First-line crizotinib versus chemotherapy in ALK-positive lung cancer

Optimizing systemic therapy for metastatic renal cell carcinoma beyond the first-line setting

The introduction of molecularly targeted therapies (TTs) has transformed the management of metastatic renal cell carcinoma (mRCC). Within a relatively short period of time, systemic treatment of mRCC has evolved from a disease treated only by cytokines to a disease where TT is the cornerstone of patient management. Since the approval of sorafenib, an inhibitor of vascular endothelial growth factor receptor (VEGFR), in December 2005, 7 drugs have been introduced that have provided a high level of clinical efficacy in patients with mRCC, with a median survival of ~30 months in an unselected patient population that generally fits trials eligibility. Despite such success, advancements in therapies have reached a plateau: different combinations of targeted agents have not demonstrated additional benefit mainly owing to toxicity concerns, and some novel agents have failed to show benefit over approved drugs in clinics. In this review, we aim to focus on optimizing selection of agents in mRCC after progression on first-line TT. We also review how new drugs may transform existing guidelines and break through the current plateau reached with approved agents.

The impact of the Cancer Genome Atlas on lung cancer

The Cancer Genome Atlas (TCGA) has profiled more than 10,000 samples derived from 33 types of cancer to date, with the goal of improving our understanding of the molecular basis of cancer and advancing our ability to diagnose, treat, and prevent cancer. This review focuses on lung cancer as it is the leading cause of cancer-related mortality worldwide in both men and women. Particularly, non-small cell lung cancers (including lung adenocarcinoma and lung squamous cell carcinoma) were evaluated. Our goal was to demonstrate the impact of TCGA on lung cancer research under 4 themes: diagnostic markers, disease progression markers, novel therapeutic targets, and novel tools. Examples are given related to DNA mutation, copy number variation, messenger RNA, and microRNA expression along with methylation profiling.

Responses to the multitargeted MET/ALK/ROS1 inhibitor crizotinib and co-occurring mutations in lung adenocarcinomas with MET amplification or MET exon 14 skipping mutation

INTRODUCTION

Genomic aberrations involving ALK, ROS1 and MET can be driver oncogenes in lung adenocarcinomas. Identification of tyrosine kinase inhibitors (TKIs) with activity against these tumors and of preclinical systems to model response are warranted.

METHODS

We analyzed cases with lung adenocarcinomas for representative genomic aberrations, evaluated the response to the multitargeted MET/ALK/ROS1 crizotinib TKI in cases with MET aberrations and profiled lung cancer cell lines with the aforementioned genomic changes.

RESULTS

Lung cancer cell lines with ALK rearrangement, ROS1 rearrangement or MET amplification had expected in vitro responses to crizotinib and the ALK/ROS1 TKI ceritinib. However, a commercially-available cell line with MET exon 14 skipping mutation and co-occurring PIK3CA-p.Glu545Lys mutation did not respond to crizotinib; suggesting the latter abrogated response. 10% of MET exon 14 skipping mutation co-occurred with PIK3CA mutation in the TCGA cohort. Putative crizotinib-responsive somatic mutations (ALK rearrangements, ROS1 rearrangements, high level MET amplification or MET exon 14 skipping mutations) were present in 10% of lung adenocarcinomas analyzed at our service and in 9.5% of the TCGA lung adenocarcinoma database. One patient each whose advanced tumors harbored high level MET amplification with wild-type PIK3CA or MET exon 14 skipping mutation with PIK3CA-p.Glu542Lys had significant responses to crizotinib; suggesting that PIK3CA co-mutation did not affect clinical response.

CONCLUSIONS

Approximately 10% of lung adenocarcinomas harbor aberrations that are targetable using the approved multitargeted TKI crizotinib. MET exon 14 skipping mutation predicts for response to MET TKIs in human lung adenocarcinomas but co-occurrence of PIK3CA mutation needs to be better evaluated as a modifier of response to TKI therapy. MET TKIs should not be omitted from MET exon 14 skipping mutated tumors until further preclinical and clinical data can confirm or refute mechanisms of primary or acquired resistance to crizotinib and other MET TKIs in these recalcitrant cancers.

Towards manageable toxicities from targeted lung cancer treatment

Targeted agents are now considered standard of care for patients whose tumors possess a sensitizing mutation in EGFR or ALK rearrangement. As the toxicity profiles of these agents differ significantly from that of cytotoxic chemotherapy, physicians need to be cognizant of the clinically relevant adverse events and manage them aggressively. Early recognition of these toxicities is vital to ensure medication compliance and maintain quality of life for patients. As more novel agents enter the treatment armamentarium, such as third-generation EGFR and ALK inhibitors, it will be important for physicians to understand class-specific toxicities and rare but serious side effects associated with these drugs.

Management of advanced non-small cell lung cancers with known mutations or rearrangements: latest evidence and treatment approaches

Precision oncology is now the evidence-based standard of care for the management of many advanced non-small cell lung cancers (NSCLCs). Expert consensus has defined minimum requirements for routine testing and identification of epidermal growth factor (EGFR) mutations (15% of tumors harbor EGFR exon 19 deletions or exon 21 L858R substitutions) and anaplastic lymphoma kinase (ALK) rearrangements (5% of tumors) in advanced lung adenocarcinomas (ACs). Application of palliative targeted therapies with oral tyrosine kinase inhibitors (TKIs) in advanced/metastatic lung ACs harboring abnormalities in EGFR (gefitinib, erlotinib, afatinib) and ALK/ROS1/MET (crizotinib) has consistently led to more favorable outcomes compared with traditional cytotoxic agents. In addition, mutations leading to resistance to first-line EGFR and ALK TKIs can now be successfully inhibited by soon to be approved third-generation EGFR TKIs (osimertinib, rociletinib) and second-generation ALK TKIs (ceritinib, alectinib). Notably, increasing feasibility, accessibility, and application of molecular profiling technologies has permitted dynamic growth in the identification of actionable driver oncogenes. Emerging genomic aberrations for which TKIs have shown impressive results in clinical trials and expansion of drug labels for approved agents are awaited include ROS1 rearrangements (1-2% of tumors, drug: crizotinib) and BRAF-V600E mutations (1-3% of tumors, drugs: vemurafenib, dafrafenib + trametinib). Evolving genomic events in which TKI responses have been reported in smaller series include MET exon 14 skipping mutations (2-4% of tumors, drug: crizotinib); high-level MET amplification (1-2% of tumors, drug: crizotinib); RET rearrangements (1% of tumors, drug: cabozantinib); and ERBB2 mutations (2-3% of tumors, drug: afatinib), among others. Unfortunately, the most common genomic event in NSCLC, KRAS mutations (25-30% of tumors), is not targetable with approved or in development small molecule inhibitors. Here, we review currently approved, emerging, and evolving systemic precision therapies matched with their driver oncogenes for the management of advanced NSCLC.

