A Neuro-oncologist's Perspective on Management of Brain Metastases in Patients with EGFR Mutant Non-small Cell Lung Cancer

Brain Metastases and Leptomeningeal Disease

OBJECTIVE

Central nervous system (CNS) metastases include brain parenchymal, spinal cord, and leptomeningeal metastases. This article discusses the diagnostic and therapeutic advances of the last decade that have improved outcomes for patients with these CNS metastases.

LATEST DEVELOPMENTS

The diagnostic tools for CNS metastases, particularly leptomeningeal disease, have evolved over the past decade with respect to advancements in CSF analysis. Multiple medical therapies are now available for brain metastasis treatment that have shown CNS efficacy, including targeted therapies and antibody-drug conjugates. Molecular testing for CNS metastases has become more common and the repertoire of molecularly targeted therapies continues to expand. Advancements in radiation therapy, including improvements in stereotactic radiation techniques, whole-brain radiation with hippocampal avoidance, and proton beam radiation, have changed the radiation management of patients with CNS metastases. New intrathecal agents are currently being tested for the management of leptomeningeal metastases.

ESSENTIAL POINTS

CNS metastases are far more common than primary brain tumors and are increasing in prevalence in the setting of improved treatments and prolonged survival in patients with systemic cancers. There have been many changes in the diagnostics and treatment of CNS metastases, yielding subsequent improvements in patient outcomes with further advancements on the horizon.

Therapeutic effectiveness and safety of sequential ICIs with radiotherapy for symptomatic brain and bone metastases in NSCLC patients

In advanced non-small cell lung cancer (NSCLC), the brain and bones are common metastatic sites, and the disease seriously affects the survival time and quality of life. For metastatic lesions with symptoms, local treatment often precedes systemic treatment. However, in clinical trials, patients with symptomatic brain or bone metastases are often excluded. Therefore, limited data are available on the efficacy of immune checkpoint inhibitors (ICIs) in those patients. We aimed to evaluate the effectiveness and safety of local radiotherapy followed by ICIs in driver gene-negative NSCLC patients with symptomatic local metastasis in the brain and bone. This is a 29-month 2 centered retrospective cohort study performed in China between March 2019 and August 2021. A total of 22 patients with advanced NSCLC were included. All patients received radiotherapy in the brain or bone before the administration of ICIs. For all patients, the overall response rate was 59.09%, the median progression-free survival (PFS) was 7.5 months, the PFS rate at 6 months was 72.73%, and the PFS rate at 1 year was 13.64%. Waterfall plots showed that tumor size was mostly reduced compared with baseline. The spider map showed that the tumor continued to shrink. In terms of symptom improvement, 100% pain control and 83.33% improvement were observed in epilepsy and neurological function. Sequential ICIs with local radiotherapy is effective for the treatment of patients with symptomatic brain and bone metastases of driver gene-negative NSCLC, which will benefit patients and improve their symptoms.

Advances in the Diagnosis and Treatment of Leptomeningeal Disease

PURPOSE OF REVIEW

Leptomeningeal disease (LMD) is a rare, late complication of systemic cancer and is associated with significant neurological morbidity and high mortality. Here we provide an overview of this condition, summarizing key recent research findings and clinical practice trends in its diagnosis and treatment. We also review current clinical trials for LMD.

RECENT FINDINGS

Improved molecular diagnostic tools are in development to enable more sensitive detection of LMD, including circulating tumor cells and circulating tumor DNA. The use of targeted and CNS-penetrant therapeutics has shown survival improvements with tyrosine kinase inhibitors, antibody-drug conjugates, and select chemotherapy. However, these studies have primarily been phase I/II and retrospective analyses. There remains a dearth of clinical trials that include LMD patients. The combination of patient-specific molecular information and novel therapeutic approaches holds significant promise for improving outcomes in patients with LMD.

