 and pancreatic cancer xenograft model BxPC3/hCLDN18.2 without affecting the body weight of mice.

Radiotherapy plus cetuximab or cisplatin in head and neck squamous cell carcinoma: an updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The present meta-analysis was updated with randomized controlled trials (RCTs) to revaluate the efficacy and safety of cetuximab vs. cisplatin combined with radiotherapy in patients of head and neck squamous cell carcinoma (HNSCC).

METHODS

A meta-analysis containing RCTs that compared the efficacy or toxicity of cetuximab and cisplatin in HNSCC patients was conducted.

RESULTS

Seven RCTs were included in the final analysis. The patients treated by cetuximab plus radiotherapy showed an inferior overall survival (OS) and locoregional control (LRC) compared to cisplatin plus radiotherapy. The tendency of progression-free survival (PFS) was in agreement with OS and LRC. Subgroup analysis showed that cetuximab had poorer OS relative to cisplatin in the absence of induction chemotherapy. The profile of severe adverse events (SAEs) varied between the two groups, no significant difference in total SAEs was shown for the two arms.

DISCUSSION

Cetuximab combined with radiotherapy shows significantly reduced therapeutic efficacy compared to cisplatin plus radiotherapy in HNSCC patients.

Toward Targeted Therapies in Oesophageal Cancers: An Overview

Oesophageal cancer is one of the leading causes of cancer-related death worldwide. Oesophageal cancer occurs as squamous cell carcinoma (ESCC) or adenocarcinoma (EAC). Prognosis for patients with either ESCC or EAC is poor, with less than 20% of patients surviving more than 5 years after diagnosis. A major progress has been made in the development of biomarker-driven targeted therapies against breast and lung cancers, as well as melanoma. However, precision oncology for patients with oesophageal cancer is still virtually non-existent. In this review, we outline the recent advances in oesophageal cancer profiling and clinical trials based on targeted therapies in this disease.

Safety and efficacy of anti-EGFR monoclonal antibody (SCT200) as second-line therapy in advanced esophageal squamous cell carcinoma

OBJECTIVE

The mainstay treatment of esophageal squamous cell carcinoma (ESCC) involves chemotherapy and immunotherapy. However, alternative therapies are required for patients who are refractory or intolerant to existing therapies.

METHODS

In this single-arm, multicenter, open-label phase Ib study, 30 patients received an intravenous infusion of SCT200, an antiepidermal growth factor receptor (EGFR) monoclonal antibody, 6.0 mg/kg once a week for 6 weeks, followed by 8.0 mg/kg once every 2 weeks until disease progression or intolerable toxicity. The primary endpoint was the objective response rate (ORR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Thirty patients were enrolled between July 2018 and May 2019. The ORR was 16.7% (95% CI: 5.6%-34.7%). The median PFS and OS were 3.1 months (95% CI: 1.5-4.3) and 6.8 months (95% CI: 4.7-10.1), respectively. A numerical difference without any statistical significance in ORR was observed in patients with different EGFR expressions (≥ 50%: 25.0% vs. < 50%: 0%, P = 0.140) or TP53 mutation abundance (< 10%: 23.8% vs. ≥ 10%: 0%, P = 0.286). Improved median PFS (3.4 vs. 1.4 months, P = 0.006) and OS (8.0 vs. 4.2 months, P = 0.027) were associated with TP53 mutation abundance of < 10%. The most common treatment-related adverse events of grade 3 or 4 (occurring in ≥ 2 patients) were hypomagnesemia [7 (23.3%)] and rash [2 (6.7%)]. No treatment-related death occurred.

CONCLUSIONS

SCT200 monotherapy as the second- or further-line treatment for advanced ESCC showed favorable efficacy, with an acceptable safety profile. TP53 mutation abundance might serve as a potential predictive biomarker.

Early TP53 Alterations Shape Gastric and Esophageal Cancer Development

Gastric and esophageal (GE) adenocarcinomas are the third and sixth most common causes of cancer-related mortality worldwide, accounting for greater than 1.25 million annual deaths. Despite the advancements in the multi-disciplinary treatment approaches, the prognosis for patients with GE adenocarcinomas remains poor, with a 5-year survival of 32% and 19%, respectively, mainly due to the late-stage diagnosis and aggressive nature of these cancers. Premalignant lesions characterized by atypical glandular proliferation, with neoplastic cells confined to the basement membrane, often precede malignant disease. We now appreciate that premalignant lesions also carry cancer-associated mutations, enabling disease progression in the right environmental context. A better understanding of the premalignant-to-malignant transition can help us diagnose, prevent, and treat GE adenocarcinoma. Here, we discuss the evidence suggesting that alterations in TP53 occur early in GE adenocarcinoma evolution, are selected for under environmental stressors, are responsible for shaping the genomic mechanisms for pathway dysregulation in cancer progression, and lead to potential vulnerabilities that can be exploited by a specific class of targeted therapy.

Genomic Analysis of Response to Neoadjuvant Chemotherapy in Esophageal Adenocarcinoma

Neoadjuvant therapy followed by surgery is the standard of care for locally advanced esophageal adenocarcinoma (EAC). Unfortunately, response to neoadjuvant chemotherapy (NAC) is poor (20-37%), as is the overall survival benefit at five years (9%). The EAC genome is complex and heterogeneous between patients, and it is not yet understood whether specific mutational patterns may result in chemotherapy sensitivity or resistance. To identify associations between genomic events and response to NAC in EAC, a comparative genomic analysis was performed in 65 patients with extensive clinical and pathological annotation using whole-genome sequencing (WGS). We defined response using Mandard Tumor Regression Grade (TRG), with responders classified as TRG1-2 (n = 27) and non-responders classified as TRG4-5 (n =38). We report a higher non-synonymous mutation burden in responders (median 2.08/Mb vs. 1.70/Mb, p = 0.036) and elevated copy number variation in non-responders (282 vs. 136/patient, p < 0.001). We identified copy number variants unique to each group in our cohort, with cell cycle (CDKN2A, CCND1), c-Myc (MYC), RTK/PIK3 (KRAS, EGFR) and gastrointestinal differentiation (GATA6) pathway genes being specifically altered in non-responders. Of note, NAV3 mutations were exclusively present in the non-responder group with a frequency of 22%. Thus, lower mutation burden, higher chromosomal instability and specific copy number alterations are associated with resistance to NAC.

Recent insights in the PI3K/Akt pathway as a promising therapeutic target in combination with EGFR-targeting agents to treat head and neck squamous cell carcinoma

Resistance to therapies targeting the epidermal growth factor receptor (EGFR), such as cetuximab, remains a major roadblock in the search for effective therapeutic strategies in head and neck squamous cell carcinoma (HNSCC). Due to its close interaction with the EGFR pathway, redundant or compensatory activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway has been proposed as a major driver of resistance to EGFR inhibitors. Understanding the role of each of the main proteins involved in this pathway is utterly important to develop rational combination strategies able to circumvent resistance. Therefore, the current work reviewed the role of PI3K/Akt pathway proteins, including Ras, PI3K, tumor suppressor phosphatase and tensing homolog, Akt and mammalian target of rapamycin in resistance to anti-EGFR treatment in HNSCC. In addition, we summarize PI3K/Akt pathway inhibitors that are currently under (pre)clinical investigation with focus on overcoming resistance to EGFR inhibitors. In conclusion, genomic alterations in and/or overexpression of one or more of these proteins are common in both human papillomavirus (HPV)-positive and HPV-negative HNSCC tumors. Therefore, downstream effectors of the PI3K/Akt pathway serve as promising drug targets in the search for novel therapeutic strategies that are able to overcome resistance to anti-EGFR treatment. Co-targeting EGFR and the PI3K/Akt pathway can lead to synergistic drug interactions, possibly restoring sensitivity to EGFR inhibitors and hereby improving clinical efficacy. Better understanding of the predictive value of PI3K/Akt pathway alterations is needed to allow the identification of patient populations that might benefit most from these combination strategies.

