EGFR mutated non-small cell lung cancer patients: more prone to development of bone and brain metastases?

A Review of Recent Advances in the Molecular Mechanisms Underlying Brain Metastasis in Lung Cancer

Brain metastasis from lung cancer is a prevalent mode of treatment failure associated with a poor prognosis. The incidence of brain metastasis has recently shown a dramatic increase. The early detection and risk stratification of lung cancer-related brain metastasis would be highly advantageous for patients. However, our current knowledge and comprehension of the underlying mechanisms driving brain metastasis in lung cancer pose significant challenges. This review summarizes the mechanisms underlying brain metastasis, focusing on the intricate interplay between lung cancer-derived tumor cells and the unique characteristics of the brain, recent advancements in the identification of driver genes, concomitant genes, epigenetic features, including miRNAs and long noncoding RNAs, as well as the molecular characterization of brain metastasis originating from other organs, which may further enhance risk stratification and facilitate precise treatment strategies.

Prognostic implications of combining EGFR-TKIs and radiotherapy in Stage IV lung adenocarcinoma with 19-Del or 21-L858R mutations: A real-world study

OBJECTIVE

To elucidate the potential benefits of combining radiotherapy and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for individuals with Stage IV lung adenocarcinoma (LUAD) harboring either exon 19 deletion (19-Del) or exon 21 L858R mutation (21-L858R).

METHODS

In this real-world retrospective study, 177 individuals with Stage IV LUAD who underwent EGFR-TKIs and radiotherapy at Shandong Cancer Hospital from June 2012 to August 2017 were included. The main focus of this real-world study was overall survival (OS).

RESULTS

The clinical characteristics of patients with Stage IV LUAD harboring 19-Del were similar to those harboring 21-L858R (p > 0.05). Overall, the patients had a median OS (mOS) of 32.0 months (95% confidence interval [CI]: 28.6-35.5). Subsequently, multivariate analysis indicated that both EGFR mutations and thoracic radiotherapy were independent predictors of OS (p = 0.001 and 0.013). Furthermore, subgroup analysis highlighted a longer OS for the 19-Del group compared to the 21-L858R group, especially when EGFR-TKIs were combined with bone metastasis or thoracic radiotherapy (mOS: 34.7 vs. 25.1 months and 51.0 vs. 29.6 months; p = 0.0056 and 0.0013, respectively). However, no significant differences were found in OS when considering patients who underwent brain metastasis radiotherapy (mOS: 34.7 vs. 25.1 months; p = 0.088).

CONCLUSIONS

Patients with Stage IV LUAD harboring 19-Del experience a notably prolonged OS following combined therapy with EGFR-TKIs and radiotherapy, while this OS benefit is observed despite the absence of substantial differences in the clinical characteristics between the 19-Del and 21-L858R groups.

Prognostic and predictive role of liquid biopsy in lung cancer patients

Introduction

Lung cancer (LC) is a leading cause of cancer-related mortality worldwide. Approximately 80% of LC cases are of the non-small cell lung cancer (NSCLC) type, and approximately two-thirds of these cases are diagnosed in advanced stages. Only systemic treatment methods can be applied to patients in the advanced stages when there is no chance of surgical treatment. Identification of mutations that cause LC is of vital importance in determining appropriate treatment methods. New noninvasive methods are needed to repeat and monitor these molecular analyses. In this regard, liquid biopsy (LB) is the most promising method. This study aimed to determine the effectiveness of LB in detecting EGFR executive gene mutations that cause LC.

Methods

One hundred forty-six patients in stages IIIB and IV diagnosed with non-squamous cell non-small cell LC were included. Liquid biopsy was performed as a routine procedure in cases where no mutation was detected in solid tissue or in cases with progression after targeted therapy. Liquid biopsy samples were also obtained for the second time from 10 patients who showed progression under the applied treatment. Mutation analyses were performed using the Cobas® EGFR Test, a real-time PCR test designed to detect mutations in exons 18, 20, and 21 and changes in exon 19 of the EGFR gene.

Results

Mutation positivity in paraffin blocks was 21.9%, whereas it was 32.2% in LB. Solids and LB were compatible in 16 patients. Additionally, while no mutation was found in solid tissue in the evaluation of 27 cases, it was detected in LB. It has been observed that new mutations can be detected not only at the time of diagnosis, but also in LB samples taken during the follow-up period, leading to the determination of targeted therapy.

Discussion

The results showed that "liquid biopsy" is a successful and alternative non-invasive method for detecting cancer-causing executive mutations, given the limitations of conventional biopsies.

The Role of Exosome-Derived microRNA on Lung Cancer Metastasis Progression

The high mortality from lung cancer is mainly attributed to the presence of metastases at the time of diagnosis. Despite being the leading cause of lung cancer death, the underlying molecular mechanisms driving metastasis progression are still not fully understood. Recent studies suggest that tumor cell exosomes play a significant role in tumor progression through intercellular communication between tumor cells, the microenvironment, and distant organs. Furthermore, evidence shows that exosomes release biologically active components to distant sites and organs, which direct metastasis by preparing metastatic pre-niche and stimulating tumorigenesis. As a result, identifying the active components of exosome cargo has become a critical area of research in recent years. Among these components are microRNAs, which are associated with tumor progression and metastasis in lung cancer. Although research into exosome-derived microRNA (exosomal miRNAs) is still in its early stages, it holds promise as a potential target for lung cancer therapy. Understanding how exosomal microRNAs promote metastasis will provide evidence for developing new targeted treatments. This review summarizes current research on exosomal miRNAs' role in metastasis progression mechanisms, focusing on lung cancer.

Cytotoxic activity of essential oil from Leaves of Myrcia splendens against A549 Lung Cancer cells

BACKGROUND

Plants of the Myrcia genus have been widely used in folk medicine to treat various diseases, including cancer. Myrcia splendens species has a diverse chemical constitution, but the biological activities of its essential oil have not been well investigated. In this study to out the chemistry characterization of essential oil (EO) from the leaves of the species M. splendens from Brazil and evaluate cytotoxic effect in A549 lung cancer cells.

METHODS

M. splendens EO was obtained by hydrodistillation and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). EO was isolated and evaluated for cellular viability in tumor cell lines by MTT assay. The evaluation of the formation of clones and the migratory capacity of the A549 cells treated with EO was done by the clonogenic assay and the wound healing assay. Morphological changes were observed in A549 cells by fluorescence using Phalloidin/FITC and DAPI.

RESULTS

22 compounds were identified in the chemical analysis of EO, corresponding to 88% of the sample. Major compounds were the sesquiterpenic hydrocarbons bicyclogermacrene (15.4%), germacrene D (8.9%) and E-caryophyllene (10.1%). The biological analysis of the EO showed high cytotoxic activity with an IC₅₀ below 20 µg/ml in the THP-1, A549 and B16-F10 tumor cells. The treatment with EO reduced colony formation and inhibited the migratory capacity of A549 cells. Furthermore, apoptotic morphological changes in the nucleus and cytoplasm of A549 cells was observed after of treatment with EO.

CONCLUSION

The findings of this study suggest that the M. splendens EO has cytotoxic compounds for the A549 lung cancer cells. Treatment with the EO decreased the colony formation and reduced the ability of lung cancer cells to migrate. Future studies may be used to isolate compounds from the EO for the study of lung cancer.

Influence of germline variations in drug transporters ABCB1 and ABCG2 on intracerebral osimertinib efficacy in patients with non-small cell lung cancer

Background

Central nervous system (CNS) metastases are present in approximately 40% of patients with metastatic epidermal growth factor receptor-mutated (EGFRm+) non-small cell lung cancer (NSCLC). The EGFR-tyrosine kinase inhibitor osimertinib is a substrate of transporters ABCB1 and ABCG2 and metabolized by CYP3A4. We investigated relationships between single nucleotide polymorphisms (SNPs) ABCB1 3435C>T, ABCG2 421C>A and 34G>A, and CYP3A4∗22 and CNS treatment efficacy of osimertinib in EGFRm+ NSCLC patients.

Methods

Patients who started treatment with osimertinib for EGFRm+ NSCLC between November 2014 and June 2021 were included in this retrospective observational multicentre cohort study. For patients with baseline CNS metastases, the primary endpoint was CNS progression-free survival (CNS-PFS; time from osimertinib start until CNS disease progression or death). For patients with no or unknown baseline CNS metastases, the primary endpoint was CNS disease-free survival (CNS-DFS; time from osimertinib start until occurrence of new CNS metastases). Relationships between SNPs and baseline characteristics with CNS-PFS and CNS-DFS were studied with competing-risks survival analysis. Secondary endpoints were relationships between SNPs and PFS, overall survival, severe toxicity, and osimertinib pharmacokinetics.

