The Incidence of Brain Metastases in Stage IV ROS1-Rearranged Non-Small Cell Lung Cancer and Rate of Central Nervous System Progression on Crizotinib

Disease progression patterns and molecular resistance mechanisms to crizotinib of lung adenocarcinoma harboring ROS1 rearrangements

This retrospective study investigated the association between the pattern of disease progression and molecular mechanism of acquired resistance in a large cohort of 49 patients with ROS1-rearranged advanced non-small-cell lung cancer treated with first-line crizotinib. We found that treatment-emergent ROS1 point mutations were the major molecular mechanism of crizotinib resistance, particularly for patients who developed extracranial-only disease progression. Our findings highlight the importance of rebiopsy and gene testing for subsequent-line therapeutic management.

Real-World Management and Outcomes of Crizotinib-Treated ROS1-Rearranged NSCLC: A Retrospective Canadian Cohort

The use, safety and effectiveness of crizotinib as part of the management of ROS1-rearranged NSCLC patients in a real-world Canadian clinical cohort was the focus of this retrospective review. Twenty-one ROS1-rearranged patients with advanced/metastatic disease receiving crizotinib between 2014–2020 were identified; crizotinib demonstrated tolerability and effectiveness in this population where outcomes were similar to those described in other crizotinib-treated real-world cohorts, but lower than those of the PROFILE 1001 clinical trial population. Systemic anti-cancer therapy prior to crizotinib initiation occurred in half of the study cohort, with platin-pemetrexed and immune checkpoint inhibitors being most common. Platin-pemetrexed showed good effectiveness in this cohort, but despite high prevalence of upregulated PD-L1 expression, immune checkpoint inhibitors showed poor effectiveness in his cohort. Among all systemic therapies received, crizotinib showed the most effective disease control, although longer intervals between diagnosis and crizotinib initiation were more common among those showing a lack of clinical response to crizotinib, and patients with brain metastases at the time of crizotinib initiation also showed increased diagnosis to crizotinib initiation intervals and decreased clinical response to crizotinib. This study reveals crizotinib has clinical benefit, but timely identification of ROS1-rearrangements and initiation targeted therapies appears important to maximize outcome in this population.

Managing Central Nervous System Spread of Lung Cancer: The State of the Art

Brain metastases (BrM) are common in both non-small-cell lung cancer and small-cell lung cancer. Substantial progress in BrM management has occurred in the past decade related to advances in both radiation and medical oncology. Recent and ongoing radiation trials have focused on increasing the candidacy for focal therapy of BrM with stereotactic radiosurgery; reducing the toxicity and improving patient selection for whole brain radiotherapy; and, in small-cell lung cancer, evaluating brain magnetic resonance imaging surveillance without prophylactic cranial irradiation, hippocampal avoidance in prophylactic cranial irradiation and whole brain radiotherapy, and the role of upfront stereotactic radiosurgery for BrM. In medical oncology, the development of multiple tyrosine kinase inhibitors with encouraging CNS activity and emerging data on the CNS activity of immune checkpoint inhibitors in some patients have opened the door to novel systemic and multidisciplinary treatment strategies for the management of BrM. Future research will focus on more robust characterizations of the CNS activity of targeted therapy and immunotherapies, as well as optimal integration and patient selection for multidisciplinary strategies involving CNS-active drugs, radiation therapy, and CNS surveillance.

ROS-1 Fusions in Non-Small-Cell Lung Cancer: Evidence to Date

The ROS-1 gene plays a major role in the oncogenesis of numerous tumors. ROS-1 rearrangement is found in 0.9–2.6% of non-small-cell lung cancers (NSCLCs), mostly lung adenocarcinomas, with a significantly higher rate of women, non-smokers, and a tendency to a younger age. It has been demonstrated that ROS-1 is a true oncogenic driver, and tyrosine kinase inhibitors (TKIs) targeting ROS-1 can block tumor growth and provide clinical benefit for the patient. Since 2016, crizotinib has been the first-line reference therapy, with two-thirds of the patients’ tumors responding and progression-free survival lasting ~20 months. More recently developed are ROS-1-targeting TKIs that are active against resistance mechanisms appearing under crizotinib and have better brain penetration. This review summarizes current knowledge on ROS-1 rearrangement in NSCLCs, including the mechanisms responsible for ROS-1 oncogenicity, epidemiology of ROS-1-positive tumors, methods for detecting rearrangement, phenotypic, histological, and molecular characteristics, and their therapeutic management. Much of this work is devoted to resistance mechanisms and the development of promising new molecules.

Surgical resection of brain metastases prolongs overall survival in non-small-cell lung cancer

It remains unclear whether surgical resection of brain metastases prolongs overall survival in patients with non-small-cell lung cancer (NSCLC). A retrospective study was designed to evaluate the benefits of surgical resection for 296 patients with NSCLC and brain metastases. Patients were grouped into those who underwent craniotomy (brain surgery group) and those who did not (non-surgery group). Characteristics, survival, and EGFR mutation status were compared between the two groups. We found that the clinical characteristics were similar between the two groups. However, patients in the brain surgery group had metastases of larger diameters (3.67 cm vs. 2.06 cm, P<0.001) and a lower rate of extracranial metastasis (8.7% vs. 45.5%, P=0.001). Overall survival was significantly longer for those who underwent brain surgery (40.3 months vs. 8.4 months, P<0.001). The adjusted hazard ratio of craniotomy was 0.30 (95% confidence interval [CI], 0.15-0.62). The survival benefit of brain surgery was observed in both EGFR mutation-positive and EGFR mutation-negative sub-populations; the adjusted hazard ratios [aHRs] were 0.34 [95% CI, 0.11-1.00] and 0.26 [95% CI, 0.09-0.73] for EGFR mutation-positive and mutation-negative sub-populations, respectively. We concluded that for patients with NSCLC and brain metastases, surgical resection of brain metastases improved overall survival. This survival benefit was particularly evident in cases with large-sized metastases limited to the brain.