Targeting EGFR in Esophagogastric Cancer

Esophagogastric cancer (EGC) remains a major cause of cancer-related mortality. Overall survival in the metastatic setting remains poor, with few molecular targeted approaches having been successfully incorporated into routine care to-date: only first line anti-HER2 therapy in ERBB2-expressing tumors, second line anti-VEGFR2 therapy with ramucirumab in unselected patients, and pembrolizumab in PD-L1 expressing or MSI-H patients. EGFR inhibitors were extensively studied in EGC, including phase III trials with cetuximab (EXPAND), panitumumab (REAL3), and gefitinib (COG). All three trials were conducted in unselected populations, and therefore, failed to demonstrate clinical benefit. Here, we review previous attempts at targeting EGFR in EGC and potential future biomarkers for targeting this pathway in patients with EGFR-amplified tumors.

Analysis of the expression and genetic alteration of CLDN18 in gastric cancer

Claudin 18 (CLDN18) is a transmembrane protein that localizes to apical regions to form tight junction complexes. Abnormal expression of CLDN18 has been reported in gastric cancer (GC). The expression, genetic alterations, and prognostic role of CLDN18 were analyzed using public data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Human Protein Atlas (HPA) databases using multiple online tools. The biological network of CLDN18 was determined using GeneMANIA. Expression of CLDN18 was restricted to lung and stomach in normal tissues, was significantly downregulated in GC, but was ectopically overexpressed in some other cancer types. There was no correlation between mRNA expression of CLDN18 and the clinicopathology of GC, although expression was higher in the Epstein-Barr virus (EBV)-positive subgroup than other subgroups. Genetic alteration of CLDN18 was not a common event in GC; the main alteration was gene fusion with ARHGAP26. CLDN18 expression did not predict the overall survival (OS) of GC patients. This study summarizes the expression features of CLDN18 in GC and suggests it may serve as a biomarker and therapy target for GC.

EGFRvIII: An Oncogene with Ambiguous Role

Epidermal growth factor receptor variant III (EGFR^vIII) seems to constitute the perfect therapeutic target for glioblastoma (GB), as it is specifically present on up to 28–30% of GB cells. In case of other tumor types, expression and possible role of this oncogene still remain controversial. In spite of EGFR^vIII mechanism of action being crucial for the design of small active anticancer molecules and immunotherapies, i.e., CAR-T technology, it is yet to be precisely defined. EGFR^vIII is known to be resistant to degradation, but it is still unclear whether it heterodimerizes with EGF-activated wild-type EGFR (EGFR^WT) or homodimerizes (including covalent homodimerization). Constitutive kinase activity of this mutated receptor is relatively low, and some researchers even claim that a nuclear, but not a membrane function, is crucial for its activity. Based on the analyses of recurrent tumors that are often lacking EGFR^vIII expression despite its initial presence in corresponding primary foci, this oncogene is suggested to play a marginal role during later stages of carcinogenesis, while even in primary tumors EGFR^vIII expression is detected only in a small percentage of tumor cells, undermining the rationality of EGFR^vIII-targeting therapies. On the other hand, EGFR^vIII-positive cells are resistant to apoptosis, more invasive, and characterized with enhanced proliferation rate. Moreover, expression of this oncogenic receptor was also postulated to be a marker of cancer stem cells. Opinions regarding the role that EGFR^vIII plays in tumorigenesis and for tumor aggressiveness are clearly contradictory and, therefore, it is crucial not only to determine its mechanism of action, but also to unambiguously define its role at early and advanced cancer stages.

A multicentre, phase IIa study of zolbetuximab as a single agent in patients with recurrent or refractory advanced adenocarcinoma of the stomach or lower oesophagus: the MONO study

BACKGROUND

Claudin 18.2 (CLDN18.2) is physiologically confined to gastric mucosa tight junctions; however, upon malignant transformation, perturbations in cell polarity lead to CLDN18.2 epitopes being exposed on the cancer cell surface. The first-in-class monoclonal antibody, zolbetuximab (formerly known as IMAB362), binds to CLDN18.2 and can induce immune-mediated lysis of CLDN18.2-positive cells.

PATIENTS AND METHODS

Patients with advanced gastric, gastro-oesophageal junction (GEJ) or oesophageal adenocarcinomas with moderate-to-strong CLDN18.2 expression in ≥50% of tumour cells received zolbetuximab intravenously every 2 weeks for five planned infusions. At least three patients were enrolled in two sequential cohorts (cohort 1300 mg/m2; cohort 2600 mg/m2); additional patients were enrolled into a dose-expansion cohort (cohort 3600 mg/m2). The primary end point was the objective response rate [ORR: complete and partial response (PR)]; secondary end points included clinical benefit [ORR+stable disease (SD)], progression-free survival, safety/tolerability, and zolbetuximab pharmacokinetic profile.

RESULTS

From September 2010 to September 2012, 54 patients were enrolled (cohort 1, n = 4; cohort 2, n = 6; cohort 3, n = 44). Three patients in cohort 1 and 25 patients in cohorts 2/3 received at least 5 infusions. Antitumour activity data were available for 43 patients, of whom 4 achieved PR (ORR 9%) and 6 (14%) had SD for a clinical benefit rate of 23%. In a subgroup of patients with moderate-to-high CLDN18.2 expression in ≥70% of tumour cells, ORR was 14% (n = 4/29). Treatment-related adverse events occurred in 81.5% (n = 44/54) patients; nausea (61%), vomiting (50%), and fatigue (22%) were the most frequent.

CONCLUSIONS

Zolbetuximab monotherapy was well tolerated and exhibited antitumour activity in patients with CLDN18.2-positive advanced gastric or GEJ adenocarcinomas, with response rates similar to those reported for single-agent targeted agents in gastric/GEJ cancer trials.

CLINICALTRIALS.GOV NUMBER

NCT01197885.

Relationship between the expressions of PD-L1 and tumour-associated fibroblasts in gastric cancer

Previous studies have focused on the changes of tumour cells in immune escape, and less is known about the effect of tumour microenvironment (TME) on immune escape. Tumour-associated fibroblasts (TAF) is an important part of the TME and has special physiological and biochemical characteristics, but the specific mechanism has not been clarified. In order to investigate the effect of TAF on the expression of PD-L1 in gastric cancer cells, gastric cancer cell lines MNK45, SGC7901 were non-contact co-culturing with TAF 1, 3 and 7 d via transwell. PD-L1 mRNA and protein expression were detected using qRT-PCR and FCM. Then, 95 cases of gastric cancer tissues were selected and evaluated PD-L1 and TAF expressions by immunohistochemical examination. The results showed that the mRNA and protein expression of PD-L1 in the experiment group were significantly higher than that in the control group. PD-L1 expression was associated with massive lymphocyte infiltration, diffuse/mixed histology and intratumoral TAFs in gastric cancers. In conclusion, TAFs promoted the growth in gastric cancer cell lines by increased the PD-L1 expression.

