Identifying and targeting ROS1 gene fusions in non-small cell lung cancer

Diagnostic procedures for non-small-cell lung cancer (NSCLC): recommendations of the European Expert Group

BACKGROUND

There is currently no Europe-wide consensus on the appropriate preanalytical measures and workflow to optimise procedures for tissue-based molecular testing of non-small-cell lung cancer (NSCLC). To address this, a group of lung cancer experts (see list of authors) convened to discuss and propose standard operating procedures (SOPs) for NSCLC.

METHODS

Based on earlier meetings and scientific expertise on lung cancer, a multidisciplinary group meeting was aligned. The aim was to include all relevant aspects concerning NSCLC diagnosis. After careful consideration, the following topics were selected and each was reviewed by the experts: surgical resection and sampling; biopsy procedures for analysis; preanalytical and other variables affecting quality of tissue; tissue conservation; testing procedures for epidermal growth factor receptor, anaplastic lymphoma kinase and ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) in lung tissue and cytological specimens; as well as standardised reporting and quality control (QC). Finally, an optimal workflow was described.

RESULTS

Suggested optimal procedures and workflows are discussed in detail. The broad consensus was that the complex workflow presented can only be executed effectively by an interdisciplinary approach using a well-trained team.

CONCLUSIONS

To optimise diagnosis and treatment of patients with NSCLC, it is essential to establish SOPs that are adaptable to the local situation. In addition, a continuous QC system and a local multidisciplinary tumour-type-oriented board are essential.

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.

Lack of ROS1 Gene Rearrangement in Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most aggressive type of brain tumor, and the prognosis remains poor. Rearrangement of ROS1 gene, which was shown to have an oncogenic potential, was previously discovered in GBM cell lines. In this pilot study, we aimed to identify the incidence of ROS1 rearrangement in GBM patient tissues to explore novel biomarkers for therapeutic strategy. Formalin-fixed and paraffin-embedded (FFPE) tissue sections from 109 patients with GBM were screened for ROS1 rearrangement by anti-ROS immunohistochemistry (IHC) and ROS1 break-apart fluorescent in situ hybridization (FISH) assays. O⁶-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation and Isocitrate dehydrogenase 1 (IDH1) mutation status were also assessed. All samples were interpreted by two experienced pathologists who were blinded to the clinical data. A total of 109 samples were collected and all samples were examined for ROS1 rearrangement by IHC and FISH assays, and none was found to harbor ROS1 rearrangement. MGMT gene methylation was found in 42 (39.2%) cases, and IDH1 mutation was found in 6 (5.5%) cases. In this study, ROS1 rearrangement was not identified in GBM patients, and thus it is difficult to classify ROS1 rearrangement as a novel molecular subset in GBM patients for now.

The Evolution of Therapies in Non-Small Cell Lung Cancer

The landscape of advanced non-small lung cancer (NSCLC) therapies has rapidly been evolving beyond chemotherapy over the last few years. The discovery of oncogenic driver mutations has led to new ways in classifying NSCLC as well as offered novel therapeutic targets for anticancer therapy. Targets such as epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) gene rearrangements have successfully been targeted with appropriate tyrosine kinase inhibitors (TKIs). Other driver mutations such as ROS, MET, RET, BRAF have also been investigated with targeted agents with some success in the early phase clinical setting. Novel strategies in the field of immune-oncology have also led to the development of inhibitors of cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed death-1 receptor (PD-1), which are important pathways in allowing cancer cells to escape detection by the immune system. These inhibitors have been successfully tried in NSCLC and also now bring the exciting possibility of long term responses in advanced NSCLC. In this review recent data on novel targets and therapeutic strategies and their future prospects are discussed.

The Evolution of Therapies in Non-Small Cell Lung Cancer

The landscape of advanced non-small lung cancer (NSCLC) therapies has rapidly been evolving beyond chemotherapy over the last few years. The discovery of oncogenic driver mutations has led to new ways in classifying NSCLC as well as offered novel therapeutic targets for anticancer therapy. Targets such as epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) gene rearrangements have successfully been targeted with appropriate tyrosine kinase inhibitors (TKIs). Other driver mutations such as ROS, MET, RET, BRAF have also been investigated with targeted agents with some success in the early phase clinical setting. Novel strategies in the field of immune-oncology have also led to the development of inhibitors of cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed death-1 receptor (PD-1), which are important pathways in allowing cancer cells to escape detection by the immune system. These inhibitors have been successfully tried in NSCLC and also now bring the exciting possibility of long term responses in advanced NSCLC. In this review recent data on novel targets and therapeutic strategies and their future prospects are discussed.

Clinicopathologic characteristics of patients with ROS1 fusion gene in non-small cell lung cancer: a meta-analysis

BACKGROUND

The receptor tyrosine kinase ROS1 is a driver gene in the non-small cell lung cancer (NSCLC) with promising target treatment potential. The clinical features of NSCLC patients harboring ROS1 fusion gene were not fully understood due to small-to-modest sample sizes of these association studies.

METHODS

We systematically searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from their inception to March 31, 2015. We analyzed the association between ROS1 fusion genes and four common clinical variables, i.e., gender, smoking status, pathological type and clinical stage.

RESULTS

Eighteen studies consisting of 9,898 NSCLC patients were included in this meta-analysis. Pooled results showed that significantly higher rate of ROS1 fusion gene was detected in female NSCLC patients (OR =1.54, 95% CI: 1.02-2.34, P=0.042), patients without a smoking history (OR =3.27, 95% CI: 1.44-7.45, P=0.005), patients with adenocarcinomas NSCLC (OR =10.24, 95% CI: 5.13-20.40, P<0.001), and patients with an advanced clinical stages III-IV (OR =2.57, 95% CI: 1.78-3.71, P<0.001). The pooled prevalence of ROS1 fusion gene was 2.4% (95% CI: 1.8-3.1%) in adenocarcinoma and a significantly lower (0.2%) in non-adenocarcinoma tumors.

