Differences Between the East and the West in Managing Advanced-Stage Non-small Cell Lung Cancer

Lung cancer is a common cancer associated with high mortality rates worldwide. Unfortunately, it usually presents at a late stage, precluding the chance of curative therapy. The discovery of oncogenic driver mutations in patients with non-small cell lung cancer over the past 20 years has led to new molecular targeted therapies that have dramatically improved treatment efficacy and quality of life. New generations of therapy that target the drug-resistant mutations have also quickly evolved, benefiting patients who are refractory or intolerant to first-line targeted therapy. Eastern patients, from Southeast Asia, Japan and China, are known to have a higher incidence of epidermal growth factor receptor mutation. Therefore, compared with the West, more patients would benefit from these recent advances. In contrast, survival of patients without driver mutations has benefited from advances in novel therapeutics, including the immune checkpoint inhibitors. The current review aims to highlight the recent developments in the management of advanced-stage non-small cell lung cancer and to compare the differences in clinical practice between Eastern and Western countries.     

Clinical outcomes of EGFR kinase domain duplication to targeted therapies in NSCLC

Kinase domain duplications of the epidermal growth factor receptor (EGFR-KDD) have been identified and implicated to be oncogenic in nonsmall cell lung cancers (NSCLCs). However, its prevalence and clinical contributions in lung cancer are largely unknown. Here, we conducted a multicenter record review of 10,759 NSCLC patients who underwent genetic testing using next-generation sequencing (NGS) targeting EGFR exons and the introns involved in EGFR-KDD rearrangements. EGFR-KDDs were identified in a total of 13 patients, which is approximately 0.12% of the total population reviewed, and also consisted of 0.24% (13/5394) of EGFR mutation-positive patients. A total of 85% of patients (11/13) were identified with the canonical EGFR-KDD duplication of exons 18–25, while the remaining two cases harbored duplications of EGFR exons 14–26 and exons 17–25, which have not been previously described. Importantly, none of the 13 patients had other coexisting driver mutations, highlighting the potential oncogenic role of this type of alteration. Three out of five patients who had exon 18–25 duplications showed partial antitumor responses to targeted therapies, while the other two patients demonstrated no clinical improvement. Furthermore, our data suggested that the EGFR T790 M mutation and EGFR amplification may represent the major resistance mechanisms against targeted therapies in tumors bearing EGFR-KDD. In summary, our findings provide valuable insight into the prevalence of EGFR-KDDs in NSCLCs and their clinical outcomes to targeted therapies.     

Targeted agents in non-small cell lung cancer (NSCLC): clinical developments and rationale for the combination with thoracic radiotherapy

In recent years there has been undoubted progress in the evaluation and development of targeted agents for non-small cell lung cancer (NSCLC). A major contributor has been the discovery of molecular subtypes harbouring a critical oncogenic driver mutation, specifically sensitizing mutations in the epidermal growth factor receptor (EGFR) gene and the EML4-ALK gene translocation. Radiotherapy is a cornerstone of therapy for the curative intent treatment of early stage, localized disease; and for the palliation of symptoms in advanced, metastatic disease. In this molecular targeted era there is limited understanding of how best to combine targeted agents with radiotherapy and in general clinical studies with radiotherapy have lagged behind studies of targeted agents with chemotherapy. Here we summarise the progress made to date and highlight future directions.     

Oncogenic pathways, molecularly targeted therapies, and highlighted clinical trials in non-small-cell lung cancer (NSCLC)

Non-small-cell lung cancer (NSCLC) has recently been associated with interesting molecular characteristics that have important implications in carcinogenesis and response to targeted therapies. The unsatisfactory treatment outcomes in advanced NSCLC with respect to long-term survival rates may be improved through a better understanding of the molecular etiology of this disease. For instance, several molecular alterations have been defined as "driver mutations," such as mutations in epidermal growth factor receptor (EGFR), Kirsten-rous avian sarcoma (KRAS), and a chromosome 2p inversion producing an EML4-ALK fusion gene (echinoderm microtubule-associated protein-like 4 fused with the anaplastic lymphoma kinase). Other key signaling pathways such as RAS/RAF/MEK, PI3K/AKT/mTOR (mammalian target of rapamycin), mesenchymal-epithelial transition (MET) kinase, LKB1, and insulin-like growth factor 1 (IGF-1) receptor (IGF-1R) have also been identified as novel targets for lung cancer treatment. In this review we focus on the molecular discoveries that have led to the clinical applications and trials of novel targeted agents, including the clinical trials that selectively studied patients who were predicted to achieve the greatest benefit based on the expression of correlative biomarkers.     

