Efficacy of crizotinib and pemetrexed-based chemotherapy in Chinese NSCLC patients with ROS1 rearrangement

Disease control in patients with non-small cell lung cancer using pemetrexed: Investigating the best treatment strategy

BACKGROUND

Pemetrexed (PEM) is the primary chemotherapy for non-small cell lung cancer (NSCLC), showing potential for long-term disease stability in certain cases. However, studies examining disease control with PEM therapy are lacking. This study aimed to pinpoint clinical traits in patients with NSCLC responding well to PEM therapy, predict factors influencing disease control, and suggest optimal treatment approaches.

METHODS

A retrospective analysis of patients with NSCLC treated with PEM was performed to compare patients who achieved disease control after treatment with those who did not.

RESULTS

Of 73 patients, 56 (76.7%) achieved disease control with PEM therapy. In the disease control group, a significantly higher proportion of patients exhibited good performance status (PS) and received PEM doses without reduction after the second cycle. Multivariate analysis identified bevacizumab (Bev) noncompliance, PEM dose reduction, and thyroid transcription factor-1 (TTF-1) negativity as significant independent risk factors for disease progression during PEM therapy. Additionally, overall survival was significantly longer in the disease control group (p < 0.001).

CONCLUSIONS

Our findings indicated that maintaining the dose of PEM after the second treatment cycle in patients with NSCLC, along with concurrent use of Bev and the presence of TTF-1 positivity, could enhance disease control rates and extend survival.

Exceptional response to lorlatinib and cabozantinib in ROS1-rearranged NSCLC with acquired F2004V and L2086F resistance

Patients with ROS1-rearranged NSCLC demonstrate excellent disease control with ROS1-targeted therapy, but acquired resistance is inevitable. Of particular interest is the ROS1 L2086F kinase domain mutation which is refractory to all currently available ROS1 TKIs apart from cabozantinib. We present a case of a patient with metastatic ROS1-rearranged NSCLC with dual ROS1 F2004V and L2086F resistance mutations who radiographically responded to the combination of lorlatinib and cabozantinib in a patient with metastatic NSCLC. Furthermore, the patient experienced exceptional clinical improvement and tolerance with the combined use of lorlatinib and cabozantinib. This case builds the case for cabozantinib as an agent to overcome ROS1 L2086F resistance. It also highlights the efficacy and safety of using combination of ROS1 TKIs to overcome complex resistance patterns.

Evolution of acquired resistance in a ROS1+ KRAS G12C+ NSCLC through the MAPK pathway

Patients with metastatic NSCLC bearing a ROS1 gene fusion usually experience prolonged disease control with ROS1-targeting tyrosine kinase inhibitors (TKI), but significant clinical heterogeneity exists in part due to the presence of co-occurring genomic alterations. Here, we report on a patient with metastatic NSCLC with a concurrent ROS1 fusion and KRAS p.G12C mutation at diagnosis who experienced a short duration of disease control on entrectinib, a ROS1 TKI. At progression, the patient continued entrectinib and started sotorasib, a small molecule inhibitor of KRAS p.G12C. A patient-derived cell line generated at progression on entrectinib demonstrated improved TKI responsiveness when treated with entrectinib and sotorasib. Cell-line growth dependence on both ROS1 and KRAS p.G12C was further reflected in the distinct downstream signaling pathways activated by each driver. Clinical benefit was not observed with combined therapy of entrectinib and sotorasib possibly related to an evolving KRAS p.G12C amplification identified on repeated molecular testing. This case supports the need for broad molecular profiling in patients with metastatic NSCLC for potential therapeutic and prognostic information.

Clinical and economic impact of 'ROS1-testing' strategy compared to a 'no-ROS1-testing' strategy in advanced NSCLC in Spain

Background

Detection of the ROS1 rearrangement is mandatory in patients with advanced or metastatic non-small cell lung cancer (NSCLC) to allow targeted therapy with specific inhibitors. However, in Spanish clinical practice ROS1 determination is not yet fully widespread. The aim of this study is to determine the clinical and economic impact of sequentially testing ROS1 in addition to EGFR and ALK in Spain.

Methods

A joint model (decision-tree and Markov model) was developed to determine the cost-effectiveness of testing ROS1 strategy versus a no-ROS1 testing strategy in Spain. Distribution of ROS1 techniques, rates of testing, positivity, and invalidity of biomarkers included in the analysis (EGFR, ALK, ROS1 and PD-L1) were based on expert opinion and Lungpath real-world database. Treatment allocation depending on the molecular testing results was defined by expert opinion. For each treatment, a 3-states Markov model was developed, where progression-free survival (PFS) and overall survival (OS) curves were parameterized using exponential extrapolations to model transition of patients among health states. Only medical direct costs were included (€ 2021). A lifetime horizon was considered and a discount rate of 3% was applied for both costs and effects. Both deterministic and probabilistic sensitivity analyses were performed to address uncertainty.

Results

A target population of 8755 patients with advanced NSCLC (non-squamous or never smokers squamous) entered the model. Over a lifetime horizon, the ROS1 testing scenario produced additional 157.5 life years and 121.3 quality-adjusted life years (QALYs) compared with no-ROS1 testing scenario. Total direct costs were increased up to € 2,244,737 for ROS1 testing scenario. The incremental cost-utility ratio (ICUR) was 18,514 €/QALY. Robustness of the base-case results were confirmed by the sensitivity analysis.

Conclusions

Our study shows that ROS1 testing in addition to EGFR and ALK is a cost-effective strategy compared to no-ROS1 testing, and it generates more than 120 QALYs in Spain over a lifetime horizon. Despite the low prevalence of ROS1 rearrangements in NSCLC patients, the clinical and economic consequences of ROS1 testing should encourage centers to test all advanced or metastatic NSCLC (non-squamous and never-smoker squamous) patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09397-4.

Cost-effectiveness analysis of first-line treatment with crizotinib in ROS1-rearranged advanced non-small cell lung cancer (NSCLC) in Canada

Introduction

While no direct comparative data exist for crizotinib in ROS1+ non-small cell lung cancer (NSCLC), studies have suggested clinical benefit with this targeted agent. The objective of this study was to assess the cost-effectiveness of crizotinib compared to standard platinum-doublet chemotherapy for first-line treatment of ROS1+ advanced NSCLC.

Methods

A Markov model was developed with a 10-year time horizon from the perspective of the Canadian publicly-funded health care system. Health states included progression-free survival (PFS), up to two further lines of therapy post-progression, palliation and death. Given a lack of comparative data and small study samples, crizotinib or chemotherapy studies with advanced ROS1+ NSCLC patients were identified and time-to-event data from digitized Kaplan-Meier curves were collected to pool PFS data. Costs of drugs, treatment administration, monitoring, adverse events and palliative care were included in 2018 Canadian dollars, with 1.5% discounting. An incremental cost-effectiveness ratio (ICER) was estimated probabilistically using 5000 simulations.