Research Progress and Challenges in the Treatment of Central Nervous System Metastasis of Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors and has high morbidity and mortality rates. Central nervous system (CNS) metastasis is one of the most frequent complications in patients with NSCLC and seriously affects the quality of life (QOL) and overall survival (OS) of patients, with a median OS of untreated patients of only 1-3 months. There are various treatment methods for NSCLC CNS metastasis, including surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy, which do not meet the requirements of patients in terms of improving OS and QOL. There are still many problems in the treatment of NSCLC CNS metastasis that need to be solved urgently. This review summarizes the research progress in the treatment of NSCLC CNS metastasis to provide a reference for clinical practice.

Erlotinib for Non-Small Cell Lung Cancer with Leptomeningeal Metastases: A Phase II Study (LOGIK1101)

LESSONS LEARNED

This phase II trial evaluated the efficacy of erlotinib for patients with non-small cell lung cancer with leptomeningeal metastasis. The 17 cerebrospinal fluid specimens that were available for epidermal growth factor receptor mutation analysis were all negative for the resistance-conferring T790M mutation. The cytological objective clearance rate was 30.0% (95% confidence interval: 11.9%-54.3%). The median time to progression was 2.2 months. The rate of cerebrospinal fluid penetration among these patients was equivalent to those in previous reports regarding leptomeningeal metastasis.

BACKGROUND

Leptomeningeal metastases (LM) occur in approximately 5% of patients with non-small cell lung cancer (NSCLC) and are associated with a poor prognosis. However, no prospective study has identified an active chemotherapeutic drug in this setting.

METHODS

Patients were considered eligible to receive erlotinib if they had NSCLC with cytologically confirmed LM. The objective cytological clearance rate, time to LM progression (TTP), overall survival (OS), quality of life outcomes, and pharmacokinetics were analyzed. This study was closed because of slow accrual at 21 of the intended 32 patients (66%).

RESULTS

Between December 2011 and May 2015, 21 patients (17 with activating epidermal growth factor receptor [EGFR] mutations) were enrolled. The 17 cerebrospinal fluid specimens available were all negative for the T790M mutation, which confers erlotinib resistance. The clearance rate was 30.0% (95% confidence interval [CI]: 11.9%-54.3%), the median TTP was 2.2 months, and the median OS was 3.4 months. Significantly longer TTP and OS times were observed in patients with mutant EGFR (p = .0113 and p < .0054, respectively). The mean cerebrospinal fluid penetration rate was 3.31% ± 0.77%. There was a good correlation between plasma and cerebrospinal fluid (CSF) concentrations, although there was no clear correlation between pharmacokinetic parameters and clinical outcome.

CONCLUSION

Erlotinib was active for LM and may be a treatment option for patients with EGFR-mutated NSCLC and LM.

Complete Remission of Multiple Brain Metastases in a Patient with EGFR-Mutated Non-Small-Cell Lung Cancer Treated with First-Line Osimertinib without Radiotherapy

Osimertinib has demonstrated efficacy against stable or asymptomatic central nervous system (CNS) metastases of epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) in phase 2 and 3 clinical trials that allowed prior CNS radiotherapy. However, the efficacy of osimertinib only or the optimal treatment combination or sequence of radiotherapy has not been investigated. A 74-year-old woman diagnosed with T4N1M1c Stage IVB lung adenocarcinoma with EGFR mutation presented with a left upper lobe mass and multiple bilateral lung metastases. A total of more than 20 asymptomatic multiple brain metastases with a maximum diameter of 12 mm were diagnosed simultaneously. Osimertinib was administered as first-line treatment. Whole brain radiotherapy was deferred because she had no neurological symptoms. After 5 weeks, the multiple brain metastases disappeared completely, together with the response in the lung lesions. This case demonstrated that first-line treatment with osimertinib could even achieve complete remission of multiple brain metastases comprising as many as twenty lesions of EGFR-mutated NSCLC without radiation therapy. Radiation therapy for brain metastases can be deferred or even withheld. A new treatment strategy for EGFR mutated NSCLC with CNS metastases should be investigated using osimertinib, especially regarding optimal combination or sequence of radiotherapy.