TP53 and MDM2 genetic alterations in non-small cell lung cancer: Evaluating their prognostic and predictive value

The p53 pathway has been extensively studied for its role in carcinogenesis. Disruption of the pathway occurs in more than half of all cancers, often leading to a worse prognosis for the patient. In recent years several compounds have been successfully developed to target and restore the p53 pathway, either by blocking the MDM2-p53 interaction, restoring wild type conformation of mutant p53, or exploiting the presence of mutant p53 by blocking DNA damage repair pathways. In this review the known data on the role of p53 on prognosis and response to commonly used chemotherapeutics in non-small cell lung cancer is summarized. The focus is on the presence of genetic alterations in the TP53 or MDM2 gene, p53's main negative regulator. In addition, promising therapeutic options will be discussed in relation to specific alterations in the p53 pathway.

Discovery of Inhibitors That Overcome the G1202R Anaplastic Lymphoma Kinase Resistance Mutation

The treatment of patients with advanced non-small-cell lung cancer harboring chromosomal rearrangements of anaplastic lymphoma kinase (ALK) has been revolutionized by the development of crizotinib, a small-molecule inhibitor of ALK, ROS1, and MET. However, resistance to crizotinib inevitably develops through a variety of mechanisms, leading to relapse both systemically and in the central nervous system (CNS). This has motivated the development of "second-generation" ALK inhibitors, including alectinib and ceritinib, that overcome some of the mutations leading to resistance. However, most of the reported ALK inhibitors do not show inhibition of the G1202R mutant, which is one of the most common mutations. Herein, we report the development of a structural analogue of alectinib (JH-VIII-157-02) that is potent against the G1202R mutant as well as a variety of other frequently observed mutants. In addition, JH-VIII-157-02 is capable of penetrating the CNS of mice following oral dosing.

Novel targeted agents for the treatment of lung cancer in China

Since the discovery of epidermal growth factor receptor mutations and epidermal growth factor receptor tyrosine kinase inhibitors, lung cancer treatment in China has entered the precision era. However, novel targeted agents based on novel biomarkers still need to be developed. In the current study, the authors review the biomarker features of lung cancer in the Chinese population and the novel agents that are aimed at novel targets. Furthermore, they discuss issues that require improvement for the production of novel drugs and provided future directions for development in China.

Clinical potential of gene mutations in lung cancer

Lung cancer is the most common cancer type worldwide and the leading cause of cancer related deaths in the United States. The majority of newly diagnosed patients present with late stage metastatic lung cancer that is inoperable and resistant to therapies. High-throughput genomic technologies have made the identification of genetic mutations that promote lung cancer progression possible. Identification of the mutations that drive lung cancer provided new targets for non-small cell lung cancer (NSCLC) treatment and led to the development of targeted therapies such as tyrosine kinase inhibitors that can be used to combat the molecular changes that promote cancer progression. Development of targeted therapies is not the only clinical benefit of gene analysis studies. Biomarkers identified from gene analysis can be used for early lung cancer detection, determine patient’s prognosis and response to therapy, and monitor disease progression. Biomarkers can be used to identify the NSCLC patient population that would most benefit from treatment (targeted therapies or chemotherapies), providing clinicians tools that can be used to develop a personalized treatment plan. This review explores the clinical potential of NSCLC genetic studies on diagnosing and treating NSCLC.

Alectinib in Crizotinib-Refractory ALK-Rearranged Non-Small-Cell Lung Cancer: A Phase II Global Study

PURPOSE

Crizotinib confers improved progression-free survival compared with chemotherapy in anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC), but progression invariably occurs. We investigated the efficacy and safety of alectinib, a potent and selective ALK inhibitor with excellent CNS penetration, in patients with crizotinib-refractory ALK-positive NSCLC.

PATIENTS AND METHODS

Alectinib 600 mg was administered orally twice daily. The primary end point was objective response rate (ORR) by central independent review committee (IRC).

RESULTS

Of the 138 patients treated, 84 patients (61%) had CNS metastases at baseline, and 122 were response evaluable (RE) by IRC. ORR by IRC was 50% (95% CI, 41% to 59%), and the median duration of response (DOR) was 11.2 months (95% CI, 9.6 months to not reached). In 96 patients (79%) previously treated with chemotherapy, the ORR was 45% (95% CI, 35% to 55%). Median IRC-assessed progression-free survival for all 138 patients was 8.9 months (95% CI, 5.6 to 11.3 months). CNS disease control rate was 83% (95% CI, 74% to 91%), and the median CNS DOR was 10.3 months (95% CI, 7.6 to 11.2 months). CNS ORR in 35 patients with baseline measurable CNS lesions was 57% (95% CI, 39% to 74%). Of the 23 patients with baseline CNS metastases (measurable or nonmeasurable) and no prior radiation, 10 (43%) had a complete CNS response. At 12 months, the cumulative CNS progression rate (24.8%) was lower than the cumulative non-CNS progression rate (33.2%) for all patients. Common adverse events were constipation (33%), fatigue (26%), and peripheral edema (25%); most were grade 1 to 2.

CONCLUSION

Alectinib is highly active and well tolerated in patients with advanced, crizotinib-refractory ALK-positive NSCLC, including those with CNS metastases.

FGFR1 inhibition in lung squamous cell carcinoma: questions and controversies

Although the incidence of lung cancer has decreased due to the reduction of tobacco use, lung cancer remains the leading cause of cancer-related death. Lung squamous cell carcinoma represents 30% of lung cancers and only recently have possible drug-targetable mutations been identified in this disease, including fibroblast growth factor receptor 1 (FGFR1) gene amplification and genetic alterations in the phosphoinositide-3 kinase pathway. These discoveries have generated a great interest in the clinic and the initiation of clinical trials using FGFR tyrosine kinase inhibitors to treat FGFR-altered lung cancers. However, preliminary results from these studies have shown that not all patients respond to therapy. Here we review current unresolved questions on the selection of patients for their recruitment in FGFR tyrosine kinase inhibitor trials, how FGFR inhibitors could be combined with other targeted therapies or immunotherapies to improve patient outcome, and how the current preclinical models can help address these questions.