Management of brain metastases in lung cancer: evolving roles for radiation and systemic treatment in the era of targeted and immune therapies

Brain metastases are a common occurrence in both non-small cell and small cell lung cancer with the potential to affect quality of life and prognosis. Due to concerns about the accessibility of the central nervous system by systemic chemotherapy agents, the management of brain metastases has historically relied on local therapies including surgery and radiation. However, novel targeted and immune therapies that improve overall outcomes in lung cancer have demonstrated effective intracranial activity. As a result, the management of brain metastases in lung cancer has evolved, with both local and systemic therapies now playing an important role. Factors such as tumor histology (non-small versus small cell), oncogenic driver mutations, and symptom burden from intracranial disease impact treatment decisions. Here, we review the current management of brain metastases in lung cancer, highlighting the roles of stereotactic radiosurgery and novel systemic therapies as well as the ongoing questions that remain under investigation.

Deepening the Knowledge of ROS1 Rearrangements in Non-Small Cell Lung Cancer: Diagnosis, Treatment, Resistance and Concomitant Alterations

ROS proto-oncogene 1 (ROS1) rearrangements are reported in about 1-2% of non-squamous non-small-cell lung cancer (NSCLC). After efficacy of crizotinib was demonstrated, identification of ROS1 translocations in advanced disease became fundamental to give patients the chance of specific and effective treatment. Different methods are available for detection of rearrangements, and probably the real prevalence of ROS1 rearrangements is higher than that reported in literature, as our capacity to detect gene rearrangements is improving. In particular, with next generation sequencing (NGS) techniques, we are currently able to assess multiple genes simultaneously with increasing sensitivity. This is leading to overcome the "single oncogenic driver" paradigm, and in the very near future, the co-existence of multiple drivers will probably emerge more frequently and represent a therapeutic issue. Since recently, crizotinib has been the only available therapy, but today, many other tyrosine kinase inhibitors (TKI) are emerging and seem promising both in first and subsequent lines of treatment. Indeed, novel inhibitors are also able to overcome resistance mutations to crizotinib, hypothesizing a possible sequential strategy also in ROS1-rearranged disease. In this review, we will focus on ROS1 rearrangements, dealing with diagnostic aspects, new therapeutic options, resistance issues and the coexistence of ROS1 translocations with other molecular alterations.

Animal models of brain metastasis

Modeling of metastatic disease in animal models is a critical resource to study the complexity of this multi-step process in a relevant system. Available models of metastatic disease to the brain are still far from ideal but they allow to address specific aspects of the biology or mimic clinically relevant scenarios. We not only review experimental models and their potential improvements but also discuss specific answers that could be obtained from them on unsolved aspects of clinical management.

Current Landscape of Non-Small Cell Lung Cancer: Epidemiology, Histological Classification, Targeted Therapies, and Immunotherapy

Non-small cell lung cancer (NSCLC) is a subtype of the most frequently diagnosed cancer in the world. Its epidemiology depends not only on tobacco exposition but also air quality. While the global trends in NSCLC incidence have started to decline, we can observe region-dependent differences related to the education and the economic level of the patients. Due to an increasing understanding of NSCLC biology, new diagnostic and therapeutic strategies have been developed, such as the reorganization of histopathological classification or tumor genotyping. Precision medicine is focused on the recognition of a genetic mutation in lung cancer cells called "driver mutation" to provide a variety of specific inhibitors of improperly functioning proteins. A rapidly growing group of approved drugs for targeted therapy in NSCLC currently allows the following mutated proteins to be treated: EGFR family (ERBB-1, ERBB-2), ALK, ROS1, MET, RET, NTRK, and RAF. Nevertheless, one of the most frequent NSCLC molecular sub-types remains without successful treatment: the K-Ras protein. In this review, we discuss the current NSCLC landscape treatment focusing on targeted therapy and immunotherapy, including first- and second-line monotherapies, immune checkpoint inhibitors with chemotherapy treatment, and approved predictive biomarkers.

Post-chemotherapy and targeted therapy imaging of the chest in lung cancer

Non-small-cell lung cancer (NSCLC) is frequently diagnosed when it is not amenable to local therapies; therefore, systemic agents are the mainstay of therapy for many patients. In recent years, treatment of advanced NSCLC has evolved from a general approach primarily involving chemotherapy to a more personalised strategy in which biomarkers such as the presence of genomic tumour aberrations and the expression of immune proteins such as programmed death-ligand 1 (PD-L1), in combination with other elements of clinical information such as histology and clinical stage, guide management. For instance, pathways resulting in uncontrolled growth and proliferation of tumour cells due to epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements may be targeted by tyrosine kinase inhibitors (TKIs). In this article, we review the current state of medical oncology, imaging characteristics of mutations, pitfalls in response assessments and the imaging of complications.

Pathological Features of Brain Metastases

Metastases are the most common intracranial tumors in adults. Lung cancer, melanoma, renal cell carcinoma, and breast cancer are the most common primary tumors that metastasize to the brain. Improved detection of small metastases by MRI, and improved systemic therapy for primary tumors, resulted in increased incidence of brain metastasis. Advances in neuroanesthesia and neurosurgery have significantly improved the safety of surgical resection of brain metastases. Surgical approach and active management have become applicable for many patients. Subsequently, brain metastases diagnosis no longer equals palliative treatment. Moreover, the demand for diagnosing brain masses has increased with its associated challenges.

