First-line chemotherapy with vinorelbine, gemcitabine, and carboplatin in the treatment of brain metastases from non-small-cell lung cancer: a phase II study

A Review of the Molecular Determinants of Therapeutic Response in Non-Small Cell Lung Cancer Brain Metastases

Lung cancer is a leading cause of cancer-related morbidity and mortality worldwide. Metastases in the brain are a common hallmark of advanced stages of the disease, contributing to a dismal prognosis. Lung cancer can be broadly classified as either small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC). NSCLC represents the most predominant histology subtype of lung cancer, accounting for the majority of lung cancer cases. Recent advances in molecular genetics, coupled with innovations in small molecule drug discovery strategies, have facilitated both the molecular classification and precision targeting of NSCLC based on oncogenic driver mutations. Furthermore, these precision-based strategies have demonstrable efficacy across the blood-brain barrier, leading to positive outcomes in patients with brain metastases. This review provides an overview of the clinical features of lung cancer brain metastases, as well as the molecular mechanisms that drive NSCLC oncogenesis. We also explore how precision medicine-based strategies can be leveraged to improve NSCLC brain metastases.

Can we predict overall survival using machine learning algorithms at 3-months for brain metastases from non-small cell lung cancer after gamma knife radiosurgery?

Gamma knife radiosurgery (GRKS) is widely used for patients with brain metastases; however, predictions of overall survival (OS) within 3-months post-GKRS remain imprecise. Specifically, more than 10% of non-small cell lung cancer (NSCLC) patients died within 8 weeks of post-GKRS, indicating potential overtreatment. This study aims to predict OS within 3-months post-GKRS using machine learning algorithms, and to identify prognostic features in NSCLC patients. We selected 120 NSCLC patients who underwent GKRS at Chungbuk National University Hospital. They were randomly assigned to training group (n = 80) and testing group (n = 40) with 14 features considered. We used 3 machine learning (ML) algorithms (Decision tree, Random forest, and Boosted tree classifier) to predict OS within 3-months for NSCLC patients. And we extracted important features and permutation features. Data validation was verified by physician and medical physicist. The accuracy of the ML algorithms for predicting OS within 3-months was 77.5% for the decision tree, 72.5% for the random forest, and 70% for the boosted tree classifier. The important features commonly showed age, receiving chemotherapy, and pretreatment each algorithm. Additionally, the permutation features commonly showed tumor volume (>10 cc) and age as critical factors each algorithm. The decision tree algorithm exhibited the highest accuracy. Analysis of the decision tree visualized data revealed that patients aged (>71 years) with tumor volume (>10 cc) were increased risk of mortality within 3-months. The findings suggest that ML algorithms can effectively predict OS within 3-months and identify crucial features in NSCLC patients. For NSCLC patients with poor prognoses, old age, and large tumor volumes, GKRS may not be a desirable treatment.

Intracranial efficacy and safety of furmonertinib 160 mg with or without anti-angiogenic agent in advanced NSCLC patients with BM/LM as salvage therapy

OBJECTIVES

Central nervous system (CNS) metastases including brain metastases (BM) and leptomeningeal metastases (LM) are frequent in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), and are correlated with poor outcomes. In this study, we evaluated the efficacy of single-agent furmonertinib 160 mg or combining with anti-angiogenic agent in NSCLC patients who had developed BM/LM progression from previous tyrosine kinase inhibior (TKI) treatment.

METHODS

EGFR-mutated NSCLC patients who developed BM (the BM cohort) or LM progression (the LM cohort) were included, having received furmonertinib 160 mg daily as second-line or later treatment, with or without anti-angiogenic agents. The intracranial efficacy was evaluated by intracranial progression-free survival (iPFS).

RESULTS

Totally 12 patients in the BM cohort and 16 patients in the LM cohort were included. Almost one half of patients in the BM cohort and a majority in the LM cohort had a poor physical status, with a Eastern Cooperative Oncology Group performance status (ECOG-PS) ≥2. The administration of single-agent furmonertinib or combination treatment achieved a median iPFS of 3.6 months (95%CI 1.435-5.705) in the BM cohort, and 4.3 months (95%CI 2.094-6.486) in the LM cohort. Subgroup and univariate analysis has shown that a good ECOG-PS correlated with a favorable efficacy of furmonertinib in the BM cohort (median iPFS = 2.1 with ECOG-PS ≥ 2 vs. 14.6 months with ECOG-PS < 2, P < 0.05). Overall, any grade of adverse events (AEs) occured in 46.4% of patients (13/28). Among them, 14.3% of patients (4 of 28) had grade 3 or higher AEs, and were all under control, led to no dose reductions or suspension.

CONCLUSION

Single-agent furmonertinib 160 mg or in combination of anti-angiogenic agent is an optional salvage therapy for advanced NSCLC patients who developed BM/LM progression from prior EGFR-TKI treatment, with a promising efficacy and an acceptable safety profile, and is worth of further exploration.

Matched Analyses of Brain Metastases versus Primary Non-Small Cell Lung Cancer Reveal a Unique microRNA Signature

Distant spreading of tumor cells to the central nervous system in non-small cell lung cancer (NSCLC) occurs frequently and poses major clinical issues due to limited treatment options. RNAs displaying differential expression in brain metastasis versus primary NSCLC may explain distant tumor growth and may potentially be used as therapeutic targets. In this study, we conducted systematic microRNA expression profiling from tissue biopsies of primary NSCLC and brain metastases from 25 patients. RNA analysis was performed using the nCounter Human v3 miRNA Expression Assay, NanoString technologies, followed by differential expression analysis and in silico target gene pathway analysis. We uncovered a panel of 11 microRNAs with differential expression and excellent diagnostic performance in brain metastasis versus primary NSCLC. Five microRNAs were upregulated in brain metastasis (miR-129-2-3p, miR-124-3p, miR-219a-2-3p, miR-219a-5p, and miR-9-5p) and six microRNAs were downregulated in brain metastasis (miR-142-3p, miR-150-5p, miR-199b-5p, miR-199a-3p, miR-199b-5p, and miR-199a-5p). The differentially expressed microRNAs were predicted to converge on distinct target gene networks originating from five to twelve core target genes. In conclusion, we uncovered a unique microRNA profile linked to two target gene networks. Our results highlight the potential of specific microRNAs as biomarkers for brain metastasis in NSCLC and indicate plausible mechanistic connections.