Findings

From 572 included patients, 201 had baseline CNS metastases. No SNP was associated with CNS-PFS. Genotype ABCG2 34GA/AA and/or ABCB1 3435CC --present in 35% of patients-- was significantly associated with decreased CNS-DFS (hazard ratio 0.28; 95% CI 0.11-0.73; p = 0.009) in the multivariate analysis. This remained significant after applying a Bonferroni correction and internal validation through bootstrapping. ABCG2 421CA/AA was related to more severe toxicity (27.0% versus 16.5%; p = 0.010).

Interpretation

ABCG2 34G>A and ABCB1 3435C>T are predictors for developing new CNS metastases during osimertinib treatment, probably because of diminished drug levels in the CNS. ABCG2 421C>A was significantly related with the incidence of severe toxicity. Pre-emptive genotyping for these SNPs could individualize osimertinib therapy. Addition of ABCG2 inhibitors for patients without ABCG2 34G>A should be studied further, to prevent new CNS metastases during osimertinib treatment.

Funding

No funding was received for this trial.

Incidence of Bone Metastases and Skeletal-Related Events in Patients With EGFR-Mutated NSCLC Treated With Osimertinib

Introduction

Bone metastases are frequent in patients with EGFR-mutated (EGFR+) NSCLC. Skeletal-related events (SREs) are common in these patients; however, no data on SRE in osimertinib-treated patients are reported. We investigated the development of bone metastases and SREs in patients with EGFR+ NSCLC treated with osimertinib.

Methods

This is a retrospective multicenter cohort study that included patients with metastatic EGFR+ NSCLC who were treated with osimertinib between February 2016 and September 2021. Demographics, bone metastases-related outcomes, SREs, treatment efficacy, and overall survival (OS) were collected.

Results

In total, 250 patients treated with osimertinib (43% first line) were included. Of the patients, 51% had bone metastases at initiation of osimertinib. Furthermore, 16% of the patients with bone metastases used bone-targeted agents. Median follow-up from initiation of osimertinib was 23.4 months (95% confidence interval [CI]: 19.9-26.9 mo). During osimertinib treatment, 10% developed new bone metastases or bone progression. Of the patients with bone metastases, 39% had more than or equal to one SREs: 28% developed first SRE before osimertinib treatment, 1% after, and 11% during. Median OS post-bone metastasis was 30.8 months (95% CI: 21.9-39.7). Median OS after first SRE was 31.1 months (95% CI: 15.8-46.5).

Conclusions

Bone metastases and SREs are frequent before and during treatment with osimertinib in EGFR+ NSCLC. Because of these findings and the long OS post-bone metastases, we advocate prescription of bone-targeted agents in these patients and recommend adding bone-specific end points in clinical trials.

Fructose utilization enhanced by GLUT5 promotes lung cancer cell migration via activating glycolysis/AKT pathway

PURPOSE

Lung cancer is the leading cause of cancer-related mortalities worldwide, and metastasis contributes to a large number of deaths in lung carcinoma patients. New approaches for anti-metastatic treatment are urgently needed. Enhanced fructose metabolism mediated by GLUT5 directly contributes to cancer metastasis. However, the underlying mechanism remains to be elucidated, which we aimed to explore in this study.

METHODS

The overexpression and knockdown of SLC2A5, the encoding gene of GLUT5, were established by retrovirus system and CRISPR/Cas9 technology, respectively. Cell migration was conducted by trans-well assay. Western blotting assay was carried out to detect the expression of GLUT5, total AKT, phosphorylated AKT (pAKT-S473 and pAKT-T308) and LDHA. Lactate production was measured by colorimetric assay. Experimental lung metastasis model by tail vein injection was constructed to evaluate the metastatic potential of GLUT5 in vivo.

RESULTS

Overexpression of SLC2A5 promoted migration of lung cancer cells both in vitro and in vivo, and shortened the overall survival of mice. While, SLC2A5 deletion blocked the migration of lung cancer cells. GLUT5-mediated fructose utilization upregulated phosphorylated AKT, which was responsible for enhanced migration of lung cancer cells. Additionally, GLUT5-mediated fructose utilization boosted glycolysis with overproduction of lactate, resulting in upregulation of phosphorylated AKT. Moreover, lung cancer cell migration and AKT activation were restrained by glycolysis inhibitor 2-deoxy-D-glucose (2-DG) or GLUT5-specific inhibitor 2,5-anhydro-D-mannitol (2,5-AM).

CONCLUSION

Our study unveils glycolysis/lactate/AKT pathway is responsible for lung cancer cell migration induced by GLUT5-mediated fructose metabolism, providing a potential therapeutic avenue for lung cancer metastasis.

The Efficacy and Safety of Afatinib in Non-Small Cell Lung Cancer Patients with Brain Metastasis: A Meta-Analysis

Aim. The aim of this study is to evaluate the efficacy and safety of afatinib in the treatment of non-small cell lung cancer (NSCLC) patients with brain metastasis based on meta-analysis. Methods. Related literatures were searched in the following databases: EMbase, PubMed, China Knowledge Network (CNKI), Wanfang, Weipu, Google Scholar, the China Biomedical Literature Service System, and other databases. Clinical trials and observational studies that met the requirements were selected for meta-analysis using Revman 5.3. The hazard ratio (HR) was used as an indicator of the impact of afatinib. Results. A total of 142 related literatures were acquired, but after screening, five literatures were selected for data extraction. The following indices were compared: the progression-free survival (PFS), overall survival (OS), and common adverse reactions (ARs) of grade 3 and above. A total of 448 patients with brain metastases were included and were divided into two groups: the control group (no afatinib treatment, with chemotherapy alone and the first-generation EGFR-TKIs) and the afatinib group. The results showed that afatinib could improve PFS (HR: 0.58, 95% CI: 0.39–0.85, $P<0.05$ ) and ORR (OR = 2.86, 95% CI: 1.45–2.57, $P<0.05$ ), but had no benefit on OS (HR: 1.13, 95% CI: 0.15–8.75, $P>0.05$ ) and DCR (OR = 2.87, 95% CI: 0.97–8.48, $P>0.05$ ). For the safety of afatinib, the incidence of grade-3-and-above ARs was low (HR: 0.01, 95% CI: 0.00–0.02, $P<0.05$ ). Conclusion. Afatinib improves the survival of NSCLC patients with brain metastases and shows satisfactory safety.

Association of RANKL and EGFR gene expression with bone metastases in patients with metastatic non-small cell lung cancer

Introduction

Bone metastases are frequent in patients with non-small cell lung cancer (NSCLC). The receptor activator of Nuclear Factor κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) pathway is important in bone metastases development. Furthermore, epidermal growth factor receptor (EGFR) signaling promotes osteoclast formation and stimulation. The understanding of the biological mechanism of bone metastases development might have implications for treatment strategies. Therefore, we studied whether there is an association between EGFR, RANKL, RANK and OPG gene expression in the tumor and presence of bone metastases in patients with NSCLC.

Methods

From an updated multicenter study, including patients with EGFR mutated (EGFR+), Kirsten rat sarcoma (KRAS+) and EGFR/KRAS wildtype metastatic NSCLC, all patients with available formalin-fixed paraffin-embedded (FFPE) tumor samples were selected. Ribonucleic Acid (RNA) was isolated from these samples and gene expressions of EGFR, RANKL, OPG and RANKL were determined via quantitative Polymerase Chain Reaction (qPCR). Data on demographics, histology and molecular subtyping, sample origin, presence of bone metastasis, SREs and bone progression were collected. Primary endpoint was relation between EGFR, RANK, RANKL, OPG gene expression, RANKL: OPG ratio and bone metastases.

Results

In 73/335 (32% EGFR+, 49% KRAS+, 19% EGFR/KRAS wildtype) samples from unique patients, gene expression analysis could be performed. Of these 73 patients, 46 (63%) had bone metastases at diagnosis or developed bone metastases during the disease course. No association was found between EGFR expression and presence of bone metastases. Patients with bone metastases had a significantly higher RANKL expression and RANKL: OPG ratio compared to those without. An increased RANKL: OPG ratio resulted in a 1.65x increased risk to develop bone metastases, especially in the first 450 days after diagnosis of metastatic NSCLC.

Conclusion

Increased RANKL gene expression and RANKL: OPG ratio, but not EGFR expression, was associated with presence of bone metastases. Additionally, an increased RANKL: OPG gene ratio was associated with a higher incidence of bone metastases development.