c-Met as a Target for Personalized Therapy

MET and its ligand HGF are involved in many biological processes, both physiological and pathological, making this signaling pathway an attractive therapeutic target in oncology. Downstream signaling effects are transmitted via mitogen-activated protein kinase (MAPK), PI3K (phosphoinositide 3-kinase protein kinase B)/AKT, signal transducer and activator of transcription proteins (STAT), and nuclear factor-κB. The final output of the terminal effector components of these pathways is activation of cytoplasmic and nuclear processes leading to increases in cell proliferation, survival, mobilization and invasive capacity. In addition to its role as an oncogenic driver, increasing evidence implicates MET as a common mechanism of resistance to targeted therapies including EGFR and VEGFR inhibitors. In the present review, we summarize the current knowledge on the role of the HGF-MET signaling pathway in cancer and its therapeutic targeting (HGF activation inhibitors, HGF inhibitors, MET antagonists and selective/nonselective MET kinase inhibitors). Recent advances in understanding the role of this pathway in the resistance to current anticancer strategies used in lung, kidney and pancreatic cancer are discussed.

c-Met as a Target for Personalized Therapy

MET and its ligand HGF are involved in many biological processes, both physiological and pathological, making this signaling pathway an attractive therapeutic target in oncology. Downstream signaling effects are transmitted via mitogen-activated protein kinase (MAPK), PI3K (phosphoinositide 3-kinase protein kinase B)/AKT, signal transducer and activator of transcription proteins (STAT), and nuclear factor-κB. The final output of the terminal effector components of these pathways is activation of cytoplasmic and nuclear processes leading to increases in cell proliferation, survival, mobilization and invasive capacity. In addition to its role as an oncogenic driver, increasing evidence implicates MET as a common mechanism of resistance to targeted therapies including EGFR and VEGFR inhibitors. In the present review, we summarize the current knowledge on the role of the HGF-MET signaling pathway in cancer and its therapeutic targeting (HGF activation inhibitors, HGF inhibitors, MET antagonists and selective/nonselective MET kinase inhibitors). Recent advances in understanding the role of this pathway in the resistance to current anticancer strategies used in lung, kidney and pancreatic cancer are discussed.

Lung cancer patients with HER2 mutations treated with chemotherapy and HER2-targeted drugs: results from the European EUHER2 cohort

BACKGROUND

HER2 mutations have been identified as oncogenic drivers in lung cancers and are found in 1-2% of lung adenocarcinomas. There is, to date, no standard of care for these patients. We thus aim to study the therapeutic outcomes of patients harboring HER2 mutations and establish the efficacy of various drug regimens.

PATIENTS AND METHODS

This retrospective cohort study in European centers assessed patients with advanced non-small-cell lung cancer (NSCLC), a known HER2 exon-20 insertion, treated with chemotherapy and/or HER2-targeted drugs.

RESULTS

We identified 101 eligible patients from 38 centers: median age 61 years (range: 30-87), 62.4% women, 60.4% never-smokers. All tumors were adenocarcinomas. Concomitant EGFR mutations, ALK translocations, and ROS translocations were observed in 5, 1, and 1 patients, respectively. The median number of treatment lines was 3 (range: 1-11). The median overall survival was 24 months. Overall response rate (ORR) and the median progression-free survival (PFS) with conventional chemotherapy (excluding targeted therapies) were 43.5% and 6 months in first-line (n = 93), and 10% and 4.3 months in second-line (n = 52) therapies. Sixty-five patients received HER2-targeted therapies: trastuzumab = 57, neratinib = 14, afatinib = 9, lapatinib = 5, T-DM1 = 1. ORR was 50.9% and PFS was 4.8 months with trastuzumab or T-DM1.

CONCLUSION

This series shows the chemosensitivity of HER2-driven NSCLC, and the potential interest of HER2-targeted agents. Our results should help to define the best therapeutic strategy for these patients and to orient future clinical trials.

Crizotinib in the management of advanced-stage non-small-cell lung cancer

ABSTRACT  Rearrangement of ALK gene has been identified as exerting a potent transforming effect as driver oncogene in patients with non-small-cell lung cancer (NSCLC). Crizotinib is a small-molecule oral inhibitor of ALK, c-Met/HGF receptor and ROS1 receptor kinases. Its efficacy in ALK-rearranged NSCLC has been established. Crizotinib's effect on ROS1 receptor kinases and c-Met with relevance to NSCLC is also actively being explored. Resistance mechanisms such as secondary gatekeeper mutations in ALK gene and activation of other oncogenes have been identified to confer acquired resistance to crizotinib. This article reviews the pharmacological properties of crizotinib, preclinical and clinical results that led to its approval in ALK-positive NSCLC and current directions of clinical research in overcoming crizotinib resistance.

[Modalities of use of ceritinib (Zykadia™), a 2nd generation ALK inhibitor, in advanced stage non-small cell lung cancer]

Around 4% of advanced non-small cell lung cancers (NSCLC) harbor a ALK rearrangement, with high sensitivity to ALK inhibitor as crizotinib. However, the vast majority of these tumors end with a tumor progression after several months of treatment with crizotinib. Ceritinib is a 2nd generation ALK inhibitor, which showed high efficiency in NSCLC with ALK rearrangement. Results from phase I trial showed a response rate at 58% in these tumors, with a similar rate for previously crizotinib-treated patients or crizotinib-naïve patients. Moreover, cerebral responses were observed with ceritinib. Preliminary date from a phase 2 trial confirmed these results. These promising results allowed a European marketing authorization (autorisation de mise sur le marché [AMM]) since May 2015 for the treatment of advanced NSCLC with ALK rearrangement and resistance or intolerance to crizotinib.

Cancer Genomics: Diversity and Disparity Across Ethnicity and Geography

Ethnic and geographic differences in cancer incidence, prognosis, and treatment outcomes can be attributed to diversity in the inherited (germline) and somatic genome. Although international large-scale sequencing efforts are beginning to unravel the genomic underpinnings of cancer traits, much remains to be known about the underlying mechanisms and determinants of genomic diversity. Carcinogenesis is a dynamic, complex phenomenon representing the interplay between genetic and environmental factors that results in divergent phenotypes across ethnicities and geography. For example, compared with whites, there is a higher incidence of prostate cancer among Africans and African Americans, and the disease is generally more aggressive and fatal. Genome-wide association studies have identified germline susceptibility loci that may account for differences between the African and non-African patients, but the lack of availability of appropriate cohorts for replication studies and the incomplete understanding of genomic architecture across populations pose major limitations. We further discuss the transformative potential of routine diagnostic evaluation for actionable somatic alterations, using lung cancer as an example, highlighting implications of population disparities, current hurdles in implementation, and the far-reaching potential of clinical genomics in enhancing cancer prevention, diagnosis, and treatment. As we enter the era of precision cancer medicine, a concerted multinational effort is key to addressing population and genomic diversity as well as overcoming barriers and geographical disparities in research and health care delivery.