CONCLUSIONS

ROS1 rearrangement was more prevalent in female patients, patients without a smoking history, patients with adenocarcinoma, and patients on more advanced stages (stages III to IV).

Targeted therapies for patients with advanced NSCLC harboring wild-type EGFR: what's new and what's enough

Historically, non-small cell lung cancer (NSCLC) is divided into squamous and nonsquamous subtypes based on histologic features. With a growing number of oncogenic drivers being identified in squamous and nonsquamous NSCLC, this malignancy has been recently divided into several distinct subtypes according to the specific molecular alterations. This new paradigm has substantially highlighted the treatment of advanced NSCLC, shifting it from standard chemotherapy according to specific histologic subtypes to targeted therapy according to specific oncogenic drivers. The application of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in NSCLC patients harboring activating EGFR mutations has been a representative model of precise medicine in the treatment of NSCLC. As the role of EGFR-TKIs in routine management of patients with advanced NSCLC has been well established, this review provides an overview of alternative targeted therapy in the treatment of NSCLC, including EGFR-TKIs for patients with wild-type EGFR NSCLC, as well as other targeted agents either clinical available or in early- to late-stage development.

Biomarkers and targeted systemic therapies in advanced non-small cell lung cancer

The last decade has witnessed significant growth in therapeutic options for patients diagnosed with lung cancer. This is due in major part to our improved technological ability to interrogate the genomics of cancer cells, which has enabled the development of biologically rational anticancer agents. The recognition that lung cancer is not a single disease entity dates back many decades to the histological subclassification of malignant neoplasms of the lung into subcategories of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). While SCLC continues to be regarded as a single histologic and therapeutic category, the NSCLC subset has undergone additional subcategorizations with distinct management algorithms for specific histologic and molecular subtypes. The defining characteristics of these NSCLC subtypes have evolved into important tools for prognosis and for predicting the likelihood of benefit when patients are treated with anticancer agents.

Third- and further-line therapy in advanced non-small-cell lung cancer patients: an overview

Non-small-cell lung cancer (NSCLC) treatment has led to improved efficacy and compliance due to individual tailoring of the therapeutic options and the use of strategies based on both clinical characteristics and histological and biological features of the disease. In nonsquamous NSCLC, novel agents, such as pemetrexed and bevacizumab, have improved survival in the first-line setting. Maintenance therapy with pemetrexed and erlotinib resulted in improved progression-free survival compared with second-line therapy at disease progression. In the second-line setting, pemetrexed improves survival in nonsquamous NSCLC compared with docetaxel, and erlotinib has shown a survival benefit compared with best supportive care in patients who did not previously receive an EGF receptor inhibitor. Although the benefit of first- and second-line treatment over best supportive care alone has been firmly established, the role of further-line treatment remains controversial. This article summarizes the state-of-the-art treatments in this setting.

Predictive biomarkers in precision medicine and drug development against lung cancer

The molecular characterization of various cancers has shown that cancers with the same origins, histopathologic diagnoses, and clinical stages can be highly heterogeneous in their genetic and epigenetic alterations that cause tumorigenesis. A number of cancer driver genes with functional abnormalities that trigger malignant transformation and that are required for the survival of cancer cells have been identified. Therapeutic agents targeting some of these cancer drivers have been successfully developed, resulting in substantial improvements in clinical symptom amelioration and outcomes in a subset of cancer patients. However, because such therapeutic drugs often benefit only a limited number of patients, the successes of clinical development and applications rely on the ability to identify those patients who are sensitive to the targeted therapies. Thus, biomarkers that can predict treatment responses are critical for the success of precision therapy for cancer patients and of anticancer drug development. This review discusses the molecular heterogeneity of lung cancer pathogenesis; predictive biomarkers for precision medicine in lung cancer therapy with drugs targeting epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 receptor tyrosine kinase (ROS1), and immune checkpoints; biomarkers associated with resistance to these therapeutics; and approaches to identify predictive biomarkers in anticancer drug development. The identification of predictive biomarkers during anticancer drug development is expected to greatly facilitate such development because it will increase the chance of success or reduce the attrition rate. Additionally, such identification will accelerate the drug approval process by providing effective patient stratification strategies in clinical trials to reduce the sample size required to demonstrate clinical benefits.

Clinicopathological characteristics and outcomes of ROS1-rearranged patients with lung adenocarcinoma without EGFR, KRAS mutations and ALK rearrangements

Background

c-ros oncogene 1 (ROS1) rearrangement presents one of the newest molecular targets in non-small cell lung cancer (NSCLC). ROS1 rearrangement is predominantly found in adenocarcinoma cases and is exclusive to other oncogenes, such as epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), and anaplastic lymphoma kinase (ALK). The aim of this study was to investigate the clinicopathological characteristics and outcomes of ROS1-rearranged patients with lung adenocarcinoma without EGFR and KRAS mutations and ALK rearrangements.

Methods

Wild-type EGFR/KRAS/ALK patients with lung adenocarcinoma were selected from Beijing Chest Hospital. Specimens were conducted in tissue microarrays. ROS1 rearrangement was screened using fluorescence in situ hybridization.

Results

Our study included 127 patients with lung adenocarcinoma without EGFR and KRAS mutations and ALK rearrangements. ROS1 rearrangement was detected in five (3.9%) of the 127 patients. Compared with ROS1-negative patients, the positive rate of ROS1 in female patients was significantly higher than in male patients (9.8% vs. 0.0%, P = 0.009). There were no differences in age, smoking status, stage or histological subtype between ROS1-positive and ROS1-negative patients. No significant difference in survival was detected between the ROS1-positive and ROS1-negative patients.

Conclusions

ROS1 rearrangement is a rare subset of lung adenocarcinoma. In 127 patients with lung adenocarcinoma, 3.9% of ROS1-positive patients with wild-type EGFR/KRAS/ALK were found.