Safety but Limited Efficacy of Ensartinib in ROS1-Positive NSCLC: A Single-Arm, Multicenter Phase 2 Study

INTRODUCTION

Some ALK inhibitors with good inhibition of ROS1 in preclinical studies have been reported to be possibly beneficial in ROS1-positive NSCLC. In this work, we studied the efficacy and safety of ensartinib in the treatment of patients with ROS1-positive NSCLC.

METHODS

The exploratory study was a phase 2, single-arm, multicenter design (NCT03608007). Patients with ROS1-positive NSCLC with a previous chemotherapy line number of less than or equal to 1 who received ensartinib at the dose of 225 mg once daily were enrolled. The primary end point was objective response rate evaluated by an investigator per Response Evaluation Criteria in Solid Tumors version 1.1.

RESULTS

From June 2018 to July 2019, a total of 59 patients were enrolled at 23 centers in the People's Republic of China. At the time of data cutoff, the median follow-up was 19.8 months (range: 0.8-22.5). The median objective response rate was 27.0 % (95 % confidence interval [CI]: 13.8-44.1) with 10 partial responses. Median duration of response was 4.8 months (95 % CI: 1.8-10.8). The median progression-free survival was 4.6 months (95 % CI: 4.0-6.4). The median overall survival was not estimable (95 % CI: 14.9-not estimable). Of four patients with brain metastases, intracranial disease control was reported in three (75.0 %, 95 % CI: 19.4-99.4). The most common treatment-related adverse events (TRAEs) were rash and liver enzyme abnormalities, with good prognosis after adjustment for dosage and concomitant medication. Most of the TRAEs were of grades 1 to 2, and incidence of grade greater than or equal to 3 TRAEs was 25.4 %.

CONCLUSIONS

Ensartinib had a modest efficacy in patients with ROS1-positive NSCLC with an acceptable safety profile.

ROS1 Targeted Therapies: Current Status

PURPOSE OF REVIEW

Molecular drivers are increasingly identified as therapeutic targets for non-small cell lung cancer (NSCLC). This review focuses on the role of ROS1 inhibitors in treating relapsed/metastatic ROS-1 altered (ROS1+) NSCLC.

RECENT FINDINGS

Four FDA-approved drugs have significant activity against ROS1+ NSCLC: crizotinib, ciritinib, lorlatinib, and entrectinib. Each drug yields an overall response rates exceeding 60% with ciritinib, lorlatinib, and entrectinib possessing intracranial activity. The drugs have manageable toxicity profiles. ROS1 alterations are rare molecular drivers of NSCLC that can be effectively treated with a variety of ROS1-targetd drugs. New agents are being identified that may treat resistance mutations.

Leptomeningeal Metastases from Solid Tumors: Recent Advances in Diagnosis and Molecular Approaches

Leptomeningeal metastases (LM) from solid tumors represent an unmet need of increasing importance due to an early use of MRI for diagnosis and improvement of outcome of some molecular subgroups following targeted agents and immunotherapy. In this review, we first discussed factors limiting the efficacy of targeted agents in LM, such as the molecular divergence between primary tumors and CNS lesions and CNS barriers at the level of the normal brain, brain tumors and CSF. Further, we reviewed pathogenesis and experimental models and modalities, such as MRI (with RANO and ESO/ESMO criteria), CSF cytology and liquid biopsy, to improve diagnosis and monitoring following therapy. Efficacy and limitations of targeted therapies for LM from EGFR-mutant and ALK-rearranged NSCLC, HER2-positive breast cancer and BRAF-mutated melanomas are reported, including the use of intrathecal administration or modification of traditional cytotoxic compounds. The efficacy of checkpoint inhibitors in LM from non-druggable tumors, in particular triple-negative breast cancer, is discussed. Last, we focused on some recent techniques to improve drug delivery.

Different clinical features between patients with ROS1-positive and ALK-positive advanced non-small cell lung cancer

Objective

To compare the baseline clinical characteristics between patients with ROS1-positive and ALK-positive advanced non-small cell lung cancer (NSCLC), and the correlations of these subtypes with the distribution of metastases.

Methods

We compared the clinical characteristics and imaging features of patients with ROS1-positive and ALK-positive NSCLC using statistical methods.

Results

Data for 232 patients were analyzed. Compared with ALK-positive NSCLC, ROS1-positive NSCLC was more likely to occur in women (71% vs 53%), and primary lesions ≤3 cm were more common in patients with ROS1-positive compared with ALK-positive NSCLC (58% vs 37%). There was no significant difference in the distribution of metastases between the two groups. Subgroup analysis within the ROS1-positive group showed that, compared with primary lesions >3 cm, primary lesions ≤3 cm were more likely to present as peripheral tumors (72% vs 43%) and more likely to exhibit non-solid density (44% vs 4%).

Conclusions

Although ROS1-positive and ALK-positive NSCLCs show similar clinical features, the differences may help clinicians to identify patients requiring further genotyping at initial diagnosis.