KRAS Testing in Metastatic Colorectal Cancer: Implications on the Use of Biologic Agents

Colorectal cancer is a significant healthcare problem in the United States, with meaningful improvement in survival over the past few years. Much of that improvement is attributable to the availability of molecularly targeted therapies, such as inhibitors of the vascular endothelial growth factor (bevacizumab) and epidermal growth factor receptor (cetuximab and panitumumab), in addition to active cytotoxic agents. KRAS mutations have long been described to play an adverse prognostic role in colorectal cancer. KRAS is downstream from EGFR, and oncogenic mutations will yield a constitutively active protein that will override EGFR control of downstream signaling. Such mutations in KRAS would therefore confer resistance to anti-EGFR antibodies. The cumulative results of several trials incorporating more than a thousand patients in studies of cetuximab and panitumumab confirm that the presence of KRAS mutation in tumors is highly predictive of resistance to anti-EGFR therapy. These findings are likely to change the landscape of metastatic CRC treatment by providing an improved patient-tailored approach.     

Pathophysiologie und Molekulardiagnostik beim nichtkleinzelligen Lungenkarzinom

Lung cancer is the most common tumor-related cause of death in western industrialized countries, despite continuous improvement in both diagnostic and therapeutic approaches. However, the development of targeted drugs against the critical oncogenic mechanisms in lung cancer is promising. Compounds targeting epidermal growth factor receptors (EGFR) and EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and anaplastic lymphoma kinase) fusion protein are already in use. However, predominantly patients with adenocarcinomas of the lung who have never smoked gain benefit from these developments. Targeted therapies for the more frequent squamous cell carcinomas often found in smokers have been lacking. Recently, the amplification of the fibroblast growth factor receptor type 1 (FGFR1) gene was identified as a possible target in this patient group and is currently finding its way into clinical trials. The underlying pathology and molecular diagnostics necessary to successfully stratify patients for the novel, targeted therapies in lung cancer are discussed.     

Oncogenic driver mutations in non-small cell lung cancer: Past,present and future

Lung cancer, of which non-small lung cancer is the most common subtype, represents the leading cause of cancer related-death worldwide. It is now recognized that a significant proportion of these patients present alterations in certain genes that drive oncogenesis. In recent years, more of these so-called oncogenic drivers have been identified, and a better understanding of their biology has allowed the development new targeted agents. This review aims to provide an update about the current landscape of driver mutation in non-small-cell lung cancer. Alterations in Kirsten rat sarcoma, epidermal growth factor receptor, MET, anaplastic lymphoma kinase, c-ROS oncogene 1, v-raf murine sarcoma viral oncogene homolog B, neurotrophic receptor tyrosine kinase, human epidermal growth factor 2, neuregulin-1 and rearranged during transfection are discussed, as well as agents targeting these alterations. Current standards of treatment as well as promising future strategies are presented. Currently, more than fifteen targeted agents are food and Drug administration-approved for seven oncogenic drivers in non-small-cell lung cancer, highlighting the importance of actively searching for these mutations. Continuous and future efforts made in defining the biology of each of these alterations will help to elucidate their respective resistance mechanisms, and to define the best treatment strategy and therapeutic sequence.     