The minority report: targeting the rare oncogenes in NSCLC

OPINION STATEMENT

Lung cancer is still responsible for the highest number of cancer deaths worldwide. Despite this fact, significant progress has been made in the treatment of non-small cell lung cancer (NSCLC). Specifically, efforts to identify and treat genetic alterations (gene mutations, gene fusions, gene amplification events, etc.) that result in oncogenic drivers are now standard of care (EGFR and ALK) or an intense area of research. The most prevalent oncogenic drivers have likely already been identified; thus, there is now a focus on subgroups of tumors with less common genetic alterations. Interestingly, as we explore these less common mutations, we are discovering that many occur across other tumor types (i.e., non-lung cancer), further justifying their study. Furthermore, many studies have demonstrated that by searching broadly for multiple genetic alterations in large subsets of patients they are able to identify potentially targetable alterations in the majority of patients. Although individually, the rare oncogenic drivers subgroups may seem to occur too infrequently to justify their exploration, the fact that the majority of patients with NSCLC harbor a potentially actionable driver mutation within their tumors and the fact that different types of cancers often have the same oncogenic driver justifies this approach.

Targeted Therapies in Non-Small Cell Lung Cancer-Beyond EGFR and ALK

Systemic therapy for non-small cell lung cancer (NSCLC) has undergone a dramatic paradigm shift over the past decade. Advances in our understanding of the underlying biology of NSCLC have revealed distinct molecular subtypes. A substantial proportion of NSCLC depends on oncogenic molecular aberrations (so-called "driver mutations") for their malignant phenotype. Personalized therapy encompasses the strategy of matching these subtypes with effective targeted therapies. EGFR mutations and ALK translocation are the most effectively targeted oncogenes in NSCLC. EGFR mutations and ALK gene rearrangements are successfully being targeted with specific tyrosine kinase inhibitors. The number of molecular subgroups of NSCLC continues to grow. The scope of this review is to discuss recent data on novel molecular targets as ROS1, BRAF, KRAS, HER2, c-MET, RET, PIK3CA, FGFR1 and DDR2. Thereby the review will focus on therapeutic strategies targeting these aberrations. Moreover, the emerging challenge of acquired resistance to initially effective therapies will be discussed.

Clinical and the prognostic characteristics of lung adenocarcinoma patients with ROS1 fusion in comparison with other driver mutations in East Asian populations

INTRODUCTION

The prevalence, demographic features, and clinical outcomes of lung adenocarcinoma patients with novel ROS1 oncogenic rearrangement in East Asian populations are not clear. This study aimed to investigate the clinical and prognostic characteristics of lung adenocarcinoma in patients with ROS1 fusion compared with other driver mutations.

METHODS

Multiplex reverse transcription-polymerase chain reaction was used to detect the ROS1 fusion gene in lung adenocarcinoma cases. Immunohistochemistry was used to confirm the expression of ROS1. The demographic data and clinical outcomes of patients with the ROS1 fusion gene were compared with those of patients without the ROS1 fusion gene, including those with the EGFR mutation, EML4-ALK fusion, KRAS mutation, and quadruple-negative patients.

RESULTS

Of 492 patients with lung adenocarcinoma, 12 (2.4%) had the ROS1 fusion gene. Their median age was 45.0 years, significantly younger than that of the ROS1 fusion-negative cohorts (p < 0.001). Acinar (including cribriform) and solid patterns were the two most common histologic subtypes in the ROS1 fusion tumors (7 of 12, 58.3%) and were predominantly seen in CD74-ROS1 fusion tumors (66.7%). There was no significant survival difference between the ROS1 fusion-positive and ROS1 fusion-negative cohorts in surgical group, but ROS1 fusion-positive patients might have worse outcomes than EGFR-mutant patients in the stage IV group.

CONCLUSIONS

The ROS1 fusion gene can be successfully detected in East Asian patients with lung adenocarcinoma using multiplex reverse transcription-polymerase chain reaction. These patients tend to be younger and have characteristic histologic subtypes. Due to the small number of ROS1 fusion patients, the prognostic value of ROS1 fusion need further studies to confirm.

The Frequency and Clinical Implication of ROS1 and RET Rearrangements in Resected Stage IIIA-N2 Non-Small Cell Lung Cancer Patients

To evaluate the frequency and clinicopathological features of ROS1 and RET rearrangements in N2 node positive stage IIIA (IIIA-N2) non-small cell lung cancer (NSCLC) patients, we retrospectively screened 204 cases with a tissue microarray (TMA) panel by fluorescent in situ hybridization (FISH), and confirmed by direct sequencing and immunohistochemistry (IHC). The relationship between ROS1 or RET rearrangements, clinicopathological features, and prognostic factors were analyzed in resected stage IIIA-N2 NSCLC. Of the 204 cases, 4 cases were confirmed with ROS1 rearrangement, but no RET rearrangement was detected. All 4 ROS1-rearranged cases were adenocarcinomas. The predominant pathological type was acinar pattern in ROS1-rearranged tumors, except for 1 case harboring a mixture acinar and mucous tumor cells. Variants of ROS1 rearrangement were SDC4-ROS1 (E2:E32), SDC4-ROS1 (E4:E32) and SDC4-ROS1 (E4:E34). There was no significant association between ROS1 rearrangement and clinicopathological characteristics. In this cohort, multivariate analysis for overall survival (OS) indicated that squamous cell carcinoma and lobectomy were independent predictors of poor prognosis; R0 surgical resection and non-pleural invasion were independent predictors of good prognosis. In resected stage IIIA-N2 NSCLC patients, ROS1-rearranged cases tended to occur in younger patients with adenocarcinomas. The prognosis of resected stage IIIA-N2 is generally considered poor, but patients with ROS1 rearrangement will benefit from the targeted therapy.