Treatment of Rare Mutations in Patients with Lung Cancer

Lung cancer is a worldwide prevalent malignancy. This disease has a low survival rate due to diagnosis at a late stage challenged by the involvement of metastatic sites. Non-small-cell lung cancer (NSCLC) is presented in 85% of cases. The last decade has experienced substantial advancements in scientific research, leading to a novel targeted therapeutic approach. The newly developed pharmaceutical agents are aimed towards specific mutations, detected in individual patients inflicted by lung cancer. These drugs have longer and improved response rates compared to traditional chemotherapy. Recent studies were able to identify rare mutations found in pulmonary tumors. Among the gene alterations detected were mesenchymal epithelial transition factor (MET), human epidermal growth factor 2 (HER2), B-type Raf kinase (BRAF), c-ROS proto-oncogene (ROS1), rearranged during transfection (RET) and neurotrophic tyrosine kinase (NTRK). Ongoing clinical trials are gaining insight onto possible first and second lines of medical treatment options intended to enable progression-free survival to lung cancer patients.

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

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

Entrectinib: A Review in NTRK+ Solid Tumours and ROS1+ NSCLC

Entrectinib (Rozlytrek^®) is an orally active, CNS-penetrant, small-molecule, selective inhibitor of the tropomyosin receptor tyrosine kinases TRKA/B/C [encoded by the neurotrophic tyrosine receptor kinase (NTRK) genes NTRK1/2/3, respectively], the proto-oncogene tyrosine-protein kinase ROS1 (ROS1) and the anaplastic lymphoma kinase gene (ALK). It is approved for the treatment of adults and paediatric patients aged ≥ 12 years with NTRK fusion-positive (NTRK+) solid tumours and adults with ROS1 fusion-positive (ROS1+) non-small-cell lung cancer (NSCLC). In trials in adults, entrectinib induced clinically meaningful and durable systemic responses in tyrosine kinase inhibitor (TKI)-naïve patients with locally-advanced or metastatic NTRK+ solid tumours or ROS1+ NSCLC, irrespective of the presence or absence of CNS metastases at baseline. Moreover, entrectinib demonstrated substantial intracranial efficacy in patients with baseline CNS metastases. Entrectinb efficacy in paediatric patients was established on the basis of extrapolation of clinical trial data from adults with NTRK+ solid tumours and children and adolescents aged < 21 years with recurrent or refractory NTRK+ CNS/solid tumours. Entrectinib was generally well tolerated, with a manageable safety profile. Thus, entrectinib expands the range of treatment options for advanced NTRK+ solid tumours and ROS1+ NSCLC, and may be of particular value in patients with existing CNS metastases and those who are at risk of developing CNS metastases.

Meningeal "Lazarus Response" to Lorlatinib in a ROS1-Positive NSCLC Patient Progressing to Entrectinib

Background

ROS1 tyrosine kinase inhibitors (TKIs) have showed activity and efficacy in ROS1-rearranged non-small cell lung cancer (NSCLC). In the clinical practice, besides the utilization of crizotinib, less is known about the best treatment strategies involving additional, new-generation TKIs for the sequential treatment of ROS1-positive NSCLC patients.

Case Presentation

A patient suffering from a ROS1-rearranged lung adenocarcinoma, after receiving cisplatin-pemetrexed chemotherapy, was treated with entrectinib, a new-generation ALK/ROS1/NTRK inhibitor. After 16 months, central nervous system (CNS) metastases appeared, without extra-cerebral disease progression. Stereotactic brain radiotherapy was performed and entrectinib was maintained, due to the global systemic disease control. Approximately one month after radiotherapy, thoracic and meningeal progressions were detected, the latter highly symptomatic with neurocognitive disorders, visual hallucinations and worsening of psycho-motor impairment. A lumbar puncture was positive for tumor cells and for an EZR-ROS1 fusion. The administration of lorlatinib (a third-generation ALK/ROS1 inhibitor) prompted an extremely rapid improvement of clinical conditions, anticipating the positive results observed at radiologic evaluation that confirmed the disease response still ongoing after nine months since treatment start.

Discussion

With the expanding availability of targeted agents with differential activity on resistance mechanism and on CNS disease, choosing wisely the best treatment strategies is pivotal to assure the best clinical outcomes in oncogene-addicted NSCLC patients. Here we have reported lorlatinib reverted an almost fatal meningeal carcinomatosis developing during entrectinib in a ROS1-positive NSCLC patient.

Current treatment and future challenges in ROS1- and ALK-rearranged advanced non-small cell lung cancer

Non─small cell lung cancer (NSCLC) presents different druggable genetic abnormalities, including ROS1 and ALK rearrangements, which share relevant clinical features and therapeutic strategies. The homology between the tyrosine kinase domains of ROS1 and ALK defines unique subsets of patients highly sensitive to targeted tyrosine kinase inhibitors (TKIs). Genomic profiling in advanced NSCLC is standard, immunohistochemistry and fluorescence in situ hybridization being the main techniques used to detect genomic rearrangements. Personalized treatment with TKIs in ROS1- and ALK-positive NSCLC patients has dramatically improved patients' outcomes. Crizotinib has been the first-line standard of care treatment in ALK-rearranged NSCLC patients for a long time, while crizotinib still represents the best upfront therapeutic option in ROS1-positive NSCLC patients, followed by next-generation TKIs at the time of disease progression. However, the improved intracranial efficacy of next-generation TKIs has led to these drugs becoming first-line options, widening treatment opportunities for these patients. Since all patients will develop disease progression under TKI therapy, understanding the mechanisms of acquired resistance is crucial to define the optimal sequential therapeutic strategy. Despite the positive correlation between personalized treatment and patients' outcome, access to next-generation TKIs and genomic profiling at the time of disease progression are major challenges to achieving this goal. In this review, we present updated evidence on ROS1- and ALK-rearranged NSCLC regarding epidemiology and diagnostics, current therapies and the most suitable sequential treatment approaches, as well as mechanisms of acquired resistance and strategies to overcome them.