Statistical controversies in clinical research: end points other than overall survival are vital for regulatory approval of anticancer agents

There is an ongoing debate about the relative merits of overall survival (OS) and other metrics that can be used as primary end points in cancer clinical trials. Although survival time is arguably the most objective metric for assessing the efficacy of anticancer treatment, OS as a clinical-trial end point needs to be conceptually distinguished from increased survival time as a goal desired by patients, clinicians and public-health policy makers. OS presents several drawbacks as a primary end point that threatens to hamper further drug development, including the increase in the number of patients and the much longer follow-up required in a clinical trial. In many settings of first-line therapy for metastatic disease, median OS is currently two to four times longer than median progression-free survival. As a result, the analysis of OS may be increasingly confounded by the effect of salvage therapies used after disease progression. In this review, we use straightforward statistical reasoning and examples from the oncology literature to argue that OS should no longer be the primary end point of most future phase III cancer clinical trials that aim at assessing the efficacy of novel therapies in the setting of metastatic disease.

Clinical development of nintedanib for advanced non-small-cell lung cancer

Angiogenesis is an essential process in the development, growth, and metastasis of malignant tumors including lung cancer. Several angiogenesis inhibitors have been developed as potential therapies for non-small-cell lung cancer (NSCLC). Nintedanib is a small-molecule tyrosine kinase inhibitor that targets receptors for vascular endothelial growth factor, platelet-derived growth factor, and fibroblast growth factor as well as RET (rearranged during transfection) and Flt3. When administered as monotherapy, nintedanib was well tolerated at doses up to 250 mg or 200 mg twice daily in European and Japanese patients, respectively, with liver toxicity featuring prominently among dose-limiting toxicities in both populations. A recent Phase III trial demonstrated that treatment with the combination of nintedanib and docetaxel resulted in a significant and clinically meaningful improvement in both progression-free survival and overall survival compared with docetaxel alone in predefined NSCLC patients with adenocarcinoma tumor histology. Although the incidence of elevated alanine aminotransferase or aspartate aminotransferase as well as of diarrhea was higher in patients treated with nintedanib plus docetaxel, most of these adverse events were manageable with supportive treatment or dose reduction. The results of completed and ongoing clinical trials of nintedanib monotherapy and combination therapy for the treatment of NSCLC are summarized in this study.

Clinical characteristics and outcome of patients with lung cancer harboring BRAF mutations

INTRODUCTION

BRAF (v-Raf murine sarcoma viral oncogene homolog B) mutations are identified in approximately 2% of non-small cell lung cancer (NSCLC). Because of the rarity of those mutations, associated clinical features and prognostic significance have not been thoroughly described so far.

METHODS

Here we took advantage of the French National Cancer Institute Program of systematic molecular profiling of metastatic lung cancer, to collect clinical characteristics and analyze the outcome of consecutive patients with NSCLC harboring BRAF mutations at the Lyon University Hospital laboratory between February 2012 and October 2014. Especially, we compared those variables with that of patients with EGFR-, BRAF-, KRAS-, HER2-, PIK3CA- wild-type NSCLCs.

RESULTS

Among 2690 patients with genotyped NSCLC during the study period, BRAF mutations were identified in 80 (3%) cases, consisting of V600E substitution in 42 (53%) cases; non-V600E mutation were observed in 38 (48%) cases. Concurrent mutations were not observed in case of BRAF V600 mutation, and were identified in 5 patients with BRAF non-V600E mutations, in all cases consisting of KRAS mutations. Non-V600E mutations were more likely to be observed in smokers, as compared V600E mutations. There was no significant difference in age, histologic type, performance status, and stage at diagnosis between cases of V600E and non-V600E mutations. Overall survival did not significantly differ in BRAF wild-type, V600E, and non-V600E patients.

CONCLUSION

This one of the largest series of patients with BRAF mutant NSCLC. Our clinical data suggest that BRAF mutations define specific subsets of patients with NSCLC; while their oncogenic nature is yet to be established in lung cancer, especially for non-V600E mutations, the value of BRAF mutations to predict the efficacy of targeted agents remains unclear.

Safety and efficacy of targeted agents monotherapy in advanced NSCLC

The emergence of targetted therapy has revolutionised the treatment of advanced NSCLC. Increasing numbers of driver genes and related targetted agents have supplied more powerful weapons for conquering NSCLC. Depending on whether there are clear targets and therapeutic effects, we can now rank targetted agents into three categories: agents with explicit targets and pure effects, agents with theoretical targets but with no effective biomarkers, agents with vague targets and lower effects. The latest clinical data on the safety and efficacy of monotherapy with three kinds of agents will be reviewed respectively in this article.

Diverse and Targetable Kinase Alterations Drive Histiocytic Neoplasms

Histiocytic neoplasms are clonal, hematopoietic disorders characterized by an accumulation of abnormal, monocyte-derived dendritic cells or macrophages in Langerhans cell histiocytosis (LCH) and non-Langerhans cell histiocytosis (non-LCH), respectively. The discovery of BRAF(V600E) mutations in approximately 50% of these patients provided the first molecular therapeutic target in histiocytosis. However, recurrent driving mutations in the majority of patients with BRAF(V600E)-wild-type non-LCH are unknown, and recurrent cooperating mutations in non-MAP kinase pathways are undefined for the histiocytic neoplasms. Through combined whole-exome and transcriptome sequencing, we identified recurrent kinase fusions involving BRAF, ALK, and NTRK1, as well as recurrent, activating MAP2K1 and ARAF mutations in patients with BRAF(V600E)-wild-type non-LCH. In addition to MAP kinase pathway lesions, recurrently altered genes involving diverse cellular pathways were identified. Treatment of patients with MAP2K1- and ARAF-mutated non-LCH using MEK and RAF inhibitors, respectively, resulted in clinical efficacy, demonstrating the importance of detecting and targeting diverse kinase alterations in these disorders.

SIGNIFICANCE

We provide the first description of kinase fusions in systemic histiocytic neoplasms and activating ARAF and MAP2K1 mutations in non-Langerhans histiocytic neoplasms. Refractory patients with MAP2K1- and ARAF-mutant histiocytoses had clinical responses to MEK inhibition and sorafenib, respectively, highlighting the importance of comprehensive genomic analysis of these disorders.

The radiogenomic risk score stratifies outcomes in a renal cell cancer phase 2 clinical trial

OBJECTIVES

To characterize a radiogenomic risk score (RRS), a previously defined biomarker, and to evaluate its potential for stratifying radiological progression-free survival (rPFS) in patients with metastatic renal cell carcinoma (mRCC) undergoing pre-surgical treatment with bevacizumab.