Beyond ALK-RET, ROS1 and other oncogene fusions in lung cancer

Fusions of the RET and ROS1 protein tyrosine kinase oncogenes with several partner genes were recently identified as new targetable genetic aberrations in cases of non-small cell lung cancer (NSCLC) lacking activating EGFR, KRAS, ALK, BRAF, or HER2 oncogene aberrations. RET and ROS1 fusion-positive tumors are mainly observed in young, female, and/or never smoking patients. Studies based on in vitro and in vivo (i.e., mouse) models and studies of several fusion-positive patients indicate that inhibiting the kinase activity of the RET and ROS1 fusion proteins is a promising therapeutic strategy. Accordingly, there are several ongoing clinical trials aimed at examining the efficacy of tyrosine kinase inhibitors (TKIs) against RET and ROS1 proteins in patients with fusion-positive lung cancer. Other gene fusions (NTRK1, NRG1, and FGFR1/2/3) that are targetable by existing TKIs have also been identified in NSCLCs. Options for personalized lung cancer therapy will be increased with the help of multiplex diagnosis systems able to detect multiple druggable gene fusions.

Lung cancer molecular epidemiology in China: recent trends

Lung cancer is both the most common diagnosed cancer and the leading cause of cancer related deaths in China. During the past three decades, the incidence and mortality of lung cancer in China are increasing rapidly. According to data from National Central Cancer Registry (NCCR) in 2010, the crude incidence of lung cancer in China was 46.08 per 100,000 population (61.86 per 100,000 men and 29.54 per 100,000 women), with an estimated over 600,000 new diagnosed lung cancer patients (416,333 males and 189,613 females). Meanwhile, the crude mortality of lung cancer in China was 37.00 per 100,000 population (50.04 per 100,000 men and 23.33 per 100,000 women). Consistent with the change in developed countries, adenocarcinoma has become the most predominant histological subtype of lung cancer in China. For the majority advanced non-small-cell lung cancer (NSCLC) patients, especially patients with adenocarcinoma, targeted therapy became increasing important in the treatment. Chinese researcher have done a lot work in terms of lung cancer molecular epidemiology, therefore, in this review, we further summarized the epidemiology of driver genes in NSCLC, hoping to help clinicians to better screen certain driver genes in China for treatment decisions.

Detection of ROS1 gene rearrangement in lung adenocarcinoma: comparison of IHC, FISH and real-time RT-PCR

Aims

To compare fluorescence in situ hybridization (FISH), immunohistochemistry (IHC) and quantitative real-time reverse transcription-PCR (qRT-PCR) assays for detection of ROS1 fusion in a large number of ROS1-positive lung adenocatcinoma (ADC) patients.

Methods

Using IHC analysis, sixty lung ADCs including 16 cases with ROS1 protein expression and 44 cases without ROS1 expression were selected for this study. The ROS1 fusion status was examined by FISH and qRT-PCR assay.

Results

Among 60 cases, 16 (26.7%), 13 (21.7%) and 20 (33.3%) cases were ROS1 positive revealed by IHC, FISH and qRT-PCR, respectively. Using FISH as a standard method for ROS1 fusion detection, the sensitivity and specificity of IHC were 100% and 93.6%, respectively. Three IHC-positive cases, which showed FISH negative, were demonstrated with ROS1 fusion by qRT-PCR analysis. The sensitivity and specificity of qRT-PCR for detection for ROS1 fusion were 100% and 85.1%, respectively. The total concordance rate between IHC and qRT-PCR were 93.3%.

Conclusion

IHC is a reliable and rapid screening tool in routine pathologic laboratories for the identification of suitable candidates for ROS1-targeted therapy. Some ROS1 IHC-positive but FISH-negative cases did harbor the translocation events and may benefit from crizotinib.

Pharmacogenomics and targeted therapy of cancer: Focusing on non-small cell lung cancer

Recent studies have been established high degree of genetic diversity in solid organ tumors among individuals and even between individual tumor cells. This intratumor and intertumor genetic diversity results in a heterogeneous tumor with unique characteristics which potentially allows effective drug therapy. The goal of pharmacogenomics is to elucidate the genetic network(s) that underlie drug efficacy and drug resistance. Advances in targeted and personalized therapy play an increasingly important role in many common cancers, notably lung cancer, due to the high incidence, prevalence, mortality and the greater tendency towards drug resistance seen in these patients. Non-small cell lung cancer (NSCLC) is characterized by mutations in the epidermal growth factor receptor (EGFR) and or downstream kinase pathways. This has led to the development of highly selective monoclonal antibodies and EGFR tyrosine kinase inhibitors (EGFR-TKIs) to prevent cancer initiation, proliferation, differentiation, angiogenesis, survival, and invasion. However, resistance to many of these new treatments is induced and further pharmacogenomic analysis has revealed mutations associated with increased or reduced drug efficacy. Combinations of kinase inhibitors or potentially the targeting of cancer stem cells may further increase the success of pharmacogenomics in treating patients with lung cancer.

Crizotinib therapy for advanced lung adenocarcinoma and a ROS1 rearrangement: results from the EUROS1 cohort

PURPOSE

Approximately 1% of lung adenocarcinomas are driven by oncogenic ROS1 rearrangement. Crizotinib is a potent inhibitor of both ROS1 and ALK kinase domains.

PATIENTS AND METHODS

In the absence of a prospective clinical trial in Europe, we conducted a retrospective study in centers that tested for ROS1 rearrangement. Eligible patients had stage IV lung adenocarcinoma, had ROS1 rearrangement according to fluorescent in situ hybridization, and had received crizotinib therapy through an individual off-label use. Best response was assessed locally using RECIST (version 1.1). All other data were analyzed centrally.

RESULTS

We identified 32 eligible patients. One patient was excluded because next-generation sequencing was negative for ROS1 fusion. Median age was 50.5 years, 64.5% of patients were women, and 67.7% were never-smokers. Thirty patients were evaluable for progression-free survival (PFS), and 29 patients were evaluable for best response. We observed four patients with disease progression, two patients with stable disease, and objective response in 24 patients, including five complete responses (overall response rate, 80%; disease control rate, 86.7%). Median PFS was 9.1 months, and the PFS rate at 12 months was 44%. No unexpected adverse effects were observed. Twenty-six patients received pemetrexed (either alone or in combination with platinum and either before or after crizotinib) and had a response rate of 57.7% and a median PFS of 7.2 months.