Results

In the base-case probabilistic analysis, crizotinib produced additional 0.885 life-years and 0.772 quality-adjusted life-years (QALYs) at an incremental cost of $238,077, producing an ICER of $273,286/QALY gained. No simulations were found to be cost-effective at a willingness-to-pay threshold of $100,000/QALY gained. A scenario analysis assuming efficacy equivalent to the ALK+ NSCLC population showed a slightly more favorable cost-effectiveness profile for crizotinib.

Conclusions

Available data appear to support superior activity of crizotinib compared to chemotherapy in ROS1+ advanced NSCLC. At the list price, crizotinib was not cost-effective at commonly accepted willingness-to-pay thresholds across a wide range of sensitivity analyses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08746-z.

Clinical and molecular factors that impact the efficacy of first-line crizotinib in ROS1-rearranged non-small-cell lung cancer: a large multicenter retrospective study

BACKGROUND

ROS1-rearranged lung cancers benefit from first-line crizotinib therapy; however, clinical and molecular factors that could affect crizotinib efficacy in ROS1-rearranged lung cancers are not yet well-elucidated. Our retrospective study aimed to compare the efficacy of chemotherapy and crizotinib in the first-line treatment of ROS1-rearranged advanced lung cancer and evaluate various clinical and molecular factors that might impact crizotinib efficacy in real-world practice.

METHODS

Treatment responses, survival outcomes, and patterns of disease progression were analyzed for 235 patients with locally advanced to advanced disease who received first-line chemotherapy (n = 67) or crizotinib (n = 168).

RESULTS

The overall response rate was 85.7% (144/168) for first-line crizotinib and 41.8% (28/67) for chemotherapy. Patients treated with first-line crizotinib (n = 168) had significantly longer median progression-free survival (PFS) than chemotherapy (n = 67) (18.0 months vs. 7.0 months, p < 0.001). Patients harboring single CD74-ROS1 (n = 90) had significantly shorter median PFS with crizotinib than those harboring non-CD74 ROS1 fusions (n = 69) (17.0 months vs. 21.0 months; p = 0.008). Patients with baseline brain metastasis (n = 45) had a significantly shorter PFS on first-line crizotinib than those without brain metastasis (n = 123) (16.0 months vs. 22.0 months; p = 0.03). At progression, intracranial-only progression (n = 40), with or without baseline CNS metastasis, was associated with longer median PFS than those with extracranial-only progression (n = 64) (19.0 months vs. 13.0 months, p < 0.001). TP53 mutations were the most common concomitant mutation, detected in 13.1% (7/54) of patients with CD74-ROS1 fusions, and 18.8% (6/32) with non-CD74 ROS1 fusions. Patients with concomitant TP53 mutations (n=13) had significantly shorter PFS than those who had wild-type TP53 (n = 81) (6.5 months vs. 21.0 months; p < 0.001). PFS was significantly shorter for the patients who harbored concomitant driver mutations (n = 9) (11.0 months vs 24.0 months; p = 0.0167) or concomitant tumor suppressor genes (i.e., TP53, RB1, or PTEN) (n = 25) (9.5 months vs 24.0 months; p < 0.001) as compared to patients without concomitant mutations (n = 58).

CONCLUSION

Our results demonstrate that baseline brain metastatic status and various molecular factors could contribute to distinct clinical outcomes from first-line crizotinib therapy of patients with ROS1-rearranged lung cancer.

CLINICAL TRIALS REGISTRATION

CORE, NCT03646994.

Clinical and economic impact of current ALK rearrangement testing in Spain compared with a hypothetical no-testing scenario

BACKGROUND

Currently biomarkers play an essential role in diagnosis, treatment, and management of cancer. In non-small cell lung cancer (NSCLC) determination of biomarkers such as ALK, EGFR, ROS1 or PD-L1 is mandatory for an adequate treatment decision. The aim of this study is to determine the clinical and economic impact of current anaplastic lymphoma kinase testing scenario in Spain.

METHODS

A joint model, composed by decision-tree and Markov models, was developed to estimate the long-term health outcomes and costs of NSCLC patients, by comparing the current testing scenario for ALK in Spain vs a hypothetical no-testing. The current distribution of testing strategies for ALK determination and their sensitivity and specificity data were obtained from the literature. Treatment allocation based on the molecular testing result were defined by a panel of Spanish experts. To assess long-term effects of each treatment, 3-states Markov models were developed, where progression-free survival and overall survival curves were extrapolated using exponential models. Medical direct costs (expressed in €, 2019) were included. A lifetime horizon was used and a discount rate of 3% was applied for both costs and health effects. Several sensitivity analyses, both deterministic and probabilistic, were performed in order test the robustness of the analysis.

RESULTS

We estimated a target population of 7628 NSCLC patients, including those with non-squamous histology and those with squamous carcinomas who were never smokers. Over the lifetime horizon, the current ALK testing scenario produced additional 5060 and 3906 life-years and quality-adjusted life-years (QALY), respectively, compared with the no-testing scenario. Total direct costs were increased up to € 51,319,053 for testing scenario. The incremental cost-effectiveness ratio was 10,142 €/QALY. The sensitivity analyses carried out confirmed the robustness of the base-case results, being the treatment allocation and the test accuracy (sensitivity and specificity data) the key drivers of the model.

CONCLUSIONS

ALK testing in advanced NSCLC patients, non-squamous and never-smoker squamous, provides more than 3000 QALYs in Spain over a lifetime horizon. Comparing this gain in health outcomes with the incremental costs, the resulting incremental cost-effectiveness ratio reinforces that testing non-squamous and never-smoker squamous NSCLC is a cost-effective strategy in Spain.

The Road Less Traveled: A Guide to Metastatic ROS1-Rearranged Non-Small-Cell Lung Cancer

Over the past decade, significant advances have been achieved in the diagnostic testing, treatment, and prognosis of advanced non-small-cell lung cancer (NSCLC). One of the most significant developments was the identification of specific gene alterations that define subsets of NSCLC. In 2007, ROS1 rearrangements were first described and observed in approximately 1%-2% of patients with NSCLC. Currently, crizotinib remains the therapy of choice for advanced ROS1-rearranged NSCLC without CNS metastases, while entrectinib has emerged as the preferred option for those with CNS metastases. The next-generation inhibitors under development are more potent, have better CNS efficacy, and can overcome important resistance mutations. In this review, we focus on the management of patients with advanced NSCLC harboring a ROS1 rearrangement. We aim to provide insight into the diagnosis, treatment approach, and emerging treatments in this subgroup of NSCLC.

Focus on ROS1-Positive Non-Small Cell Lung Cancer (NSCLC): Crizotinib, Resistance Mechanisms and the Newer Generation of Targeted Therapies

Simple Summary

Genetic rearrangements of the ROS1 gene account for up to 2% of NSCLC patients who sometimes develop brain metastasis, resulting in poor prognosis. This review discusses the tyrosine kinase inhibitor crizotinib plus updates and preliminary results with the newer generation of tyrosine kinase inhibitors, which have been specifically conceived to overcome crizotinib resistance, including brigatinib, cabozantinib, ceritinib, entrectinib, lorlatinib and repotrectinib. After introducing each agent’s properties, we provide suggestions on the best approaches to identify resistance mechanisms at an early stage, and we speculate on the most appropriate second-line therapies for patients who reported disease progression following crizotinib administration.