Agents in the preclinical development stage for non-small cell lung cancer

Despite recent advancements in identifying distinct molecular subtypes with driver oncogenes and advances in developing targeted treatments such as epidermal growth factor receptor and anaplastic lymphoma kinase inhibitors, current therapeutic approaches for tumors with no driver mutation have achieved a plateau of effectiveness. Thus, the overall outlook of lung cancer survival for most patients remains dismal. Moreover, the inevitable acquisition of resistance to targeted therapies has prompted significant efforts to develop second-generation inhibitors. In recent years, several agents for targeted therapy of lung cancers are rapidly migrating from bench to bedside and multiple small molecule inhibitors with activity against distinct receptors, genes or molecular pathways have been developed.     

ERBB2-Mutated Metastatic Non–Small Cell Lung Cancer: Response and Resistance to Targeted Therapies

IntroductionErb-b2 receptor tyrosine kinase 2 gene (ERBB2) (also called HER2) has long been recognized as an oncogenic driver in some breast and gastroesophageal cancers in which amplification of this gene confers sensitivity to treatment with Erb-b2 receptor tyrosine kinase 2 (ERBB2)-directed agents. More recently, somatic mutations in ERBB2 have been reported in 1% to 2% of patients with lung adenocarcinoma. Previous case series have suggested clinical tumor responses using anti-ERBB2 small molecules and antibody therapies.MethodsHere we report the outcomes of nine patients with metastatic lung adenocarcinoma with ERBB2 mutations being treated with ERBB2-targeted therapies.ResultsFour of the nine patients had response to targeted therapies, with durations of response ranging from 3 to 10 months. We identified a de novo phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha gene (PIK3CA) mutation and ERBB2 copy number gain as potential resistance mechanisms.ConclusionsWe showed patients with ERBB2-mutated lung adenocarcinoma can respond to targeted therapies, and we identified potential resistance mechanisms upon progression to targeted therapies.     

肺癌驱动基因及其靶向治疗药物

随着肿瘤分子生物学的发展,针对肺癌驱动基因的分子靶向治疗已成为晚期肺癌不可或缺的一部分。目前最成功的例子就是针对表皮生长因子受体（EGFR）和间变性淋巴瘤激酶（ALK）的靶向治疗。现在越来越多的肺癌驱动基因突变已被发现,包括ROS1基因融合、成纤维细胞生长因子1扩增、KRAS、BRAF和PIK3 CA基因突变等。明确这些基因突变的频率及临床意义,对指导肺癌的临床治疗有着重要的意义。     

Afatinib successfully treated leptomeningeal metastasis during erlotinib treatment in a patient with EGFR‐mutant (Exon18:G719S) lung adenocarcinoma as a second‐line chemotherapy

Exon18 mutations are detected in 3.6% of epidermal growth factor receptor mutations. Exon 18 mutations as driver mutations have higher sensitivities in vitro to second‐generation (G)‐tyrosine kinase inhibitors (TKIs) than to first G‐ and third G‐TKIs at clinically relevant doses. In clinical trial, first G‐TKIs have moderate but insufficient efficacy, and afatinib was more active in uncommon epidermal growth factor receptor mutations. Here, we present a case of a woman who was initially prescribed erlotinib for lung adenocarcinoma with an exon18 mutation. She developed a leptomeningeal metastasis during treatment and was switched to afatinib. Subsequently, her symptoms improved and she is currently treated with maintenance afatinib therapy. This report suggests improved efficacy of afatinib compared to erlotinib for refractory leptomeningeal metastasis in exon18 mutation.     

Medical treatment for gastro-entero-pancreatic neuroendocrine tumours

Gastro-entero-pancreatic neuroendocrine neoplasms(GEPNENs) represents a various family of rare tumours. Surgery is the first choice in GEP-NENs patients with localized disease whilst in the metastatic setting many other treatment options are available. Somatostatin analogues are indicated for symptoms control in functioning tumours. Furthermore they may be effective to inhibit tumour progression. GEP-NENs pathogenesis has been extensively studied in the last years therefore several driver mutations pathway genes have been identified as crucial factors in their tumourigenesis. GEP-NENs can over-express vascular endothelial growth factor(VEGF), basic-fibroblastic growth factor, transforming growth factor(TGF-α and-β), platelet derived growth factor(PDGF), insulin-like growth factor-1(IGF-1) and their receptors PDGF receptor, IGF-1 receptor, epidermal growth factor receptor, VEGF receptor, and c-kit(stem cell factor receptor) that can be considered as potential targets. The availability of new targeted agents, such as everolimus and sunitinib that are effective in advanced and metastatic pancreatic neuroendocrine tumours, has provided new treatment opportunities. Many trials combing new drugs are ongoing.     