An EGFR-targeting antibody-drug conjugate LR004-VC-MMAE: potential in esophageal squamous cell carcinoma and other malignancies

Epidermal growth factor receptor (EGFR) is a rational target for cancer therapy, because its overexpression plays an important oncogenic role in a variety of solid tumors; however, EGFR‐targeted antibody–drug conjugate (ADC) therapy for esophageal squamous cell carcinoma (ESCC) is exceedingly rare. LR004 is a novel anti‐EGFR antibody with the advantages of improved safety and fewer hypersensitivity reactions. It may be of great value as a carrier in ADCs with high binding affinity and internalization ability. Here, we prepared an EGFR‐targeting ADC, LR004‐VC‐MMAE, and evaluated its antitumor activities against ESCC and EGFR‐positive cells. LR004 was covalently conjugated with monomethyl auristatin E (MMAE) via a VC linker by antibody interchain disulfide bond reduction. VC‐MMAE was conjugated with LR004 with approximately 4.0 MMAE molecules per ADC. LR004‐VC‐MMAE showed a potent antitumor effect against ESCC and other EGFR‐positive cells with IC₅₀ values of nM concentrations in vitro. The in vivo antitumor effects of LR004‐VC‐MMAE were investigated in ESCC KYSE520 and A431 xenograft nude mice models. Significant activity was seen at 5 mg·kg⁻¹, and complete tumor regression was observed at 15 mg·kg⁻¹ in the KYSE520 xenograft nude mice after four injections, while the naked antibody LR004 had little effect on inhibiting tumor growth. Similar promising results were obtained in the A431 models. In addition, the tumors also remained responsive to LR004‐VC‐MMAE for large tumor experiments (tumor volume 400–500 mm³). The study results demonstrated that LR004‐VC‐MMAE could be a potential therapeutic agent for ESCC and other EGFR‐expressing malignancies. We also evaluated PK profile of LR004‐VC‐MMAE ADC in the mice model, which would provide qualitative guiding significance for the further research.

Panitumumab in combination with modified docetaxel/cisplatin/5-fluorouracil as first-line treatment in gastric and gastroesophageal junction adenocarcinomas: a multicenter phase II study by the Hellenic Oncology Research Group

Background

A phase I/II study to define the maximum tolerated dose (MTD) of biweekly docetaxel/cisplatin/5-fluorouracil (DCF) plus panitumumab (P), its efficacy, and tolerability as first-line treatment in advanced gastroesophageal cancer.

Methods

In phase I part, patients with unresectable locally advanced or metastatic adenocarcinomas of the stomach or the gastroesophageal junction received cisplatin (40 mg/m² on day 1), leucovorin (400 mg/m² on day 1), 5-fluorouracil (400 mg/m² bolus on day 1), 5-fluorouracil (1000 mg/m²/daycontinuous infusion on days 1-2), and escalated doses of docetaxel (on day 1) plus P (6 mg/kg on day 1) every 2 weeks. In phase II part, patients were treated with DCF/P at the MTD and the primary endpoint was response rate. The expected response rate was set at >40%.

Results

The MTD for docetaxel in the mDCF/P was defined at 40 mg/m² and a total of 40 evaluable patients were enrolled in phase II study. One (2.5%) complete and 13 (32.5%) partial responses (overall response rate: 35%), as well as 16 (40%) disease stabilizations were documented. The median progression-free survival was 6.9 months (95% confidence interval [CI] 3.5-10.3) and the median overall survival was 11.3 months (95%CI 7.7-14.8). Grade 3-4 neutropenia occurred in 10 patients (25%) and febrile neutropenia in 2 (5%). Allergic reactions (grade 1-4) occurred in 9 patients (22.5%). There was 1 treatment-related death.

Conclusions

mDCF/P combination was feasible, though associated with a poor toxicity profile. However, the study failed to meet its primary endpoint and was terminated prematurely due to futility.

Targeted Therapies for Targeted Populations: Anti-EGFR Treatment for EGFR-Amplified Gastroesophageal Adenocarcinoma

Previous anti-EGFR trials in unselected patients with gastroesophageal adenocarcinoma (GEA) were resoundingly negative. We identified EGFR amplification in 5% (19/363) of patients at the University of Chicago, including 6% (8/140) who were prospectively screened with intention-to-treat using anti-EGFR therapy. Seven patients received ≥1 dose of treatment: three first-line FOLFOX plus ABT-806, one second-line FOLFIRI plus cetuximab, and three third/fourth-line cetuximab alone. Treatment achieved objective response in 58% (4/7) and disease control in 100% (7/7) with a median progression-free survival of 10 months. Pretreatment and posttreatment tumor next-generation sequencing (NGS), serial plasma circulating tumor DNA (ctDNA) NGS, and tumor IHC/FISH for EGFR revealed preexisting and/or acquired genomic events, including EGFR-negative clones, PTEN deletion, KRAS amplification/mutation, NRAS, MYC, and HER2 amplification, and GNAS mutations serving as mechanisms of resistance. Two evaluable patients demonstrated interval increase of CD3+ infiltrate, including one who demonstrated increased NKp46+, and PD-L1 IHC expression from baseline, suggesting an immune therapeutic mechanism of action. EGFR amplification predicted benefit from anti-EGFR therapy, albeit until various resistance mechanisms emerged.Significance: This paper highlights the role of EGFR inhibitors in EGFR-amplified GEA-despite negative results in prior unselected phase III trials. Using serial ctDNA and tissue NGS, we identified mechanisms of primary and acquired resistance in all patients, as well as potential contribution of antibody-dependent cell-mediated cytotoxicity to their clinical benefit. Cancer Discov; 8(6); 696-713. ©2018 AACR.See related commentary by Strickler, p. 679This article is highlighted in the In This Issue feature, p. 663.

Advanced malignancies treated with a combination of the VEGF inhibitor bevacizumab, anti-EGFR antibody cetuximab, and the mTOR inhibitor temsirolimus

BACKGROUND

Bevacizumab and temsirolimus are active agents in advanced solid tumors. Temsirolimus inhibits mTOR in the PI3 kinase/AKT/mTOR pathway as well as CYP2A, which may be a resistance mechanism for cetuximab. In addition, temsirolimus attenuates upregulation of HIF-1α levels, which may be a resistance mechanism for bevacizumab.

RESULTS

The median age of patients was 60 years (range, 23-80 years). The median number of prior systemic therapies was 3 (range, 1-6). The maximum tolerated dose (MTD) was determined to be bevacizumab 10 mg/kg biweekly, temsirolimus 5 mg weekly and cetuximab 100/75 mg/m2 weekly. Grade 3 or 4 toxicities were seen in 52% of patients with the highest prevalence being hyperglycemia (14%) and hypophosphatemia (14%). Eighteen of the 21 patients were evaluable for response. Three patients were taken off the study before restaging for toxicities. Partial response (PR) was observed in 2/18 patients (11%) and stable disease (SD) lasting ≥ 6 months was observed in 4/18 patients (22%) (total = 6/18 (33%)). In 8 evaluable patients with squamous cell carcinoma of the head and neck (HNSCC) there were partial responses in 2/8 (25%) patients and SD ≥ 6 months in 1/8 (13%) patients (total = 3/8, (38%)).

PATIENTS AND METHODS

We analyzed safety and responses in 21 patients with advanced solid tumors treated with bevacizumab, cetuximab, and temsirolimus.

CONCLUSION

The combination of bevacizumab, cetuximab, and temsirolimus showed activity in HNSCC; however, there were numerous toxicities reported, which will require careful management for future clinical development.