Correlation of EGFR mutation subtypes and survival in surgically treated brain metastasis from non-small-cell lung cancer

OBJECTIVE

Epidermal growth factor receptor (EGFR) mutation is a positive prognostic factor for survival in patients with non-small-cell lung cancer (NSCLC). In such patients, brain metastasis signifies negative outcomes. Patients with NSCLC brain metastasis that may benefit from neurosurgery is under investigation. We aim to investigate the impact of different mutation loci in surgically treated NSCLC brain metastasis patients.

METHODS

This retrospective cohort study included patients with NSCLC brain metastasis who underwent brain lesionectomy, followed by radiotherapy and chemotherapy or targeted therapy. Demographics and tumor characteristics were compared between the EGFR mutant type and wild type groups. Postoperative survival and risk factors were analyzed using log rank and Cox regression methods.

RESULTS

Overall, 101 patients were included, with 57 belonging to the EGFR mutant type group and 44 to the EGFR wild type group. The median postoperative survival was 17 months for the entire cohort, with the duration being 19 and 14 months for EGFR mutant type and wild type patients (p = 0.013), respectively. Multivariate analysis revealed that exon 19 del (p = 0.02) and a high Karnofsky Performance Scale score (p < 0.01) were independent positive prognostic factors to predict survival. The timing of development of the brain metastasis or the location of the intracranial metastasis was not associated with EGFR mutations.

CONCLUSION

EGFR mutations are associated with better survival outcomes in patients with NSCLC brain metastasis suitable for surgical treatment. This advantage was attributed to patients having a specific mutation of exon 19 deletion.

Immunoregulatory framework and the role of miRNA in the pathogenesis of NSCLC - A systematic review

With a 5-year survival rate of only 15%, non-small cell lung cancer (NSCLC), the most common kind of lung carcinoma and the cause of millions of deaths annually, has drawn attention. Numerous variables, such as disrupted signaling caused by somatic mutations in the EGFR-mediated RAS/RAF/MAPK, PI3K/AKT, JAK/STAT signaling cascade, supports tumour survival in one way or another. Here, the tumour microenvironment significantly contributes to the development of cancer by thwarting the immune response. MicroRNAs (miRNAs) are critical regulators of gene expression that can function as oncogenes or oncosuppressors. They have a major influence on the occurrence and prognosis of NSCLC. Though, a myriad number of therapies are available and many are being clinically tested, still the drug resistance, its adverse effect and toxicity leading towards fatality cannot be ruled out. In this review, we tried to ascertain the missing links in between perturbed EGFR signaling, miRNAs favouring tumorigenesis and the autophagy mechanism. While connecting all the aforementioned points multiple associations were set, which can be targeted in order to combat NSCLC. Here, we tried illuminating designing synthetically engineered circuits with the toggle switches that might lay a prototype for better therapeutic paradigm.

Lung Adenocarcinoma Metastasis to the Vocal Cord

Metastases to the vocal cord from a distant organ are extremely rare. This case showed metastatic adenocarcinoma on the vocal cord of lung origin in a 75-year-old nonsmoking female with a history of lung adenocarcinoma surgery 2 years earlier. The vocal cord mass was surgically removed, and the biopsy confirmed metastatic adenocarcinoma of lung origin with thyroid transcription factor (TTF)-1 positivity. A further evaluation found recurrence in the lung. The patient received gefitinib. Here, we report an extremely rare case of metastatic adenocarcinoma on the vocal cord from the lung which is the first report to our knowledge.

Brain Metastases Management in Oncogene-Addicted Non-Small Cell Lung Cancer in the Targeted Therapies Era

The therapeutic landscape in patients with advanced non-small-cell lung cancer harboring oncogenic biomarkers has radically changed with the development of targeted therapies. Although lung cancers are known to frequently metastasize to the brain, oncogene-driven non-small-cell lung cancer patients show a higher incidence of both brain metastases at baseline and a further risk of central nervous system progression/relapse. Recently, a new generation of targeted agents, highly active in the central nervous system, has improved the control of intracranial disease. The intracranial activity of these drugs poses a crucial issue in determining the optimal management sequence in oncogene-addicted non-small-cell lung cancer patients with brain metastases, with a potential change of paradigm from primary brain irradiation to central nervous system penetrating targeted inhibitors.

Amivantamab for the treatment of EGFR exon 20 insertion mutant non-small cell lung cancer

INTRODUCTION

Amivantamab is a monoclonal bispecific anti-EGFR-MET antibody that is the first targeted therapy to be approved for non-small cell lung cancer (NSCLC) patients harboring EGFR exon 20 insertion mutations following progression on chemotherapy, marking a watershed moment for a class of mutations which is generally associated with poor outcomes.

AREAS COVERED

In this article, we outline the drug profile of amivantamab compared with EGFR kinase inhibitors under evaluation in EGFR exon 20 insertion mutant NSCLC. We also review the efficacy and safety data reported from the CHRYSALIS phase I trial, which forms the basis of the recent approval of amivantamab.

EXPERT OPINION

Unlike small molecule EGFR kinase inhibitors, amivantamab has an extracellular mode of action and dual activity against EGFR and MET. It remains to be determined what role MET inhibition plays in toxicity and efficacy and whether dual target inhibition can delay the onset of drug resistance in these cancers. Due to its large molecular size, amivantamab is expected to have poor activity to treat brain metastases. Building on the clinical data so far, future trials that will evaluate combination treatments with brain-penetrant EGFR kinase inhibitors will be critical to move the drug toward a first-line treatment.

Effect of brain radiotherapy strategies on prognosis of patients with EGFR-mutant lung adenocarcinoma with brain metastasis

Purpose

Epidermal growth factor receptor (EGFR)-mutant lung cancers have a high risk of developing brain metastases (BM). Whole brain radiotherapy (WBRT), local radiotherapy, and WBRT + Boost are frequently used for treatment of BM. This retrospective study aimed to evaluate the difference in efficacy of these radiotherapy modes in patients with EGFR-mutant lung adenocarcinoma with BMs. Further, we determined the optimal radiotherapy regimen for patients based on Lung-molGPA.

Methods and materials

We retrospectively enrolled 232 patients with EGFR-mutant lung adenocarcinoma with BMs. Patients were divided into three groups based on the different modes of brain radiotherapy: WBRT group, local radiotherapy group, and WBRT + Boost group. Graded prognostic assessment for lung cancer using molecular markers (Lung molGPA), overall survival (OS), and intracranial progression-free survival (iPFS) were calculated. Kaplan–Meier was used to compare iPFS and OS in different groups.

Results

The median OS for the WBRT (n = 84), local radiotherapy (n = 65), and WBRT + Boost (n = 83) cohorts was 32.8, 59.1, and 41.7 months, respectively (P = 0.0002). After stratification according to the Lung-molGPA score, the median OS for the WBRT (n = 56), local radiotherapy (n = 19), and WBRT + Boost (n = 28) cohorts was 32.5, 30.9, and 30.8 months, respectively, in subgroup with score 1–2 (P = 0.5097). In subgroup with score 2.5–4, the median OS for the WBRT (n = 26), local radiotherapy (n = 45), and WBRT + Boost (n = 54) cohorts was 32, 68.4, and 51 months, respectively (P = 0.0041).

Conclusion

The present study showed that in patients with EGFR-mutant lung adenocarcinoma with BM, local radiotherapy and WBRT + Boost perform similarly well both in the subgroups with low and high scores of Lung-molGPA. Considering the side effect caused by whole brain radiotherapy, we recommended local radiotherapy as optimal brain radiation mode for those subtype lung cancer patients.

Extracellular Vesicles in Lung Cancer Metastasis and Their Clinical Applications

Extracellular vesicles (EVs) are heterogenous membrane-encapsulated vesicles secreted by every cell into the extracellular environment. EVs carry bioactive molecules, including proteins, lipids, DNA, and different RNA forms, which can be internalized by recipient cells, thus altering their biological characteristics. Given that EVs are commonly found in most body fluids, they have been widely described as mediators of communication in several physiological and pathological processes, including cancer. Moreover, their easy detection in biofluids makes them potentially useful candidates as tumor biomarkers. In this manuscript, we review the current knowledge regarding EVs and non-coding RNAs and their role as drivers of the metastatic process in lung cancer. Furthermore, we present the most recent applications for EVs and non-coding RNAs as cancer therapeutics and their relevance as clinical biomarkers.