Primary systemic therapy for patients with brain metastases from lung cancer ineligible for targeted agents

Purpose

The purpose of this study was to evaluate overall survival after systemic therapy, largely chemotherapy, in patients with small cell or non-small cell lung cancer and brain metastases. After completion of systemic therapy, some patients received planned brain irradiation, while others were followed.

Methods

Retrospective cohort study.

Results

Thirty-eight patients were included (28 small cell, 20 followed with imaging). Six of these 20 patients (30%) received delayed radiotherapy during follow-up. Planned radiotherapy (n = 18, intention-to-treat) was associated with longer survival from diagnosis of brain metastases, median 10.8 versus 6.1 months, p = 0.025. Delayed radiotherapy still resulted in numerically better survival than no radiotherapy at all (median 8.8 versus 5.3 months, not significant). If calculated from the start of delayed radiotherapy, median survival was only 2.7 months. In a multivariable analysis, both Karnofsky performance status ≥ 70 (p = 0.03) and planned radiotherapy (p = 0.05) were associated with better survival.

Conclusion

In patients ineligible for targeted agents, planned radiotherapy in a modern treatment setting was associated with longer survival compared to no radiotherapy. Timing and type of radiotherapy in such patients should be evaluated in prospective trials to identify patients who might not need planned radiotherapy.

Treating Metastatic Brain Cancers With Stem Cells

Stem cell therapy may present an effective treatment for metastatic brain cancer and glioblastoma. Here we posit the critical role of a leaky blood-brain barrier (BBB) as a key element for the development of brain metastases, specifically melanoma. By reviewing the immunological and inflammatory responses associated with BBB damage secondary to tumoral activity, we identify the involvement of this pathological process in the growth and formation of metastatic brain cancers. Likewise, we evaluate the hypothesis of regenerating impaired endothelial cells of the BBB and alleviating the damaged neurovascular unit to attenuate brain metastasis, using the endothelial progenitor cell (EPC) phenotype of bone marrow-derived mesenchymal stem cells. Specifically, there is a need to evaluate the efficacy for stem cell therapy to repair disruptions in the BBB and reduce inflammation in the brain, thereby causing attenuation of metastatic brain cancers. To establish the viability of stem cell therapy for the prevention and treatment of metastatic brain tumors, it is crucial to demonstrate BBB repair through augmentation of vasculogenesis and angiogenesis. BBB disruption is strongly linked to metastatic melanoma, worsens neuroinflammation during metastasis, and negatively influences the prognosis of metastatic brain cancer. Using stem cell therapy to interrupt inflammation secondary to this leaky BBB represents a paradigm-shifting approach for brain cancer treatment. In this review article, we critically assess the advantages and disadvantages of using stem cell therapy for brain metastases and glioblastoma.

Contrast-enhanced T1-weighted image radiomics of brain metastases may predict EGFR mutation status in primary lung cancer

Identification of EGFR mutations is critical to the treatment of primary lung cancer and brain metastases (BMs). Here, we explored whether radiomic features of contrast-enhanced T1-weighted images (T1WIs) of BMs predict EGFR mutation status in primary lung cancer cases. In total, 1209 features were extracted from the contrast-enhanced T1WIs of 61 patients with 210 measurable BMs. Feature selection and classification were optimized using several machine learning algorithms. Ten-fold cross-validation was applied to the T1WI BM dataset (189 BMs for training and 21 BMs for the test set). Area under receiver operating characteristic curves (AUC), accuracy, sensitivity, and specificity were calculated. Subgroup analyses were also performed according to metastasis size. For all measurable BMs, random forest (RF) classification with RF selection demonstrated the highest diagnostic performance for identifying EGFR mutation (AUC: 86.81). Support vector machine and AdaBoost were comparable to RF classification. Subgroup analyses revealed that small BMs had the highest AUC (89.09). The diagnostic performance for large BMs was lower than that for small BMs (the highest AUC: 78.22). Contrast-enhanced T1-weighted image radiomics of brain metastases predicted the EGFR mutation status of lung cancer BMs with good diagnostic performance. However, further study is necessary to apply this algorithm more widely and to larger BMs.

Systemic treatment of brain metastases in non-small cell lung cancer

Brain metastases (BrMs) are associated with significant morbidity and are found in up to 50% of patients with advanced non-small cell lung cancer (NSCLC). Most of the literature focuses on symptomatic BrMs, with a lack of baseline brain imaging in asymptomatic patients. Unfortunately, much of the data on local treatments with or without systemic treatment is retrospective. Clinical trials of systemic treatments largely exclude patients with BrMs. Chemotherapy is an active treatment for BrM with response rates in the brain similar to other sites of disease. Targeted systemic treatments in patients with driver mutations (EGFR and ALK-MET to date) have impressive central nervous system (CNS) penetrance and response rates. Unfortunately, no prospective data can currently guide the timings or modality of local therapies with systemic treatments in these patients who have a high incidence of CNS disease, but retrospective data suggest that early local therapies may give better intracranial progression-free survival (ICPFS). Recent immunotherapy trials have included patients with BrMs. These patients have largely been pre-treated with local therapies and are asymptomatic. Thus, the current standard is becoming, early local therapies before or in conjunction with immunotherapy agents. The approach seems to be safe. Prospective studies are needed in NSCLC BrMs patients to make sure any benefit from local therapies on the ICPFS and quality of life is not overlooked. Here we report what we think are reasonable conclusions from the available data and make suggestions for future clinical trials in the management of NSCLC BrMs.

An immune gene expression signature distinguishes central nervous system metastases from primary tumours in non-small-cell lung cancer

BACKGROUND

Dissemination of non-small-cell lung cancer (NSCLC) in the central nervous system is a frequent and challenging clinical problem. Systemic or local therapies rarely prolong survival and have modest activity regarding local control. Alterations in gene expression in brain metastasis versus primary tumour may increase aggressiveness and impair therapeutic efforts.

METHODS

We identified 25 patients with surgically removed NSCLC brain metastases in two different patient cohorts. For 13 of these patients, primary tumour samples were available. Gene expression analysis using the nCounter® PanCancer Immune Profiling gene expression panel (nanoString technologies Inc.) was performed in brain metastases and primary tumour samples. Identification of differentially expressed genes was conducted on normalized data using the nSolver analysis software.