CONCLUSION

Crizotinib was highly active at treating lung cancer in patients with a ROS1 rearrangement, suggesting that patients with lung adenocarcinomas should be tested for ROS1. Prospective clinical trials with crizotinib and other ROS1 inhibitors are ongoing or planned.

Molecular profiling and targeted therapy for advanced thoracic malignancies: a biomarker-derived, multiarm, multihistology phase II basket trial

PURPOSE

We conducted a basket clinical trial to assess the feasibility of such a design strategy and to independently evaluate the effects of multiple targeted agents against specific molecular aberrations in multiple histologic subtypes concurrently.

PATIENTS AND METHODS

We enrolled patients with advanced non-small-cell lung cancer (NSCLC), small-cell lung cancer, and thymic malignancies who underwent genomic characterization of oncogenic drivers. Patients were enrolled onto a not-otherwise-specified arm and treated with standard-of-care therapies or one of the following five biomarker-matched treatment groups: erlotinib for EGFR mutations; selumetinib for KRAS, NRAS, HRAS, or BRAF mutations; MK2206 for PIK3CA, AKT, or PTEN mutations; lapatinib for ERBB2 mutations or amplifications; and sunitinib for KIT or PDGFRA mutations or amplification.

RESULTS

Six hundred forty-seven patients were enrolled, and 88% had their tumors tested for at least one gene. EGFR mutation frequency was 22.1% in NSCLC, and erlotinib achieved a response rate of 60% (95% CI, 32.3% to 83.7%). KRAS mutation frequency was 24.9% in NSCLC, and selumetinib failed to achieve its primary end point, with a response rate of 11% (95% CI, 0% to 48%). Completion of accrual to all other arms was not feasible. In NSCLC, patients with EGFR mutations had the longest median survival (3.51 years; 95% CI, 2.89 to 5.5 years), followed by those with ALK rearrangements (2.94 years; 95% CI, 1.66 to 4.61 years), those with KRAS mutations (2.3 years; 95% CI, 2.3 to 2.17 years), those with other genetic abnormalities (2.17 years; 95% CI, 1.3 to 2.74 years), and those without an actionable mutation (1.85 years; 95% CI, 1.61 to 2.13 years).

CONCLUSION

This basket trial design was not feasible for many of the arms with rare mutations, but it allowed the study of the genetics of less common malignancies.

Pulmonary adenocarcinoma with signet ring cell features: a comprehensive study from 3 distinct patient cohorts

Comprehensive biological characteristics of pulmonary adenocarcinomas with signet ring cell features (SRC⁺) are not well known. Herein, we systematically evaluated clinical and molecular features of SRC⁺ cases with particular attention to smoking status. Surgically treated lung adenocarcinomas (n=763) with follow-up ≥5 years in 3 cohorts were reviewed: all patients in 2006 to 2007 ("all-comers," n=222; 168 ever-smokers), a never-smoker cohort (n=266), and a cohort of ever-smokers (n=275). SRC⁺ tumors had ≥10% of SRCs agreed by 2 pathologists. SRC⁺ cases were tested for rearrangement of ALK and ROS1, as well as 187 known mutations in 10 oncogenes including EGFR, KRAS, BRAF, ERBB2, JAK2, AKT1, AKT2, KIT, MET, and PIK3CA. Overall, 53 of 763 cases (7%) were SRC⁺. In the 2006 to 2007 "all comer" cohort, 9% were SRC⁺. In the never-smoker cohort, 9% were SRC⁺. In the smoker cohort, 3% were SRC⁺. Univariable analysis showed that SRC⁺ never-smokers had shorter overall and disease-free survival (P=0.006 and 0.0004, respectively), but the significance faded in the multivariable analysis. For the other 2 cohorts, crude 5-year survival was decreased by 6% to 27% in SRC⁺ cases without reaching statistical significance. In SRC⁺ tumors, KRAS mutation was most common (29%), followed by ALK (26%), EGFR (18%), ROS1 (6%), BRAF (6%), and PIK3CA (3%). In summary, SRC⁺ tumors in never-smokers had a worse survival by univariable analysis only. SRC⁺ cases seemed enriched for ALK⁺ and ROS1⁺, and other mutations were generally in keeping with the patient's smoking status.

Molecularly targeted therapies in non-small-cell lung cancer annual update 2014

There have been significant advances in the understanding of the biology and treatment of non-small-cell lung cancer (NSCLC) during the past few years. A number of molecularly targeted agents are in the clinic or in development for patients with advanced NSCLC. We are beginning to understand the mechanisms of acquired resistance after exposure to tyrosine kinase inhibitors in patients with oncogene addicted NSCLC. The advent of next-generation sequencing has enabled to study comprehensively genomic alterations in lung cancer. Finally, early results from immune checkpoint inhibitors are very encouraging. This review summarizes recent advances in the area of cancer genomics, targeted therapies, and immunotherapy.

Efficacy and safety of crizotinib among Chinese EML4-ALK-positive, advanced-stage non-small cell lung cancer patients

INTRODUCTION

We report the efficacy and safety of crizotinib treatment among Chinese patients with advanced-stage NSCLC.

METHODS

We retrospectively analyzed patients with EML4-ALK positive advanced NSCLC who were treated with crizotinib from May 2012 to Aug 2013. Baseline clinical parameters, treatment protocol, response to therapy and survival were noted. The primary goal was to evaluate the efficacy of crizotinib in patients who were previously treated patients or who had poor ECOG performance status (PS).

