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

The Riddle of the Sphinx: Progress in Leptomeningeal Metastasis of Non-Small Cell Lung Cancer

Leptomeningeal metastasis (LM) is a serious complication of advanced non-small cell lung cancer (NSCLC), and the incidence of LM has been increasing yearly in recent times. There is no consensus on the best treatment modality for LM, which underscores a difficult problem in the management of advanced NSCLC patients. The existing treatments include molecular targeted therapy, systemic chemotherapy, local radiotherapy, antivascular tumor therapy, intrathecal chemotherapy, and immunotherapy, but their efficacy is not satisfactory. In this article, we briefly describe the clinical manifestations, diagnosis, and treatment of NSCLC-LM and discuss progress regarding evaluation of the efficacy of LM treatment to better provide a necessary reference for clinical practice and clinical trial evaluation.

Management Paradigm of Central Nervous System Metastases in NSCLC: An Australian Perspective

Life-prolonging central nervous system active systemic therapies for metastatic NSCLC have increased the complexity of managing brain metastases (BMs). Australian medical oncologists, radiation oncologists, and neurosurgeons discussed the evidence guiding the diverse clinical approaches to the management of BM in NSCLC. The Australian context is broadly applicable to other jurisdictions; therefore, we have documented these discussions as principles with broader applications. Patient management was stratified according to clinical and radiologic factors under two broad classifications of newly diagnosed BMs: symptomatic and asymptomatic. Other important considerations include the number and location of metastases, tumor histotypes, molecular subtype, and treatment purpose. Careful consideration of the pace and burden of symptoms, risk of worsening neurologic function at a short interval, and extracranial disease burden should determine whether central nervous system active systemic therapies are used alone or in combination with local therapies (surgery with or without radiation therapy). Most clinical trial evidence currently focuses on historical treatment options or a single treatment modality rather than the optimal sequencing of multiple modern therapies; therefore, an individualized approach is key in a rapidly changing therapeutic landscape.

Diagnostic and Therapeutic Updates in Leptomeningeal Disease

PURPOSE OF REVIEW

Leptomeningeal disease (LMD) is a devastating complication of advanced metastatic cancer associated with a poor prognosis and limited treatment options. This study reviews the current understanding of the clinical presentation, pathogenesis, diagnosis, and treatment of LMD. We highlight opportunities for advances in this disease.

RECENT FINDINGS

In recent years, the use of soluble CSF biomarkers has expanded, suggesting improved sensitivity over traditional cytology, identification of targetable mutations, and potential utility for monitoring disease burden. Recent studies of targeted small molecules and intrathecal based therapies have demonstrated an increase in overall and progression-free survival. In addition, there are several ongoing trials evaluating immunotherapy in LMD. Though overall prognosis of LMD remains poor, studies suggest a potential role for soluble CSF biomarkers in diagnosis and management and demonstrate promising findings in patient outcomes with targeted therapies for specific solid tumors. Despite these advances, there continues to be a gap of knowledge in this disease, emphasizing the importance of inclusion of LMD patients in clinical trials.

Single-cell transcriptomic analyses provide insights into the cellular origins and drivers of brain metastasis from lung adenocarcinoma

BACKGROUND

Brain metastasis (BM) is the most common intracranial malignancy causing significant mortality, and lung cancer is the most common origin of BM. However, the cellular origins and drivers of BM from lung adenocarcinoma (LUAD) have yet to be defined.

METHODS

The cellular constitutions were characterized by single-cell transcriptomic profiles of 11 LUAD primary tumor (PT) and 10 BM samples (GSE131907). Copy number variation (CNV) and clonality analysis were applied to illustrate the cellular origins of BM tumors. Brain metastasis-associated epithelial cells (BMAECs) were identified by pseudotime trajectory analysis. By using machine-learning algorithms, we developed the BM-index representing the relative abundance of BMAECs in the bulk RNA-seq data indicating a high risk of BM. Therapeutic drugs targeting BMAECs were predicted based on the drug sensitivity data of cancer cell lines.

RESULTS

Differences in macrophages and T cells between PTs and BMs were investigated by single-cell RNA (scRNA) and immunohistochemistry and immunofluorescence data. CNV analysis demonstrated BM was derived from subclones of PT with a gain of chromosome 7. We then identified BMAECs and their biomarker, S100A9. Immunofluorescence indicated strong correlations of BMAECs with metastasis and prognosis evaluated by the paired PT and BM samples from Peking Union Medical College Hospital. We further evaluated the clinical significance of the BM-index and identified 7 drugs that potentially target BMAECs.

CONCLUSIONS

This study clarified possible cellular origins and drivers of metastatic LUAD at the single-cell level and laid a foundation for early detection of LUAD patients with a high risk of BM.

Leptomeningeal Metastasis: A Review of the Pathophysiology, Diagnostic Methodology, and Therapeutic Landscape