Predictive and Prognostic Biomarkers for Lung Cancer Bone Metastasis and Their Therapeutic Value

Lung cancer is the leading cause of cancer-related death worldwide. Bone metastasis, which usually accompanies severe skeletal-related events, is the most common site for tumor distant dissemination and detected in more than one-third of patients with advanced lung cancer. Biopsy and imaging play critical roles in the diagnosis of bone metastasis; however, these approaches are characterized by evident limitations. Recently, studies regarding potential biomarkers in the serum, urine, and tumor tissue, were performed to predict the bone metastases and prognosis in patients with lung cancer. In this review, we summarize the findings of recent clinical research studies on biomarkers detected in samples obtained from patients with lung cancer bone metastasis. These markers include the following: (1) bone resorption-associated markers, such as N-terminal telopeptide (NTx)/C-terminal telopeptide (CTx), C-terminal telopeptide of type I collagen (CTx-I), tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), pyridinoline (PYD), and parathyroid hormone related peptide (PTHrP); (2) bone formation-associated markers, including total serum alkaline phosphatase (ALP)/bone specific alkaline phosphatase(BAP), osteopontin (OP), osteocalcin (OS), amino-terminal extension propeptide of type I procollagen/carboxy-terminal extension propeptide of type I procollagen (PICP/PINP); (3) signaling markers, including epidermal growth factor receptor/Kirsten rat sarcoma/anaplastic lymphoma kinase (EGFR/KRAS/ALK), receptor activator of nuclear factor κB ligand/receptor activator of nuclear factor κB/osteoprotegerin (RANKL/RANK/OPG), C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4), complement component 5a receptor (C5AR); and (4) other potential markers, such as calcium sensing receptor (CASR), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2), cytokeratin 19 fragment/carcinoembryonic antigen (CYFRA/CEA), tissue factor, cell-free DNA, long non-coding RNA, and microRNA. The prognostic value of these markers is also investigated. Furthermore, we listed some clinical trials targeting hotspot biomarkers in advanced lung cancer referring for their therapeutic effects.

Cancer driver gene and non-coding RNA alterations as biomarkers of brain metastasis in lung cancer: A review of the literature

Brain metastasis (BM) is the most common event in patients with lung cancer. Despite multimodal treatments and advances in systemic therapies, development of BM remains one of the main factors associated with poor prognosis and mortality in patients with lung cancer. Therefore, better understanding of mechanisms involved in lung cancer brain metastasis (LCBM) is of great importance to suppress cancer cells and to improve the overall survival of patients. Several cancer-related genes such as EGFR and KRAS have been proposed as potential predictors of LCBM. In addition, there is ample evidence supporting crucial roles of non-coding RNAs (ncRNAs) in mediating LCBM. In this review, we provide comprehensive information on risk assessment, predictive, and prognostic panels for early detection of BM in patients with lung cancer. Moreover, we present an overview of LCBM molecular mechanisms, cancer driver genes, and ncRNAs which may predict the risk of BM in lung cancer patients. Recent clinical studies have focused on determining mechanisms involved in LCBM and their association with diagnosis, prognosis, and treatment outcomes. These studies have shown that alterations in EGFR, KRAS, BRAF, and ALK, as the most frequent coding gene alterations, and dysregulation of ncRNAs such as miR-423, miR-330-3p, miR-145, piR-651, and MALAT1 can be considered as potential biomarkers of LCBM.

Reporting of Incidence and Outcome of Bone Metastases in Clinical Trials Enrolling Patients with Epidermal Growth Factor Receptor Mutated Lung Adenocarcinoma-A Systematic Review

Bone metastases, occurring in 30-60% of patients with non-small cell lung cancer (NSCLC), are associated with decreased survival, cancer-induced bone pain, and skeletal-related events (SREs). Those with an activating epidermal growth factor mutation (EGFR+) seem to be more prone to develop bone metastases. To gain more insight into bone metastases-related outcomes in EGFR+ NSCLC, we performed a systematic review on Pubmed (2006-2021). Main inclusion criteria: prospective, phase II/III trials evaluating EGFR-tyrosine kinase inhibitors, ≥10 EGFR+ patients included, data on bone metastases and/or bone-related outcomes available. Out of 663 articles, 21 (3176 EGFR+ patients) met the eligibility criteria; 4 phase III (one double blind), 17 phase II trials (three randomized) were included. In seven trials dedicated bone imaging was performed at baseline. Mean incidence of bone metastases at diagnosis was 42%; 3-33% had progression in the bone upon progression. Except for one trial, it was not specified whether the use of bone target agents was permitted, and in none of the trials, occurrence of SREs was reported. Despite the high incidence of bone metastases in EGFR+ adenocarcinoma, there is a lack of screening for, and reporting on bone metastases in clinical trials, as well as permitted bone-targeted agents and SREs.

Inferior outcome of bone metastasis in non-small-cell-lung-cancer patients treated with epidermal growth factor receptor inhibitors

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BoM was prone to multiple organs metastases and had more complex aberrations.

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BoM was associated with worse prognosis which cannot be salvaged by Osimertinib.

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BoM was an independent prognostic factor for EGFR-TKI treatment in PFS and OS.

Background

Targeted therapy has been established as the standard-of-care for patients with advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. Among patients with advanced lung cancer, 30–40% have bone metastases (BoM) at first diagnosis. However, little is known on the clinical characteristics and prognostic factors of BoM in patients with NSCLC harboring EGFR mutations.

Methods

Treatment-naive patients with advanced NSCLC harboring EGFR mutations who were prescribed tyrosine kinase inhibitors (TKIs) were screened and enrolled between June 2009 and April 2019 from West China Hospital. Patients were dichotomized according to whether they had BoM. The demographic characteristics, gene mutation status and therapeutic efficacy, including objective response rate (ORR), progression-free survival (PFS) and overall survival (OS), were collected.

Results

A cohort of 604 patients were enrolled. The BoM group had worse PFS (11.7 vs. 14.0 months, HR = 0.73, p = 0.00013) and OS (32.8 vs. 46.1 months, HR = 0.54, p < 0.0001) compared with the non-BoM group. No significant differences were observed in disease control rate (p = 0.407) or ORR (p = 0.537) between the two groups. The metastatic sites in the two groups exhibited obvious differences. In multivariate analysis, BoM was found to be an independent factor of worse prognosis.

Conclusion

BoM was identified as an independent inferior prognostic factor for EGFR-TKI treatment, and may have complex biological implications.

GNAQ knockdown promotes bone metastasis through epithelial-mesenchymal transition in lung cancer cells

AIMS

Bone metastasis ultimately occurs due to a complex multistep process, during which the interactions between cancer cells and bone microenvironment play important roles. Prior to colonization of the bone, cancer cells must succeed through a series of steps that will allow them to gain migratory and invasive properties; epithelial-to-mesenchymal transition (EMT) is known to be integral here. The aim of this study was to determine the effects of G protein subunit alpha Q (GNAQ) on the mechanisms underlying bone metastasis through EMT pathway.

METHODS

A total of 80 tissue samples from patients who were surgically treated during January 2012 to December 2014 were used in the present study. Comparative gene analysis revealed that the GNAQ was more frequently altered in metastatic bone lesions than in primary tumour sites in lung cancer patients. We investigated the effects of GNAQ on cell proliferation, migration, EMT, and stem cell transformation using lung cancer cells with GNAQ-knockdown. A xenograft mouse model tested the effect of GNAQ using micro-CT analyses and histological analyses.

RESULTS

GNAQ-knockdown showed down-regulation of tumour growth through mitogen-activated protein kinase (MAPK) signalling in lung cancer cells, but not increased apoptosis. We found that GNAQ-knockdown induced EMT and promoted invasiveness. GNAQ-knockdown cells injected into the bone marrow of murine tibia induced tumour growth and bone-to-lung metastasis, whereas it did not in control mice. Moreover, the knockdown of GNAQ enhanced cancer stem cell-like properties in lung cancer cells, which resulted in the development of resistance to chemotherapy.

CONCLUSION

The present study reveals that the GNAQ-knockdown induced cancer stem cell-like properties. Cite this article: Bone Joint Res 2021;10(5):310-320.

Overcoming therapy resistance in EGFR-mutant lung cancer

Tyrosine kinase inhibitors (TKIs) have dramatically changed the clinical prospects of patients with non-small cell lung cancer harboring epidermal growth factor receptor (EGFR)-activating mutations. Despite prolonged disease control and high tumor response rates, all patients eventually progress on EGFR TKI treatment. Here, we review the mechanisms of acquired EGFR TKI resistance, the methods for monitoring its appearance, as well as current and future efforts to define treatment strategies to overcome resistance.