Abstract

The treatment of patients affected by non-small cell lung cancer (NSCLC) has been revolutionised by the discovery of druggable mutations. ROS1 (c-ros oncogene) is one gene with druggable mutations in NSCLC. ROS1 is currently targeted by several specific tyrosine kinase inhibitors (TKIs), but only two of these, crizotinib and entrectinib, have received Food and Drug Administration (FDA) approval. Crizotinib is a low molecular weight, orally available TKI that inhibits ROS1, MET and ALK and is considered the gold standard first-line treatment with demonstrated significant activity for lung cancers harbouring ROS1 gene rearrangements. However, crizotinib resistance often occurs, making the treatment of ROS1-positive lung cancers more challenging. A great effort has been undertaken to identify a new generation or ROS1 inhibitors. In this review, we briefly introduce the biology and role of ROS1 in lung cancer and discuss the underlying acquired mechanisms of resistance to crizotinib and the promising new agents able to overcome resistance mechanisms and offer alternative efficient therapies.

ROS1-rearranged Non-small Cell Lung Cancer

ROS1-rearranged non-small cell lung cancer (NSCLC) makes up approximately 1% to 2% of all NSCLC, is oncogenically driven by a constitutively activated ROS1 kinase paired with certain fusion partners, and can be detected by several different assays. These patients are initially treated with tyrosine kinase inhibitors (TKIs), which target the activated ROS1 kinase. Eventually these tumors develop resistance to initial TKI treatment through secondary kinase mutations that block TKI binding or activation of bypass signaling pathways, which subvert ROS1 as the driver of the malignancy. Investigation of several TKIs that have shown efficacy in secondary resistant patients is underway.

Identification of a Novel MPRIP-ROS1 Fusion and Clinical Efficacy of Crizotinib in an Advanced Lung Adenocarcinoma Patient: A Case Report

Objective

ROS1 fusions have been identified in 1-2% of non-small-cell lung cancer (NSCLC) patients; they are validated as a driver of carcinogenesis and could be subjected to inhibition by crizotinib. However, previous studies suggested a variable progression-free survival (PFS) ranging from 9.1 to 20.0 months for crizotinib treatment in ROS1-rearranged NSCLC. Here, we reported a 45-year-old female diagnosed with stage IVB lung adenocarcinoma with multiple lymph nodes and bone metastasis carrying a novel MPRIP-ROS1 fusion, which was identified by RNA-based NGS (next-generation sequencing) and was sensitive to crizotinib treatment.

Materials and Methods

A targeted NGS panel was used to analyze genomic DNA and total RNA isolated from formalin-fixed paraffin-embedded (FFPE) tissue block of the patient. An RNA fusion panel based on amplicon sequencing was designed for detection fusion variation. Fusion results were validated using reverse transcriptase polymerase chain reaction and Sanger sequencing.

Results

We reported a novel MPRIP-ROS1 fusion identified in this advanced lung adenocarcinoma case. The rearrangement was generated by exons 1-21 of MPRIP at chr17: p11.2 joined to exons 35-43 of ROS1 at chr6: q22.1, which retained an intact kinase domain of ROS1. The primary tumor and metastatic lymph nodes were eliminated on computed tomographic (CT) scan imaging after 2 months' crizotinib treatment, and the multiple bone metastatic lesions were significantly relieved according to bone scintigraphy images. To date, the treatment has lasted 16 months, and the patient is still in follow-up showing sustained response to crizotinib.

Conclusion

The study identified a novel MPRIP-ROS1 fusion that was sensitive to crizotinib, which provided a new driver of lung adenocarcinoma and potential therapeutic target for crizotinib. It also expanded NSCLC treatment of ROS1 rearrangement and highlighted the importance of genetic testing for precise treatment decision-making.

Cost-effectiveness analysis comparing companion diagnostic tests for EGFR, ALK, and ROS1 versus next-generation sequencing (NGS) in advanced adenocarcinoma lung cancer patients

BACKGROUND

The treatment of choice for advanced non-small cell lung cancer is selected according to the presence of specific alterations. Patients should undergo molecular testing for relevant modifications and the mutational status of EGFR and translocation of ALK and ROS1 are commonly tested to offer the best intervention. In addition, the tests costs should also be taken in consideration. Therefore, this work was performed in order to evaluate the cost-effectiveness of a unique exam using NGS (next generation sequencing) versus other routinely used tests which involve RT-PCR and FISH.

METHODS

The target population was NSCLC, adenocarcinoma, and candidates to first-line therapy. Two strategies were undertaken, strategy 1 corresponded to sequential tests with EGFR RT-PCR, then FISH for ALK and ROS1. Strategy 2 differed from 1 in that ALK and ROS1 translocation testing were performed simultaneously by FISH. Strategy 3 considered single test next-generation sequencing, a platform that includes EGFR, ALK and ROS1 genes. A decision tree analysis was used to model genetic testing options. From the test results, a microsimulation model was nested to estimate survival outcomes and costs of therapeutic options.

RESULTS

The use of NGS added 24% extra true cases as well as extra costs attributed to the molecular testing. The ICER comparing NGS with sequential tests was US$ 3479.11/correct case detected. The NGS improved a slight gain in life years and QALYs.

CONCLUSION

Our results indicated that, although precise, the molecular diagnosis by NGS of patients with advanced stage NSCLC adenocarcinoma histology was not cost-effective in terms of quality-adjusted life years from the perspective of the Brazilian supplementary health system.

Efficacy and Safety of Crizotinib in the Treatment of Advanced Non-Small-Cell Lung Cancer with ROS1 Rearrangement or MET Alteration: A Systematic Review and Meta-Analysis

BACKGROUND

Crizotinib has been approved for the treatment of non-small-cell lung cancer (NSCLC) with ROS proto-oncogene 1 (ROS1) gene fusion. This drug has also been granted breakthrough designation for NSCLCs with MET exon 14 alterations.

OBJECTIVE

This systematic review and meta-analysis aimed to investigate the efficacy and safety of crizotinib in patients with these diseases.

METHODS

We searched PubMed and Web of Science for relevant studies. Meta-analysis of proportions was conducted to calculate the pooled rate of complete response, partial response, stable disease, progressive disease, disease control rate (DCR), objective response rate (ORR), and drug adverse effects (AEs) of crizotinib in NSCLCs with ROS1 rearrangement or MET alterations.

RESULTS

A total of 20 studies were included for meta-analysis. Among patients with ROS1-positive NSCLC, crizotinib exhibited a pooled DCR of 93.2% (95% confidence interval [CI] 90.8-95.5) and a pooled ORR of 77.4% (95% CI 72.8-82.1). The median progression-free survival (PFS) and overall survival (OS) of patients in this group was 14.5 and 32.6 months, respectively. For NSCLC with MET alterations, crizotinib was associated with a lower efficacy (DCR 78.9% [95% CI 70.3-87.4] and ORR 40.6% [95% CI 28.3-53.0]). The median PFS was 5.2 months, and median OS was 12.7 months. The most common drug AEs were vision impairment (43.7%), edema (42.9%), and fatigue (40.1%).