METHODOLOGY

In this IRB-approved study, prospective imaging analysis of the RRS was performed on phase II clinical trial data of mRCC patients (n = 41) evaluating whether patient stratification according to the RRS resulted in groups more or less likely to have a rPFS to pre-surgical bevacizumab prior to cytoreductive nephrectomy. Survival times of RRS subgroups were analyzed using Kaplan-Meier survival analysis.

RESULTS

The RRS is enriched in diverse molecular processes including drug response, stress response, protein kinase regulation, and signal transduction pathways (P < 0.05). The RRS successfully stratified rPFS to bevacizumab based on pre-treatment computed tomography imaging with a median progression-free survival of 6 versus >25 months (P = 0.005) and overall survival of 25 versus >37 months in the high and low RRS groups (P = 0.03), respectively. Conventional prognostic predictors including the Motzer and Heng criteria were not predictive in this cohort (P > 0.05).

CONCLUSIONS

The RRS stratifies rPFS to bevacizumab in patients from a phase II clinical trial with mRCC undergoing cytoreductive nephrectomy and pre-surgical bevacizumab.

KEY POINTS

• The RRS SOMA stratifies patient outcomes in a phase II clinical trial. • RRS stratifies subjects into prognostic groups in a discrete or continuous fashion. • RRS is biologically enriched in diverse processes including drug response programs.

Efficacy of pemetrexed in a patient with brain metastases during crizotinib treatment

ALK-positive patients with non-small-cell lung cancer (NSCLC) exhibit more aggressive clinical progression, a poorer response to chemotherapy, and less favorable survival outcomes in comparison with ALK-negative patients. Although crizotinib has proved effective in treating ALK-positive NSCLC, this agent penetrates the blood-brain barrier poorly and CNS progression is common. As pemetrexed, a multitargeted antifolate chemotherapeutic agent, has demonstrated benefit in the control of brain metastases in patients with NSCLC, treatment with pemetrexed was added to crizotinib in a young male patient with ALK-positive NSCLC who had developed brain metastases during crizotinib therapy. After four cycles of pemetrexed chemotherapy, the patient's brain lesions were significantly reduced in size and a chest CT scan showed that the lung lesions had stabilized.

[Crizotinib treatment in a lung adenocarcinoma harboring ALK fusion gene with bone marrow metastasis: case report and literature review]

背景与目的

肺癌患者常伴远处转移，其中伴骨髓转移患者治疗手段有限，预后差。Crizotinib已被证实可用于治疗间变淋巴瘤激酶（anaplastic lymphoma kinase, ALK）阳性的肺腺癌，但对于骨髓转移癌的疗效如何罕见报道。本文总结1例crizotinib治疗ALK阳性肺腺癌伴骨髓转移患者，并对其有效性及安全性进行讨论和分析。

方法

采用原位免疫荧光杂交法（fluorescence in situ hybridization, FISH）检测ALK融合基因阳性，一线化疗失败后给予crizotinib治疗，250 mg，2次/d。按照实体瘤疗效评价标准1.1版（Response Evaluation Criteriation in Solid Tumours, RECIST v1.1）评价客观疗效，采用骨髓活检评价骨髓转移瘤疗效。按照不良反应通用术语标准4.0版（Common Terminology Criteria for Adverse Events v4.0, CTC AE v4.0）评估用药期间发生的不良事件。

结果

该患者服用crizotinib 6周后，总体疗效评价为部分缓解（partial response, PR），骨髓疗效为完全缓解（complete response, CR）。因出现肺炎停药，无进展生存期（progression-free survival, PFS）20周，总生存期（overall survival, OS）22周。

结论

Crizotinib治疗ALK阳性的肺癌伴骨髓转移患者可达骨髓完全缓解，耐受性好。

Non-Small Cell Lung Cancer in a Very Young Woman: A Case Report and Critical Review of the Literature

BACKGROUND

Lung cancer in young patients is quite uncommon; clinical presentation and outcome in this population compared to the older group are not yet well defined and data about this setting are mostly single-institutional retrospective analyses.

CASE REPORT

We report here a case of a very young woman with diagnosis of early-stage lung adenocarcinoma harboring EML4-ALK rearrangement; she underwent radical surgery and adjuvant chemotherapy according to the pathologic stage. Potential risk factors for lung cancer in our patient are discussed and clinico-pathologic features and outcomes of lung cancer in the young population compared to the elderly are reviewed through discussing studies with sample sizes larger than 100 patients.

CONCLUSIONS

A wide clinical overview should be performed when lung cancer is diagnosed in a young patient. Large-population studies are required to define the molecular signature and clinical behavior of lung cancer in young patients.

EML4-ALK enhances programmed cell death-ligand 1 expression in pulmonary adenocarcinoma via hypoxia-inducible factor (HIF)-1α and STAT3

Programmed cell death (PD)-1/PD-1 ligand-1 (PD-L1)-targeted therapy has emerged as a promising therapeutic strategy for lung cancer. However, whether EML4-ALK regulates PD-L1 expression in lung cancer remains unknown. A total of 532 pulmonary adenocarcinomas (pADCs), including 58 ALK-translocated tumors, were immunohistochemically evaluated for PD-L1 and PD-1. H23 (EGFR^Wild-typeEML4-ALK^-PD-L1^Low) and H2228 (EGFR^Wild-typeEML4-ALK⁺PD-L1^High) cells were transfected with EML4-ALK or ALK short interfering RNAs and used to investigate the alterations in PD-L1 expression. PD-L1 expression was detected in 81% of ALK-translocated pADCs; this value was significantly higher than those of pADCs with EGFR mutation, KRAS mutation or lacking ALK, EGFR or KRAS mutation (p <0.005 for all). Moreover, ALK-translocated pADC with PD-L1 expression showed significantly higher numbers of tumor-infiltrating PD-1⁺ cells. ALK knockdown or inhibition (crizotinib treatment) in H2228 cells downregulated PD-L1 expression. Transfection of H23 cells with EML4-ALK enhanced PD-L1 expression, which was compromised by crizotinib treatment. This ALK-dependent upregulation of PD-L1 expression was mediated by STAT3 and hypoxia-inducible factor (HIF)-1α under normoxia and hypoxia. Furthermore, EML4-ALK enhanced HIF-1α expression through increasing transcription and decreasing ubiquitination of HIF-1α. In ALK-translocated pADC tissues, significant positive correlations between PD-L1 and nuclear HIF-1α (p < 0.05) or pSTAT3 expression levels (p<0.005) were observed. Among patients with ALK-translocated pADC, strong PD-L1 expression was significantly associated with shorter progression-free (p = 0.001) and overall survival (p = 0.002) after crizotinib treatment. Collectively, our findings demonstrate that ALK-derived pADCs increase PD-L1 expression via HIF-1α and/or STAT3, thus providing a rationale for PD-1/PD-L1 pathway-targeted therapy in ALK-translocated lung cancer.