RESULTS

Forty patients were evaluable for safety and efficacy. Median age was 43 years, 100% had adenocarcinoma and stage IV disease, and 42.5% were female. Six patients received frontline treatment with crizotinib, 17 patients had 1 prior treatment, and 17 patients had more than 2 lines of prior treatment. Patients received a median of 5 cycles of treatment (range 1-15 cycles). After the first cycle, 92.5% (37/40) patients archived partial remission (PR). At the end of the follow-up period, the overall PR rate was 70% (28/40), and progression of disease (PD) occurred in 30% of patients (12/40). The median PFS was 28 weeks (95% CI 15.4 to 40.5 weeks), and median OS was 40 weeks (95% CI 38.6 to 49.3 weeks). The most frequent treatment-related AEs were vomiting (47.5%), vision disorder (27.5%) and increased ALT/AST (42%); most toxicities were Grade 1/2. Observed treatment-related Grade 3/4 AEs included increased ALT/AST (10%) and vomiting (5%). The EML4-ALK fusion rate and number of prior chemotherapy cycles did not appear to significantly affect the efficacy of crizotinib. However, PS 0-2 patients had improved PFS (50 weeks vs. 24 weeks, p = 0.015).

CONCLUSIONS

Crizotinib was safe, well-tolerated, and effective in Chinese patients with pre-treated ALK-rearranged NSCLC. QOL was improved and PS appears to have an effect on the efficacy of crizotinib, but prior treatment and ALK fusion rate do not.

Parallel screening for ALK, MET and ROS1 alterations in non-small cell lung cancer with implications for daily routine testing

OBJECTIVES

ALK, MET and ROS1 are prognostic and predictive markers in NSCLC, which need to be implemented in daily routine. To evaluate different detection approaches and scoring systems for optimal stratification of patients eligible for mutation testing in the future, we screened a large and unselected cohort of NSCLCs for all three alterations.

MATERIAL AND METHODS

Using tissue microarrays, 473 surgically resected NSCLCs were tested for ALK and MET expression by IHC and genomic alterations in the ALK, MET and ROS1 gene by FISH. For MET IHC, two different criteria (MetMAb and H-score), for MET FISH, three different scoring systems (UCCC, Cappuzzo, PathVysion) were investigated.

RESULTS

ALK and ROS1 positivity was seen in 2.6% and 1.3% of all ADCs, respectively, but not in pure SCCs. One ROS1 translocated tumor showed additional ROS1 amplification. MET IHC+/FISH+ cases were found in both histological subtypes (8.6% in all NSCLCs; 10.6% in ADCs; 5.0% in SCCs) and were associated with pleural invasion, lymphatic vessel invasion and lymph node metastasis. MET altered ADCs more frequently showed a papillary growth pattern. Whereas ALK testing revealed homogenous results in IHC and FISH, we saw discordant results for MET in about 10% of cases. Both METIHC scoring systems revealed almost identical results. We did not encounter any combined FISH positivity for ALK, MET or ROS1. However, three ALK positive cases harbored MET overexpression.

CONCLUSION

In daily routine, IHC could support FISH in the identification of ALK altered NSCLCs. Further research is needed to assess the role of discordant MET results by means of IHC and FISH as well as the relevance of tumors with an increased ROS1 gene copy number.

Republished: lung cancer in never-smokers. Does smoking history matter in the era of molecular diagnostics and targeted therapy?

Lung cancer in never-smokers was recognised as a distinct clinical entity around the mid-2000s because these patients tended to be Asian women and diagnosed at a younger age with a preponderance of adenocarcinoma and better survival outcome despite a more advanced stage of presentation. It was soon discovered that lung cancer in never-smokers had a higher prevalence of activating EGFR mutations and we tend to classify lung cancer by smoking status for screening purpose. With the discoveries of many actionable driver mutations such as activating EGFR mutations and ALK rearrangement in adenocarcinoma of the lung we have switched to classifying non-small cell lung cancer into different individual molecular subgroups based on the presence of a dominant driver mutation. Although many actionable driver mutations are found in never-smokers with adenocarcinoma, this review will summarise that a substantial proportion of patients with these actionable driver mutations had a previous smoking history. Alternatively among the driver mutations that are associated with smoking history, a fair amount of these patients were never-smokers. Thus smoking status should not be used as a screen strategy for identifying driver mutations in clinical practice. Finally smoking history may have predictive and/or prognostic significance within individual molecular subgroups and identifying the difference according to smoking history may help optimise future targeted therapy.

Promising Targets and Current Clinical Trials in Metastatic Non-Squamous NSCLC

Lung adenocarcinoma is the most common subtype of lung cancer today. With the discovery of epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) rearrangements, and effective targeted therapy, personalized medicine has become a reality for patients with lung adenocarcinoma. Here, we review potential additional targets and novel therapies of interest in lung adenocarcinoma including targets within the cell surface (receptor tyrosine kinases EGFR, human epidermal growth factor receptor 2, RET, ROS1, mesenchymal-epidermal transition, TRK), targets in intracellular signal transduction (ALK, RAS-RAF-MEK, PI3K-AKT-PTEN, WNT), nuclear targets such as poly-ADP ribose polymerase, heat shock protein 90, and histone deacetylase, and selected pathways in the tumor environment. With the evolving ability to identify specific molecular aberrations in patient tumors in routine practice, our ability to further personalize therapy in lung adenocarcinoma is rapidly expanding.

Crizotinib in ROS1-rearranged non-small-cell lung cancer

BACKGROUND

Chromosomal rearrangements of the gene encoding ROS1 proto-oncogene receptor tyrosine kinase (ROS1) define a distinct molecular subgroup of non-small-cell lung cancers (NSCLCs) that may be susceptible to therapeutic ROS1 kinase inhibition. Crizotinib is a small-molecule tyrosine kinase inhibitor of anaplastic lymphoma kinase (ALK), ROS1, and another proto-oncogene receptor tyrosine kinase, MET.

METHODS

We enrolled 50 patients with advanced NSCLC who tested positive for ROS1 rearrangement in an expansion cohort of the phase 1 study of crizotinib. Patients were treated with crizotinib at the standard oral dose of 250 mg twice daily and assessed for safety, pharmacokinetics, and response to therapy. ROS1 fusion partners were identified with the use of next-generation sequencing or reverse-transcriptase-polymerase-chain-reaction assays.