Factors affecting treatment selection and overall survival for first-line EGFR-tyrosine kinase inhibitor therapy in non-small-cell lung cancer

Aim: To investigate the factors associated with treatment selection and overall survival for first-line EGFR-tyrosine kinase inhibitors (EGFR-TKIs) therapy among patients with non-small-cell lung cancer. Materials & methods: We conducted a retrospective cohort study of linked administrative health databases in Ontario, Canada. Results: A total of 1011 patients received an EGFR-TKI as first-line therapy. Treatment selection and overall survival associated with these treatments were affected by age, sex, geographical residency, comorbidities and different sites of metastasis. Conclusion: Though recent approval of osimertinib offers a potential new standard of care in the first-line setting, earlier generation TKIs remain pillars in treatment of non-small-cell lung cancer therapeutic armamentarium. Our findings may contribute to optimizing treatment sequencing of EGFR-TKIs to maximize clinical benefits.

Vimentin expression status is a potential biomarker for brain metastasis development in EGFR-mutant NSCLC patients

Background

Despite advances in systemic therapy and improvements in survival for advanced epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC), brain metastasis (BM) remains a poor outcome. Previous studies on risk factors for BM occurrence included unselected patients and biomarker prediction of BM in these populations were not well studied. We aimed to identify the role of epithelial mesenchymal transition (EMT) marker and clinical factors predicting BM in

EGFR

mutant NSCLC patients.

Methods

Advanced EGFR-mutant NSCLC patients in the King Chulalongkorn Memorial Hospital from January 2013 to December 2017 were included. Vimentin expression was assessed by immunohistochemistry. The correlation between vimentin expression and factors associated with BM occurrence was analyzed by univariate and multivariate analyses.

Results

304 patients were enrolled. Of these, 149 patients (49%) developed BM. In multivariate analysis, the occurrence of BM was associated with age <60 years, metastatic disease at diagnosis, and 3 or more metastatic sites. Moreover, positive vimentin expression was also found more common in patients with BM than those without BM (52.4% vs. 27.6%, respectively) and predicted overall BM development in EGFR-mutant patients (OR 2.53, 95% CI, 1.11–5.77; P=0.027). Overall survival (OS) was shorter in vimentin^positive group than in vimentin^negative group. Median OS was 20.0 months (95% CI, 14.51–25.51) and 30.9 months (95% CI, 20.99–40.84), respectively (HR, 1.57; P=0.04).

Conclusions

Younger patients with EGFR-mutant NSCLC who had high disease burden were more likely to develop BM. Vimentin served as a biomarker for predicting BM and poor prognostic factor in EGFR-mutant patients. EMT pathway may be considered as a therapeutic target in these high-risk populations.

Impact of different patterns of metastasis in non-small-cell lung cancer patients

Aim: The aim of this study was to evaluate the frequency and median time for the development of metastases and prognosis by metastatic site after the diagnosis of non-small-cell lung cancer (NSCLC). Patients & methods: This cohort study was conducted with 1096 patients diagnosed with NSCLC between 2006 and 2014. Results: The most prevalent site of NSCLC metastases was the respiratory system. The nervous and adrenal systems presented the longest median time for the development of metastases. The 6-month survival varied from 68.2% for liver to 79.9% for the nervous system. Bone metastases were associated with a higher risk of death. Conclusion: The respiratory system was the most prevalent site of metastases. OS and risk of death varied according to the metastatic site.

MiR-142-5p Suppresses Lung Cancer Cell Metastasis by Targeting Yin Yang 1 to Regulate Epithelial-Mesenchymal Transition

This study aimed to investigate the mechanism of miR-142-5p and Yin Yang 1 (YY1) on regulating epithelial-mesenchymal transition (EMT) in lung cancer cell metastasis. The expressions of YY1 and miR-142-5p in different lung cancer cell lines were negatively correlated. The results of the dual-luciferase reporter assay further validated that miR-142-5p directly targeted YY1. Subsequently, transwell assays, wound-healing assay, and transplantation tumor model in nude mice proved that YY1 could promote the metastasis of lung cancer cells, whereas miR-142-5p impaired the stimulating effect of YY1 on the metastasis ability of lung cancer cells in vitro and in vivo. Western blot and quantitative real-time polymerase chain reaction analysis of the EMT-related proteins indicated that YY1 could enhance the metastasis ability of lung cancer cells by promoting EMT. On the contrary, miR-142-5p constrained the expression of mesenchymal markers by targeting YY1, reversed the differentiation of cells into mesenchymal cells, and weakened the metastasis ability of tumor cells in vitro and in vivo. In summary, miR-142-5p may regulate the expressions of EMT-related proteins by targeting YY1, thereby inhibiting lung cancer metastasis, which provides a promising therapeutic target for lung cancer.

Central nervous system metastases and oligoprogression during treatment with tyrosine kinase inhibitors in oncogene-addicted non-small cell lung cancer: how to treat and when?

Up to 70% of non-small cell lung cancer (NSCLC) patients develop central nervous system (CNS) metastases during the course of their disease, especially those with oncogenic drivers treated with a first-generation tyrosine kinase inhibitor (TKI), because of the relatively poor CNS penetration. CNS metastases are associated with a negative impact on quality of life and survival. As, with the introduction of newer generation TKIs, the survival rates are increasing in this particular population, treatment and/or prevention of CNS metastases becomes even more relevant and the TKI with the best CNS efficacy should be selected. Unfortunately, CNS efficacy data in clinical trials are not fully comparable. Furthermore, oligoprogression to the brain without extracranial progression regularly occurs in the oncogenic driver population and both local therapy and switch of systemic therapy are possible treatment options. However, the best order of systemic and local therapy is still not precisely known. In this narrative review, we will summarize incidence and treatment of CNS metastases in oncogene driven NSCLC, including the optimal treatment of CNS oligometastatic disease (synchronous as well as oligoprogressive).

High Prevalence and Early Occurrence of Skeletal Complications in EGFR Mutated NSCLC Patients With Bone Metastases

Objectives

The prevalence of Skeletal Related Adverse Events (SREs) in EGFR mutated non-small cell lung cancer (NSCLC) patients with bone metastases, treated with modern tyrosine kinase inhibitors (TKIs), has been scarcely investigated.

Materials and Methods

We retrospectively evaluated the data of EGFR mutated NSCLC patients with bone metastases treated with TKIs in 12 Italian centers from 2014 to 2019, with the primary aim to explore type and frequency of SREs.

Results

Seventy-seven out of 274 patients enrolled (28%) developed at least one major SRE: 55/274 (20%) bone fractures, 30/274 (11%) spinal cord compression, 5/274 (2%) hypercalcemia. Median time to the onset of SRE was 3.63 months. Nine patients (3%) underwent bone surgery and 150 (55%) radiation therapy on bone. SREs were more frequently observed within the 12 months from TKI start than afterwards (71 vs 29%, p 0.000). Patient Performance Status and liver metastases where independently associated with the risk of developing SREs. Median TKI exposure and overall survival were 11 and 28 months, respectively. Bone resorption inhibitors were associated with a lower risk of death (HR 0.722, 95% CI: 0.504–1.033, p = 0.075) although not statistically significant at multivariate analysis.

Conclusion

Bone metastatic NSCLC patients with EGFR mutated disease, treated with EGFR TKIs, have a relatively long survival expectancy and are at high risk to develop SREs. The early SRE occurrence after the TKI start provides the rationale to administer bone resorption inhibitors.

Non-Radiation Based Early Pain Relief Treatment Options for Patients With Non-Small Cell Lung Cancer and Cancer Induced Bone Pain: A Systematic Review

INTRODUCTION

Cancer induced bone pain (CIBP) is frequent in patients with non-small cell lung cancer (NSCLC). Radiation therapy continues to be the gold standard for treatment of painful bone metastases, however only a limited number of metastases can be irradiated. We evaluated non-radiation based early CIBP relief options in NSCLC through a systematic review.

METHODS

Systematic review including all prospective articles published between 01-1994 and 06-2020 on Pubmed, Cochrane Library and ClinicalTrials.gov database. Inclusion: non-radiation based trials evaluating CIBP early pain relief options (initially defined as pain score evaluated within two weeks, because of no randomized trials, later inclusion broadened to pain score evaluated within six weeks) in ≥10 NSCLC patients. Radioisotope trials were excluded as these treatments have interactions with systemic anticancer therapy.

RESULTS

188 articles were found; 10 articles (6 randomized controlled (4 double blinded), 1 phase II single-arm, and 3 prospective trials) fulfilled the inclusion criteria. Six of these trials consisted of ≥2 treatment arms, whereas the others were single-arm studies. In total, 554 NSCLC patients were evaluated in these trials. The included trials were very heterogeneous regarding evaluated treatment options, methods of pain measuring, and endpoints. No high-level evidence for specific early pain relief treatment options was found.