CONCLUSION

Our study highlighted and confirmed the efficacy of crizotinib in patients with NSCLC with ROS1 or MET genetic alterations. Crizotinib had remarkable effects on advanced NSCLC with ROS1 fusion, as previously reported. However, the role of this targeted therapy in MET-altered NSCLC remains investigational.

ROS1-dependent cancers - biology, diagnostics and therapeutics

The proto-oncogene ROS1 encodes a receptor tyrosine kinase with an unknown physiological role in humans. Somatic chromosomal fusions involving ROS1 produce chimeric oncoproteins that drive a diverse range of cancers in adult and paediatric patients. ROS1-directed tyrosine kinase inhibitors (TKIs) are therapeutically active against these cancers, although only early-generation multikinase inhibitors have been granted regulatory approval, specifically for the treatment of ROS1 fusion-positive non-small-cell lung cancers; histology-agnostic approvals have yet to be granted. Intrinsic or extrinsic mechanisms of resistance to ROS1 TKIs can emerge in patients. Potential factors that influence resistance acquisition include the subcellular localization of the particular ROS1 oncoprotein and the TKI properties such as the preferential kinase conformation engaged and the spectrum of targets beyond ROS1. Importantly, the polyclonal nature of resistance remains underexplored. Higher-affinity next-generation ROS1 TKIs developed to have improved intracranial activity and to mitigate ROS1-intrinsic resistance mechanisms have demonstrated clinical efficacy in these regards, thus highlighting the utility of sequential ROS1 TKI therapy. Selective ROS1 inhibitors have yet to be developed, and thus the specific adverse effects of ROS1 inhibition cannot be deconvoluted from the toxicity profiles of the available multikinase inhibitors. Herein, we discuss the non-malignant and malignant biology of ROS1, the diagnostic challenges that ROS1 fusions present and the strategies to target ROS1 fusion proteins in both treatment-naive and acquired-resistance settings.

Cases of ROS1-rearranged lung cancer: when to use crizotinib, entrectinib, lorlatinib, and beyond?

ROS1-rearranged (also known as ROS1 fusion-positive) non-small-cell lung cancer is an uncommon but distinct molecular subgroup seen in approximately 1–2% of cases. Oncogene addiction due to constitutive ROS1 tyrosine kinase activation has allowed development of molecularly targeted therapies with remarkable anti-tumor activity. Both crizotinib and entrectinib, multitargeted tyrosine kinase inhibitors (TKIs) have now received approval by the FDA for treatment of patients with advanced ROS1-rearranged lung cancers; however, the clinical efficacy and safety of these drugs have been derived from expansion cohorts of single-arm phase I or basket clinical trials with relatively small populations of this clinically and molecularly distinct subgroup. Both drugs lead to high objective response rates (approximately 70–80%) and have manageable side effects, although only entrectinib has potent intracranial efficacy. Lorlatinib is an oral brain-penetrant ALK/ROS1 TKI with activity in both TKI-naïve and some crizotinib-resistant settings (albeit with limited potency against the crizotinib/entrectinib-resistant ROS1-G2032R mutation). We describe cases of advanced ROS1-rearranged lung cancer receiving crizotinib, entrectinib, and/or lorlatinib in first and later line treatment settings to dissect the current state of evidence supporting management decisions for these patients. The next generation ROS1 TKIs (repotrectinib and DS-6051b), owing to their broad activity against kinase mutations including ROS1-G2032R in preclinical studies, hold promise to transform the current treatment paradigm and permit even further gains with regards to long-term outcomes in this subset of patients.

Analysis of lung biopsies using the 2015 WHO criteria and detection of sensitizing mutations--a single-institution experience of 5032 cases

BACKGROUND

A specialized classification for small biopsies was added to the 2015 WHO classification of lung tumors. The purpose of this study is to explore and summarize the experience of applying the newly proposed classifications and criteria to clinical practice.

METHODS

We used the 2015 WHO criteria to sort out 5032 small lung biopsies from a group of Chinese patients, and demonstrated their clinicopathological features, mutational status and the relationship between these factors.

RESULTS

The most common diagnosis was primary lung carcinoma (3130, 62.2%), among which adenocarcinoma (1421, 28.2%) was the most frequent histological type. The mutational assays using ARMS-PCR technology demonstrated that EGFR was positive in 56.1% cases(499/889, from adenocarcinoma and NSCC, favor adenocarcinoma), ALK in 5.7% cases(12/211, from NSCC, which comprised all the primary lung carcinomas except small cell carcinomas), and ROS1 in 0.9% cases(2/211, from NSCC). Another 898 NSCC specimens went through an immunohistochemical (IHC) examination for ALK (D5F3) and 38 of them were positive (4.2%). The overall mutation rate of ALK was 4.5% (50/1119). There was no significant difference between ARMS-PCR and immunohistochemistry in the positive rate of ALK mutation detection (P = 0.359). EGFR mutations (P = 0.02) and ALK mutations (P < 0.001) both decreased with an increasing patient age. Furthermore, the amount of EGFR mutations was higher in adenocarcinoma (64.1% vs 34.1%, P < 0.001) than in NSCC, favor adenocarcinoma. In contrast, ALK mutations were more common in NSCC, favor adenocarcinoma (4.2% vs 8.4%, P = 0.021).

CONCLUSIONS

This single-center study exhibited a large subset of small lung biopsies from a Chinese institution and demonstrated that applying the 2015 WHO classification for small lung biopsies can help predict the mutational status of primary lung carcinomas.

First-line crizotinib versus platinum-pemetrexed chemotherapy in patients with advanced ROS1-rearranged non-small-cell lung cancer

OBJECTIVES

Food and Drug Administration (FDA) approved crizotinib for advanced ROS1-rearranged (ROS1+) non-small-cell lung cancer (NSCLC) patients due to a single-arm study PROFILE 1001. However, there is no direct comparison between crizotinib and platinum-pemetrexed chemotherapy.

MATERIALS AND METHODS

Clinical data of advanced ROS1+NSCLC patients treated with first-line crizotinib or platinum-pemetrexed chemotherapy between August 2010 and December 2017 were analyzed.

RESULTS

Seventy-seven patients were eligible, including 30 (39.0%) in the crizotinib group and 47 (61.0%) in the platinum-pemetrexed chemotherapy group. The median follow-up was 28.1 months (95% confidence interval [CI]: 19.2-39.0). The objective response rate (ORR) of crizotinib (86.7%, 95% CI: 73.3-96.7) was higher than that of platinum-pemetrexed chemotherapy (44.7%, 95% CI: 29.8-57.4, P < .001). The disease control rate (DCR) was 96.7% (95% CI: 90.0-100) in the crizotinib group and 85.1% (95% CI: 74.5-95.7) in the chemotherapy group (P = .140). Significantly longer progression-free survival (PFS) was observed in the patients treated with crizotinib (18.4 months, 95% CI: 6.4-30.3) versus platinum-pemetrexed chemotherapy (8.6 months, 95% CI: 6.9-10.3, P < .001). Overall survival (OS) was also compared between the two groups and no significant difference was seen (Not reach vs 28.4 months [95% CI: 20.7-36.0], P = .176). Notably, a total of 37 patients have treatment crossover after the failure of first-line treatment. Among those patients, difference in OS was not statistically significant between seven patients who have given first-line crizotinib (38.6 months, 95% CI: 0-81.0) and 30 patients who have given platinum-pemetrexed chemotherapy initially (32.8 months, 95% CI: 11.9-53.8, P = .805).