RESULTS

We compared gene expression patterns in brain metastases with primary tumours. Brain metastasis samples displayed a distinct clustering pattern compared to primary tumour samples with a statistically significant downregulation of genes related to immune response and immune cell activation. Results from KEGG term analysis on differentially expressed genes revealed a concomitant enrichment of multiple KEGG terms associated with the immune system. We identified a 12-gene immune signature that clearly separated brain metastases from primary tumours.

CONCLUSIONS

We identified a unique gene downregulation pattern in brain metastases compared with primary tumours. This finding may explain the lower intracranial efficacy of systemic therapy, especially immunotherapy, in brain metastasis of patients with NSCLC.

Icotinib is as efficacious as gefitinib for brain metastasis of EGFR mutated non-small-cell lung cancer

BACKGROUND

The prognosis of non-small-cell lung cancer (NSCLC) with brain metastases is very poor. Currently, therapeutic methods for this patient population include whole-brain radiation therapy (WBRT), surgery, radiosurgery and systemic treatment. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) could be effective on cerebral metastases of mutated NSCLC. However, which EGFR-TKIs is more appropriate is still unknown.

METHODS

We conducted a retrospective analysis of advanced NSCLC patients with brain metastases for EGFR targeted therapy from November 2013 to April 2018 at Dongguan People's Hospital, Southern Medical University, China. A total of 43 patients were recruit in this study. Among them, 21 cases received icotinib (125 mg, thrice a day) and 22 cases received gefitinib (250 mg, once a day) until disease progression or unacceptable toxicity. The primary end point of this study was intracranial PFS (iPFS). The relationships between therapeutic arms and patients characteristics were performed using Pearson's chi-square test or Fisher's exact test. The differences in PFS among the two arms were analyzed using Kaplan-Meier curves and log rank tests.

RESULTS

There was no significant difference of intracranial ORR (66.6% versus 59.1%, P = 0.62) and DCR (85.7% versus 81.8%, P = 0.73) between the two arms. The median intracranial PFS (iPFS) for icotinib and gefitinib arms were 8.4 months (95% CI, 5.4 to 11.3 months) and 10.6 months (95% CI, 6.3 to 14.8 months), respectively (P = 0.17). Adverse events of the two study arms were generally mild. None of the patients experienced dose reduction of EGFR-TKIs.

CONCLUSIONS

Our study showed that icotinib and gefitinib had similar efficacy for brain metastasis of EGFR mutated NSCLC. Large randomized studies are suggested to further illuminate the effect of these two EGFR-TKIs on cerebral lesions of NSCLC.

Bevacizumab for the treatment of non-small cell lung cancer patients with synchronous brain metastases

Bevacizumab is FDA-approved in the treatment of primary brain tumors, but its efficacy in patients with brain metastases could be better-studied. This study examines a population of non-small cell lung cancer (NSCLC) patients with synchronous brain metastases to identify predictors of the decision to use bevacizumab and survival following bevacizumab treatment. Primary cancer registry data were used to determine which NSCLC patients diagnosed in the years 2010 through 2012 had synchronous brain metastases at the time of diagnosis, and Medicare claims used to identify a population of patients treated with bevacizumab. Record of bevacizumab treatment was found for 81 and 666 patients with and without brain metastases, respectively. After adjusting for clinical and demographic characteristics, bevacizumab was associated with 0.88 times the hazard of mortality in the elderly NSCLC population (95% CI: 0.81–0.96, p: 0.003) and a corresponding hazard ratio of 0.75 in the population of elderly NSCLC patients with synchronous brain metastases (95% CI: 0.59–0.96, p: 0.020). Bevacizumab may benefit NSCLC patients with synchronous brain metastases more than it does patients without intracranial disease, possibly as a result of its multiple potential mechanisms of action simultaneously inhibiting angiogenesis and minimizing vasogenic edema.

Dramatic Response of Leptomeningeal Carcinomatosis to Nivolumab in PD-L1 Highly Expressive Non-small Cell Lung Cancer: A Case Report

In a patient who had been diagnosed of located squamous cell lung carcinoma, pneumonectomy, and adjuvant chemotherapy were performed. Brain recurrence and subsequent lung metastatic disease were uncontrolled by neurosurgery, holocranial radiotherapy, and first-line chemotherapy. In August 2015, appearance of leptomeningeal carcinomatosis triggered severe clinical deterioration and threatened the patient's life. Anti-PD1 immune checkpoint inhibitor Nivolumab was initiated in an attempt to stop tumor growth, achieving a spectacular brain and pulmonary complete response and clinical improvement, without serious adverse effects. High expression PD-L1 level (100%) was found in the pathological tissue sample. Nivolumab was maintained for more than 2 years and stopped in December 2017 after 28 months of treatment, with no disease evidence. More than 3 years after its onset, the patient maintains an outstanding PS with complete tumor response and no evidence of disease in last surveillance CT scan and brain MRI.

Management of Leptomeningeal Metastases in Non-oncogene Addicted Non-small Cell Lung Cancer

Brain metastases in non-small cell lung cancer (NSCLC) patients are more often detected due to imaging modalities improvements but also emerge because of improved treatments of the primary tumor which lead to a longer survival. In this context, development of leptomeningeal metastases (LM) is a devastating complication and its prognosis remains poor despite advances in systemic and local approaches. Histology characterization of NSCLC and molecular expression influence LM management. For those with “oncogene addiction,” new generation epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) were developed to strongly penetrate the blood-brain barrier (BBB) with the aim to prevent central nervous system cancer dissemination, eventually impacting on LM appearance and its subsequent management. Systemic chemotherapy, often combined with intrathecal chemotherapy (when possible), was one of common indications for lung cancer patients affected by LM, without driver mutations and a good performance status but currently, with the advent of innovative systemic approaches treatment solutions in this subgroup of patients are rapidly evolving. Whole brain radiation therapy (WBRT) is the conventional treatment for patients with brain metastases. Furthermore, modern radiation techniques, as stereotactic radiotherapy (SRT), improve outcomes in those cases with a limited number of lesions. However, LM represent a minority of CNS metastases and few literature data are available to drive the radiotherapy approach. Considering all relevant progress made in this setting, after a literature review, the aim of this paper is to discuss about recent developments and therapeutic options in LM management of non-oncogene addicted NSCLC.