DISCUSSION

Non-radiation based studies evaluating treatment options to rapidly reduce CIBP in NSCLC are scarce. This systematic review shows that there is no high-level evidence to recommend a specific treatment for early pain relief. Future research should focus on early pain relief treatment options for CIBP in NSCLC.

Dissecting the Crosstalk between NRF2 Signaling and Metabolic Processes in Cancer

The transcription factor NRF2 (nuclear factor-erythroid 2 p45-related factor 2 or NFE2L2) plays a critical role in response to cellular stress. Following an oxidative insult, NRF2 orchestrates an antioxidant program, leading to increased glutathione levels and decreased reactive oxygen species (ROS). Mounting evidence now implicates the ability of NRF2 to modulate metabolic processes, particularly those at the interface between antioxidant processes and cellular proliferation. Notably, NRF2 regulates the pentose phosphate pathway, NADPH production, glutaminolysis, lipid and amino acid metabolism, many of which are hijacked by cancer cells to promote proliferation and survival. Moreover, deregulation of metabolic processes in both normal and cancer-based physiology can stabilize NRF2. We will discuss how perturbation of metabolic pathways, including the tricarboxylic acid (TCA) cycle, glycolysis, and autophagy can lead to NRF2 stabilization, and how NRF2-regulated metabolism helps cells deal with these metabolic stresses. Finally, we will discuss how the negative regulator of NRF2, Kelch-like ECH-associated protein 1 (KEAP1), may play a role in metabolism through NRF2 transcription-independent mechanisms. Collectively, this review will address the interplay between the NRF2/KEAP1 complex and metabolic processes.

Primary tumor and metastasis-sectioning the different steps of the metastatic cascade

Patients with lung cancer in the majority die of metastases. Treatment options include surgery, chemo- and radiotherapy, targeted therapy by tyrosine kinase inhibitors (TKIs), and immuno-oncologic treatment. Despite the success with these treatment options, cure of lung cancer is achieved in only a very small proportion of patients. In most patients’ recurrence and metastasis will occur, and finally kill the patient. Metastasis is a multistep procedure. It requires a change in adhesion of tumor cells for detachment from their neighboring cells. The next step is migration either as single cells [epithelial-mesenchymal transition (EMT)], or as cell clusters (hybrid-EMT or bulk migration). A combination of genetic changes is required to facilitate migration. Then tumor cells have to orient themselves along matrix proteins, detect oxygen concentrations, prevent attacks by immune cells, and induce a tumor-friendly switch of stroma cells (macrophages, myofibroblasts, etc.). Having entered the blood stream tumor cells need to adapt to shear stress, avoid being trapped by coagulation, but also use coagulation in small veins for adherence to endothelia, and express homing molecules for extravasation. Within a metastatic site, tumor cells need a well-prepared niche to establish a metastatic focus. Tumor cells again have to establish a vascular net for maintaining nutrition and oxygen supply, communicate with stroma cells, grow out and set further metastases. In this review the different steps will be discussed with a focus on pulmonary carcinomas. The vast amount of research manuscripts published so far are not easy to analyze: in most reports’ single steps of the metastatic cascade are interpreted as evidence for the whole process; for example, migration is interpreted as evidence for metastasis. In lung cancer most often latency periods are shorter, in between 1–5 years. In other cases, despite widespread migration occurs, tumor cells die within the circulation and do not reach a metastatic site. Therefore, migration is a requisite, but does not necessarily predict metastasis. The intention of this review is to point to these different aspects and hopefully provoke research directed into a more functional analysis of the metastatic process.

Efficacy of Ibandronate Loading Dose on Rapid Pain Relief in Patients With Non-Small Cell Lung Cancer and Cancer Induced Bone Pain: The NVALT-9 Trial

Introduction: Approximately 80% of non-small cell lung cancer (NSCLC) patients with bone metastases have cancer induced bone pain (CIBP).

Methods: The NVALT-9 was an open-label, single arm, phase II, multicenter study. Main inclusion criterion: bone metastasized NSCLC patients with uncontrolled CIBP [brief pain inventory [BPI] ≥ 5 over last 7 days]. Patients were treated with six milligram ibandronate intravenously (day 1–3) once a day. Main exclusion criteria: active secondary malignancy, systemic anti-tumor treatment and radiotherapy ≤4 weeks before study start, previous bisphosphonate treatment. Statistics: Simon's Optimal two-stage design with a 90% power to declare the treatment active if the pain response rate is ≥ 80% and 95% confidence to declare the treatment inactive if the pain response rate is ≤ 60%. If pain response is observed in ≤ 12 of the first 19 patients further enrollment will be stopped. Primary endpoint: bone pain response, defined as 25% decrease in worst pain score (PSc) over a 3-day period (day 5–7) compared to baseline PSc with maximum of 25% increase in mean analgesic consumption during the same period. Secondary endpoints: BPI score, quality of life, toxicity and World Health Organization Performance Score.

Results: Of the 19 enrolled patients in the first stage, 18 were evaluable for response. All completed ibandronate treatment according to protocol. In 4 (22.2%), a bone pain response was observed. According to the stopping rule, further enrollment was halted.

Discussion: Ibandronate loading doses lead to insufficient pain relief in NSCLC patients with CIBP.

Single nucleotide polymorphisms within the Wnt pathway predict the risk of bone metastasis in patients with non-small cell lung cancer

The Wingless-type (Wnt) signaling pathway plays an important role in the development and progression of cancer. This study aimed to evaluate the relationship between single nucleotide polymorphisms (SNPs) in the Wnt pathway and the risk of bone metastasis in patients with non-small cell lung cancer (NSCLC). We collected 500 blood samples from patients with NSCLC and genotyped eight SNPs from four core genes (WNT2, AXIN1, CTNNB1 and APC) present within the WNT pathway. Moreover, we assessed the potential relationship of these genes with bone metastasis development. Our results showed that the AC/AA genotype of CTNNB1: rs1880481 was associated with a decreased risk of bone metastasis. Polymorphisms with an HR of < 1 had a cumulative protective impact on the risk of bone metastasis. Furthermore, patients with the AC/AA genotype of CTNNB1: rs1880481 was associated with Karnofsky performance status score, squamous cell carcinoma antigen and Ki-67 proliferation index. Lastly, patients with the AC/AA genotype of CTNNB1: rs1880481 had significantly longer median progression free survival time than those with the CC genotype. In conclusion, SNPs within the Wnt signaling pathway are associated with a decreased risk of bone metastasis, and may be valuable biomarkers for bone metastasis in patients with NSCLC.

Association of metastatic pattern and molecular status in stage IV non-small cell lung cancer adenocarcinoma

OBJECTIVES

The aim of our study was to investigate the association between driver oncogene alterations and metastatic patterns on imaging assessment, in a large cohort of metastatic lung adenocarcinoma patients.

METHODS

From January 2010 to May 2017, 550 patients with stage IV lung adenocarcinoma with molecular analysis were studied retrospectively including 135 EGFR-mutated, 81 ALK-rearrangement, 47 BRAF-mutated, 141 KRAS-mutated, and 146 negative tumors for these 4 mutations (4N). After review of the complete imaging report by two radiologists (junior and senior) to identify metastatic sites, univariate correlation analyzes were performed.

RESULTS

We found differences in metastatic tropism depending on the molecular alteration type when compared with the non-mutated 4N group: in the EGFR group, pleural metastases were more frequent (32% versus 20%; p = 0.021), and adrenal and node metastases less common (6% versus 23%; p < 0.001 and 11% versus 23%; p = 0.011). In the ALK group, there were more brain and lung metastases (respectively 42% versus 29%; p = 0.043 and 37% versus 24%; p = 0.037). In the BRAF group, pleural and pericardial metastases were more common (respectively 47% versus 20%; p < 0.001 and 11% versus 3%; p = 0.04) and bone metastases were rarer (21% versus 42%; p = 0.011). Lymphangitis was more frequent in EGFR, ALK, and BRAF groups (respectively 6%, 7%, and 15% versus 1%); p = 0.016; p = 0.009; and p < 0.001.

CONCLUSION

The application of these correlations between molecular status and metastatic tropism in clinical practice may lead to earlier and more accurate identification of patients for targeted therapy.

KEY POINTS

• Bone and brain metastasis are the most common organs involved in lung adenocarcinoma but the relative incidence of each metastatic site depends on the molecular alteration. • EGFR-mutated tumors preferentially spread to the pleura and less commonly to adrenals, ALK-rearrangement tumors usually spread to the brain and the lungs, whereas BRAF-mutated tumors are unlikely to spread to bones and have a serous (pericardial ad pleural) tropism. • These correlations could help in the clinical management of patients with metastatic lung adenocarcinoma.