Nuclear expression of Gli-1 is predictive of pathologic complete response to chemoradiation in trimodality treated oesophageal cancer patients

Background:

Predictive biomarkers or signature(s) for oesophageal cancer (OC) patients undergoing preoperative therapy could help administration of effective therapy, avoidance of ineffective ones, and establishment new strategies. Since the hedgehog pathway is often upregulated in OC, we examined its transcriptional factor, Gli-1, which confers therapy resistance, we wanted to assess Gli-1 as a predictive biomarker for chemoradiation response and validate it.

Methods:

Untreated OC tissues from patients who underwent chemoradiation and surgery were assessed for nuclear Gli-1 by immunohistochemistry and labelling indices (LIs) were correlated with pathologic complete response (pathCR) or <pathCR (resistance) and validated in a unique cohort.

Results:

Initial 60 patients formed the discovery set (TDS) and then unique 167 patients formed the validation set (TVS). 16 (27%) patients in TDS and 40 (24%) patients in TVS achieved a pathCR. Nuclear Gli-1 LIs were highly associated with pathCR based on the fitted logistic regression models (P<0.0001) in TDS and TVS. The areas under the curve (AUCs) for receiver-operating characteristics (ROCs) based on a fitted model were 0.813 (fivefold cross validation (0.813) and bootstrap resampling (0.816) for TDS and 0.902 (fivefold cross validation (0.901) and bootstrap resampling (0.902)) for TVS. Our preclinical (including genetic knockdown) studies with FU or radiation resistant cell lines demonstrated that Gli-1 indeed mediates therapy resistance in OC.

Conclusions:

Our validated data in OC show that nuclear Gli-1 LIs are predictive of pathCR after chemoradiation with desirable sensitivity and specificity.

Predictive biomarkers along gastric cancer pathogenetic pathways

INTRODUCTION

Gastric cancer is the second leading cause of cancer all over the world. Unfortunately, several gastric cancers are diagnosed in an advanced stage and chemotherapy and/or target therapies remain the only options to treat patients. Areas covered: Herein we evaluate the new molecular proposal of gastric cancer classification, offering the possibility to recognize different pathogenetic mechanisms and molecular biomarkers potentially useful for target therapies. Expert commentary: The possibility of introducing new specific tests for identification of molecular biomarkers critical for targeted therapies response represents the new frontier in the selection of gastric cancer patients to improve their survival. Besides HER2, already used in clinical settings as a target biomarker for biological therapy in gastric cancer patients with tissue cancer cells overexpressing HER2, other promising target biomarkers which are deregulated in gastric cancer, such as MET and FGFR, could be identified in tissue and then used for therapeutic purposes. In addition immunotherapy represents the most promising possibility of advanced gastric cancer treatment. In particular, as in other solid tumors, PD-1/PDL1 pathway has emerged in several clinical trials as an interesting therapeutic target.

Targeted therapies for advanced and metastatic adenocarcinoma of the gastroesophageal junction: is there something new?

Despite improvements in systemic chemotherapy (CT), the prognosis of metastatic adenocarcinoma of the gastroesophageal junction remains poor. Over the years, new targeting agents have become available and were tested, with or without CT, in first or subsequent lines of therapy. The epidermal growth factor receptor family was targeted with monoclonal antibodies (MoAbs) (trastuzumab, cetuximab, panitumumab) and tyrosin kinase inhibitors (TKIs) (lapatinib, erlotinib, gefitinib). Only trastuzumab, in combination with cisplatin and fluoropyrimidines, significantly improved overall survival (OS) in first-line therapy (13.8 vs. 11.1 months). Angiogenesis also was targeted with MoAbs (bevacizumab and ramucirumab); ramucirumab, a vascular endothelial growth factor-receptor 2 antagonist, enhanced OS in two phase III studies in the first (9.6 vs. 7.4 months) and subsequent lines of treatment (5.2 vs. 3.8 months), while the bevacizumab study was negative. TKIs (sunitinib, sorafenib, regorafenib, apatinib) were tested in this setting in phase II studies in the second/third line, only showing modest antitumor activity. The hepatocyte growth factor receptor (MET) was targeted in untreated patients in a phase III trial with MoAb rilotumumab, with or without CT, but the study was stopped because of mortality excess in the rilotumumab arm. Mammalian target of rapamycin (MTOR) pathway inhibition with everolimus was tested in pretreated patients in a placebo-controlled phase III trial who failed to improve OS (5.4 vs. 4.3 months). In conclusion, considering the modest survival gain obtained overall, the high cost of these therapies and the quality of life issue must be primarily considered in treating these patients.

Beyond HER2: recent advances and future directions in targeted therapies in esophagogastric cancers

Esophagogastric cancers (EGCa) are a leading cause of cancer related mortality worldwide. It has been recognized that they represent heterogenous diseases based on histology and anatomy. However, it is also increasingly evident that these are diverse malignancies based on genetic alterations, and this is increasingly making these diseases amenable to targeted therapies. While epidermal growth factor receptor (EGFR) and mTOR inhibitors have failed to prove effective in the treatment of advanced EGCa, vascular endothelial growth factor (VEGF) inihibitor have now been demonstrated to improve survival, at least in the 2nd line setting of adenocarcinomas. Other promising approaches are being investigated, including targeted therapies such as MET and FGFR inhibitors, as well as immunotherapy and agents that may affect synthetic lethality.

Molecular classification of gastric cancer: Towards a pathway-driven targeted therapy

Gastric cancer (GC) is the third leading cause of cancer mortality worldwide. Although surgical resection is a potentially curative approach for localized cases of GC, most cases of GC are diagnosed in an advanced, non-curable stage and the response to traditional chemotherapy is limited. Fortunately, recent advances in our understanding of the molecular mechanisms that mediate GC hold great promise for the development of more effective treatment strategies. In this review, an overview of the morphological classification, current treatment approaches, and molecular alterations that have been characterized for GC are provided. In particular, the most recent molecular classification of GC and alterations identified in relevant signaling pathways, including ErbB, VEGF, PI3K/AKT/mTOR, and HGF/MET signaling pathways, are described, as well as inhibitors of these pathways. An overview of the completed and active clinical trials related to these signaling pathways are also summarized. Finally, insights regarding emerging stem cell pathways are described, and may provide additional novel markers for the development of therapeutic agents against GC. The development of more effective agents and the identification of biomarkers that can be used for the diagnosis, prognosis, and individualized therapy for GC patients, have the potential to improve the efficacy, safety, and cost-effectiveness for GC treatments.

PD-L1 expression is associated with massive lymphocyte infiltration and histology in gastric cancer

The mechanism of carcinogenesis of gastric cancer (GC) is still unclear now. This study aimed to explore the correlations among PD-L1, Epstein-Barr virus (EBV) infection, lymphocyte infiltration, HER2 expression, HER2 gene status, histology, and other clinicopathological factors in GC. A total of 44 GC patients with massive lymphocyte infiltration (GC-MLI) and 93 GC patients without massive lymphocyte infiltration were involved in this study. Immunohistochemical analysis was used to test the expression levels of PD-L1 and HER2. Fluorescence in situ hybridization was used on HER2-positive cases with a score of 2+ to test the HER2 gene status. EBV-encoded RNA was used to test for EBV infection. In univariate analysis, PD-L1 expression was significantly associated with GC-MLI (P<.001), lower age (P=.019), EBV infection (P<.001), lower HER2 expression (P=.011), and diffuse/mixed type of histology (P=.022). EBV-encoded RNA-positive cases were significantly associated with GC-MLI (P<.001), lower age (P=.016), diffuse/mixed type of histology (P=.011), and lower HER2 expression (P=.032). In the multivariate logistic regression model, GC-MLI and the diffuse/mixed type histology were identified as 2 independent factors that affected PD-L1 expression (P<.001). Furthermore, PD-L1-positive cases have worse overall survival than do PD-L1-negative cases (P=.011). These results suggest that massive lymphocyte infiltration and the diffuse/mixed type histology of GC should be taken into consideration to select the appropriate patients for PD-L1 inhibitory treatment in the future.