Updated Integrated Analysis of the Efficacy and Safety of Entrectinib in Locally Advanced or Metastatic ROS1 Fusion-Positive Non-Small-Cell Lung Cancer

Genetic rearrangements of the tyrosine receptor kinase ROS proto-oncogene 1 (ROS1) are oncogenic drivers in non-small-cell lung cancer (NSCLC). We report the results of an updated integrated analysis of three phase I or II clinical trials (ALKA-372-001, STARTRK-1, and STARTRK-2) of the ROS1 tyrosine kinase inhibitor, entrectinib, in ROS1 fusion–positive NSCLC.

2020 Innovation-Based Optimism for Lung Cancer Outcomes

Lung cancer is the leading cause of cancer death in both males and females in the U.S. and worldwide. Owing to advances in prevention, screening/early detection, and therapy, lung cancer mortality rates are decreasing and survival rates are increasing. These innovations are based on scientific discoveries in imaging, diagnostics, genomics, molecular therapy, and immunotherapy. Outcomes have improved in all histologies and stages. This review provides information on the clinical implications of these innovations that are practical for the practicing physicians, especially oncologists of all specialities who diagnose and treat patients with lung cancer. IMPLICATIONS FOR PRACTICE: Lung cancer survival rates have improved because of new prevention, screening, and therapy methods. This work provides a review of current standards for each of these areas, including targeted and immunotherapies. Treatment recommendations are provided for all stages of lung cancer.

Lorlatinib in pretreated ALK- or ROS1-positive lung cancer and impact of TP53 co-mutations: results from the German early access program

Introduction:

We report on the results of the German early access program (EAP) with the third-generation ALK- and ROS1-inhibitor lorlatinib.

Patients and Methods:

Patients with documented treatment failure of all approved ALK/ROS1-specific therapies or with resistance mutations not covered by approved inhibitors or leptomeningeal carcinomatosis were enrolled and analyzed.

Results:

In total, 52 patients were included [median age 57 years (range 32–81), 54% female, 62% never smokers, 98% adenocarcinoma]; 71% and 29% were ALK- and ROS1-positive, respectively. G1202R and G2032R resistance mutations prior to treatment with lorlatinib were observed in 10 of 26 evaluable patients (39%), 11 of 39 patients showed TP53 mutations (28%). Thirty-six patients (69%) had active brain metastases (BM) and nine (17%) leptomeningeal carcinomatosis when entering the EAP. Median number of prior specific TKIs was 3 (range 1–4). Median duration of treatment, progression-free survival (PFS), response rate and time to treatment failure were 10.4 months, 8.0 months, 54% and 13.0 months. Calculated 12-, 18- and 24-months survival rates were 65, 54 and 47%, overall survival since primary diagnosis (OS2) reached 79.6 months. TP53 mutations were associated with a substantially reduced PFS (3.7 versus 10.8 month, HR 3.3, p = 0.003) and were also identified as a strong prognostic biomarker (HR for OS2 3.0 p = 0.02). Neither prior treatments with second-generation TKIs nor BM had a significant influence on PFS and OS.

Conclusions:

Our data from real-life practice demonstrate the efficacy of lorlatinib in mostly heavily pretreated patients, providing a clinically meaningful option for patients with resistance mutations not covered by other targeted therapies and those with BM or leptomeningeal carcinomatosis.

Therapeutic Sequencing in ALK+ NSCLC

Anaplastic lymphoma kinase-rearranged non-small-cell lung cancer (ALK⁺ NSCLC) is a model disease for the use of targeted pharmaceuticals in thoracic oncology. Due to higher systemic and intracranial efficacy, the second-generation ALK tyrosine kinase inhibitors (TKI) alectinib and brigatinib have irrevocably displaced crizotinib as standard first-line treatment, based on the results of the ALEX and ALTA-1L trials. Besides, lorlatinib and brigatinib are the preferred second-line therapies for progression under second-generation TKI and crizotinib, respectively, based on the results of several phase II studies. Tissue or liquid rebiopsies at the time of disease progression, even though not mandated by the approval status of any ALK inhibitor, are gaining importance for individualization and optimization of patient management. Of particular interest are cases with off-target resistance, for example MET, HER2 or KRAS alterations, which require special therapeutic maneuvers, e.g., inclusion in early clinical trials or off-label administration of respectively targeted drugs. On the other hand, up to approximately half of the patients failing TKI, develop anatomically restricted progression, which can be initially tackled with local ablative measures without switch of systemic therapy. Among the overall biologically favorable ALK⁺ tumors, with a mean tumor mutational burden uniquely below 3 mutations per Mb and the longest survival among NSCLC currently, presence of the EML4-ALK fusion variant 3 and/or TP53 mutations identify high-risk cases with earlier treatment failure and a need for more aggressive surveillance and treatment strategies. The potential clinical utility of longitudinal ctDNA assays for earlier detection of disease progression and improved guidance of therapy in these patients is a currently a matter of intense investigation. Major pharmaceutical challenges for the field are the development of more potent, fourth-generation TKI and effective immuno-oncological interventions, especially ALK-directed cell therapies, which will be essential for further improving survival and achieving cure of ALK⁺ tumors.