Systemic Therapy of Lung Cancer CNS Metastases Using Molecularly Targeted Agents and Immune Checkpoint Inhibitors

Central nervous system (CNS) metastases most commonly arise from lung cancer, with the majority of patients affected during their disease course. The prognosis for patients with untreated brain metastases is poor, with surgical resection and/or radiotherapy as classic therapeutic options. However, the value of systemic therapy in the management of CNS metastases from lung cancer is growing. Novel targeted agents for the treatment of non-small cell lung cancer (NSCLC) have demonstrated activity in treating patients with CNS involvement, and are potential alternatives to radiation and surgery. These agents include anaplastic lymphoma kinase (ALK) inhibitors such as alectinib, crizotinib, ceritinib, lorlatinib, and others; epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, including the recently developed third-generation inhibitor osimertinib, and even immune checkpoint inhibitors such as nivolumab, pembrolizumab, and atezolizumab. This review summarizes current activity of systemic agents in the management of CNS metastases from NSCLC, as well as potential mechanisms of action of these small and large molecules.

Cauda equina syndrome secondary to leptomeningeal metastases from recurrent primary peritoneal carcinoma

The patient is a 42-year-old woman with metastatic primary peritoneal carcinoma and known brain metastases, who subsequently developed cauda equina syndrome after presenting with ataxia, lower extremity weakness, and bowel and bladder incontinence secondary to leptomeningeal metastasis after treatment with neoadjuvant chemotherapy, surgical debulking, and adjuvant chemotherapy. Metastases to the central nervous system (CNS) and leptomeninges are rare events in epithelial ovarian and primary peritoneal carcinomas as these tumours do not have a predilection for the CNS. Cauda equina syndrome is often characterised by gait disturbances, bowel and bladder dysfunction, saddle anaesthesia, and lower extremity muscle weakness. In patients with known metastatic gynaecologic carcinomas presenting with nonspecific neurologic symptoms, cauda equina syndrome should remain high in the differential diagnosis.

Systemic treatment of non-small cell lung cancer brain metastases

In the systemic treatment of brain metastases from non-small cell lung cancer (BMF-NSCLC) chemo- and targeted therapy are used. Response rates after platinum-based chemotherapy, range from 23% to 45%. Development of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs): gefitinib or erlotinib, was an improvement in treatment of advanced NSCLC patients. EGFR mutations are present in 10-25% of NSCLC (mostly adenocarcinoma), and up to 55% in never-smoking women of East Asian descent. In the non-selected group of patients with BMF-NSCLC, the overall response rates after gefitinib or erlotinib treatment range from 10% to 38%, and the duration of response ranges from 9 to 13.5 months. In the case of present activating EGFR mutation, the response rate after EGRF-TKIs is greater than 50%, and in selected groups (adenocarcinoma, patients of Asian descent, never-smokers, asymptomatic BMF-NSCLC) even 70%. Gefitinib or erlotinib treatment improves survival of BMF-NSCLC patients with EGFR mutation in comparison to cases without the presence of this mutation. There is no data on the activity of the anti-EML4-ALK agent crizotinib. Bevacizumab, recombinant humanised monoclonal antibody anti-VEGF, in the treatment of advanced non-squamous NSCLC patients is a subject of intense research. Data from a clinical trial enrolling patients with pretreated or occult BMF-NSCLC proved that the addition of bevacizumab to various chemotherapy agents or erlotinib is a safe and efficient treatment, associated with a low incidence of CSN haemorrhages. However, the efficacy and safety of bevacizumab used for therapeutic intent, regarding active brain metastases is unknown.

Non-small cell lung cancer (NSCLC) and central nervous system (CNS) metastases: role of tyrosine kinase inhibitors (TKIs) and evidence in favor or against their use with concurrent cranial radiotherapy

Central nervous system (CNS) metastases, including brain metastases (BM) and leptomeningeal metastases (LM) represent a frequent complication of non-small cell lung cancer (NSCLC). Patients with BM comprise a heterogeneous group, with a median survival that ranges from 3 to 14 months. However, in the majority of patients, the occurrence of CNS metastases is usually accompanied by severe morbidity and substantial deterioration in quality of life. Local therapies, such as whole brain radiotherapy (WBRT), stereotactic radiosurgery (SRS) or surgical resection, either alone or as part of a multimodality treatment are available treatment strategies for BM and the choice of therapy varies depending on patient group and prognosis. Meanwhile, introduction of tyrosine kinase inhibitors (TKIs) in clinical practice has led to individualization of therapy based upon the presence of the exact abnormality, resulting in a major therapeutic improvement in patients with NSCLC who harbor epidermal growth factor receptor (EGFR) activating mutations or anaplastic lymphoma kinase (ALK) gene rearrangements, respectively. Based on their clinical activity in systemic disease, such molecular agents could offer the promise of improved BM control without substantial toxicity; however, their role in combination with radiotherapy is controversial. In this review, we discuss the controversy regarding the use of TKIs in combination with radiotherapy and illustrate future perspectives in the treatment of BM in NSCLC.

State of the art of chemotherapy for the treatment of central nervous system metastases from non-small cell lung cancer

Chemotherapy is the mainstay of treatment of advanced non-small cell lung cancer (NSCLC) without molecular drivers. Despite a low penetration of central nervous system (CNS), chemotherapy drugs demonstrated encouraging activity against CNS metastases from NSCLC. Based on the available data, chemotherapy should be considered as an important part of the multidisciplinary treatment of CNS metastases. Particularly, platinum-based regimens represent the most active combinations and pemetrexed is associated with a meaningful clinical benefit for patients with non-squamous histology. How to integrate chemotherapy and radiotherapy for newly diagnosed brain metastases (BMs) is still debated. Although flawed by some limitations, the available evidence suggests a role for upfront chemotherapy for the treatment of NSCLC patients with synchronous, asymptomatic BMs, thus allowing a delay of radiotherapy. Despite the introduction of modern and more effective chemotherapy, however, the prognosis of NSCLC patients with CNS metastases remains poor, especially for those with progressive BMs or leptomeningeal carcinomatosis (LC).

Epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of central nervous system metastases from non-small cell lung cancer: the present and the future

Lung cancer is one of the major causes of cancer related mortality worldwide. Brain metastases (BM) complicate clinical evolution of non-small cell lung cancer (NSCLC) in approximately 25-40% of cases, adversely influencing quality of life (QoL) and overall survival (OS). Systemic therapy remains the standard strategy for metastatic disease. Nevertheless, the blood-brain barrier (BBB) makes central nervous system (CNS) a sanctuary site. To date, the combination of chemotherapy with whole brain radiation therapy (WBRT), surgery and/or stereotactic radiosurgery (SRS) represents the most used treatment for patients (pts) with intracranial involvement. However, due to their clinical conditions, many pts are not able to undergo local treatments. Targeted therapies directed against epidermal growth factor receptor (EGFR), such as gefitinib, erlotinib and afatinib, achieved important improvements in EGFR mutated NSCLC with favorable toxicity profile. Although their role is not well defined, the reported objective response rate (ORR) and the good tolerance make EGFR-tyrosine kinase inhibitors (TKIs) an interesting valid alternative for NSCLC pts with BM, especially for those harboring EGFR mutations. Furthermore, new-generation TKIs, such as osimertinib and rociletinib, have already shown important activity on intracranial disease and several trials are still ongoing to evaluate their efficacy. In this review we want to highlight literature data about the use and the effectiveness of EGFR-TKIs in pts with BM from NSCLC.

Are immune checkpoint blockade monoclonal antibodies active against CNS metastases from NSCLC?-current evidence and future perspectives

Brain metastases occur in approximately half of patients with non-small cell lung cancer (NSCLC) and are associated with a poor prognosis and an inferior quality of life. Historically systemic therapy has had a limited role in CNS disease with a reliance placed on local treatments. The emergence of targeted therapies and immune checkpoint inhibitors (ICIs) in recent years has dramatically changed the treatment landscape of NSCLC. Programmed cell death-1 (PD-1) inhibitors have demonstrated efficacy in three randomized trials and now represent standard second line therapy after platinum failure. Trials have largely excluded patients with symptomatic or untreated CNS disease as the brain has been considered an 'immune-privileged' organ. We review the evidence and future prospects of ICIs in treating brain metastases in NSCLC.

Anti-angiogenetic therapies for central nervous system metastases from non-small cell lung cancer

Central nervous system (CNS) metastases are common in patients with advanced non-small cell lung cancer (NSCLC), occurring in 24% to 44% of patients in the course of their disease and confer significant morbidity and mortality. Systemic therapies have been deemed ineffective in brain metastases (BM) under the hypothesis that the blood-brain barrier (BBB) limits their delivery to the brain. Angiogenesis, which is mainly mediated by vascular endothelial growth factor (VEGF) pathway, is crucial for tumor survival, growth and invasion both in primary and metastatic brain lesions. Two major categories of agents have been developed to target this pathway: antibody-based agents and VEGF receptor tyrosine kinase inhibitors (TKIs). Clinical benefits have been shown with anti-angiogenetic therapies in the treatment of metastatic NSCLC. However, patients with CNS metastases were often excluded from trials with these agents, due to concerns about a potentially greater risk of cerebral haemorrhage and thromboembolic disease. Therefore, the overall efficacy and safety of angiogenetic agents in patients with BM from NSCLC are yet to be clarified. This paper aims to review available data about the efficacy and safety of anti-angiogenetic therapies for CNS metastases in NSCLC patients.

The evolving clinical management of cerebral metastases

Concepts in the management of brain metastases are evolving. Until recently, brain metastases have been considered as a homogenous condition, managed with whole brain radiotherapy, surgical resection for large lesions and stereotactic radiosurgery for smaller lesions. Increasingly, specific systemic medical therapies are being used to treat brain metastases based on the primary site of disease. This disease specific management is causing a change in perspective about brain metastases and has led to improved survival for patients with primary disease subtypes amenable to tailored medical therapies. We review the recent literature to present evidence for the use of subtype specific medical therapies, advances in surgical resection techniques and stereotactic radiosurgery as the primary treatment modalities. The decline in use of whole brain radiotherapy as first line treatment is also discussed. Based on the recent literature, we propose a new management algorithm to reflect the progress in available options for tailoring disease specific treatments and support the change in paradigm to consider brain metastases as separate disease states based on the primary site of cancer rather than as a homogenous entity.

Bevacizumab, pemetrexed and carboplatin in first-line treatment of non-small cell lung cancer patients: Focus on patients with brain metastases

Data concerning bevacizumab plus pemetrexed plus carboplatin as first-line treatment for patients with non-squamous non-small cell lung cancer (NSCLC) with or without brain metastases (BM) are lacking. The present study analyzed the efficacy and safety of this combination as induction therapy, followed by maintenance therapy with bevacizumab plus pemetrexed in non-squamous NSCLC patients with or without BM. Treatment-naïve patients with advanced non-squamous NSCLC and an Eastern Cooperative Oncology Group performance status score of 0-2 were eligible. Treatment consisted of carboplatin (area under the curve of 5), pemetrexed (500 mg/m²) and bevacizumab (15 mg/kg) every 3 weeks for 6 cycles. Responders and patients with stable disease received maintenance therapy with bevacizumab plus pemetrexed until disease progression, which was evaluated every 3 cycles, or unacceptable toxicity. Kaplan-Meier median progression-free survival (PFS) and overall survival (OS) times were the primary endpoints, and safety was the secondary endpoint. In total, 39 patients, aged 44-78 years (median, 60 years), were treated; 11 (28.2%) of whom presented with BM. The majority of patients (56.4%) completed 6 cycles of induction therapy, and 26 patients continued on to maintenance therapy. The median PFS time was 8.2 months [95% confidence interval (CI), 7.05-9.35] and the median OS time was 14.0 months (95% CI, 8.46-19.54). Median PFS and OS times did not differ significantly between patients with or without BM (log rank (Mantel-Cox): PFS, P=0.748 and OS, P=0.447). The majority of patients (76.9%) did not experience adverse events during treatment. Overall, bevacizumab plus pemetrexed plus carboplatin as induction therapy, followed by bevacizumab plus pemetrexed as maintenance therapy was effective and well tolerated in advanced NSCLC, whether brain metastases were present or not.