Evolving treatments for advanced gastric cancer: appraisal of the survival trend

Introduction and areas covered: We analysed the results of the main clinical studies looking at patients with advanced gastric or esophagogastric junction cancer, in order to differentiate between what is already clinical evidence and what is a promise for the cure of such patients. Thus, achievements from key studies, which had been purposely directed at chemotherapy, molecular target therapies and immunotherapy in both first and second-line setting were analysed. Metronomic chemotherapy, which consists of the administration of continuative low-dose anticancer drugs, was considered also. Expert commentary: It was found that patients included in experimental arms of randomized trials compared with controls have often benefited from a statistically significant extension of overall survival. However, further studies are awaited to bring new drugs into clinical practice and to validate candidate biomarkers predictive of response.

Current advances in targeted therapies for metastatic gastric cancer: improving patient care

In this article, we review the literature on the current advances in targeted therapies for metastatic gastric cancer aimed at improving patient care. We conclude that the key to guiding targeted therapy is individual biomarkers, which are not completely elucidated. HER2 overexpression is the only predictive biomarker currently in use. Furthermore, it is necessary to understand that gastric tumors are heterogeneous; therefore, is impossible to evaluate a novel biological compound without evaluating personal biomarkers. The selection of patients who are able to receive each treatment is paramount for improving advanced gastric cancer survival and reducing unnecessary costs.

Changing strategies for target therapy in gastric cancer

In spite of a worldwide decrease in the incidence of gastric cancer, this malignancy still remains one of the leading causes of cancer mortality. Great efforts have been made to improve treatment outcomes in patients with metastatic gastric cancer, and the introduction of trastuzumab has greatly improved the overall survival. The trastuzumab treatment took its first step in opening the era of molecular targeted therapy, however several issues still need to be resolved to increase the efficacy of targeted therapy. Firstly, many patients with metastatic gastric cancer who receive trastuzumab in combination with chemotherapeutic agents develop resistance to the targeted therapy. Secondly, many clinical trials testing novel molecular targeted agents with demonstrated efficacy in other malignancies have failed to show benefit in patients with metastatic gastric cancer, suggesting the importance of the selection of appropriate indications according to molecular characteristics in application of targeted agents. Herein, we review the molecular targeted agents currently approved and in use, and clinical trials in patients with metastatic gastric cancer, and demonstrate the limitations and future direction in treatment of advanced gastric cancer.

Phase II clinical and exploratory biomarker study of dacomitinib in recurrent and/or metastatic esophageal squamous cell carcinoma

The purpose of this study was to investigate the clinical activity, safety and predictive biomarkers of dacomitinib, an irreversible pan-HER inhibitor, in patients with recurrent or metastatic esophageal squamous cell carcinoma (R/M-ESCC). Patients, whose diseases were not amenable to curative treatment and had progressed on platinum-based chemotherapy, were treated with dacomitinib 45 mg/day. The primary endpoint was objective response rate by RECISTv 1.1. Predictive biomarker analyses included the characterization of somatic mutations and gene expression using the Ion Torrent AmpliSeq Cancer Hotspot Panel and Nanostring nCounter, and investigation of their relationship with clinical outcomes. Of the 48 evaluable patients, 6 (12.5%) achieved partial responses and 29 (60.4%) had stable disease. The median response duration was 7.1 months. The median progression free survival (PFS) and overall survival (OS) was 3.3 months (95% CI, 2.4-4.3 months) and 6.4 months (95% CI, 4.4-8.4 months). Adverse events were mostly grade 1-2. Gene set enrichment analysis revealed that ERBB signaling pathway is significantly enriched in patients with PFS ≥ 4 months (n = 12) than PFS < 4 months (n = 21) (p < 0.001). Upregulation of ERBB signaling pathway was significantly associated with longer PFS (5.0 vs. 2.9 months, P = 0.016) and OS (10.0 vs. 4.8 months, P = 0.022). The most frequent mutations were TP53 (61%) followed by CDKN2A (8%), MLH1 (8%), FLT3 (8%) and EGFR (8%). Dacomitinib demonstrated clinical efficacy with manageable toxicity in platinum-failed R/M-ESCC. Screening of ERBB pathway-related gene expression profiles may help identify patients who are most likely benefit from dacomitinib.

Targeted therapy in gastroesophageal cancers: past, present and future

Gastroesophageal cancer is a significant global problem that frequently presents at an incurable stage and has very poor survival with standard chemotherapy approaches. This review will examine the epidemiology and molecular biology of gastroesophageal cancer and will focus on the key deregulated signaling pathways that have been targeted in the clinic. A comprehensive overview of clinical data highlighting successes and failures with targeted agents will be presented. Most notably, HER2-targeted therapy with the monoclonal antibody trastuzumab has proven beneficial in first-line therapy and has been incorporated into standard practice. Targeting the VEGF pathway has also proven beneficial, and the VEGFR-targeted monoclonal antibody ramucirumab is now approved for second-line therapy. In contrast to these positive results, agents targeting the EGFR and MET pathways have been evaluated extensively in gastroesophageal cancer but have repeatedly failed to show benefit. An increased understanding of the molecular predictors of response to targeted therapies is sorely needed. In the future, improved molecular pathology approaches should subdivide this heterogeneous disease entity to allow individualization of cancer therapy based on integrated and global identification of deregulated signaling pathways. Better patient selection, rational combinations of targeted therapies and incorporation of emerging immunotherapeutic approaches should further improve the treatment of this deadly disease.

Cetuximab plus pemetrexed as second-line therapy for fluorouracil-based pre-treated metastatic esophageal squamous cell carcinoma

PURPOSE

The aim of this study was to evaluate the efficacy and toxicity of cetuximab and pemetrexed as the second-line treatment for advanced esophageal cancer patients, who had undergone treatment with the standard cisplatin and 5-FU regimens.

METHODS

A total of 29 patients accepted this treatment. Cetuximab was administered at an initial dose of 400 mg/m(2) IV followed by weekly doses of 250 mg/m(2) IV, whereas pemetrexed 500 mg/m(2) was administered on day 1 every 3 weeks.

RESULTS

Twelve patients (41.4 %) presented PR, ten (34.5 %) had SD, and seven (24.1 %) had PD. The response rate was 41.4 %. The median PFS was 4.5 months (95 % CI 4.1-4.9), and the median OS was 9.4 months (95 % CI 8.4-10.5). The expression levels of serum miR-335 were determined, and the subsequent analysis suggested that PFS was significantly different between the patients with higher level of serum miR-335 and those with low level of serum miR-335. The former had a PFS of 4.9 months (95 % CI 4.2-5.7) and the latter 4.1 months (95 % CI 3.7-4.5) (log rank = 0.025). None of the patients experienced grade 4 toxicity. Twenty-four patients presented rash.

CONCLUSIONS

A combination of cetuximab plus pemetrexed was marginally effective and well tolerated in patients with advanced esophageal squamous cell carcinoma as the second-line treatment.