The impact of systemic treatment on brain metastasis in patients with non-small-cell lung cancer: A retrospective nationwide population-based cohort study

To compare the incidence of brain metastases of advanced non-small cell lung cancer (NSCLC) treated with systemic cytotoxic chemotherapy (CC) and targeted therapy (TT), we performed a large-scale, retrospective, nationwide, cohort study. The population data were extracted from the Health Insurance Review and Assessment Service of Korea database from January 1, 2011, to November 30, 2016. Of the 29,174 patients newly diagnosed with stage IIIB or IV NSCLC who received systemic treatment, we investigated the initial and subsequent incidence of brain metastases. Besides, among 22,458 patients without initial brain metastasis, the overall cumulative incidence of subsequent brain metastases was compared according to systemic treatment administered. In total, 1,126 (5.0%) patients subsequently developed brain metastasis. The overall cumulative incidence of brain metastasis was significantly higher in the TT group than in the CC group (1-year cumulative incidence: 8.7% vs. 3.8%; 3-year: 17.2% vs. 5.0%; P < 0.001). Younger age, female sex, and first-line TT were significant risk factors for subsequent brain metastasis. In conclusion, the overall cumulative incidence of brain metastasis was significantly higher in patients received TT as the first-line treatment than in those received CC.

Neurological Death is Common in Patients With EGFR Mutant Non-Small Cell Lung Cancer Diagnosed With Brain Metastases

Purpose

Brain metastases (BrM) are common in patients with epidermal growth factor receptor (EGFRm) mutant non-small cell lung cancer (NSCLC). We sought to determine the rate of neurologic death (ND) in this population.

Methods and Materials

We analyzed data from 198 patients who received a diagnosis of BrM from EGFRm NSCLC between 2004 and 2016, comparing patients whose initial treatment for BrM was stereotactic radiosurgery with or without tyrosine kinase inhibitors (TKI), whole brain radiation therapy (WBRT) with or without TKI, or TKI alone. The incidence of ND was determined using a competing risks analysis. Univariate and multivariate analyses were used to identify clinical variables associated with this outcome.

Results

The percentage of patients who initially received stereotactic radiosurgery, whole brain radiation therapy, or TKI alone was 22%, 61%, and 17%, respectively. Median overall survival in these subgroups was 31.1, 14.6, and 24.6 months, respectively (P = .0016). The 5-year incidence of ND among all patients was 40% and did not significantly vary according to treatment group. In a multivariable model, only leptomeningeal disease at any point in a patient’s disease course significantly correlated with ND (hazard ratio 4.75, P <.001).

Conclusions

Among our cohort of patients with BrM from EGFRm NSCLC, the incidence of ND was significantly higher than suggested by previous reports. BrM should be considered a driver of mortality in many patients with EGFRm NSCLC, and treatments providing better control of BrM, lower neurocognitive side effects, and maintenance of quality of life are needed.

In-vitro Pre-Treatment of Cancer Cells with TGF-β1: A Novel Approach of Tail Vein Lung Cancer Metastasis Mouse Model for Anti-Metastatic Studies

Background:

Aggressive behavior of tumor metastasis comes from certain mutations, changes in cellular metabolic and signaling pathways that are majorly altered by tumor microenvironment (TME), its other components and growth factors like transforming growth factor-β1 (TGF-β1) which is chiefly known for its epithelial to mesenchymal transformation (EMT). EMT is a critical step of metastasis cascade in actual human lung cancer scenario.

Objective:

Our present study is focused on unveiling the in-vivo metastatic behavior of TGF-β1 treated lung cancer cells that undergo EMT.

Methods:

The lung cancer epithelial A549 cells were treated in-vitro with TGF-β1 (3-5ng/ml for 72 h) for EMT. After confirming the transformation of cells by phenotype modifications, wound healing and cell migration assay and qRT-PCR analyses of EMT biomarkers including E. Cadherin, Vimentin, Snail, Slug, MMP2 and MMP9; those TGF-β1 modified cells were probed with fluorescent trackers and were injected into the tail vein of BALB/c nude mice for metastatic dissemination studies.

Results:

Our findings indicate that the distribution of TGF-β1 treated A549 cells as compared to W.T A549 towards lungs is less in terms of total relative fluorescent cluster count, however, the difference is insignificant (52±4, 60±5 respectively). Additionally, we show that TGF-β1 treated cells tend to metastasize almost 2, 3, 1.5, 2 and 1.7 times more than W.T towards liver, brain, ovaries, bones and adrenal gland, respectively, which is very much like human lung cancer metastasis.

Conclusion:

Conclusively, it is the first study ever reporting that a pre-treatment of cells with TGF-β1 for experimental lung cancer metastasis mouse model may portray a more precise approach for the development of potential therapeutic treatments. Additional pre-treatment studies with the application of other TME conditions like hypoxia and factors like NFκB, VEGF etc. may be a future prospect to develop a better understanding.

EGFR-TKI plus brain radiotherapy versus EGFR-TKI alone in the management of EGFR-mutated NSCLC patients with brain metastases

Background

It has been confirmed that epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) presented better efficacy than brain radiotherapy (brain RT) in the treatment of brain metastasis (BM) in EGFR mutated NSCLC patients. However, whether the combination of EGFR-TKIs and brain RT is better than EGFR-TKIs alone remains unclear. We aim to compare the outcomes of adding brain RT to EGFR-TKIs and to screen for the beneficial population by a meta-analysis of currently available data.

Methods

A systematic search for relevant articles was conducted in six databases. The outcomes were overall survival (OS) and intracranial progression-free survival (iPFS) between groups, both were measured as hazard ratios (HRs). Meta-regression and dominant subgroup analysis were used to explore advantageous subgroups.

Results

A total of 12 retrospective studies involving 1,553 EGFR mutated patients with BM at the first diagnosis were included. EGFR-TKIs plus brain RT showed a significant prolonged OS (HR =0.64, 95% CI: 0.52-0.78; P<0.001) and iPFS (HR =0.62, 95% CI: 0.50-0.78; P<0.001) compared to EGFR-TKIs alone. Meta-regression analyses showed that potential factors contributed to the heterogeneity were the proportion of ECOG performance score (2+ vs. 0-1, P=0.070) and brain symptomatic patients (no vs. yes, P=0.077) regarding iPFS and was age (younger vs. older, P=0.075) for OS. Dominant subgroup analyses suggested that symptomatic patients (HR 0.46 vs. 0.74, interaction P=0.01) for iPFS, and older patients (HR 0.55 vs. 0.75, interaction P=0.03) and 19Del mutation (HR 0.55 vs. 0.74, interaction P=0.04) for OS, seemed to benefit more from the combination therapy than their counterparts. However, direct subgroup results based on only two studies did not show significant difference in iPFS benefit between age, mutation type and sex subgroup.

Conclusions

EGFR-TKIs plus brain RT is superior to EGFR-TKIs alone in the management of EGFR-mutated NSCLC patients with BM, of which the benefits might be influenced by age, BM-related symptoms and mutation type.

Brain metastases in resected non-small cell lung cancer: The impact of different tyrosine kinase inhibitors

Objectives

The purpose of this study was to examine the impact of epidermal growth factor receptor (EGFR) mutation status and tyrosine kinase inhibitors (TKIs) on the survival of brain metastases (BM) in patients with surgically resected non-small cell lung cancer (NSCLC).

Methods

We selected the patients who had developed metastatic NSCLC; analyzed the differences between brain metastases and other sites of metastases, including patient characteristics, EGFR status, and survival; and selected the patients who had BM for further investigation. We also compared the treatment effects of first-generation TKIs with those of second-/third-generation TKIs.

Results

A total of 785 cases of stage I-IIIa NSCLC were reviewed. Thirty-six (4.6%) patients were identified as having BM. Among them, 14 patients had a mutated EGFR status. No association between EGFR mutation and the incidence of BM was observed (p = 0.199). Patients with mutated EGFRs had significantly longer overall survival and post-recurrence survival than patients with wild-type EGFR mutation (p = 0.001 for both). However, there was no survival difference between patients with exon 19 and exon 21 mutations (p = 0.426). Furthermore, patients who received the second- and/or third-generation EGFR-TKIs had better survival than patients who only received first-generation EGFR-TKIs (p = 0.031). A multivariate analysis indicated that the next-generation TKIs (HR, 0.007; 95% CI, 0.000 to 0.556; p = 0.026) and a longer interval before BM development (HR, 0.848; 95% CI, 0.733 to 0.980; p = 0.025) were significant factors in longer survival.