RESULTS

The objective response rate was 72% (95% confidence interval [CI], 58 to 84), with 3 complete responses and 33 partial responses. The median duration of response was 17.6 months (95% CI, 14.5 to not reached). Median progression-free survival was 19.2 months (95% CI, 14.4 to not reached), with 25 patients (50%) still in follow-up for progression. Among 30 tumors that were tested, we identified 7 ROS1 fusion partners: 5 known and 2 novel partner genes. No correlation was observed between the type of ROS1 rearrangement and the clinical response to crizotinib. The safety profile of crizotinib was similar to that seen in patients with ALK-rearranged NSCLC.

CONCLUSIONS

In this study, crizotinib showed marked antitumor activity in patients with advanced ROS1-rearranged NSCLC. ROS1 rearrangement defines a second molecular subgroup of NSCLC for which crizotinib is highly active. (Funded by Pfizer and others; ClinicalTrials.gov number, NCT00585195.).

[Targeted therapies in non-small cell lung cancer in 2014]

For several years, the identification of molecular sequencing alterations has considerably changed the perception and treatment of non-small cell lung cancer (NSCLC). These alterations have been defined as "driver mutations", such as mutations in EGFR and EML4-ALK fusion gene, and are highly sensitive to specific therapies. Other targets have also been identified recently. Personalized medicine is now a reality for patients with advanced NSCLC on the basis of routine screening for EGFR, HER2, KRAS, BRAF, PI3KCA mutations and EML4-ALK rearrangement. This article describes identified biomarkers, available targeted therapies, and the main clinical research approaches in NSCLC.

Alectinib shows potent antitumor activity against RET-rearranged non-small cell lung cancer

Alectinib/CH5424802 is a known inhibitor of anaplastic lymphoma kinase (ALK) and is being evaluated in clinical trials for the treatment of ALK fusion-positive non-small cell lung cancer (NSCLC). Recently, some RET and ROS1 fusion genes have been implicated as driver oncogenes in NSCLC and have become molecular targets for antitumor agents. This study aims to explore additional target indications of alectinib by testing its ability to inhibit the activity of kinases other than ALK. We newly verified that alectinib inhibited RET kinase activity and the growth of RET fusion-positive cells by suppressing RET phosphorylation. In contrast, alectinib hardly inhibited ROS1 kinase activity unlike other ALK/ROS1 inhibitors such as crizotinib and LDK378. It also showed antitumor activity in mouse models of tumors driven by the RET fusion. In addition, alectinib showed kinase inhibitory activity against RET gatekeeper mutations (RET V804L and V804M) and blocked cell growth driven by the KIF5B-RET V804L and V804M. Our results suggest that alectinib is effective against RET fusion-positive tumors. Thus, alectinib might be a therapeutic option for patients with RET fusion-positive NSCLC.

ROS1 immunohistochemistry among major genotypes of non-small-cell lung cancer

Identification of ROS1 rearrangements in patients with lung cancer allows them to benefit from targeted therapy. We compared immunohistochemistry (IHC) with more cumbersome methods such as fluorescence in situ hybridization and reverse transcriptase polymerase chain reaction for identification of ROS1 rearrangements in patients with lung adenocarcinoma (n = 33). Our results showed that IHC is a sensitive (100%) and specific (100%) method to identify ROS1 rearrangements in patients with lung cancer.

Responses to crizotinib in a patient with c-ros oncogene 1, receptor tyrosine kinase-positive advanced lung adenocarcinoma: A case report

Rearrangements to the c-ros oncogene 1, receptor tyrosine kinase (ROS1) gene are reported in 1–2% of lung adenocarcinomas. These rearrangements are associated with a response to the small-molecule tyrosine kinase inhibitor crizotinib. ROS1 rearrangements can be detected using fluorescence in situ hybridization (FISH), which is considered the gold standard technique in detecting ROS1 rearrangements, and determining whether a patient would respond well to crizotinib treatment. However, FISH is an expensive and time-consuming assay, requiring specialized microscopy equipment and some level of technical expertise. The present report describes the case of a patient with advanced lung adenocarcinoma, who was identified to be negative for ROS-1 rearrangements by FISH, but positive by immunohistochemistry (IHC). The health of the patient improved following treatment with crizotinib. These results indicate that IHC assay could be an alternative option for the detection of ROS1 gene rearrangements.

Screening for the FIG-ROS1 fusion in biliary tract carcinomas by nested PCR

ROS1 rearrangements have been detected in a variety of tumors and are considered as suitable targets of anticancer therapies. We developed a new, quick, specific, and sensitive PCR test to screen for the FIG-ROS1 fusion and applied it to a series of Italian patients with bile duct carcinoma (BTC). Formalin-fixed, paraffin-embedded tissues, derived from 65 Italian BTC patients, and six cell lines were analyzed by nested PCR to investigate the prevalence of a previously reported FIG-ROS1 fusion. The specificity and sensitivity of nested PCR were investigated in FIG-ROS1 positive U118MG cells in reconstitution experiments with peripheral blood mononuclear cells. We found that six out of 65 (9%) BTC patients were positive for the FIG-ROS1 fusion, comprising two out of 14 (14%) gallbladder carcinoma (GBC) patients and four out of 25 (16%) extrahepatic cholangiocarcinoma (ECC) patients. None of the 26 intrahepatic cholangiocarcinoma cases harbored the FIG-ROS1 fusion. All the cell lines were negative for this variant. In conclusion, 14-16% of GBC and ECC were positive for FIG-ROS1. This may have clinical implications, since these patients will potentially benefit from the treatment with specific ROS1 inhibitors.