Phase II trial of everolimus in patients with refractory metastatic adenocarcinoma of the esophagus, gastroesophageal junction and stomach: possible role for predictive biomarkers

PURPOSE

Our study was designed to evaluate the efficacy and safety of everolimus in patients with pre-treated metastatic gastric and esophagus cancers in a US-based population focusing on biomarker correlation.

METHODS

Patients with advanced upper GI adenocarcinomas who progressed after 1-2 prior regimens received everolimus 10 mg PO daily. The primary endpoint was disease control rate (DCR). Secondary endpoints included progression-free survival (PFS), toxicity, overall survival (OS) and biomarker correlatives of the mTOR pathway. Target accrual was 50 patients based on one-sided type I error of 10 % and power of 90 %.

RESULTS

Forty-five patients were evaluable, 21 gastric, 11 esophagus and 13 from the GEJ. The median age was 64 (range 38-73); all patients had an ECOG of 0 or 1; and 18 patients (40 %) had only 1 prior regimen. The most common grade 3-4 adverse events included fatigue (24 %) and thrombocytopenia (22 %). We observed 1 partial response with 39 % of evaluable patients having stable disease. Median OS was 3.4 months (95 % CI 2.7-5.6 months), and PFS was 1.8 months (95 % CI 1.7-2.2 months). There was a strong correlation between ≥2 + IHC staining for p-S6 in tumor samples with better PFS (p < 0.0001) and DCR (p = 0.0001).

CONCLUSIONS

Our clinical outcomes were inferior to the Asian studies, which may be explained by disease heterogeneity. However, there was a similar strong correlation between clinical benefit and tumor high pS6. Testing this biomarker in patient samples from the randomized phase III Granite trial may lead to a positive predictive marker.

Esophageal Carcinoma: Current Concepts in the Role of Imaging in Staging and Management

Over the past few decades, the survival of esophageal cancer patients has improved owing to early detection and advances in multimodality treatment strategies. Imaging plays an important role in every step in the management of esophageal cancer, including diagnosis, staging, assessment of treatment response, and post-treatment surveillance. In this article, we provide a comprehensive review of the role of imaging in these various time points of esophageal cancer management.

The role of biological markers of epithelial to mesenchymal transition in oesophageal adenocarcinoma, an immunohistochemical study

BACKGROUND

E-cadherin, β-catenin, epidermal growth factor receptor (EGFR), neuronal cadherin (N-cadherin) and Cyclin D1 are involved in epithelial to mesenchymal transition (EMT). However, the prognostic significance of EMT markers in oesophageal adenocarcinoma (OAC) is unknown. Aim of this study was to evaluate the prognostic value of, and the association between different EMT markers in OAC.

METHODS

Tumour cores of 154 patients with OAC were included in a tissue microarray. Scoring criteria was based on immunohistochemical staining intensity.

RESULTS

EMT-associated markers were expressed in OAC: reduced membranous E-cadherin and β-catenin were seen in 11.4% and 51.7%, nuclear β-catenin in 19.1% and EGFR and Cyclin D1 overexpression in 56.5% and 27.4% of tumours. Mesenchymal marker N-cadherin was not expressed in OAC. A positive correlation was seen between membranous β-catenin and E-cadherin expression (R=0.209, p=0.001) and between EGFR and Cyclin D1 (R=0.257, p=0.002). In univariate analysis, EGFR overexpression and membranous β-catenin staining were significantly associated with a poor survival (HR 2.145; 95% CI 1.429 to 3.218, p<0.001 and HR 1.665; 95% CI 1.114 to 2.488; p=0.013). However, Cyclin D1 (HR 1.092; 95% CI 0.702 to 1.698; p=0.697), nuclear β-catenin (HR 1.322; 95% CI 0.799 to 2.189; p=0.277) and E-cadherin (HR 1.012; 95% CI 0.554 to 1.851; p=0.968) were not associated with survival. In multivariate analysis, EGFR overexpression was an independent prognostic factor for poor survival (HR 1.678; 95% CI 1.055 to 2.668; p=0.029) together with T stage (HR 2.759; 95% CI 1.356 to 5.576; p=0.005).

CONCLUSIONS

This study supports the presence of EMT in OAC. Moreover, EGFR overexpression was independently associated with a poor survival.

Identification of KRAS and PIK3CA but not BRAF mutations in patients with gastric cancer

Cetuximab, an immunoglobulin G1 chimeric monoclonal antibody directed against the epidermal growth factor receptor, is currently considered to be the strategy with the most potential for the treatment of gastric cancer due to the low frequency of KRAS mutations in patients with gastric cancer. However, the therapeutic success of cetuximab in colorectal cancer (CRC) has demonstrated that the clinical effect of cetuximab is closely dependent not only on KRAS mutations, but also BRAF and phosphoinositide-3-kinase, catalytic, α polypeptide (PIK3CA) mutations. In the present study, the status of KRAS, BRAF and PIK3CA mutations in gastric cancer were investigated concomitantly in order to aid the selection of patients eligible for treatment with cetuximab. Mutations in KRAS (exon 2), BRAF (exon 15) and PIK3CA (exon 9 and exon 20) were retrospectively evaluated by high resolution melting analysis and DNA direct sequencing in samples from 156 patients with gastric cancer. Mutations in either KRAS or PIK3CA were identified in 13 samples (8.3%), 7 samples with KRAS mutations and 6 samples with PIK3CA mutations. No mutations in the BRAF gene were identified. The frequency of mutations in either KRAS or PIK3CA were significantly higher in patients without lymph node metastasis than those with. Furthermore, KRAS and PIK3CA mutations were mutually exclusive. The present study, therefore, suggested that it may be necessary to evaluate KRAS and PIK3CA mutations concomitantly for the selection of patients eligible for treatment with cetuximab.

The Hippo Coactivator YAP1 Mediates EGFR Overexpression and Confers Chemoresistance in Esophageal Cancer

PURPOSE

Esophageal cancer is an aggressive malignancy and often resistant to therapy. Overexpression of EGFR has been associated with poor prognosis of patients with esophageal cancer. However, clinical trials using EGFR inhibitors have not provided benefit for patients with esophageal cancer. Failure of EGFR inhibition may be due to crosstalk with other oncogenic pathways.

EXPERIMENTAL DESIGN

In this study, expression of YAP1 and EGFR were examined in EAC-resistant tumor tissues versus sensitive tissues by IHC. Western blot analysis, immunofluorescence, real-time PCR, promoter analysis, site-directed mutagenesis, and in vitro and in vivo functional assays were performed to elucidate the YAP1-mediated EGFR expression and transcription and the relationship with chemoresistance in esophageal cancer.

RESULTS

We demonstrate that Hippo pathway coactivator YAP1 can induce EGFR expression and transcription in multiple cell systems. Both YAP1 and EGFR are overexpressed in resistant esophageal cancer tissues compared with sensitive esophageal cancer tissues. Furthermore, we found that YAP1 increases EGFR expression at the level of transcription requiring an intact TEAD-binding site in the EGFR promoter. Most importantly, exogenous induction of YAP1 induces resistance to 5-fluorouracil and docetaxcel, whereas knockdown of YAP1 sensitizes esophageal cancer cells to these cytotoxics. Verteporfin, a YAP1 inhibitor, effectively inhibits both YAP1 and EGFR expression and sensitizes cells to cytotoxics.

CONCLUSIONS

Our data provide evidence that YAP1 upregulation of EGFR plays an important role in conferring therapy resistance in esophageal cancer cells. Targeting YAP1-EGFR axis may be more efficacious than targeting EGFR alone in esophageal cancer.