Dacomitinib in non-small-cell lung cancer: a comprehensive review for clinical application

Dacomitinib is a second-generation EGFR tyrosine kinase inhibitor (TKI) that irreversibly binds to and inhibits EGFR/Her1, Her2 and Her4 subtypes with an efficacy comparable to other TKIs. In the ARCHER 1050 trial, progression-free survival was improved by dacomitinib compared with gefitinib, supporting dacomitinib as a first-line treatment option for advanced non-small-cell lung cancer with sensitive EGFR mutation. Regarding to the higher adverse events rate, dose reductions did not reduce the efficacy of dacomitinib and could effectively decreased the incidence and severity of adverse events. Considering the evolving landscape of EGFR-mutant non-small-cell lung cancer, future head to head comparison between dacomitinib and osimertinib could provide key information to determine the optimal TKI treatment schedule.

Afatinib for Advanced Non-small Cell Lung Cancer in a Case With an Uncommon Epidermal Growth Factor Receptor Mutation (G719A) Identified in the Cerebrospinal Fluid

Few previous studies of patients with non-small cell lung cancer (NSCLC) and leptomeningeal metastases have used liquid biopsy of cerebrospinal fluid (CSF) to identify epidermal growth factor receptor (EGFR) mutations and guide therapy. A 34-year-old male patient with NSCLC and leptomeningeal metastases was admitted to the Interventional Radiology Department, Tianjin Huanhu Hospital on 18th April 2018 after showing no response to chemoradiotherapy. On admission, the patient was in critical condition with an estimated survival <1 month. A ventriculoperitoneal shunt was placed in the right lateral ventricle. The CSF level of carcinoembryonic antigen (CEA) was 9,869 ng/mL. Next-generation sequencing (NGS) of the CSF revealed an EGFR G719A mutation (frequency: 55.63%), whereas sequencing of circulating tumor DNA or cells in the peripheral blood identified no clinically significant mutations. Afatinib therapy was initiated based on the NGS results. During follow-up, the patient's symptoms improved, ventricular dilatation lessened, and pulmonary lesions decreased in size. At the last follow-up (7 months), the patient continued to show a good response to afatinib therapy with minimal adverse effects. This is the first clinical study to report the use of simultaneous genetic testing of CSF and peripheral blood to guide the successful implementation of afatinib therapy in a patient with NSCLC and leptomeningeal metastases. Notably, NGS of CSF was superior to genetic testing of peripheral blood at identifying an uncommon EGFR mutation (G719A) in a patient with NSCLC and leptomeningeal metastases.

Targeting lonidamine to mitochondria mitigates lung tumorigenesis and brain metastasis

Lung cancer often has a poor prognosis, with brain metastases a major reason for mortality. We modified lonidamine (LND), an antiglycolytic drug with limited efficacy, to mitochondria-targeted mito-lonidamine (Mito-LND) which is 100-fold more potent. Mito-LND, a tumor-selective inhibitor of oxidative phosphorylation, inhibits mitochondrial bioenergetics in lung cancer cells and mitigates lung cancer cell viability, growth, progression, and metastasis of lung cancer xenografts in mice. Mito-LND blocks lung tumor development and brain metastasis by inhibiting mitochondrial bioenergetics, stimulating the formation of reactive oxygen species, oxidizing mitochondrial peroxiredoxin, inactivating AKT/mTOR/p70S6K signaling, and inducing autophagic cell death in lung cancer cells. Mito-LND causes no toxicity in mice even when administered for eight weeks at 50 times the effective cancer inhibitory dose. Collectively, these findings show that mitochondrial targeting of LND is a promising therapeutic approach for investigating the role of autophagy in mitigating lung cancer development and brain metastasis.

EGFR first- and second-generation TKIs-there is still place for them in EGFR-mutant NSCLC patients

Identification of epidermal growth factor receptor (EGFR) as a molecular target has radically changed the treatment of metastatic non-small cell lung cancer (NSCLC) from standard chemotherapy to personalized, targeted therapy. First-, second- and third-generation EGFR tyrosine kinase inhibitors (TKIs) are now available for the treatment of EGFR-mutant NSCLC patients. This review will focus on the clinical development of first- and second-generation EGFR TKIs. We will emphasize on essential points like the head-to-head comparison among EGFR TKIs, their activity on brain metastases, mechanisms of resistance, as well as their combination with anti-angiogenic compounds, other targeted therapies, or immunotherapy. The efficacy of first- and second-generation EGFR TKIs in early-stage EGFR-mutant NSCLC will be also finally reviewed.