[Research Progress of EGFR-TKI Therapy for Patients with Central Nervous System Metastases from Non-small Cell Lung Cancer]

Approximately half of all patients with non-small cell lung cancer (NSCLC) develop central nervous system metastases during the course of their disease which indicate poor prognosis. A part of NSCLC patients demonstrates activating epidermal growth factor receptor gene (EGFR) mutations who represent effectiveness and well tolerance of EGFR-specific tyrosine kinase inhibitors (TKIs) therapy. Although the systemic efficacy of targeted agents is established, the efficacy of central nervous system (CNS) metastases is not as well characterized. In this article, we review recent data on the use of EGFR inhibitors for treatment of patients with NSCLC and CNS metastases.

Systemic therapies in the treatment of non-small-cell lung cancer brain metastases

Non-small-cell lung cancer (NSCLC) brain metastases are common. Even though there are various subsets of NSCLC with molecular alterations, there is a common theme of brain metastases. Current treatment modalities are suboptimal. Systemic therapies for the treatment of NSCLC brain metastases have been explored and recent advances may pave the way for their successful employment in this patient population. While no specific agents have been associated with a marked benefit, stability of disease as well as radiographic responses have been noted in some patients. Biological activity of systemic therapies in some patients with NSCLC brain metastases raises hope for future advances and supports further investigation for this patient population with limited treatment options.

Systemic therapy of brain metastases

Brain metastases are a common complication of cancer and continue to be associated with a poor prognosis. Management of brain metastases typically requires a multidisciplinary approach which may include whole-brain radiation therapy, stereotactic radiosurgery, surgery, and systemic therapy. Historically, the use of systemic therapy in brain metastases has been challenging because of the resistance to conventional chemotherapies secondary to the blood-brain barrier and an often heavily pre-treated patient population, and the paucity of well-conducted randomized trials in these heterogeneous patient populations. Newer agents, including immunotherapy and targeted therapies, are playing increasingly important roles in the up-front management of brain metastases. In this overview, we review recent advances in systemic therapies for brain metastases and the evidence supporting their use in this patient population.

Bone marrow-derived stem cell therapy for metastatic brain cancers

We propose that stem cell therapy may be a potent treatment for metastatic melanoma in the brain. Here we discuss the key role of a leaky blood-brain barrier (BBB) that accompanies the development of brain metastases. We review the need to characterize the immunological and inflammatory responses associated with tumor-derived BBB damage in order to reveal the contribution of this brain pathological alteration to the formation and growth of brain metastatic cancers. Next, we discuss the potential repair of the BBB and attenuation of brain metastasis through transplantation of bone marrow-derived mesenchymal stem cells with the endothelial progenitor cell phenotype. In particular, we review the need for evaluation of the efficacy of stem cell therapy in repairing a disrupted BBB in an effort to reduce neuroinflammation, eventually attenuating brain metastatic cancers. The demonstration of BBB repair through augmented angiogenesis and vasculogenesis will be critical to establishing the potential of stem cell therapy for the treatment/prevention of metastatic brain tumors. The overarching hypothesis we advanced here is that BBB breakdown is closely associated with brain metastatic cancers of melanoma, exacerbating the inflammatory response of the brain during metastasis, and ultimately worsening the outcome of metastatic brain cancers. Abrogating this leaky BBB-mediated inflammation via stem cell therapy represents a paradigm-shifting approach to treating brain cancer. This review article discusses the pros and cons of cell therapy for melanoma brain metastases.

Bone and brain metastasis in lung cancer: recent advances in therapeutic strategies

Bone and brain metastases are a very common secondary localization of disease in patients with lung cancer. The prognosis of these patients is still poor with a median survival of less than 1 year. Current therapeutic approaches include palliative radiotherapy and systemic therapy with chemotherapy and targeted agents. For bone metastasis, zoledronic acid is the most commonly used bisphosphonate to prevent, reduce the incidence and delay the onset of skeletal-related events (SREs). Recently, denosumab, a fully human monoclonal antibody directed against the receptor activator of nuclear factor κB (RANK) ligand inhibiting the maturation of pre-osteoclasts into osteoclasts, showed increased time to SREs and overall survival compared with zoledronic acid. The treatment of brain metastasis is still controversial. Available standard therapeutic options, such as whole brain radiation therapy and systemic chemotherapy, provide a slight improvement in local control, overall survival and symptom relief. More recently, novel target agents such as the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) erlotinib, gefitinib and afatinib have shown activity in patients with brain metastasis. Inter alia, in patients harboring EGFR mutations, the administration of EGFR TKIs is followed by a response rate of 70-80%, and a longer progression-free and overall survival than those obtained with standard chemotherapeutic regimens. This review is focused on the evidence for therapeutic strategies in bone and brain metastases due to lung cancer.

Current approaches to the treatment of metastatic brain tumours

Metastatic tumours involving the brain overshadow primary brain neoplasms in frequency and are an important complication in the overall management of many cancers. Importantly, advances are being made in understanding the molecular biology underlying the initial development and eventual proliferation of brain metastases. Surgery and radiation remain the cornerstones of the therapy for symptomatic lesions; however, image-based guidance is improving surgical technique to maximize the preservation of normal tissue, while more sophisticated approaches to radiation therapy are being used to minimize the long-standing concerns over the toxicity of whole-brain radiation protocols used in the past. Furthermore, the burgeoning knowledge of tumour biology has facilitated the entry of systemically administered therapies into the clinic. Responses to these targeted interventions have ranged from substantial toxicity with no control of disease to periods of useful tumour control with no decrement in performance status of the treated individual. This experience enables recognition of the limits of targeted therapy, but has also informed methods to optimize this approach. This Review focuses on the clinically relevant molecular biology of brain metastases, and summarizes the current applications of these data to imaging, surgery, radiation therapy, cytotoxic chemotherapy and targeted therapy.

Brain metastases in non-small-cell lung cancer: better outcomes through current therapies and utilization of molecularly targeted approaches

Non-small-cell lung cancer (NSCLC) patients experience a high incidence of brain metastases, de novo and recurrent. We review the mechanisms of brain metastases and promising NSCLC molecular markers to delineate potential future therapeutic targets. Discussed are the current and previously utilized roles of surgery, radiation (both therapeutic and prophylactic), and systemic therapies in the treatment of NSCLC brain metastases. Future directions for treatment of NSCLC brain metastases will conclude our review.

