Targeting the Epidermal Growth Factor Receptor in Addition to Chemotherapy in Patients with Advanced Pancreatic Cancer: A Systematic Review and Meta-Analysis

Overexpression of epidermal growth factor receptors (EGFR) occurs in >90% of pancreatic ductal adenocarcinomas (PDACs) and is associated with a poorer prognosis. A systematic review of electronic databases identified studies exploring the addition of EGFR-targeted treatment to chemotherapy in patients with locally advanced (LA)/metastatic PDAC. Efficacy, safety and tolerability of EGFR-targeted therapy were explored using meta-analysis of randomised controlled trials (RCTs). Meta-regression was utilised to explore factors associated with improved prognosis (all studies) and benefit from EGFR-targeted therapy (RCTs). Twenty-eight studies (7 RCTs and 21 cohort studies) comprising 3718 patients were included. The addition of EGFR-targeted treatment to chemotherapy did not improve progression-free (pooled hazard ratio (HR): 0.90, p = 0.15) or overall survival (HR: 0.94, p = 0.18). EGFR-targeted therapy was associated with increased treatment-related deaths (pooled odds ratio (OR): 5.18, p = 0.007), and grade (G)3/4 rash (OR: 4.82, p = 0.03). There was a borderline significant increase in G3/4 diarrhoea (OR: 1.75, p = 0.06), but no effect on treatment discontinuation without progression (OR: 0.87, p = 0.25). Neither G3/4 rash nor diarrhoea were associated with increased survival benefit from EGFR-targeted therapy. The effect of EGFR-targeted therapy on overall survival (OS) appeared greater in studies with a greater proportion of LA rather than metastatic patients (R = -0.69, p < 0.001). Further studies in unselected patients with advanced PDAC are not warranted. The benefit from EGFR inhibitors may be limited to patient subgroups not yet clearly defined.

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.

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.

Targeting the ERBB family in cancer: couples therapy

The ERBB family of receptor tyrosine kinases has a central role in the tumorigenesis of many types of solid tumour. Various therapeutics targeting these receptors have been approved for the treatment of several cancers. Considerable preclinical data have shown that the administration of two inhibitors against an individual ERBB family member--particularly epidermal growth factor receptor (EGFR) or ERBB2--leads to markedly higher antitumour activity than the administration of single agents. This Opinion article describes the preclinical and clinical performance of these dual-targeting approaches, discusses the key mechanisms that mediate their increased efficacy and highlights areas for ongoing investigation.

Investigational therapies targeting the ErbB (EGFR, HER2, HER3, HER4) family in GI cancers

INTRODUCTION

Gastrointestinal (GI) malignancies account for nearly one-fourth of all cancer-related deaths in the United States and approximately 30% of all cancer-related deaths worldwide. Use of combination cytotoxic therapy offers a modest improvement in survival, but the prognosis and long-term survival of most patients with GI cancer remains poor. In certain GI malignancies, therapies that target members of the HER family of receptors have positively impacted patient care.

AREAS COVERED

In this review, we discuss the significance of the HER family of receptors in esophagogastric, hepatobiliary, pancreatic, and colorectal cancers and explain the rationale supporting the use of monoclonal antibodies (mAbs) and small molecule tyrosine kinase inhibitors (TKIs) to inhibit HER activation and downstream events that contribute to tumor proliferation, migration, and survival.

EXPERT OPINION

Despite recent advances, the treatment of GI cancers remains challenging. Therapies targeting the HER family of receptors have been extensively studied in these malignancies with inconsistent results. The rationale behind varied tumor responses with these agents remains uncertain. We believe that additional studies are needed to identify biomarkers that could help identify a population of patients who would be more responsive to a given therapy.