Management of Brain Metastases in Epidermal Growth Factor Receptor Mutant Non-Small-Cell Lung Cancer

Lung cancer remains a leading cause of mortality with 1.69 million deaths worldwide. Activating mutations in epidermal growth factor receptor (EGFR), predominantly exon 19 deletions and exon 21 L858R mutations, are known oncogenic drivers identified in 20-40% of non-small-cell lung cancers (NSCLC). 70% of EGFR-mutant NSCLC patients develop brain metastases (BM), compared to 38% in EGFR wild-type patients. First-generation tyrosine kinase inhibitors (TKIs), such as erlotinib and gefitinib have proven to be superior to chemotherapy in the front-line treatment of EGFR-mutant NSCLC, as has afatinib, a second-generation TKI. The most common acquired resistance mechanism is the development of a gatekeeper mutation in exon 20 T790M. Osimertinib has emerged as a third-generation EGFR TKI with proven activity in the front-line setting as well as in patients with a T790M acquired resistance mutation with remarkable CNS activity. As long-term survival outcomes in EGFR-mutant NSCLC continue to improve, the burden of BM becomes a greater challenge. Here, we review the literature related to the management of BM in EGFR-mutant NSCLC including the role of the three generations of EGFR TKIs, immunotherapy, and brain radiation.

IL‑17 induces NSCLC A549 cell proliferation via the upregulation of HMGA1, resulting in an increased cyclin D1 expression

Non-small cell lung cancer (NSCLC) is considered to be an inflammation-associated carcinoma. Although interleukin‑17 (IL‑17) production contributes to the proliferation and growth of NSCLC, the mechanisms underlying IL‑17-induced NSCLC cell proliferation have not been fully elucidated. In the present study, by using ELISA and immunohistochemical analyses, we first found that the expression levels of IL‑17, IL‑17 receptor (IL‑17R), high-mobility group A1 (HMGA1) and cyclin D1 were elevated in the samples of patients with NSCLC. Subsequently, by RT-qPCR, western blot analysis and cell proliferation assay in vitro, we revealed that stimulation with recombinant human IL‑17 (namely IL‑17A) markedly induced the expression of HMGA1 and cyclin D1 in the A549 cells (a human lung adenocarcinoma cell line) and promoted cell proliferation. Furthermore, luciferase reporter and ChIP assays confirmed that upregulated HMGA1 directly bound to the cyclin D1 gene promoter and activated its transcription. Notably, the response element of HMGA1 binding to the cyclin D1 promoter was disclosed for the first time, at least to the best of our knowledge. Taken together, our findings indicate that the IL‑17/HMGA1/cyclin D1 axis plays an important role in NSCLC cell proliferation and may provide new insight into NSCLC pathogenesis and may thus aid in the development of novel therapeutic targets for NSCLC.

Emerging uses of biomarkers in lung cancer management: molecular mechanisms of resistance

Management of patients with advanced non-small cell lung cancer (NSCLC) has recently been transformed by molecularly targeted and immunotherapeutic agents. In patients with EGFR/ALK/ROS mutated NSCLC, first line molecular therapy is the standard of care. Moreover, immune checkpoint inhibitors are revolutionary treatment options for advanced NSCLC and are now the standard of care in front-line or later line settings. Both classes of agents have led to improved patient outcomes, however, primary resistance and development of acquired resistance to both targeted and immunotherapeutic agents is commonly observed, limiting the use of these agents in clinical settings. In this review, we will discuss the most recent advances in understanding the mechanisms of primary and acquired resistance, progress in the spectrum of assays detecting causative molecular events and the development of new generations of inhibitors to overcome acquired resistance.