[Clinical Efficacy of Crizotinib in Advanced ALK Positive Non-small Cell Lung Cancer]

BACKGROUND

The aim of this study is to explore clinical efficacy of crizotinib in advanced anaplastic lymphoma kinase (ALK) positive non-small cell lung cancer.

METHODS

patients with advanced non-small cell lung cancer habouring ALK positive were randomly divided into crizotinib group (n=14) and chemotherapy group (n=14). Patients in the crizotinib group were receive oral treatment with crizotinib (250 mg) twice daily. Patients in the chemotherapy group were administrated docetaxel injection (75 mg/m2) every three weeks and every patient was treated at least 3 period. Then clinical efficacy was observed after 12 mo followed-up.

RESULTS

Effective rate of patients in the crizotinib group was 64.29%. It was significantly higher than that of the chemotherapy group (21.43%)(P=0.026). The stable rate of patients in the crizotinib group was 85.71%. It was significantly higher than that of the chemotherapy group 40.86% (χ2=5.600, P=0.018). Median progression free survival (PFS) of the crizotinib group was 7.0 mo. It was longer than that of the chemotherapy group (4.0 mo)(P=0.002).

CONCLUSIONS

Crizotinib is superior to standard chemotherapy in patients with previously treated, advanced ALK positive non-small cell lung cancer. The median PFS of patients is shorter. It can improve the quality of life about patients.
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Systemic Therapy for Stage IV Non-Small-Cell Lung Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update

PURPOSE

To provide evidence-based recommendations to update the American Society of Clinical Oncology guideline on systemic therapy for stage IV non-small-cell lung cancer (NSCLC).

METHODS

An Update Committee of the American Society of Clinical Oncology NSCLC Expert Panel based recommendations on a systematic review of randomized controlled trials from January 2007 to February 2014.

RESULTS

This guideline update reflects changes in evidence since the previous guideline.

RECOMMENDATIONS

There is no cure for patients with stage IV NSCLC. For patients with performance status (PS) 0 to 1 (and appropriate patient cases with PS 2) and without an EGFR-sensitizing mutation or ALK gene rearrangement, combination cytotoxic chemotherapy is recommended, guided by histology, with early concurrent palliative care. Recommendations for patients in the first-line setting include platinum-doublet therapy for those with PS 0 to 1 (bevacizumab may be added to carboplatin plus paclitaxel if no contraindications); combination or single-agent chemotherapy or palliative care alone for those with PS 2; afatinib, erlotinib, or gefitinib for those with sensitizing EGFR mutations; crizotinib for those with ALK or ROS1 gene rearrangement; and following first-line recommendations or using platinum plus etoposide for those with large-cell neuroendocrine carcinoma. Maintenance therapy includes pemetrexed continuation for patients with stable disease or response to first-line pemetrexed-containing regimens, alternative chemotherapy, or a chemotherapy break. In the second-line setting, recommendations include docetaxel, erlotinib, gefitinib, or pemetrexed for patients with nonsquamous cell carcinoma; docetaxel, erlotinib, or gefitinib for those with squamous cell carcinoma; and chemotherapy or ceritinib for those with ALK rearrangement who experience progression after crizotinib. In the third-line setting, for patients who have not received erlotinib or gefitinib, treatment with erlotinib is recommended. There are insufficient data to recommend routine third-line cytotoxic therapy. Decisions regarding systemic therapy should not be made based on age alone. Additional information can be found at http://www.asco.org/guidelines/nsclc and http://www.asco.org/guidelineswiki.

Characterization of anaplastic lymphoma kinase-positive medulloblastomas

Medulloblastomas are the most common pediatric malignant primary brain tumor. To our knowledge, there are no known critical and druggable tyrosine kinases in medulloblastomas, precluding the use of established tyrosine kinase inhibitors that have shown efficacy in other tumor types. We studied the expression of anaplastic lymphoma kinase (ALK), a well-characterized tyrosine kinase and drug target, in a cohort of medulloblastomas by immunohistochemistry, and identified three ALK-positive cases. Mutational analyses did not reveal a definite underlying genetic mechanism for the ALK expression, although one of the cases showed increased ALK copy number. Our findings have clinical implications and warrant further pharmacological and functional studies, as well as evaluation in larger patient cohorts, to fully characterize the value of ALK as a prognostic and predictive therapeutic marker in medulloblastomas.

First line crizotinib in anaplastic lymphoma kinase (ALK) rearranged squamous cell lung cancer

Recently the superiority of Crizotinib to standard first-line pemetrexed-plus-platinum chemotherapy in patients with previously untreated advanced ALK-positive NSCLC has been demonstrated. We report of a 36-year-old never smoker with advanced squamous cell carcinoma, presenting with a left lower lobe lesion, N3 nodal disease and multiple metastases (pleura, adrenal, muscle, bone). Despite squamous histology we decided on molecular testing. IHC for ALK was positive and confirmatory fluorescent in situ hybridization showed translocation of ALK. Although there is little evidence on ALK rearrangements in squamous NSCLC we decided on first line treatment with Crizotinib (250 mg twice daily). Eight and twelve weeks after treatment initiation a whole-body FDG fusion PET/CT scan showed dramatic tumor response with little remaining metabolic uptake in the left lobe and a single bone lesion. This evidence raises the question whether ALK testing should be done in never smokers with squamous NSCLC in the absence of oncogenic driver mutations. To our knowledge, this the first report of first line treatment of full squamous ALK-positive NSCLC with crizotinib.

Clinical significance of expanded Foxp3⁺ Helios⁻ regulatory T cells in patients with non-small cell lung cancer

The functions of different regulatory T cell (T_reg) types in cancer progression are unclear. Recently, expression of the transcription factor Helios was proposed as a marker for natural (non-induced) T_regs. The present study investigated the clinical significance of Helios expression in patients with non-small cell lung cancer (NSCLC). We enrolled 64 patients with NSCLC, of whom 45 were treated surgically and 19 received chemotherapy because of advanced/recurrent disease. Their peripheral blood mononuclear cells were examined by flow cytometry. From the 45 surgery patients, we matched 9 patients with recurrent disease with 9 stage-matched patients without recurrence (n=18), compared their specimens immunohistochemically for tumor infiltrating lymphocytes (TILs) and analyzed these data against clinicopathological factors. Helios expression in Foxp3⁺ T_regs was 47.5±13.3% in peripheral blood and 18.1±13.4% in tumor specimens. Percentage of Helios⁻ T_regs among CD4⁺ T cells were significantly higher in the cancer patients (2.4%), especially those with stage IA disease (2.6%) than in healthy donors (1.5%; P<0.001). Patients with low levels of Helios expression in T_regs among their TILs had significantly poorer survival (P=0.038). Helios⁻ T_regs may affect immune suppression, even in early stage NSCLC; they could also be a useful prognostic biomarker in patients with NSCLC, and possibly a novel cancer immunotherapy target.