Advances in Lung Cancer Driver Genes Associated With Brain Metastasis

Brain metastasis, one of the common complications of lung cancer, is an important cause of death in patients with advanced cancer, despite progress in treatment strategies. Lung cancers with positive driver genes have higher incidence and risk of brain metastases, suggesting that driver events associated with these genes might be biomarkers to detect and prevent disease progression. Common lung cancer driver genes mainly encode receptor tyrosine kinases (RTKs), which are important internal signal molecules that interact with external signals. RTKs and their downstream signal pathways are crucial for tumor cell survival, invasion, and colonization in the brain. In addition, new tumor driver genes, which also encode important molecules closely related to the RTK signaling pathway, have been found to be closely related to the brain metastases of lung cancer. In this article, we reviewed the relationship between lung cancer driver genes and brain metastasis, and summarized the mechanism of driver gene-associated pathways in brain metastasis. By understanding the molecular characteristics during brain metastasis, we can better stratify lung cancer patients and alert those at high risk of brain metastasis, which helps to promote individual therapy for lung cancer.

How selecting best upfront therapy for metastatic disease?-Focus on ROS1-rearranged disease

ROS proto-oncogene 1 (ROS1) rearrangements defines a distinct group of non-small cell lung cancer (NSCLC), mainly represented by younger subjects, never smokers and with adenocarcinoma histology. Fusions involving ROS1 gene are present in 1-2% of lung adenocarcinomas and other solid tumors. Identification of patients harboring ROS1 rearrangements is a critical issue and current guidelines recommend screening of all advanced non-squamous NSCLC and certain squamous lung cancer patients. A number of trials have supported crizotinib as the best option for NSCLC patients with ROS1 translocations, irrespective of line of therapy. Unfortunately, the majority of patients become insensitive to crizotinib, due to the occurrence of secondary ROS1 mutations or failure within the central nervous system (CNS). Several highly potent and CNS penetrant ROS1 inhibitors have been developed and recent data highlight their potential role in the front-line treatment of this disease. Among them entrectinib, also known as RXDX-101, is a potent second-generation, multitarget oral inhibitor against the neurotrophin receptors TRKA, TRKB, TRKC ALK, and ROS1 with the ability to cross the blood-brain barrier. In the next few years, results of ongoing trials with novel ROS1 inhibitors and dedicated translational research studies might help to define the optimal sequence of treatment for ROS1-positive NSCLC patients.

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.

Molecular and clinicopathological characteristics of ROS1-rearranged non-small-cell lung cancers identified by next-generation sequencing

ROS1 gene rearrangements have been reported in diverse cancer types including non-small-cell lung cancer (NSCLC), and with a notably higher prevalence in lung adenocarcinoma. The tyrosine kinase inhibitors, crizotinib, lorlatinib, and entrectinib, have demonstrated favorable efficacy in treating ROS1-rearranged NSCLCs. Herein, we retrospectively reviewed 17 158 NSCLC patients whose tumor specimen and/or circulating cell-free DNA underwent comprehensive genomic profiling. A total of 258 unique patients were identified with ROS1 rearrangements, representing an overall prevalence of approximately 1.5% of ROS1 fusions in newly diagnosed and relapsed NSCLC patients. CD74 (38%) was the most common fusion partner of ROS1, followed by EZR (13%), SDC4 (13%), SLC34A2 (10%), and other recurrent fusion partners with lower frequencies, including TPM3, MYH9, and CCDC6. Variant breakpoints occurred in ROS1 introns 33 (37%), 31 (25%), 32 (17%), and 34 (11%) with no obvious hotspots. CD74 (63%) and EZR (50%) were more frequently fused to ROS1 intron 33 than other introns, while ROS1 intron 31 was most frequently fused with SDC4 (79%) and SLC34A2 (81%). Crizotinib progression-free survival (PFS) was not significantly different between fusion variants involving breakpoints in different ROS1 introns, nor was there a significant difference in PFS between CD74-ROS1 and non-CD74-ROS1 groups of patients. Furthermore, TP53 was most frequently mutated in patients who progressed on crizotinib, and TP53 mutations were significantly associated with shorter crizotinib PFS. ROS1 mutations, including G2032R, were observed in approximately 33% of post-crizotinib samples. Collectively, we report the prevalence of ROS1 fusions in a large-scale NSCLC population and the efficacy of crizotinib in treating patients with ROS1-rearranged NSCLC.

Tyrosine Kinase Inhibitors as a Treatment of Symptomatic CNS Metastases in Oncogene-Driven NSCLC

Central nervous system (CNS) metastases occur frequently in oncogene-driven non-small cell lung cancer (NSCLC). Standard treatment approaches can potentially delay systemic treatment (surgical intervention) or result in neurocognitive impairment (radiotherapy). Recently, next-generation tyrosine kinase inhibitors (TKIs) have demonstrated remarkable intracranial activity. However, most clinical trials did not enroll patients suffering neurological symptoms. Our study aimed to assess the CNS activity of targeted therapies in this patient population. We present a case series of nine NSCLC patients with either EGFR mutation or ALK rearrangement and symptomatic CNS metastases that were treated with TKIs. Clinicopathological characteristics, treatment, and outcomes were analyzed. Most patients presented with symptomatic CNS metastases at time of metastatic disease presentation (6/9). Additionally, the majority of patients had leptomeningeal disease (6/9) and multiple parenchymal metastases. Patients presented with a variety of CNS symptoms with the most common being nausea, vomiting, headache, and confusion. Most patients (6/9) responded rapidly both clinically and radiographically to the targeted treatment, with a marked correlation between systemic and intracranial radiographic response. In conclusion, upfront use of next-generation TKIs in patients with oncogene-driven NSCLC with symptomatic CNS metastases is associated with reasonable intracranial activity and represents a valuable treatment option.