CONCLUSIONS

Our results suggested that first-line crizotinib had higher ORR and longer PFS than platinum-pemetrexed chemotherapy in patients with advanced ROS1+NSCLC, but the differences were not observed for OS.

Impact of lorlatinib on patient-reported outcomes in patients with advanced ALK-positive or ROS1-positive non-small cell lung cancer

OBJECTIVES

To evaluate patient-reported outcomes (PROs) from a phase 1/2 study (NCT01970865) in patients with anaplastic lymphoma kinase (ALK)- or ROS1-positive advanced non-small cell lung cancer (NSCLC) treated with lorlatinib 100 mg once daily.

MATERIALS AND METHODS

PRO measures, including global quality of life (QoL), functioning domains and symptoms, were assessed by the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) and the 13-item Lung Cancer (QLQ-LC13) module. Mean changes of absolute scores from baseline were assessed. Percentages of patients showing improvement, stability or worsening on each scale were reported, with a change of ≥10 points considered clinically meaningful (CM).

RESULTS

255 patients completed baseline and ≥1 post-baseline PRO assessment. Most patients had CM improvement (42.4 %) or stable (38.0 %) scores for global QoL. Functioning domains with the greatest proportion of patients with improved scores were role (37.6 %) and emotional (36.9 %); only one domain had more patients showing worsening than improving function (cognitive [24.3 % vs 22.4 %]). Most patients showed improved or stable scores for disease-related symptoms. No QLQ-C30 symptom domains had more patients worsening than improving. Symptoms on the QLQ-C30 scale with the greatest proportion of patients with improved scores were fatigue (49.4 %) and insomnia (46.3 %). Four QLQ-LC13 domains had more patients worsening than improving (two most affected were peripheral neuropathy [37.3 % vs 13.7 %] and alopecia [19.2 % vs 13.3 %]). Symptoms on the QLQ-LC13 scale with the greatest proportion of patients with improved scores were cough (42.7 %) and pain in other parts (32.9 %).

CONCLUSIONS

Lorlatinib treatment showed CM improvement from baseline in global QOL that was maintained over time. Additionally, there were improvements in physical, emotional, social, and role functioning. Improvements were shown in appetite loss and key symptoms such as pain, dyspnea, cough and fatigue; a worsening in peripheral neuropathy was noted.

Crizotinib inhibition of ROS1-positive tumours in advanced non-small-cell lung cancer: a Canadian perspective

The ros1 kinase is an oncogenic driver in non-small-cell lung cancer (nsclc). Fusion events involving the ROS1 gene are found in 1%-2% of nsclc patients and lead to deregulation of a tyrosine kinase-mediated multi-use intracellular signalling pathway, which then promotes the growth, proliferation, and progression of tumour cells. ROS1 fusion is a distinct molecular subtype of nsclc, found independently of other recognized driver mutations, and it is predominantly identified in younger patients (<50 years of age), women, never-smokers, and patients with adenocarcinoma histology. Targeted inhibition of the aberrant ros1 kinase with crizotinib is associated with increased progression-free survival (pfs) and improved quality-of-life measures. As the sole approved treatment for ROS1-rearranged nsclc, crizotinib has been demonstrated, through a variety of clinical trials and retrospective analyses, to be a safe, effective, well-tolerated, and appropriate treatment for patients having the ROS1 rearrangement. Canadian physicians endorse current guidelines which recommend that all patients with nonsquamous advanced nsclc, regardless of clinical characteristics, be tested for ROS1 rearrangement. Future integration of multigene testing panels into the standard of care could allow for efficient and cost-effective comprehensive testing of all patients with advanced nsclc. If a ROS1 rearrangement is found, treatment with crizotinib, preferably in the first-line setting, constitutes the standard of care, with other treatment options being investigated, as appropriate, should resistance to crizotinib develop.

[Investigation on the Possibility of EGFR Mutation Testing on DNA Extracted from Fixation Liquid of Lung Cancer Biopsy]

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation is the most common gene mutation in patients with non-small cell lung cancer (NSCLC). Many international guidelines are recommended to detected the EGFR mutation before the treatment of advanced non-small cell lung cancer. To investigate the possibility of EGFR mutation testing on DNA extracted from fixation liquid of lung cancer biopsy.

METHODS

Fixation liquid of lung cancer biopsy was collected and stored at -80 oC after centrifugal. DNA was extracted and EGFR gene mutation was detected by ARMS. Compared with EGFR mutation status of paraffin-embedded tissues, the consistency, the sensitivity and specificity of EGFR mutation testing were analyzed.

RESULTS

Among the 28 cases of EGFR mutation positive and 20 cases of EGFR mutation negative previously tested on paraffin-embedded tissue by clinic test, 20 cases with EGFR mutation positive and 20 cases with negative were detected by matched fixation liquid of lung cancer biopsy, respectively. The sensitivity and specificity were 71.4% and 100%. Moreover, 52 paraffin-embedded tissues and matched fixation liquid of lung cancer biopsy with unknown EGFR mutation status were detected, and the EGFR mutation positive rate were 36.5% and 28.8% respectively. The sensitivity and specificity of fixation liquid of lung cancer biopsy were 78.9% and 100.0%.

CONCLUSIONS

Extracting the DNA from fixation liquid of lung cancer biopsy may be a kind of feasible way to detect EGFR mutation.

Efficacy and safety of crizotinib in patients with ROS1 rearranged non-small cell lung cancer: a retrospective analysis

Background

Tyrosine kinase inhibitors (TKIs) are remarkably effective in patients with non-small cell lung carcinoma (NSCLC) harboring driver gene mutations and rearrangements. Crizotinib, a small-molecule TKI, has been demonstrated to be an efficacious drug against c-ros oncogene 1-rearranged NSCLC (ROS1-NSCLC) in clinical trials. However, information regarding the use of crizotinib in clinical practice in Japan is limited.

Methods

Subjects with a definite diagnosis of advanced/relapsed ROS1-NSCLC were selected from consecutive NSCLC patients treated at the National Cancer Center Hospital between December 2014 and May 2018. We retrospectively assessed the efficacy and safety of crizotinib in clinical practice.