Promises and pitfalls in the prediction of antiepidermal growth factor receptor activity

There is a constant examination of the features that may anticipate or predict the likelihood of the clinical benefit that a patient may experience from a given therapy. This is especially true in the case of novel targeted therapies, as proof-of-principle experimental or pilot analyses are increasingly being embedded into clinical protocols. An unprecedented number of significant developments in the field of epidermal growth factor receptor-targeted therapy have occurred in recent months. This is exemplified by the discovery of activating mutations in the catalytic domain of the epidermal growth factor receptor that increase sensitivity to antiepidermal growth factor receptor small-molecule inhibitors. This review discusses the recent advances and controversies of the different approaches to predict the efficacy of antiepidermal growth factor receptor agents and the effectiveness of the tools that we are using to evaluate and predict the efficacy of epidermal growth factor receptor-targeted drugs and their potential pitfalls.     

Promises and pitfalls in the prediction of antiepidermal growth factor receptor activity

There is a constant examination of the features that may anticipate or predict the likelihood of the clinical benefit that a patient may experience from a given therapy. This is especially true in the case of novel targeted therapies, as proof-of-principle experimental or pilot analyses are increasingly being embedded into clinical protocols. An unprecedented number of significant developments in the field of epidermal growth factor receptor-targeted therapy have occurred in recent months. This is exemplified by the discovery of activating mutations in the catalytic domain of the epidermal growth factor receptor that increase sensitivity to antiepidermal growth factor receptor small-molecule inhibitors. This review discusses the recent advances and controversies of the different approaches to predict the efficacy of antiepidermal growth factor receptor agents and the effectiveness of the tools that we are using to evaluate and predict the efficacy of epidermal growth factor receptor-targeted drugs and their potential pitfalls.     

Somatic STK11 and Concomitant STK11/KRAS Mutational Frequency in Stage IV Lung Adenocarcinoma Adrenal Metastases

Somatic serine/threonine kinase 11 (STK11) also known as liver kinase B1 (LKB1) is a tumor suppressor gene and ranks as the third most frequently mutated gene in lung adenocarcinoma. However, current molecular testing guidelines recommend evaluating for epidermal growth factor receptor mutations and ALK fusions to guide therapy in all patients with advanced stage adenocarcinoma, regardless of gender, race, or smoking history. Identifying alternative “driver” mutations and using actionable targeted pharmacotherapy is a key approach to providing effective individualized medical care. The analytical sensitivity and parallel multigene approach of targeted next-generation sequencing is an attractive methodology for use for cytology specimens. The presented lung adenocarcinoma study revealed that STK11 mutations alone and concomitant KRAS/STK11 mutations were identified in 18.2% and 4.5% of solitary adrenal metastases, respectively. Molecular profiling of epidermal growth factor receptor tyrosine kinase inhibitor resistant tumors may help to identify patients who would most benefit from alternative single or dual pathway inhibition potentially leading to a revision in current molecular testing guidelines.     

The role of molecular diagnostics in cancer diagnosis and treatment

The field of molecular diagnostics has improved our understanding of the pathophysiological mechanisms of malignant alteration, especially in lung cancer which remains the leading cause of cancer-related mortality worldwide. The role of the epidermal growth factor receptor (EGFR) and other molecules linked to the EGFR signaling pathway has been extensively studied, and they have become the target of new, specific therapies in lung adenocarcinomas. Similarly, the amplification of the fibroblast growth factor receptor 1 (FGFR1) gene described in squamous cell lung carcinomas has opened new possibilities for molecular targeted therapy. Next generation sequencing (NGS) methods have made possible an even more accurate detection of rare somatic mutations.     