Survival of patients with non-small-cell lung cancer after a diagnosis of brain metastases

BACKGROUND

The prognosis of patients with brain metastases from non-small-cell lung cancer (nsclc) is poor. However, some reports suggest that patients with brain metastases at the time of initial diagnosis have a more favourable survival than do patients with advanced nsclc without brain metastases.

METHODS

In a retrospective cohort of all new lung cancer patients seen at a Canadian tertiary centre between July 2005 and June 2007, we examined survival after a diagnosis of brain metastases for patients with brain metastases at initial diagnosis and patients who developed brain metastases later in their illness.

RESULTS

During the 2-year period, 91 of 878 patients (10.4%) developed brain metastases. Median age in this cohort was 64 years. In 45, brain metastases were present at initial diagnosis, and in 46, brain metastases developed later in the course of the illness. Median survival in the entire cohort was 7.8 months. Survival after the diagnosis of brain metastases was similar for patients with brain metastases at diagnosis and later in the illness (4.8 months vs. 3.7 months, p = 0.53). As a result, patients who developed brain metastases later in their illness had a longer overall survival than did patients with brain metastases at diagnosis (9.8 months vs. 4.8 months). Among patients who received chemotherapy, the survival of patients with brain metastases at diagnosis was still poor (6.2 months).

CONCLUSIONS

Our data show limited survival in patients with brain metastases from nsclc. Careful patient selection for more aggressive treatment approaches is necessary.

[Brain metastases of non small cell lung cancers: systemic treatments]

Chemotherapy, as all systemic treatments, is generally effective in brain metastases because the brain blood barrier (BBB) does not affect treatment's diffusion. Platinum-based chemotherapy provides response rates ranging from 23 to 50% for brain metastases. Anti-EGFR therapies are effective mostly when a somatic EGFR activating mutation is detected, or in selected population (adenocarcinoma, Asian population, never-smokers and women): response rate ranges from 38 to 69.6%. Bevacizumab is now allowed for non-small cell lung cancer (NSCLC) patients with brain metastases and non-squamous histology. The presence of untreated brain metastases may not influence its efficacy combined with paclitaxel-carboplatin. The best sequence for multimodality management of brain metastases has to be established but upfront systemic treatments in patients with asymptomatic brain metastases is a valid option.

Epidermal growth factor receptor tyrosine kinase inhibitors in the treatment of epidermal growth factor receptor-mutant non-small cell lung cancer metastatic to the brain

Brain metastases are a common and devastating consequence of disease progression in patients with non-small cell lung cancer (NSCLC). The epidermal growth factor receptor (EGFR) inhibitors erlotinib and gefitinib have shown efficacy in patients with NSCLC and brain metastases. The cerebrospinal fluid (CSF) exposure to these drugs is a small fraction of the plasma levels achieved with standard doses, but disruption of the blood-brain barrier in the presence of central nervous system metastases is likely to lead to locally increased drug concentration, and dose escalation to boost CSF exposure has documented clinical efficacy. The use of gefitinib and erlotinib in this setting is reviewed here, including evidence from case reports, case series, and single-arm phase II trials. High response rates in the brain are seen in patients with EGFR mutation, or in populations in which this genotype is expected. By contrast, activity in the context of documented wild-type EGFR in disease metastatic to the brain is not common. These drugs may potentiate the effectiveness of radiotherapy to the brain, and their use may also delay development of disease within the brain.

Two cases of leptomeningeal metastases from lung adenocarcinoma which progressed during gefitinib therapy but responded to erlotinib

We present two patients with leptomeningeal metastases (LM) from lung adenocarcinoma that progressed or newly developed, respectively, during gefitinib therapy which had exhibited substantial antitumor effects on widespread lesions. In both cases, a switch to erlotinib therapy brought about long-lasting dramatic symptomatic improvement and markedly prolonged survival. The first patient is a 46-year-old female who presented with progressive headache and vomiting. Multiple pulmonary, hepatic and bone metastases immediately shrank in response to gefitinib. However, 1 month after completion of concurrent whole brain radiation, dizziness and urinary retention newly emerged, worsening the symptoms observed at presentation. Magnetic resonance imaging (MRI) demonstrated enlargement of ventricles and new gadolinium (Gd)-enhanced disseminated nodules on the surface of the cerebral cortex, suggesting the existence of uncontrollable LM. Sequential erlotinib therapy resulted in symptomatic improvement with a finding of regression of Gd-enhancement on MRI. The beneficial effect lasted for 10 months, though a follow-up brain MRI showed further enlarged ventricles. She finally died due to LM after surviving for 11 months under erlotinib treatment. The other patient is a 55-year-old female in whom headache and vomiting occurred while gefitinib therapy had maintained shrinkage of all pre-existing tumors in the thorax and bones. Brain MRI strongly suggested occurrence of LM with a finding of Gd-enhanced sulci. A switch to erlotinib therapy relieved the symptoms with disappearance of Gd-enhancement. However, the symptoms recurred with a finding of further enlargement of ventricles on brain MRI after 11 months. Finally, she died due to LM after surviving for 12 months under erlotinib treatment.

[Management of brain metastases from non-small cell lung carcinoma]

INTRODUCTION

In France, approximately 30,000 new patients per year develop brain metastases (BM), most of them resulting from a lung cancer.

STATE OF THE ART

Surgery and radiosurgery of all the BM must be considered when possible. In other cases, whole brain radiotherapy remains the standard of care.

PERSPECTIVES

The role of chemotherapy, poorly investigated so far, should be revisited.

CONCLUSION

This review focused on BM secondary to a non-small cell lung carcinoma.

Combining temozolomide with other antitumor drugs and target-based agents in the treatment of brain metastases: an unending quest or chasing a chimera?

INTRODUCTION

Medical treatment of brain metastases (BM) is still a controversial issue in cancer therapy being mainly limited by the existence of the BBB. Temozolomide (TMZ) can cross BBB and several clinical trials have been performed attempting to demonstrate the activity of TMZ in combination with whole brain radiotherapy (WBRT) in the treatment of BM.