Results

Among 24 patients with ROS1-NSCLC, the ROS1 rearrangement status was assessed using reverse transcription polymerase chain reaction (RT-PCR) (n=17), fluorescence in situ hybridization (FISH) (n=8), or next-generation sequencing (n=5) (some overlap occurred). Thirteen patients were treated with crizotinib in clinical practice. Among the 10 patients in whom clinical efficacy could be evaluated, the objective response rate (ORR) was 80.0% [95% confidence interval (CI), 49.0 to 94.3]. The median follow-up time was 35.5 months (95% CI, 8.9 to 44.6), the median progression-free survival (PFS) time was 10.0 months (95% CI, 5.1 to 27.0), and the median overall survival (OS) time was 28.7 months (95% CI, 6.7 to not reached). The most common adverse events were an aspartate/alanine aminotransferase (AST/ALT) increased and vision disorder. No severe adverse events related to crizotinib occurred.

Conclusions

The use of crizotinib in patients with ROS1-NSCLC was effective and well tolerated in clinical practice in Japan without severe adverse events.

High feasibility of cytological specimens for detection of ROS1 fusion by reverse transcriptase PCR in Chinese patients with advanced non-small-cell lung cancer

Purpose

Our previous study demonstrated that cytological specimens can be used as alternative samples for detecting anaplastic lymphoma kinase (ALK) fusion with the method of reverse transcriptase PCR (RT-PCR) in patients with advanced non-small-cell lung cancer (NSCLC). The current study aimed to investigate the feasibility of cytological specimens for ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) fusion detection by RT-PCR in advanced NSCLC patients.

Patients and methods

A total of 2,538 patients with advanced NSCLC, including 2,101 patients with cytological specimens and 437 patients with tumor tissues, were included in this study. All patients were screened for ROS1 fusion status by RT-PCR. The efficacy of crizotinib treatment was evaluated in ROS1 fusion-positive NSCLC patients.

Results

Among 2,101 patients with cytological specimens, the average concentration of RNA acquired from cytological specimens was 47.68 ng/μL (95% CI, 43.24–52.62), which was lower than the average of 66.54 ng/μL (95% CI, 57.18–76.60, P=0.001) obtained from 437 tumor tissues. Fifty-five patients harbored ROS1 fusion gene that was detected by RT-PCR, and 14 of them were treated with crizotinib. The incidence of ROS1 fusion was 1.95% (41/2,101) in 2,101 patients with cytological specimens, similar to the rate of 3.20% (14/437, P=0.102) for the 437 patients with tumor tissue. Regarding crizotinib treatment, no statistically significant differences were observed in the objective response rate (ORR) (81.8% vs 100%, P=0.604) between the cytological and tissue subgroups of ROS1-positive patients.

Conclusion

This study shows that cytological specimens can be utilized as alternative samples for ROS1 fusion detection by RT-PCR in advanced NSCLC patients.

Different Types of ROS1 Fusion Partners Yield Comparable Efficacy to Crizotinib

ROS1 rearrangements define a distinct molecular subset of non-small-cell lung cancer (NSCLC), which can be treated effectively with crizotinib, a tyrosine kinase inhibitor (TKI) targeting ROS1/MET/ALK rearrangements. Diverse efficacy was observed in ROS1-rearranged NSCLC patients. Because of its rareness, very limited studies have investigated the correlation between different fusion partners and response to crizotinib. In this study, we retrospectively screened 6,235 advanced NSCLC patients (stage IIIB to IV) from five hospitals and identified 106 patients with ROS1 rearrangements based on either plasma or tumor tissue testing using capture-based targeted sequencing. The most frequently occurring fusion partners included cluster of differentiation 74 (CD74), ezrin (EZR), syndecan 4 (SDC4), and tropomyosin 3 (TPM3), occurring in 49.1%, 17%, 14.2%, and 4.7% of patients, respectively. Among them, 38 patients were treated with crizotinib. Seventeen patients were treatment naive, and the remaining were previously treated with pemetrexed-based chemotherapy. Collectively, there was no significant difference among patients with various types of ROS1 fusion partners in overall survival (OS) and progression-free survival (PFS). Patients who were treated with crizotinib as first-line therapy showed comparable PFS (p = 0.26) to patients who were previously treated with pemetrexed-based chemotherapy. For treatment-naive patients, patients with low baseline ROS1 allelic fraction (AF) had a statistically significant longer OS than those with high ROS1 AF (184 vs. 110 days, p = 0.048). Collectively, our study demonstrates that ROS1⁺ patients with various fusion partners show comparable efficacy to crizotinib.

Clinicopathological features and clinical efficacy of crizotinib in Chinese patients with ROS1-positive non-small cell lung cancer

C-ros oncogene 1 receptor tyrosine kinase (ROS1) rearrangement forms a novel molecular subgroup of non-small cell lung cancer (NSCLC). The present study explored the clinicopathological features and clinical efficacy of crizotinib in patients with ROS1-positive NSCLC. A retrospective analysis of 2,617 cases of NSCLC diagnosed between January 2013 and December 2016 was performed. ROS1 fusion genes were detected by reverse transcription-quantitative polymerase chain reaction, fluorescence in situ hybridization or next-generation sequencing techniques, and patients positive for the ROS1 fusion gene received oral treatment with crizotinib. The ROS1 fusion was identified in 67 out of 2,617 cases (2.56%), including 21 cases that were male and 46 cases that were female. The median age was 68 years. Among these cases, 59 (88.06%) were adenocarcinoma and 8 were non-adenocarcinoma. According to Tumor-Node-Metastasis (TNM) staging, 4 cases were stage I-IIIa and 63 (94.02%) were stage IIIb-IV. The epidermal growth factor receptor (EGFR) gene status included 60 cases of wild-type, 1 case of co-mutation and 6 unknown cases. Statistically significant differences were identified for sex, TNM staging and EGFR gene status between ROS1 fusion gene-positive and -negative patients (P<0.001). A total of 23 patients received oral treatment with crizotinib, of which 13 (56.52%), 5 (21.74%) and 5 (21.74%) patients demonstrated a partial response, stable disease and progressive disease, respectively. The objective response rate was 56.52% and the disease control rate was 78.26%. Among all patients, the median progression-free survival (mPFS) time was 14.5 months. No differences were revealed in the mPFS time with regard to age, sex, smoking history, performance status score, histopathological type, TNM staging, tumor protein p53 gene status, EGFR gene status and first-line crizotinib treatment, whether by single or multiple factor analysis. The grade 3/4 treatment-associated adverse events included gastrointestinal disturbance, followed by increased transaminase concentration. In conclusion, the rate of ROS1 fusion in NSCLC among the patients is low, and crizotinib is an effective and safe drug for the treatment of ROS1-positive advanced NSCLC.