Emerging targeted therapies in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related deaths in United States, accounting for more than one-fourth of the deaths annually. Although comparatively rare and relatively less studied, genetic abnormalities other than epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) rearrangements, and Kirsten rat sarcoma (KRAS) mutations account for significant proportion of the driver mutations identified thus far. The targeted agents against B-rapidly accelerated fibrosarcoma (BRAF) V600E mutation, MNNG-HOS transforming gene (MET) pathway, ROS1 rearrangement, rearranged during transfection (RET) rearrangement, and HER2 pathways offer promising therapeutic options. Recruiting patients with these rarer mutations to well-designed, large multicenter trials to further validate the use of targeted agents remains a challenge. The clinical data and ongoing trials with these agents are reviewed in this article.     

MET alterations in NSCLC—Current Perspectives and Future Challenges

Targeted therapies have revolutionized the treatment and improved the outcome for oncogene-driven NSCLC and an increasing number of oncogenic driver therapies have become available. For MET-dysregulated NSCLC (especially MET exon 14 skipping mutations and MET-amplifications, which is one of the most common bypass mechanisms of resistance in oncogene-addicted NSCLC), several anti–MET-targeted therapies have been approved recently (MET exon 14 skipping mutation) and multiple others are in development. In this narrative review, we summarize the role of MET as an oncogenic driver in NSCLC, discuss the different testing methods for exon 14 skipping mutations, gene amplification, and protein overexpression, and review the existing data and ongoing clinical trials regarding targeted therapies in MET-altered NSCLC. As immunotherapy with or without chemotherapy has become the standard of care for advanced NSCLC, immunotherapy data for MET-dysregulated NSCLC are put into perspective. Finally, we discuss future challenges in this rapidly evolving landscape.     

Narrowing the focus: Therapeutic cell surface targets for refractory triple-negative breast cancer

Triple-negative breast cancer (TNBC) is defined as a type of breast cancer with lack of expression of estrogen receptor, progesterone receptor and human epidermal growth factor 2 protein. In comparison to other types of breast cancer, TNBC characterizes for its aggressive behavior, more prone to early recurrence and a disease with poor response to molecular target therapy. Although TNBC is identified in only 25%-30% of American breast cancer cases annually, these tumors continue to be a therapeutic challenge for clinicians for several reasons: Tumor heterogeneity, limited and toxic systemic therapy options, and often resistance to current standard therapy, characterized by progressive disease on treatment, residual tumor after cytotoxic chemotherapy, and early recurrence after complete surgical excision. Cell-surface targeted therapies have been successful for breast cancer in general, however there are currently no approved cell-surface targeted therapies specifically indicated for TNBC. Recently, several cell-surface targets have been identified as candidates for treatment of TNBC and associated targeted therapies are in development. The purpose of this work is to review the current clinical challenges posed by TNBC, the therapeutic approaches currently in use, and provide an overview of developing cell surface targeting approaches to improve outcomes for treatment resistant TNBC.     

Targeted Therapies for Breast Cancer Brain Metastases

The management of breast cancer, the most common cancer in the female population, has changed dramatically over years with the introduction of newer therapies. An increased incidence of brain metastases in recent years has created a challenge for oncologists because this population continues to have a poorer prognosis compared to metastatic breast cancer without central nervous system involvement. Historically, the exclusion of breast cancer patients with brain metastases from clinical trials has made treatment options even more limited. Nonetheless, more recently, this unmet need has been recognized by basic and clinical researchers and has led to the development of targeted therapies with better blood–brain barrier penetration and intracranial efficacy. Here we review targeted therapies directed at human epidermal growth factor receptor type 2 (HER2), vascular endothelial growth factor (VEGF), mammalian target of rapamycin (mTOR), epidermal growth factor receptor (EGFR), cyclin-dependent kinase 4 and 6 (CDK4/6) and poly(ADP-ribose) polymerase (PARP) for breast cancer patients with brain metastases. These therapies aim to be more efficacious and less toxic to represent a paradigm shift in the management of breast cancer brain metastases.