Conclusions

EGFR-TKIs were effective in treating NSCLC patients with BM after curative pulmonary surgery, especially in those patients harboring EGFR mutations. Furthermore, the second-/third-generation EGFR-TKIs showed more promising results than the first-generation EGFR-TKIs in treating those particular patients, though larger studies needed to further prove the results.

A Comprehensive Meta-Analysis of Association between EGFR Mutation Status and Brain Metastases in NSCLC

Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation have different clinicopathological characteristics compared with EGFR wild type NSCLC. A growing number of studies focused on the relevance between EGFR mutation status and brain metastases (BM) in NSCLC, but it remains controversial. Therefore, this study performed a comprehensive meta-analysis to untangle this issue. Several electronic databases including Pubmed, Embase, Web of science and Cochrane database were thoroughly searched. The odds ratio (OR) with 95% confidence interval (95%CI) was pooled to evaluate the relevance. Meta-regression analysis and subgroup analysis were conducted according to the heterogeneity. A total of 26 studies were identified finally in this meta-analysis. The overall OR was 1.58 (95%CI: 1.36-1.84), which indicated that EGFR mutation had a positive association with BM of NSCLC. The subgroup analysis resulted from eleven studies with lung adenocarcinoma revealed a higher possibility of BM in NSCLC with EGFR mutation compared with EGFR wild (p < 0.05). There was no significant difference in the risk of BM between NSCLC EGFR exon 19 mutation and exon 21 point mutation (p = 0.23). This meta-analysis suggests that EGFR mutation can be a risk factor for BM in NSCLC.

The role of EGFR mutation as a prognostic factor in survival after diagnosis of brain metastasis in non-small cell lung cancer: a systematic review and meta-analysis

Background

The brain is a common site for metastasis in non-small-cell lung cancer (NSCLC). This study was designed to evaluate the relationship between the mutational of the epidermal growth factor receptor (EGFR) and overall survival (OS) in NSCLC patients with brain metastases.

Methods

Searches were performed in PubMed, EmBase, and the Cochrane Library to identify studies evaluating the association of EGFR mutation with OS in NSCLC patients through September 2017.

Results

4373 NSCLC patients with brain metastases in 18 studies were involved. Mutated EGFR associated with significantly improved OS compared with wild type. Subgroup analyses suggested that this relationship persisted in studies conducted in Eastern, with retrospective design, with sample size ≥500, mean age of patients ≥65.0 years, percentage male < 50.0%, percentage of patients receiving tyrosine kinase inhibitor ≥30.0%. Finally, although significant publication bias was observed using the Egger test, the results were not changed after adjustment using the trim and fill method.

Conclusions

This meta-analysis suggests that EGFR mutation is an important predictive factor linked to improved OS for NSCLC patients with brain metastases. It can serve as a useful index in the prognostic assessment of NSCLC patients with brain metastases.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5331-z) contains supplementary material, which is available to authorized users.

Incidence and Risk Factors for Bone Metastasis in Non-Small Cell Lung Cancer

Background:

Bone is a frequent site of metastasis from various primary cancers including with Non-Small Cell Lung Cancer. The aim of this study was to investigate the incidence and risk factors for Bone Metastasis in patients with Non-Small Cell Lung Cancer.

Methodology:

A cohort study was carried out in patients diagnosed with Non-Small Cell Lung Cancer between 2006 and 2014 in a single cancer centre. A descriptive analysis of the population was compiled based on mean ± standard deviation (SD) for continuous variables and percentage (%) for categorical variables. Univariate and multivariate Cox proportional hazards regression analyses were carried out to quantify the relationship between independent variables and the outcome variable (Bone Metastasis).

Results:

During the study period 1025 patients were diagnosed with Non-Small Cell Lung Cancer. Bone Metastasis was detected in 136 patients (13.2%) with a mean interval between Non-Small Cell Lung Cancer diagnosis and Bone Metastasis of 8.07 months (95% CI: 7.68 8.45). Multivariate analysis revealed that younger age (HR 0.97; 95%CI, 0.95–0.99; p=0.002), adenocarcinoma (HR 1.51; 95%CI, 1.06–2.15; p=0.021) and treatment with chemotherapy, radiotherapy or chemotherapy combined with radiotherapy (HR 3.73; 95%CI, 2.30–6.05; p<0.001) were associated with the occurrence of Bone Metastasis.

Conclusion:

The incidence of Bone Metastasis was 13.2%. Younger age, histological subtype adenocarcinoma and treatment with chemotherapy, radiotherapy or chemotherapy combined with radiotherapy are independent risk factors for Bone Metastasis.

Brain metastases in ALK-positive NSCLC - time to adjust current treatment algorithms

The progress in molecular biology has revolutionized systemic treatment of advanced non-small-cell lung cancer (NSCLC) from conventional chemotherapy to a treatment stratified by histology and genetic aberrations. Tumors harboring a translocation of the anaplastic-lymphoma-kinase (ALK) gene constitute a distinct genetic and clinico-pathologic NSCLC subtype with patients with ALK-positive disease being at a higher risk for developing brain metastases. Due to the introduction of effective targeted therapy with ALK-inhibitors, today, patients with advanced ALK-positive NSCLC achieve high overall response rates and remain progression-free for long time intervals. Moreover, ALK-inhibitors seem to exhibit efficacy in the treatment of brain metastases. In the light of this, it needs to be discussed how treatment algorithms for managing patients with brain metastases should be modified. By integrating systemic ALK-inhibitor therapy, radiotherapy, in particular whole brain radiotherapy might be postponed deferring potential long-term impairment by neurocognitive deficits to a later time point in the course of the disease. An early treatment of asymptomatic brain metastases might offer patients a longer time without impairment of cerebral symptoms or radiotherapeutic interventions. Based on an updated extensive review of the literature this article provides an overview on the epidemiology and the treatment of patients’ brain metastases. It describes the specifics of ALK-positive disease and proposes an algorithm for the treatment of patients with advanced ALK-positive NSCLC and brain metastases.

Clinicopathological and genetic characteristics associated with brain metastases from lung adenocarcinoma and utility as prognostic factors

Brain metastases (BM) are common in patients with lung adenocarcinoma, and represent a significant cause of morbidity in the disease. A more comprehensive understanding of the clinicopathological characteristics that serve as prognostic factors for survival in patients with BM from lung adenocarcinoma may aid in informing treatment strategies for this patient population. In the present study, clinicopathological factors, including EGFR mutation status, were evaluated in 59 patients who were diagnosed with BM from lung adenocarcinoma, and underwent BM resection between January 1985 and December 2014 at Fukuoka University Hospital. The most frequent subtype of BM from lung adenocarcinoma was solid adenocarcinoma (57.6%), followed by papillary adenocarcinoma (22.0%) and acinar adenocarcinoma (18.6%). A total of 14 patients (23.7%) exhibited EGFR mutations, which were significantly associated with female sex (9/14, 64.3%), non-smoker status (8/14, 57.1%), BM in the frontal lobes (9/14, 64.3%) and papillary adenocarcinoma (5/14, 35.7%). Statistical analysis revealed a significant association between non-smoker status and BM in the frontal lobes, and more favorable disease prognosis. The results of the present study suggest that histological and genetic analysis of tissue from BM provides information useful for managing treatment of patients with resectable BM arising from lung adenocarcinoma.

Medical Treatment Options for Patients with Epidermal Growth Factor Receptor Mutation-Positive Non-Small Cell Lung Cancer Suffering from Brain Metastases and/or Leptomeningeal Disease

Brain metastases and/or leptomeningeal disease (LMD) with associated central nervous system (CNS) metastases are known complications of advanced epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC). It is important, therefore, to assess the activity of EGFR tyrosine kinase inhibitors (TKIs) versus such CNS complications. This review explores the literature reporting the intracranial activity of EGFR TKIs, and finds that there is evidence for varying efficacy of the approved agents, erlotinib, gefitinib, afatinib, and osimertinib in patients with CNS metastases. Other EGFR TKIs in development, such as AZD3759, may have a future role as therapeutic options in this setting. Emerging evidence indicates that the second- and third-generation EGFR TKIs, afatinib and osimertinib, effectively penetrate the blood-brain barrier, and therefore represent viable treatment options for CNS lesions, and can reduce the risk of CNS progression. These agents should therefore be considered as first-line treatment options in patients with EGFR mutation-positive NSCLC who have brain metastases and/or LMD. While there are currently no prospective data comparing the intracranial efficacy of second- and third-generation EGFR TKIs in this setting, CNS activity and protection offered by different EGFR TKIs should be an additional consideration when making decisions about the optimal sequence of treatment with EGFR TKIs in order to maximize survival benefit in individual patients.