Management of Brain Metastases in Non-Small-Cell Lung Cancer

Lung cancer is the leading cause of cancer-related death in the United States. Approximately 20% of these patients present with brain metastases (BMs). Surgical resection, stereotactic radiosurgery, and whole-brain radiation therapy have historically been the primary treatment modalities for patients with non-small-cell lung cancer (NSCLC) and BMs. The treatments for BMs have become complex with the discovery of targetable molecular drivers and the development of an astonishing number of tyrosine kinase inhibitors. Many of these tyrosine kinase inhibitors have robust and durable efficacy against CNS metastases. In many circumstances, these drugs can defer local therapy and even reduce the risk of CNS progression. More recently, immune checkpoint inhibitors have changed the treatment landscape for many patients with NSCLC; however, the role of immunotherapy in patients with BMs is the subject of ongoing investigations. This article will review the current data and our approach to patients with NSCLC and BMs.

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.

Evaluating entrectinib as a treatment option for non-small cell lung cancer

INTRODUCTION

Entrectinib, an oral pan-TRK, ALK, and ROS1 inhibitor is approved as a first-line treatment for NTRK-rearranged solid tumors and ROS1-rearranged non-small cell lung cancer (NSCLC). It has demonstrated clinical efficacy for patients harboring the relevant gene rearrangement in both systemic and intracranial disease, regardless of the tumor type.

AREAS COVERED

In this review, the authors analyzed data from preclinical and clinical studies, the characteristics of entrectinib compared to those of other relevant inhibitors (currently available and/or under investigation), and the emerging resistance mechanisms. The authors then provide the readers with their future perspectives.

EXPERT OPINION

Entrectinib has been well studied across many tumor types, including NSCLC with ALK, ROS1, and NTRK rearrangements. The drug has demonstrated favorable properties with oral administration, prolonged response duration, high intracranial efficacy, and a favorable toxicity profile. However, with acquisition of resistance and the development of newer generation TKIs, the optimal place for entrectinib in the landscape of targeted therapies for NSCLC warrants further validation.

Role of imaging biomarkers in mutation-driven non-small cell lung cancer

Lung cancer remains the leading cause of cancer-related deaths worldwide. The treatment of non-small cell lung cancer (NSCLC), which accounts for a vast majority of lung cancers, has shifted to personalized, targeted therapy following discoveries of several targetable oncogenic mutations. Targeting of specific mutations has improved outcomes in many patients. This success has led to several target-specific agents replacing chemotherapy as first-line treatment in certain mutated NSCLC. Several researchers have reported that there may be imaging biomarkers that may be predictive of the presence of these mutations. These features, when present, have the potential in triaging patients into the most appropriate diagnostic and treatment algorithms. Distinct imaging features and patterns of metastases that have been associated with NSCLC with various targetable oncogenic mutations are presented in this review.

Matching-adjusted indirect comparison: entrectinib versus crizotinib in ROS1 fusion-positive non-small cell lung cancer

Aim: To perform indirect treatment comparisons of entrectinib versus alternative ROS1 fusion-positive non-small cell lung cancer treatments. Methods: Relevant studies with crizotinib and chemotherapy as comparators of interest identified by systematic literature review were selected for matching-adjusted indirect comparison by feasibility assessment. Matching was based on known prognostic/predictive factors and scenario analyses were used for unreported confounders in comparator trials. Results: Entrectinib yielded significantly better responses versus crizotinib in all scenarios (odds ratio [OR]: 2.43-2.74). Overall survival (hazard ratio: 0.47-0.61) and adverse event-related discontinuation (OR: 0.79-0.90) favored entrectinib. Progression-free survival was similar across treatments, except in one scenario. Conclusion: These results suggested improved outcomes with entrectinib versus crizotinib/chemotherapy and may help to make better informed treatment decisions.

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.

Repotrectinib Exhibits Potent Antitumor Activity in Treatment-Naïve and Solvent-Front-Mutant ROS1-Rearranged Non-Small Cell Lung Cancer

PURPOSE

Although first-line crizotinib treatment leads to clinical benefit in ROS1⁺ lung cancer, high prevalence of crizotinib-resistant ROS1-G2032R (ROS1^G2032R) mutation and progression in the central nervous system (CNS) represents a therapeutic challenge. Here, we investigated the antitumor activity of repotrectinib, a novel next-generation ROS1/TRK/ALK-tyrosine kinase inhibitor (TKI) in ROS1⁺ patient-derived preclinical models.

EXPERIMENTAL DESIGN

Antitumor activity of repotrectinib was evaluated in ROS1⁺ patient-derived preclinical models including treatment-naïve and ROS1^G2032R models and was further demonstrated in patients enrolled in an on-going phase I/II clinical trial (NCT03093116). Intracranial antitumor activity of repotrectinib was evaluated in a brain-metastasis mouse model.

RESULTS

Repotrectinib potently inhibited in vitro and in vivo tumor growth and ROS1 downstream signal in treatment-naïve YU1078 compared with clinically available crizotinib, ceritinib, and entrectinib. Despite comparable tumor regression between repotrectinib and lorlatinib in YU1078-derived xenograft model, repotrectinib markedly delayed the onset of tumor recurrence following drug withdrawal. Moreover, repotrectinib induced profound antitumor activity in the CNS with efficient blood-brain barrier penetrating properties. Notably, repotrectinib showed selective and potent in vitro and in vivo activity against ROS1^G2032R. These findings were supported by systemic and intracranial activity of repotrectinib observed in patients enrolled in the on-going clinical trial.