Advances in targeted therapies and new promising targets in esophageal cancer

Esophageal cancer, comprising squamous carcinoma and adenocarcinoma, is a leading cause of cancer-related death in the world. Notably, the incidence of esophageal adenocarcinoma has increased at an alarming rate in the Western world. Unfortunately, the standard first-line chemo-radiotherapeutic approaches are toxic and of limited efficacy in the treatment of a significant number of cancer patients. The molecular analysis of cancer cells has uncovered key genetic and epigenetic alterations underlying the development and progression of tumors. These discoveries have paved the way for the emergence of targeted therapy approaches. This review will highlight recent progress in the development of targeted therapies in esophageal cancer. This will include a review of drugs targeting receptor tyrosine kinases and other kinases in esophageal cancer. Additional studies will be required to develop a rational integration of these targeted agents with respect to histologic types of esophageal cancer and the optimal selection of cancer patients who would most likely benefit from targeted therapy. Identification of AURKA and AXL as key molecular players in esophageal tumorigenesis and drug resistance strongly justifies the evaluation of the available drugs against these targets in clinical trials.

Incidence and risk of xerosis with targeted anticancer therapies

BACKGROUND

Many targeted therapies used in the treatment of cancer can lead to the development of xerosis, but the incidence and relative risk of xerosis have not been ascertained.

OBJECTIVE

We conducted a systematic review and metaanalysis of clinical trials, to ascertain the incidence and risk of developing xerosis after taking anticancer drugs.

METHODS

The PubMed (1966-October 2013), Web of Science (January 1998-October 2013), and American Society of Clinical Oncology abstracts (2004-2013) databases were searched for clinical trials of 58 targeted agents. Results were calculated using random or fixed effects models.

RESULTS

The incidences of all- and high-grade xerosis were 17.9% (95% confidence interval [CI]: 15.6-20.4%) and 1.0% (95% CI: 0.9-1.5%), respectively. The risk of developing all-grade xerosis was 2.99 (95% CI: 2.0-4.3), and it varied across different drugs (P < .001).

LIMITATIONS

The reporting of xerosis may vary among clinicians and institutions, and the incidence may be affected by age, concomitant medications, comorbidities, and underlying malignancies or skin conditions.

CONCLUSION

Patients receiving targeted therapies have a significant risk of developing xerosis. Patients should be counseled and treated early for this symptom to prevent suboptimal dosing and quality of life impairment.

How prognostic and predictive biomarkers are transforming our understanding and management of advanced gastric cancer

BACKGROUND

Gastric cancer (GC) is the second leading cause of cancer death worldwide. GC is a heterogeneous disease in terms of histology, anatomy, and epidemiology. There is also wide variability in how GC is treated in both the resectable and unresectable settings. Identification of prognostic and predictive biomarkers is critical to help direct and tailor therapy for this deadly disease.

METHODS

A literature search was done using Medline and MeSH terms for GC and predictive biomarkers and prognostic biomarkers. The search was limited to human subjects and the English language. There was no limit on dates. Published data and unpublished abstracts with clinical relevance were included.

RESULTS

Many potential prognostic and predictive biomarkers have been assessed for GC, some of which are becoming practice changing. This review is focused on clinically relevant biomarkers, including EGFR, HER2, various markers of angiogenesis, proto-oncogene MET, and the mammalian target of rapamycin.

CONCLUSION

GC is a deadly and heterogeneous disease for which biomarkers are beginning to change our understanding of prognosis and management. The recognition of predictive biomarkers, such as HER2 and vascular endothelial growth factor, has been an exciting development in the management of GC, validating the use of targeted drugs trastuzumab and ramucirumab. MET is another potential predictive marker that may be targeted in GC with drugs such as rilotumumab, foretinib, and crizotinib. Further identification and validation of prognostic and predictive biomarkers has the potential transform how this deadly disease is managed.

Genetic mutation analysis of human gastric adenocarcinomas using ion torrent sequencing platform

Gastric cancer is the one of the major causes of cancer-related death, especially in Asia. Gastric adenocarcinoma, the most common type of gastric cancer, is heterogeneous and its incidence and cause varies widely with geographical regions, gender, ethnicity, and diet. Since unique mutations have been observed in individual human cancer samples, identification and characterization of the molecular alterations underlying individual gastric adenocarcinomas is a critical step for developing more effective, personalized therapies. Until recently, identifying genetic mutations on an individual basis by DNA sequencing remained a daunting task. Recent advances in new next-generation DNA sequencing technologies, such as the semiconductor-based Ion Torrent sequencing platform, makes DNA sequencing cheaper, faster, and more reliable. In this study, we aim to identify genetic mutations in the genes which are targeted by drugs in clinical use or are under development in individual human gastric adenocarcinoma samples using Ion Torrent sequencing. We sequenced 737 loci from 45 cancer-related genes in 238 human gastric adenocarcinoma samples using the Ion Torrent Ampliseq Cancer Panel. The sequencing analysis revealed a high occurrence of mutations along the TP53 locus (9.7%) in our sample set. Thus, this study indicates the utility of a cost and time efficient tool such as Ion Torrent sequencing to screen cancer mutations for the development of personalized cancer therapy.

Gefitinib for oesophageal cancer progressing after chemotherapy (COG): a phase 3, multicentre, double-blind, placebo-controlled randomised trial

BACKGROUND

Evidence is scarce for the effectiveness of therapies for oesophageal cancer progressing after chemotherapy, and no randomised trials have been reported. We aimed to compare gefitinib with placebo in previously treated advanced oesophageal cancer.

METHODS

For this phase 3, parallel, randomised, placebo-controlled trial, eligible patients were adults with advanced oesophageal cancer or type I/II Siewert junctional tumours, histologically confirmed squamous-cell carcinoma or adenocarcinoma, who had progressed after chemotherapy, with WHO performance status 0-2, and with measurable or evaluable disease on CT scan. Participants were recruited from 48 UK centres and randomly assigned (1:1) to gefitinib (500 mg) or matching placebo by simple randomisation with no stratification factors. Patients, clinicians, and trial office staff were masked to treatment allocation. Treatment continued until disease progression, unacceptable toxicity, or patient choice. The primary outcome was overall survival, analysed by intention to treat. This trial is registered, number ISRCTN29580179.

FINDINGS

Between March 30, 2009, and Nov 18, 2011, 450 patients were randomly assigned to treatment groups (one patient withdrew consent; 224 patients allocated gefitinib and 225 allocated placebo included in analyses). Overall survival did not differ between groups (median 3·73 months, 95% CI 3·23-4·50, for gefitinib vs 3·67 months, 95% CI 2·97-4·37, for placebo; hazard ratio [HR] 0·90, 95% CI 0·74-1·09, p=0·29). Among the prespecified patient-reported outcomes (110 patients on gefitinib and 121 on placebo completed both baseline and 4 week questionnaires and were included in analyses), odynophagia was significantly better in the gefitinib group (adjusted mean difference -8·61, 95% CI -14·49 to -2·73; n=227; p=0·004), whereas the other outcomes were not significantly improved compared with placebo: global quality of life (2·69, 95% CI -2·33 to 7·72, n=231, p=0·293), dysphagia (-3·18, 95% CI -8·36 to 2·00, n=231, p=0·228), and eating (-4·11, 95% CI -9·96 to 1·75, n=229, p=0·168). Median progression-free survival was marginally longer with gefitinib than it was with placebo (1·57 months, 95% CI 1·23-1·90 in the gefitinib group vs 1·17 months, 95% CI 1·07-1·37 in the placebo group; HR 0·80, 95% CI 0·66-0·96, p=0·020). The most common toxicities were diarrhoea (36 [16%] of 224 patients on gefitinib vs six [3%] of 225 on placebo) and skin toxicity (46 [21%] vs two [1%]), both mostly grade 2. The commonest grade 3-4 toxicities were fatigue (24 [11%] vs 13 [6%] patients) and diarrhoea (13 [6%] vs two [1%]). Serious adverse events were reported in 109 (49%) of 224 patients assigned to gefitinib and 101 (45%) of 225 on placebo. 54 (24%) of patients in the gefitinib group achieved disease control at 8 weeks, as did 35 (16%) of patients on placebo (p=0·023).