Epiregulin as a therapeutic target in non-small-cell lung cancer

Epiregulin (EREG) belongs to the ErbB family of ligands. EREG binds to EGFR and ErbB4 receptor and stimulates homodimers of EGFR and ErbB4 in addition to all possible heterodimeric ErbB complexes, resulting in the activation of downstream signaling pathways. EREG is overexpressed in various human cancers and has been implicated in tumor progression and metastasis. Oncogenic activation of the MEK/ERK pathway plays a central role in the regulation of EREG expression. Non-small-cell lung cancers (NSCLCs) harboring KRAS, BRAF, or EGFR mutations overexpress EREG, and abrogation of such mutations or inhibition of MEK or ERK downregulates the expression of EREG. Elevated EREG expression in NSCLC is associated with aggressive tumor phenotypes and unfavorable prognosis, especially in oncogenic KRAS-driven lung adenocarcinomas. The finding that attenuation of EREG inhibits cell growth and induces apoptosis in KRAS-mutant and EREG-overexpressing NSCLC cell lines suggests that targeting EREG might be a treatment option for KRAS-mutant NSCLC, although further studies are necessary to elucidate its therapeutic value. These observations suggest that oncogenic mutations in the EGFR, KRAS, or BRAF genes induce EREG upregulation through the activation of MEK/ERK pathway in NSCLC cells, whereas overproduced EREG stimulates the EGFR/ErbB receptors and activates multiple downstream signaling pathways, leading to tumor progression and metastasis of these oncogene-driven NSCLCs. This paper reviews the current understanding of the oncogenic role of EREG and highlights its potential as a therapeutic target for NSCLC.

Current and future treatment of anaplastic lymphoma kinase-rearranged cancer

Aberrant forms of the anaplastic lymphoma kinase (ALK) are involved in the pathogenesis of several types of cancer, including anaplastic large cell lymphoma, non-small-cell lung cancer (NSCLC), inflammatory myofibroblastic tumors, colorectal cancer, neuroblastoma and others. In general, the ALK catalytic domain is rearranged and fused to a dimerization domain encoded by an unrelated gene. Less frequently, full-length ALK is activated by point mutations. The common theme is unregulated firing of ALK downstream signalling, leading to uncontrolled cell division and increased cell survival. ALK-driven tumors can be treated with Crizotinib, an orally available dual ALK/MET inhibitor, currently approved for advanced ALK-positive NSCLCs. Crizotinib-treated patients achieve high response rates, with an excellent toxicity profile. However, drug-resistant disease often develops, particularly in NSCLC patients. The processes leading to drug resistance include both ALK-dependent (point mutations or gene amplification), as well as ALK-independent mechanisms, which are here briefly discussed. Recently, Ceritinib has been approved for Crizotinib-refractory NSCLC, further extending patients' survival, but resistance again emerged. Novel ALK kinase inhibitors are currently under clinical development, showing great promise for improved efficacy in drug-resistance disease. It is opinion of the author that drug-resistance is likely to arise under any treatment, due to intrinsic heterogeneity and adaptability of cancer. To prevent or delay this phenomenon, we need to treat less advanced disease, with drugs that are rapidly effective in order not to allow enough time for tumor evolution, and we want to have more and more drugs with non-overlapping resistance profiles, for subsequent lines of targeted therapy. Finally, the use of drug combinations may exponentially decrease the chances of resistance.

More than a Decade of Tyrosine Kinase Inhibitors in the Treatment of Solid Tumors: What We Have Learned and What the Future Holds

The use of tyrosine kinase inhibitors (TKIs) in the treatment of solid tumors is the expected standard of care for many types of tumors. Since the description of signal transduction pathways, followed by the development of small molecules designed to inhibit those pathways, there has been significant improvement not only in progression-free survival and overall survival but also in aiming toward chemotherapy-free treatment of solid tumors to maximize quality of life. This article reviews available TKIs and discusses toxicity, dosing, and resistance.

Crizotinib as a personalized alternative for targeted anaplastic lymphoma kinase rearrangement in previously treated patients with non-small-cell lung cancer

Crizotinib, the first clinically designed and synthesized as a tyrosine kinase inhibitor targeting mesenchymal–epithelial transition factor, indicating marked anticancer activity in patients with advanced, anaplastic lymphoma kinase-positive non-small-cell lung cancer, was approved by the US Food and Drug Administration in 2011. In this review, we focus on the efficacy of crizotinib compared with chemotherapy in advanced anaplastic lymphoma kinase-positive lung cancer and present the role of crizotinib as a personalized alternative in previously treated patients with non-small-cell lung cancer.

Circulating DNA in diagnosis and monitoring EGFR gene mutations in advanced non-small cell lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are current treatments for advanced non-small cell lung cancer (NSCLC) harboring activating EGFR gene mutations. Histological or cytological samples are the standard tumor materials for EGFR mutation analysis. However, the accessibility of tumor samples is not always possible and satisfactory in advanced NSCLC patients. Moreover, totality of EGFR mutated NSCLC patients will develop resistance to EGFR-TKIs. Repeat biopsies to study genetic evolution as a result of therapy are difficult, invasive and may be confounded by intra-tumor heterogeneity. Thus, exploring accurate and less invasive techniques to (I) diagnosis EGFR mutation if tissue is not available or not appropriate for molecular analysis and to (II) monitor EGFR-TKI treatment are needed. Circulating DNA fragments carrying tumor specific sequence alterations [circulating cell-free tumor DNA (cftDNA)] are found in the cell-free fraction of blood, representing a variable and generally small fraction of the total circulating DNA. cftDNA has a high degree of specificity to detect EGFR gene mutations in NSCLC. Studies have shown the feasibility of using cftDNA to diagnosis of EGFR activating gene mutations and also to monitor tumor dynamics in NSCLC patients treated with EGFR-TKIs. These evidences suggested that non-invasive techniques based on blood samples had a great potential in EGFR mutated NSCLC patients. In this review, we summarized these non-invasive approaches and relative scientific data now available, considering their possible applications in clinical practice of NSCLC treatment.