CONCLUSIONS

Repotrectinib is a novel next-generation ROS1-TKI with improved potency and selectivity against treatment-naïve and ROS1^G2032R with efficient CNS penetration. Our findings suggest that repotrectinib can be effective both as first-line and after progression to prior ROS1-TKI.

Risk of brain metastases in T1-3N0 NSCLC: a population-based analysis

Aim:

Several consensus guidelines recommend against routine brain imaging at diagnosis of T1-3N0 non-small cell lung cancer (NSCLC).

Methods:

From the Surveillance, Epidemiology and End Results registry, patients with pathologically confirmed T1-3N0 NSCLC were identified. Risks of brain metastases at time of initial diagnosis were analyzed.

Results:

Patients selected to not undergo primary NSCLC resection had approximately tenfold greater incidence of brain metastases versus those who did. Younger age, adenocarcinoma histology, higher tumor stage and higher histologic grade were all significantly (p < 0.0001) associated with greater likelihood of presenting with brain metastases.

Conclusion:

Given the morbidity and mortality of brain metastases, routine brain screening after NSCLC diagnosis (particularly adenocarcinoma) may be justifiable, though more refined cost-benefit analyses are warranted.

Brain Metastases in Lung Cancers with Emerging Targetable Fusion Drivers

The management of non-small cell lung cancer (NSCLC) has transformed with the discovery of therapeutically tractable oncogenic drivers. In addition to activating driver mutations, gene fusions or rearrangements form a unique sub-class, with anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) targeted agents approved as the standard of care in the first-line setting for advanced disease. There are a number of emerging fusion drivers, however, including neurotrophin kinase (NTRK), rearrangement during transfection (RET), and neuregulin 1 (NRG1) for which there are evolving high-impact systemic treatment options. Brain metastases are highly prevalent in NSCLC patients, with molecularly selected populations such as epidermal growth factor receptor (EGFR) mutant and ALK-rearranged tumors particularly brain tropic. Accordingly, there exists a substantial body of research pertaining to the understanding of brain metastases in such populations. Little is known, however, on the molecular mechanisms of brain metastases in those with other targetable fusion drivers in NSCLC. This review encompasses key areas including the biological underpinnings of brain metastases in fusion-driven lung cancers, the intracranial efficacy of novel systemic therapies, and future directions required to optimize the control and prevention of brain metastases.

18F-FDG PET/CT Evaluation of Crizotinib and Lorlatinib Therapy in Metastatic ROS-1-Positive Non-Small Cell Lung Cancer

ROS-1-positive non-small cell lung cancers (NSCLCs) are rare (approximately 1% of all NSCLCs) and require a first-line treatment by crizotinib. Crizotinib resistance is frequent within the first 12 months of treatment. Lorlatinib is a novel tyrosine kinase inhibitor of ROS-1 recently indicated for metastatic or locally advanced crizotinib-resistant NSCLC. We report the use of lorlatinib as second-line with a complete tumoral response after only 3 months of treatment. This case shows the major role of F-FDG PET/CT in treatment evaluation and monitoring targeted therapy in metastatic NSCLC.

Targeting non-small cell lung cancer: driver mutation beyond epidermal growth factor mutation and anaplastic lymphoma kinase fusion

The identification of driver mutations in epidermal growth factor receptor, anaplastic lymphoma kinase, the BRAF and ROS1 genes and subsequent successful clinical development of kinase inhibitors not only significantly improves clinical outcomes but also facilitates the discovery of other novel driver mutations in non-small cell lung cancer. These driver mutations can be categorized into mutations in or near the kinase domain, gene amplification or fusion. In this review, BRAF V600E, EGFR and HER-2 exon 20 mutation, FGFR1-4, K-RAS, MET, neuregulin-1, NRTK, PI3K/AKT/mTOR, RET and ROS1 gene aberration and their therapeutics will be discussed.

Clinicopathologic and Imaging Features of Non-Small-Cell Lung Cancer with MET Exon 14 Skipping Mutations

MET exon 14 (METex14) skipping mutations are an emerging potentially targetable oncogenic driver mutation in non-small-cell lung cancer (NSCLC). The imaging features and patterns of metastasis of NSCLC with primary METex14 skipping mutations (METex14-mutated NSCLC) are not well described. Our goal was to determine the clinicopathologic and imaging features that may suggest the presence of METex14 skipping mutations in NSCLC. This IRB-approved retrospective study included NSCLC patients with primary METex14 skipping mutations and pre-treatment imaging data between January 2013 and December 2018. The clinicopathologic characteristics were extracted from electronic medical records. The imaging features of the primary tumor and metastases were analyzed by two thoracic radiologists. In total, 84 patients with METex14-mutated NSCLC (mean age = 71.4 ± 10 years; F = 52, 61.9%, M = 32, 38.1%; smokers = 47, 56.0%, nonsmokers = 37, 44.0%) were included in the study. Most tumors were adenocarcinoma (72; 85.7%) and presented as masses (53/84; 63.1%) that were peripheral in location (62/84; 73.8%). More than one in five cancers were multifocal (19/84; 22.6%). Most patients with metastatic disease had only extrathoracic metastases (23/34; 67.6%). Fewer patients had both extrathoracic and intrathoracic metastases (10/34; 29.4%), and one patient had only intrathoracic metastases (1/34, 2.9%). The most common metastatic sites were the bones (14/34; 41.2%), the brain (7/34; 20.6%), and the adrenal glands (7/34; 20.6%). Four of the 34 patients (11.8%) had metastases only at a single site. METex14-mutated NSCLC has distinct clinicopathologic and radiologic features.