Second ESMO consensus conference on lung cancer: pathology and molecular biomarkers for non-small-cell lung cancer

To complement the existing treatment guidelines for all tumour types, ESMO organises consensus conferences to focus on specific issues in each type of tumour. The Second ESMO Consensus Conference on Lung Cancer was held on 11-12 May 2013 in Lugano. A total of 35 experts met to address several questions on management of patients with non-small-cell lung cancer (NSCLC) in each of four areas: pathology and molecular biomarkers, early stage disease, locally advanced disease and advanced (metastatic) disease. For each question, recommendations were made including reference to the grade of recommendation and level of evidence. This consensus paper focuses on recommendations for pathology and molecular biomarkers in relation to the diagnosis of lung cancer, primarily non-small-cell carcinomas.

A three-microRNA signature predicts responses to platinum-based doublet chemotherapy in patients with lung adenocarcinoma

PURPOSE

To examine the clinical utility of intratumor microRNAs (miRNA) as a biomarker for predicting responses to platinum-based doublet chemotherapy in patients with recurring lung adenocarcinoma (LADC).

EXPERIMENTAL DESIGN

The expression of miRNAs was examined in LADC tissues surgically resected from patients treated with platinum-based doublet chemotherapy at the time of LADC recurrence. Microarray-based screening of 904 miRNAs followed by quantitative reverse transcription-PCR-based verification in 40 test cohort samples, including 16 (40.0%) responders, was performed to identify miRNAs that are differentially expressed in chemotherapy responders and nonresponders. Differential expression was confirmed in a validation cohort (n = 63 samples), including 18 (28.6%) responders. An miRNA signature that predicted responses to platinum-based doublet chemotherapy was identified and its accuracy was examined by principal component and support vector machine analyses. Genotype data for the TP53-Arg72Pro polymorphism, which is associated with responses to platinum-based doublet chemotherapy, were subsequently incorporated into the prediction analysis.

RESULTS

A signature comprising three miRNAs (miR1290, miR196b, and miR135a*) enabled the prediction of a chemotherapeutic response (rather than progression-free and overall survival) with high accuracy in both the test and validation cohorts (82.5% and 77.8%). Examination of the latter was performed using miRNAs extracted from archived formalin-fixed paraffin-embedded tissues. Combining this miRNA signature with the TP53-Arg72Pro polymorphism genotype marginally improved the predictive power.

CONCLUSION

The three-miRNA signature in surgically resected primary LADC tissues may by clinically useful for predicting responsiveness to platinum-based doublet chemotherapy in patients with LADC recurrence.

Crizotinib: a review of its use in the treatment of anaplastic lymphoma kinase-positive, advanced non-small cell lung cancer

Crizotinib (Xalkori(®)) is an orally active, small molecule inhibitor of multiple receptor tyrosine kinases, including anaplastic lymphoma kinase (ALK), c-Met/hepatocyte growth factor receptor and c-ros oncogene 1. In the EU, crizotinib has been conditionally approved for the treatment of adults with previously treated, ALK-positive, advanced non-small cell lung cancer (NSCLC). This approval has been based on objective response rate and tolerability data from two ongoing phase I/II studies (PROFILE 1001 and PROFILE 1005); these results have been substantiated and extended by findings from an ongoing phase III study (PROFILE 1007) in patients with ALK-positive, advanced NSCLC who had received one prior platinum-based regimen. Those treated with crizotinib experienced significant improvements in progression-free survival, objective response rate, lung cancer symptoms and global quality of life, as compared with those treated with standard second-line chemotherapy (pemetrexed or docetaxel). The relative survival benefit with crizotinib is unclear, however, as the data are still immature and likely to be confounded by the high cross-over rate among chemotherapy recipients. Crizotinib treatment was generally well tolerated in the three PROFILE studies, with liver transaminase elevations and neutropenia being the most common grade 3 or 4 adverse events. Crizotinib is the standard of care in terms of the treatment of patients with ALK-positive, advanced NSCLC; while the current EU approval is for second (or subsequent)-line use only, the first-line use of the drug is being evaluated in ongoing phase III studies. Key issues relating to the use of crizotinib in clinical practice include identifying the small subset of eligible patients, the almost inevitable development of resistance and the high cost of treatment.

Non-small-cell lung cancers: a heterogeneous set of diseases

Non-small-cell lung cancers (NSCLCs), the most common lung cancers, are known to have diverse pathological features. During the past decade, in-depth analyses of lung cancer genomes and signalling pathways have further defined NSCLCs as a group of distinct diseases with genetic and cellular heterogeneity. Consequently, an impressive list of potential therapeutic targets was unveiled, drastically altering the clinical evaluation and treatment of patients. Many targeted therapies have been developed with compelling clinical proofs of concept; however, treatment responses are typically short-lived. Further studies of the tumour microenvironment have uncovered new possible avenues to control this deadly disease, including immunotherapy.

Non-small-cell lung cancers: a heterogeneous set of diseases

Non-small-cell lung cancers (NSCLCs), the most common lung cancers, are known to have diverse pathological features. During the past decade, in-depth analyses of lung cancer genomes and signalling pathways have further defined NSCLCs as a group of distinct diseases with genetic and cellular heterogeneity. Consequently, an impressive list of potential therapeutic targets was unveiled, drastically altering the clinical evaluation and treatment of patients. Many targeted therapies have been developed with compelling clinical proofs of concept; however, treatment responses are typically short-lived. Further studies of the tumour microenvironment have uncovered new possible avenues to control this deadly disease, including immunotherapy.

From single-gene to multiplex analysis in lung cancer, challenges and accomplishments: a review of a single institution's experience

Molecular selection has led to the successful use of novel tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancers (NSCLCs). For instance, mutations in EGFR and translocations and fusions in ALK render tumor cells sensitive to some TKIs, leading to substantial clinical benefits. Molecular testing such as DNA sequencing or fragment analysis following PCR, and evaluation of copy number and gene positioning by FISH, have been developed and used clinically to identify mutations/fusions. Meanwhile, TKIs to target actionable mutations/fusions in several other oncogenes are being evaluated. High-throughput sequencing can provide therapy-predictive information as well as identify novel targetable genomic alterations. In this article, we report our experience enabling single-gene testing, and our evolution to panel-based next-generation sequencing.