INTERPRETATION

The use of gefitinib as a second-line treatment in oesophageal cancer in unselected patients does not improve overall survival, but has palliative benefits in a subgroup of these difficult-to-treat patients with short life expectancy. Future research should focus on identification of predictive biomarkers to identify this subgroup of benefiting patients.

FUNDING

Cancer Research UK.

Challenges in first line chemotherapy and targeted therapy in advanced gastric cancer

Chemotherapy prolongs survival in advanced gastric cancer (AGC). The challenges involved in this procedure are providing a framework to aid in determining the best single or combined chemotherapy protocols for targeted agents in front-line therapy for patients in a clinical setting. A review of Phase II-III studies published or referenced in major oncology congress publications from 1970 to 2013 was performed. Cisplatin and fluoropyrimidine remain the reference regimen. Fluoropyrimidine combined with oxaliplatin or irinotecan may also be employed in special situations. There are no comparative studies of the same regimens with or without anthacyclines; thus, the effectiveness of anthacyclines remains under debate. The introduction of trastuzumab in the front-line therapy of HER2-positive patients and ramucirumab in refractory patients ushered in an age of targeted therapy for this disease.

Investigational therapies targeting the ErbB family in oesophagogastric cancer

INTRODUCTION

The prognosis for patients with oesophagogastric (OG) cancer remains poor, with a median survival of approximately 9 - 11 months for patients with metastatic disease. However, a more personalised approach to treatment, using drugs tailored to the molecular characteristics of patients' tumours, has the potential to improve patient outcomes. Drugs targeting the ErbB family of receptors have been developed, but these have had varying degrees of success in clinical practice.

AREAS COVERED

The authors provide an overview of the ErbB receptor family with regard to OG cancers. Furthermore, they evaluate the evidence from preclinical and clinical trials of therapeutics targeting this family, including monoclonal antibodies, tyrosine kinase inhibitors and novel agents.

EXPERT OPINION

Drugs targeting the ErbB family have been evaluated in OG cancer, with a notable success story in the case of trastuzumab, although there have been disappointing failures with anti-EGFR therapy. The response to targeted treatment remains variable and further biomarker research is essential to identify patients most likely to benefit from these therapies. The treatment of OG cancer remains challenging, but new anti-HER2 therapies and combination therapies hold promise for the future.

Expression of the EGF family in gastric cancer: downregulation of HER4 and its activating ligand NRG4

Gastric cancer is a major cause of cancer-related deaths in both men and women. The epidermal growth factor receptors are EGFR, HER2, HER3 and HER4. Of the four epidermal growth factor receptors, EGFR and HER2 are well-known oncogenes involved in gastric cancer. Little, however, is known about the role played by HER3 and HER4 in this disease. We obtained paired samples from the tumor and the adjacent normal tissue from the same patient undergoing surgery for gastric cancer. Using RT-qPCR, we quantified the mRNA expression of the four receptors including the HER4 splicing isoforms and all the ligands activating these receptors. Using immunohistochemistry, the protein expression of HER4 was also quantified. We found that HER2 mRNA expression was upregulated in the tumor tissue compared to the matched normal tissue (p = 0.0520). All ligands with affinity for EGFR were upregulated, whereas the expression of EGFR was unchanged. Interestingly, we found the mRNA expression of HER4 (p = 0.0002) and its ligand NRG4 (p = 0.0009) to be downregulated in the tumor tissue compared to the matched normal tissue. HER4 downregulation was demonstrated for all the alternatively spliced isoforms of this receptor. These results support the involvement of EGFR and HER2 in gastric cancer and suggest an interesting association of reduced HER4 expression with development of gastric cancer.

EGFR, HER2 and HER3 dimerization patterns guide targeted inhibition in two histotypes of esophageal cancer

Receptor tyrosine kinases (RTKs) are in the focus of targeted therapy for epithelial tumors. Our study addressed the role of EGFR, HER2 and HER3 expression and dimerization in esophageal cancers in situ and in vitro in the context of therapeutic EGFR and HER2 inhibitors. In archival pretreatment biopsies of esophageal carcinomas (n = 110), EGFR was preferentially expressed in esophageal squamous cell carcinomas (ESCCs) (22.4%; p = 0.088) and HER2 (34.4%; p < 0.001) with HER3 (91.5%; p < 0.001) in esophageal (Barrett's) adenocarcinomas (EACs). In situ proximity ligation assays revealed mainly EGFR and HER2 homodimers in ESCC and EAC cases, respectively. However, EAC cases also exhibited HER2/HER3 heterodimers. In vitro ESCC (OE21) cells displayed a significant response to erlotinib, gefitinib and lapatinib, with loss of AKT phosphorylation, G0/G1 cell cycle arrest and induction of apoptosis. In EAC cells (OE19, OE33 and SK-GT-4), lapatinib was similarly effective in strongly HER2-positive (mainly HER2 homodimers and some HER2/EGFR heterodimers) OE19 and OE33 cells. The HER2-targeting antibodies (trastuzumab and pertuzumab) given alone were largely ineffective in ESCC and EAC cells. However, both antibodies significantly induced antibody-dependent cellular cytotoxicity in EAC (OE19 and OE33) cells upon co-culture with peripheral blood mononuclear cells. The study reveals that overexpression of EGFR and HER2 predominantly results in homodimers in ESCCs and EACs, respectively. Still, some EACs also show HER2 dimerization plasticity, e.g., with HER3. Such RTK dimerization patterns affect responses to EGFR and HER2 targeting inhibitors in ESCC and EAC cells in vitro and hence may influence future prediction for particularly HER2-targeting inhibitors in EACs.

Long-term survival in an advanced gastric cancer patient treated with cetuximab in association with FOLFIRI: a case report

In December 2004, a 52-year-old woman with metastatic gastric cancer was enrolled in the phase II clinical trial FOLCETUX, receiving cetuximab at an initial dose of 400 mg/m(2) i.v. followed by weekly doses of 250 mg/m(2), irinotecan 180 mg/m(2) i.v. on day 1, LFA 100 mg/m(2) i.v. followed by 5-FU 400 mg/m(2) i.v. bolus and 600 mg/m(2) i.v. 22-h continuous infusion on days 1 and 2 every two weeks, to a total of 17 cycles. CT and PET-CT performed after six weeks treatment failed to show any residual disease, with complete radiological response in accord to RECIST criteria and complete metabolic response. A total of 24 maintenance administrations with cetuximab alone (250 mg/m(2) weekly) were performed, as foreseen by the protocol in responders. In November 2012 a clinical, radiological (CT) and metabolic (PET-CT) patient examination proved negative for recurrent disease, signifying 95 months' progression free survival.