Driver mutations of young lung adenocarcinoma patients with malignant pleural effusion

Young lung cancer patients have several distinct characteristics. However, there are limited epidemiological data of genetic abnormalities in this population. We conducted a prospective cohort study to delineate the various oncogenic driver mutations of lung adenocarcinoma in young Asian patients. We consecutively collected malignant pleural effusions (MPEs) from lung adenocarcinoma patients. RNA was extracted from MPEs for mutation analysis by reverse transcription-polymerase chain reaction and direct sequencing. Selected gene mutations for testing included EGFR, HER2, BRAF, KRAS, PIK3CA, JAK2, MEK1, NRAS, and AKT2 mutations, as well as EML4-ALK, ROS1, and RET fusions. We collected MPEs from 142 patients aged ≤50 years and 730 patients aged >50 years. Patients aged ≤50 years (91%) had a higher incidence of driver gene mutations than those aged >50 years (84%; P = .036), especially EML4-ALK (P < .001) and ROS1 (P < .001). Among patients aged ≤50 years, EGFR mutation was the major oncogenic driver mutation. The mutation rates of other genes were 18% EML4-ALK, 6% ROS1, 5% HER2, 1% RET, 1% BRAF, and 1% KRAS. We did not detect PIK3CA, JAK2, MEK1, NRAS, or AKT2 mutations. No difference in gender or smoking history was noted among those with different driver mutations. Patients who had a good performance status or received appropriate targeted therapy had longer overall survival. In conclusion, lung adenocarcinoma in Asian patients aged ≤50 years had a higher gene mutation rate than in those aged >50 years, especially EML4-ALK and ROS1 fusion. Mutation analysis may be helpful in determining targeted therapy for the majority of these patients.

MiR-760 suppresses non-small cell lung cancer proliferation and metastasis by targeting ROS1

MicroRNAs (miRNAs) have been shown to be critical regulators in many types of tumors. The aim of our study was to investigate the role of miR-760 in non-small cell lung cancer (NSCLC). We demonstrated that the expression of miR-760 was downregulated in NSCLC tissues compared with the adjacent normal tissues. We also demonstrated that the expression of miR-760 was downregulated in the NSCLC cell lines. Overexpression of miR-760 suppressed the NSCLC cell proliferation, cell cycle, and migration. Moreover, we identified that ROS1 was a direct target of miR-760 in the NSCLC cell. Elevated expression of miR-760 suppressed ROS1 expression in the NSCLC cell. We also demonstrated that the expression of ROS1 was higher in the NSCLC tissues than in the adjacent lung tissues. MiR-760 expression level was reversely associated with the expression level of ROS1 in the NSCLC tissues. In summary, we showed that miR-760 suppressed the NSCLC cell proliferation, cell cycle, and migration through regulating the ROS1 expression. These data suggested that miR-760 may act as a tumor suppressor gene in the NSCLC partly through regulating ROS1 expression.

Systematic review and meta-analysis of selected toxicities of approved ALK inhibitors in metastatic non-small cell lung cancer

Introduction

Anaplastic lymphoma kinase (ALK) inhibitors are the mainstay treatment for patients with non-small cell lung carcinoma (NSCLC) harboring a rearrangement of the ALK gene or the ROS1 oncogenes. With the recent publication of pivotal trials leading to the approval of these compounds in different indications, their toxicity profile warrants an update.

Materials and Methods

A systematic literature search was performed in July 2017. Studies evaluating US FDA approved doses of one of the following ALK inhibitors: Crizotinib, Ceritinib, Alectinib or Brigatinib as monotherapy were included. Data were analyzed using random effects meta-analysis for absolute risks (AR), study heterogeneity, publication bias and differences among treatments.

Results

Fifteen trials with a total of 2,005 patients with evaluable toxicity data were included in this report. There was significant heterogeneity amongst different studies. The pooled AR of death and severe adverse events were 0.5% and 34.5%, respectively. Grade 3/4 nausea, vomiting, diarrhea, and constipation were uncommon: 2.6%, 2.5%, 2.7%, 1.2%, respectively.

Conclusions

ALK inhibitors have an acceptable safety profile with a low risk of treatment-related deaths. Important differences in toxicity profile were detected amongst the different drugs.

Outcomes of Pemetrexed-based chemotherapies in HER2-mutant lung cancers

Background

HER2 mutation has been found to be an oncogenic driver gene in non-small cell lung cancers(NSCLC) and HER2-directed therapies have shown promising results in this unique population, while little is known about its association with outcomes of chemotherapy. The aim of this study was to investigate the efficacy of first line chemotherapy in patients with advanced HER2-mutant lung adenocarcinomas.

Methods

Patients with advanced NSCLC(N = 1714) initially underwent testing for EGFR, KRAS, BRAF mutations and ALK, ROS1 rearrangements, and negative cases were then assessed for HER2 mutations using the method of amplification refractory mutation system(ARMS). The efficacy of first line pemetrexed-based chemotherapy was investigated in patients with HER2-mutant and those with EGFR-mutant, ALK/ROS1-rearranged and KRAS-mutant advanced adenocarcinomas.

Results

HER2 mutations were detected in 29 of 572(5.1%) specimens from a selected population of EGFR/KRAS/BRAF/ALK/ROS1 negative patients. All of them are adenocarcinomas. Among patients with HER2-mutant lung cancers, 25 received pemetrexed-based first line chemotherapy. The objective response rate(ORR) was 36.0%. Their median progression free survival(PFS) was 5.1 months, which was similar with that of KRAS-mutant group (n = 40,5.0 months, p = 0.971), numerically shorter than that of EGFR-mutant group(n = 74, 6.5 months, p = 0.247) and statistically significantly shorter than that of ALK/ROS1-rearranged group (n = 39,9.2 months, p = 0.004). Furthermore, HER2 variants subgroup analysis showed that PFS was inferior in A775_G776insYVMA group compared with other variants (4.2 vs 7.2 months, p = 0.085).

Conclusions

Patients with advanced HER2-mutant lung adenocarcinomas showed an inferior outcome of first line pemetrexed-based chemotherapy compared to those with ALK/ROS1 rearrangements, which strengthen the need for effective HER2-targeted drugs in clinical practice.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4277-x) contains supplementary material, which is available to authorized users.

Long-term progression-free survival in an advanced lung adenocarcinoma patient harboring EZR-ROS1 rearrangement: a case report

Background

Crizotinib is recommended as first-line therapy in ROS1-driven lung adenocarcinoma. However, the optimal first-line therapy for this subgroup of lung cancer is controversial according to the available clinical data.

Case presentation

Here, we describe a 57-year-old man who was diagnosed with stage IIIB lung adenocarcinoma and EGFR/KRAS/ALK-negative tumors. The patient received six cycles of pemetrexed plus cisplatin as first-line therapy and then pemetrexed as maintenance treatment, with a progression-free survival (PFS) of 42 months. The patient relapsed and underwent re-biopsy. EZR-ROS1 fusion mutation was detected by next-generation sequencing (NGS). The patient was prescribed crizotinib as second-line therapy and achieved a PFS of 6 months. After disease progression, lorlatinib was administered as third-line therapy, with a favorable response.

Conclusions

Prolonged PFS in patients receiving pemetrexed chemotherapy might be related to the EZR-ROS1 fusion mutation. Lorlatinib is an optimal choice in patients showing crizotinib resistance.