AREAS COVERED

This review summarizes TMZ-WBRT combination trials highlighting the confounding factors that limit the interpretation of the achieved results and describes the main clinical trials using TMZ in combination with other cytotoxic or biological agents. The main limitations of these trials are: i) patient selection for heterogenous primitive neoplasms and for heterogeneous neuro-functional score; ii) poor penetration across BBB of the other drugs; iii) cumulative toxicity and iv) poor control of extracranial tumor sites.

EXPERT OPINION

Biotechnological, biological and biochemical advances in the management of BM could allow in short time the definition of new schedules based on the rational use of new anticancer weapons. The latter could be cytotoxic agents encapsulated in nanotechnological tools able to cross BBB, lipophilic small kinase inhibitors (lapatinib, sunitinib), mTOR inhibitors and PARP inhibitors combined with old drugs such as TMZ.

Cisplatin, fotemustine and whole-brain radiotherapy in non-small cell lung cancer patients with asymptomatic brain metastases: a multicenter phase II study of the Gruppo Oncologico Italia Meridionale (GOIM 2603)

BACKGROUND

More than 50% of brain metastases (BMs) occur in advanced non-small cell lung cancer (NSCLC) patients. Untreated patients with BMs have a poor prognosis with a median survival of 2 months. In most cases BMs are multiple and their optimal therapy is whole-brain radiation therapy (WBRT). The role of systemic therapies for these patients is still a matter for investigation due to concerns about the ability of these drugs to cross the blood-brain barrier (BBB). Cisplatin (CDDP) remains the backbone for medical treatment of NSCLC and fotemustine (FTM) is a nitrosurea able to cross the BBB.

METHODS

Patients with advanced NSCLC, ECOG performance status (PS) 0-1 and multiple BMs not amenable to surgery or stereotactic radiotherapy were treated with 2 cycles of FTM 80 mg/m(2) days 1, 8 and CDDP 80 mg/m(2) day 1, every 3 weeks followed by WBRT 30 Gy (3 Gy daily in 10 fractions). Radiological restaging was performed before WBRT to assess the role of chemotherapy both for cranial and extracranial disease. Patients with disease control (DC: complete response plus partial response) received 4 more cycles. To assess the basic activities of daily living (ADL), the Barthel ADL Index was used to score patients' performance every 2 cycles. The trial design provides a two-step evaluation according to the optimal two-stage design of Simon. In the first phase 29 patients were enrolled in order to verify if this schedule showed more than 25% response rate both for cranial and extracranial disease. If so, enrollment added up to a total of 81 patients.

RESULTS

After the first evaluation 4 out of 29 patients were excluded from the study (3 untreated/1 not included for administrative reasons). At the time of the planned interim analysis patient's characteristics were the following: median age 61 years (range 44-70), M/F = 16/9, adenocarcinoma 11, squamous 5, large cell 2, undefined NSCLC 7; PS 0/1 in 11/14 cases, median Barthel Index score was 20 [13-20]. Three (12%) partial responses were observed, 9 subjects (36%) with stable disease and 13 (52%) showing disease progression. These data did not satisfy the pre-planned hypothesis and the study was stopped. At the time of the first evaluation before WBRT 12/25 (48%) patients had a systemic DC in contrast with 15/25 (60%) patients with BMs DC. Chemotherapy was relatively well tolerated with a prevalence of asthenia as the most relevant specific toxicity while the haematological toxicity was mild.

CONCLUSION

CDDP and FTM combined with WBRT do not represent a therapeutic option for patients with NSCLC. Therefore further studies to evaluate the combination of systemic treatments with WBRT are warranted.

Recursive Partitioning Analysis Groups II-III brain metastases of non-small cell lung cancer: a phase II randomized study comparing two concurrent chemoradiotherapy regimens

PURPOSE

To compare the response rates and safety profiles of two investigational chemotherapies that were delivered concurrently with whole-brain radiotherapy in a population of patients with chemonaive non-small cell lung cancer.

METHODS

Eligible patients included those presenting with brain metastases belonging to the Recursive Partitioning Analysis of prognostic factors from the Radiation Therapy Oncology groups II or III, who were not able to undergo surgery or stereotactic radiotherapy. Other main eligibility criteria were age <75 years and Eastern Cooperative Oncology Group performance status = 0 to 2. The study design was as follows: all patients received whole-brain radiotherapy in three split courses of 18 gy/10 fractions. They were randomly (1:1) assigned to regimen A, consisting of a triplet cisplatin-vinorelbine-ifosfomide, or to regimen B, consisting of high-dose single-drug ifosfamide. In both groups, chemotherapy was delivered on a 4-week cycle, for three courses. Each course was delivered concurrently with radiotherapy. Brain and other tumor lesion assessments were performed in both groups at the end of the three courses (RECIST). Neurologic symptoms were evaluated quantitatively at each step of the treatment program. All analyses were carried out in an intention to treat basis, and statistical tests were two sided.

RESULTS

Seventy patients were randomly allocated into groups A (n = 37) and B (n = 33). With regards to the whole lesions, overall response rates did not significantly differ between the groups (group A: 45.9%; group B: 33.3%; chi(2); p = 0.28). When brain-target lesions were separately analyzed, respective response rates were 59.5% and 48.5%; (chi(2); p = 0.0.53). Febrile neutropenia was more frequently observed in the former group (n = 19, 54.29%) than in the latter (n = 12, 36.36%; p = 0.13), and a similar difference was also observed regarding documented infections. Red blood cell transfusions and readmission for antibiotic infusions significantly affected more patients in group A than in group B. The longitudinal evaluation of neurologic symptoms (by means of Generalized Estimating Equation) slightly improved during the treatment program, and there was no difference between the groups. Median overall survival did not significantly differ between the two groups (months [95% confidence interval], 8.5 [6.4-10.8] and 5.7 [4.6-11.9] in groups A B, respectively; p= 0.82). In the Cox model, a high neuron-specific enolase serum level was the only significant prognostic determinant.

CONCLUSION

Both regimens were active and induced a high rate of response, particularly for brain-target lesions. Myelotoxicity jeopardizes the acceptability of both regimens. Despite such an aggressive approach, none of the regimens suggested a putative overall improvement of outcome in this poor prognosis presentation of metastatic non-small cell lung cancer. The search for alternative therapies to chemotherapy, such as targeted therapy, is urgently warranted in this setting.