Biomarkers of Tumour Radiosensitivity and Predicting Benefit from Radiotherapy

Radiotherapy is an essential component of treatment for more than half of newly diagnosed cancer patients. The response to radiotherapy varies widely between individuals and although advances in technology have allowed the adaptation of radiotherapy fields to tumour anatomy, it is still not possible to tailor radiotherapy based on tumour biology. A biomarker of intrinsic radiosensitivity would be extremely valuable for individual dosing, aiding decision making between radical treatment options and avoiding toxicity of neoadjuvant or adjuvant radiotherapy in those unlikely to benefit. This systematic review summarises the current evidence for biomarkers under investigation as predictors of radiotherapy benefit. Only 10 biomarkers were identified as having been evaluated for their radiotherapy-specific predictive value in over 100 patients in a clinical setting, highlighting that despite a rich literature there were few high-quality studies for inclusion. The most extensively studied radiotherapy predictive biomarkers were the radiosensitivity index and MRE11; however, neither has been evaluated in a randomised controlled trial. Although these biomarkers show promise, there is not enough evidence to justify their use in routine practice. Further validation is needed before biomarkers can fulfil their potential and predict treatment outcomes for large numbers of patients.

Personalized treatment options for ALK-positive metastatic non-small-cell lung cancer: potential role for Ceritinib

The fusion of echinoderm microtubule-associated protein-like 4 with the anaplastic lymphoma kinase (EML4-ALK) is found in 3%–7% of non-small-cell lung cancer (NSCLC) cases and confers sensitivity to crizotinib, the first United States Food and Drug Administration (FDA)-approved ALK inhibitor drug. Although crizotinib has an excellent initial therapeutic effect, acquired resistance to this drug invariably develops within the first year of treatment. Resistance may involve secondary gatekeeper mutations within the ALK gene interfering with crizotinib–ALK interactions, or compensatory activation of aberrant bypass signaling pathways. New therapeutic strategies to overcome crizotinib resistance are needed. Ceritinib, a second-generation ALK inhibitor, overcomes several crizotinib-resistant ALK mutations and has demonstrated efficacy against tumor growth in several in vitro and in vivo preclinical models of crizotinib resistance. Notably, the dose-escalation Phase I ASCEND-1 trial has shown a marked activity of ceritinib in both crizotinib-naïve and crizotinib-resistant ALK-rearranged lung cancer. The overall response rate was 58% in a subgroup of patients with ALK-rearranged late-stage NSCLC. Drug discontinuation rate due to toxicity was 10%. The standard dose was established at 750 mg daily. This paper outlines the pathogenesis and treatment of ALK-positive lung cancer, focuses on the preclinical and clinical results surrounding the accelerated FDA approval of ceritinib for the treatment of ALK-positive metastatic NSCLC patients who have progressed on/or are crizotinib intolerant, and discusses the potential efforts seeking to maximize ceritinib efficacy and expand its usage to other indications in cancer therapy.

EML4-ALK translocation is associated with early onset of disease and other clinicopathological features in Chinese female never-smokers with non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) with echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) translocation is resistant to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib, but responds to the ALK-TKI crizotinib. Characterization of EML4-ALK translocation may provide invaluable information to facilitate disease diagnosis and improve the outcome of customized treatment. Although the occurrence of EML4-ALK translocation is likely to be affected by the smoking habits and gender of patients, the translocation has not been characterized extensively in female never-smokers with NSCLC. Therefore, 280 female never-smokers that were diagnosed with NSCLC were enrolled in the present study, and characteristics of EML4-ALK translocation, including the frequency, were determined in these NSCLC patients. EML4-ALK fusion variants were detected using Multiplex one-step reverse transcription-polymerase chain reaction and subsequently confirmed by DNA sequencing and Vysis ALK Break Apart fluorescence in situ hybridization analysis. The EML4-ALK fusion variants were detected in 21 carcinoma tissue specimens, accounting for 7.5% of the enrolled patients. Out of these patients with EML4-ALK fusion variants, EML4-ALK fusion variant 1 was identified in 12 patients, indicating that variant 1 is the most common type of EML4-ALK fusion gene in the present cohort of patients. ALK mRNA was aberrantly expressed in all the tissues with EML4-ALK translocation, but not in the carcinoma tissues without EML4-ALK translocation. In addition, the EML4-ALK translocation was more frequently found in younger patients. The median age of patients with EML4-ALK translocation was 50.95±2.29 years, which was significantly younger (P<0.01) than the median age of the patients without EML4-ALK translocation (57.15±0.56). The EML4-ALK translocation was detected exclusively in undifferentiated tumors that were graded as poorly- or moderately-differentiated carcinomas and suspected to be more malignant compared with well-differentiated tumors. In summary, the present study found that 7.5% of patients with NSCLC that are female never-smokers harbor EML4-ALK translocations, which are associated with the aberrant expression of ALK mRNA, early onset of disease and undifferentiated carcinomas.

Anaplastic Lymphoma Kinase Variants and the Percentage of ALK-Positive Tumor Cells and the Efficacy of Crizotinib in Advanced NSCLC

BACKGROUND

Anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer patients exhibited heterogeneous magnitude of response and duration time to criztotinib treatment. This study explored ALK variants and the percentage of ALK-positive cells using fluorescent in situ hybridization (FISH) on clinical efficacy of crizotinib.

PATIENTS AND METHODS

A total of 120 patients with ALK rearrangement who were treated with criztotinib were enrolled. ALK variants were clarified in 61 patients, and ALK percentages were evaluated using FISH in 114 ALK-positive patients. Retrospectively, objective response rate, and progression-free survival (PFS) were evaluated.

RESULTS

A total of 61 patients with specific ALK variants were divided into 3 subgroups, echinoderm microtubule-associated protein like 4 (EML4)-ALK variant 1 (n = 22), EML4-ALK variant 3a/b (n = 18), and other ALK variants (n = 21). Median PFS in the 3 subgroups was 11.0 months (95% confidence interval [CI], 5.5-16.5), 10.9 months (95% CI, 5.9-15.8), 7.4 months (95% CI, 3.2-11.6), respectively, and no significant difference (P = .795) existed among them. The percentage of ALK-positive cells in FISH analysis was weakly correlated with PFS (rs = 0.235; P = .015). Additionally, it was also weakly correlated with best response to crizotinib (rs = 0.288; P = .003). Overall, there were 45, 49, and 26 patients receiving first, second, and third or further-line crizotinib, respectively. Median PFS in the first-line setting (10.5 months; 95% CI, 8.6-12.4) was significantly longer than that in the second-line setting (8.3 months; 95% CI, 4.7-12.0; P = .020).

CONCLUSION

Anaplastic lymphoma kinase variants might have no correlation with clinical response to crizotinib. The percentage of ALK-positive cells might correlate with the extent of benefit from crizotinib treatment.