Precision oncology: neither a silver bullet nor a dream

Precision oncology is not an illusion, nor is it the magic bullet that will eradicate all cancers. Precision oncology is simply another weapon in our growing armament against cancer. Rather than honing in on the failures of a relatively young field, one should advocate for integrating its successes into widespread clinical practice, especially for indications, such as: ABL, ALK, BRAF, BRCA1, BRCA2, EGFR, KIT, KRAS, PDGFRA, PDGFRB, ROS1, BCR-ABL, FLT3 and ROS1, where aberrations have been shown to alter responses to US FDA approved drugs - that is, level 1 data. Moreover, to truly assess the promise of precision oncology, we must first begin by defining our expectations for this field. Importantly, we must recognize that the conception of precision oncology arose as an antithesis of the 'one-size fits all' cancer therapeutics approach. Consequently, tools used for evaluating these conventional, large-scale trials, are not directly transferable for assessing nonconventional, smaller-scale trials needed for evaluating precision oncology. Hence, a thorough vetting of precision oncology as another tool of the trade, must first begin by reassessing our expectations for this field, as well as current clinical trial designs and end point measurements. Importantly, we must recognize that most targeted therapy approaches are in their infancy, with only monotherapy approaches being assessed and combination therapies likely being necessary to fulfill the promise of precision oncology.

Concurrent ROS1 gene rearrangement and KRAS mutation in lung adenocarcinoma: A case report and literature review

Lung adenocarcinomas with gene rearrangement in the receptor tyrosine kinase ROS1 have emerged as a rare molecular subtype. Although these lung adenocarcinomas respond to ROS1tyrosine kinase inhibitors, many patients ultimately acquire resistance. ROS1gene rearrangement is generally mutually exclusive with other driver genomic alterations, such as those in EGFR, KRAS, or ALK, thus multiple genomic alterations are extremely rare. Herein, we report a case of a 42-year-old man diagnosed with lung adenocarcinoma positive for a SDC4-ROS1 fusion, who was treated with crizotinib followed by three cycles of chemotherapy. A biopsy acquired after disease progression revealed the original SDC4-ROS1 fusion along with a KRAS point mutation (p.G12D).We reviewed the related literature to determine the frequency of gene mutations in non-small cell lung cancer patients. A better understanding of the molecular biology of non-small cell lung cancer with multiple driver genomic aberrations will assist in determining optimal treatment.

Targeting Novel but Less Common Driver Mutations and Chromosomal Translocations in Advanced Non-Small Cell Lung Cancer

Discovery of the epidermal growth factor receptor gene mutation and the anaplastic lymphoma kinase chromosomal translocation in non-small cell lung cancer has prompted efforts around the world to identify many less common targetable oncogenic drivers. Such concerted efforts have been variably successful in both non-squamous and squamous cell carcinomas of the lung. Some of the targeted therapies for these oncogenic drivers have received regulatory approval for clinical use, while others have modest clinical benefit. In this mini-review, several of these targets will be reviewed.

Patterns of Metastatic Spread and Mechanisms of Resistance to Crizotinib in ROS1-Positive Non-Small-Cell Lung Cancer

PURPOSE

The ROS1 tyrosine kinase is activated through ROS1 gene rearrangements in 1-2% of non-small cell lung cancer (NSCLC), conferring sensitivity to treatment with the ALK/ROS1/MET inhibitor crizotinib. Currently, insights into patterns of metastatic spread and mechanisms of crizotinib resistance among ROS1-positive patients are limited.

PATIENTS AND METHODS

We reviewed clinical and radiographic imaging data of patients with ROS1- and ALK-positive NSCLC in order to compare patterns of metastatic spread at initial metastatic diagnosis. To determine molecular mechanisms of crizotinib resistance, we also analyzed repeat biopsies from a cohort of ROS1-positive patients progressing on crizotinib.

RESULTS

We identified 39 and 196 patients with advanced ROS1- and ALK-positive NSCLC, respectively. ROS1-positive patients had significantly lower rates of extrathoracic metastases (ROS1 59.0%, ALK 83.2%, P=0.002), including lower rates of brain metastases (ROS1 19.4%, ALK 39.1%; P = 0.033), at initial metastatic diagnosis. Despite similar overall survival between ALK- and ROS1-positive patients treated with crizotinib (median 3.0 versus 2.5 years, respectively; P=0.786), ROS1-positive patients also had a significantly lower cumulative incidence of brain metastases (34% vs. 73% at 5 years; P<0.0001). Additionally, we identified 16 patients who underwent a total of 17 repeat biopsies following progression on crizotinib. ROS1 resistance mutations were identified in 53% of specimens, including 9/14 (64%) non-brain metastasis specimens. ROS1 mutations included: G2032R (41%), D2033N (6%), and S1986F (6%).

CONCLUSIONS

Compared to ALK rearrangements, ROS1 rearrangements are associated with lower rates of extrathoracic metastases, including fewer brain metastases, at initial metastatic diagnosis. ROS1 resistance mutations, particularly G2032R, appear to be the predominant mechanism of resistance to crizotinib, underscoring the need to develop novel ROS1 inhibitors with activity against these resistant mutants.

Detection of ROS1 rearrangement in non-small cell lung cancer: current and future perspectives

ROS1 rearrangement characterizes a small subset (1%-2%) of non-small cell lung cancer and is associated with slight/never smoking patients and adenocarcinoma histology. Identification of ROS1 rearrangement is mandatory to permit targeted therapy with specific inhibitors, demonstrating a significantly better survival when compared with conventional chemotherapy. Detection of ROS1 rearrangement is based on in situ (immunohistochemistry, fluorescence in situ hybridization) and extractive non-in situ assays. While fluorescence in situ hybridization still represents the gold standard in clinical trials, this technique may fail to recognize rearrangements of ROS1 with some gene fusion partner. On the other hand, immunohistochemistry is the most cost-effective screening technique, but it seems to be characterized by low specificity. Extractive molecular assays are expensive and laborious methods, but they specifically recognize almost all ROS1 fusions using a limited amount of mRNA even from formalin-fixed, paraffin-embedded tumor tissues. This review is a discussion on the present and futuristic diagnostic scenario of ROS1 identification in lung cancer.

The role of endobronchial ultrasound elastography in the diagnosis of mediastinal and hilar lymph nodes

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been widely used for diagnosis and mediastinal lymph nodes staging in patients with suspicious lung cancer. Ultrasound elastography is a novel sonographical technique that can evaluate tissue compressibility. The aim of the present study was to investigate the diagnostic yield of elastography for differentiating malignant and benign mediastinal lymph nodes. Conventional EBUS B-mode features, including size, shape, border distinction, echogenicity, central hilar structure with central blood vessel and coagulation necrosis were also evaluated. The ultrasonic features were compared with the pathological results from EBUS-TBNA. 133 lymph nodes in 60 patients were assessed. Elastography displayed the highest area under the curve (AUC) (type 3 versus type 1: AUC, 0.825; 95% confidence interval [CI], 0.707-0.910) with an impressive sensitivity (100%) and an acceptable specificity (65%). The combined model covering the four positive criteria (elastography, heterogeneity, size, and shape) showed that the odds ratio for malignance is 9.44 with a 95% CI of 3.99 to 22.32 (p <0.0001). The combined model was superior to elastography alone (AUC, 0.851; sensitivity, 89.89%; specificity, 72.73%; p <0.0001). This prospective study showed that elastography is a feasible technique for classifying mediastinal lymph nodes, especially in combination with conventional EBUS imaging.