The present review aimed to establish an understanding of the pathophysiology of leptomeningeal disease as it relates to late-stage development among different cancer types. For our purposes, the focused metastatic malignancies include breast cancer, lung cancer, melanoma, primary central nervous system tumors, and hematologic cancers (lymphoma, leukemia, and multiple myeloma). Of note, our discussion was limited to cancer-specific leptomeningeal metastases secondary to the aforementioned primary cancers. LMD mechanisms secondary to non-cancerous pathologies, such as infection or inflammation of the leptomeningeal layer, were excluded from our scope of review. Furthermore, we intended to characterize general leptomeningeal disease, including the specific anatomical infiltration process/area, CSF dissemination, manifesting clinical symptoms in patients afflicted with the disease, detection mechanisms, imaging modalities, and treatment therapies (both preclinical and clinical). Of these parameters, leptomeningeal disease across different primary cancers shares several features. Pathophysiology regarding the development of CNS involvement within the mentioned cancer subtypes is similar in nature and progression of disease. Consequently, detection of leptomeningeal disease, regardless of cancer type, employs several of the same techniques. Cerebrospinal fluid analysis in combination with varied imaging (CT, MRI, and PET-CT) has been noted in the current literature as the gold standard in the diagnosis of leptomeningeal metastasis. Treatment options for the disease are both varied and currently in development, given the rarity of these cases. Our review details the differences in leptomeningeal disease as they pertain through the lens of several different cancer subtypes in an effort to highlight the current state of targeted therapy, the potential shortcomings in treatment, and the direction of preclinical and clinical treatments in the future. As there is a lack of comprehensive reviews that seek to characterize leptomeningeal metastasis from various solid and hematologic cancers altogether, the authors intended to highlight not only the overlapping mechanisms but also the distinct patterning of disease detection and progression as a means to uniquely treat each metastasis type. The scarcity of LMD cases poses a barrier to more robust evaluations of this pathology. However, as treatments for primary cancers have improved over time, so has the incidence of LMD. The increase in diagnosed cases only represents a small fraction of LMD-afflicted patients. More often than not, LMD is determined upon autopsy. The motivation behind this review stems from the increased capacity to study LMD in spite of scarcity or poor patient prognosis. In vitro analysis of leptomeningeal cancer cells has allowed researchers to approach this disease at the level of cancer subtypes and markers. We ultimately hope to facilitate the clinical translation of LMD research through our discourse.

Imaging of brain metastasis in non-small-cell lung cancer: indications, protocols, diagnosis, post-therapy imaging, and implications regarding management

Increased survival (due to the use of targeted therapies based on genomic profiling) has resulted in the increased incidence of brain metastasis during the course of disease, and thus, made it essential to have proper imaging guidelines in place for brain metastasis from non-small-cell lung cancer (NSCLC). Brain parenchymal metastases can have varied imaging appearances, and it is pertinent to be aware of the various molecular risk factors for brain metastasis from NSCLC along with their suggestive imaging appearances, so as to identify them early. Leptomeningeal metastasis requires additional imaging of the spine and an early cerebrospinal fluid (CSF) analysis. Differentiation of post-therapy change from recurrence on imaging has a bearing on the management, hence the need for its awareness. This article will provide in-depth literature review of the epidemiology, aetiopathogenesis, screening, detection, diagnosis, post-therapy imaging, and implications regarding the management of brain metastasis from NSCLC. In addition, we will also briefly highlight the role of artificial intelligence (AI) in brain metastasis screening.

Case report: Cerebrospinal fluid-derived circulating tumor DNA diagnoses and guides the treatment of a lung adenocarcinoma case with leptomeningeal metastasis

Leptomeningeal metastasis (LM) occurs in 3~5% of non-small cell lung cancer (NSCLC) patients. Diagnosis of patients with LM and disease monitoring remains challenging due to the low sensitivity and specificity of the commonly used approaches, such as cerebrospinal fluid (CSF) cytology and magnetic resonance imaging (MRI). Therefore, new approaches are necessary to improve the detection of LM. Recent studies have shown that circulating tumor DNA (ctDNA) in CSF can be used to detect and monitor LM, but whether it can serve as an early diagnostic biomarker prior to cytological and radiographic evidence of LM involvement requires further evaluation. Here we report a lung adenocarcinoma patient who had detectable oncogenic mutations in the CSF ctDNA prior to confirmation of LM by CSF cytology and MRI, highlighting the potential application of CSF ctDNA in early detection of LM.

A Retrospective Study of Intrathecal Pemetrexed Combined With Systemic Therapy for Leptomeningeal Metastasis of Lung Cancer

Objective This retrospective study aimed to investigate the clinical features of lung cancer patients with leptomeningeal metastasis (LM) and explore the clinical efficacy and tolerance of intrathecal pemetrexed (IP) combined with systemic antitumor therapy. Methods Thirty-four lung cancer patients (11 men, 23 women) with LM receiving IP at our hospital were retrospectively reviewed between August 2018 and December 2019. Identified cases showed either positive cerebrospinal fluid cytology or typical findings (leptomeningeal enhancement or ventricle broadening) upon imaging examination. Results Before the diagnosis of LM, 24 (70.6%) patients received EGFR-TKI therapy with or without other agents (antivascular therapy, or chemotherapy), 5 (14.7%) patients received chemotherapy, 1 (2.9%) patient received antivascular therapy, and 3 (8.8%) patients received ALK inhibitors. Fourteen (41.2%) patients did not change the systematic regimen at the beginning of IP, while 20 (58.8%) patients changed to antitumor agents. IP was administered for a median of 3 times (range, 1-12 times). The IP dose was 15, 20, 25, 30, and 40 mg in 8 (23.5%), 21 (58.8%), 2 (5.9%), 2 (5.9%), and 1 (5.9%) patient, respectively. In all IP dose levels, the major adverse events were myelosuppression and elevation of hepatic aminotransferases (EHA). Grade 1/2 myelosuppression occurred in 4 (11.8%) patients. Grade 1/2 EHA also occurred in 4 (11.8%) patients. Grades 3/4 adverse events were not observed. After IP and systematic therapy, the clinical manifestations related to LM in 26 (76.5%) patients improved. In the whole cohort, the median overall survival was 20 months. The median time from the initial IP administration until death or the last follow-up was 3.5 months. Conclusions IP showed controllable toxicity and good efficacy, prolonged the survival time, and improved the quality of life when combined with tailored systemic antitumor therapy in lung cancer patients.

Two Cases of Cranial Nerve Metastasis Treated with Radiotherapy and Chemotherapy in Patients with Lung Adenocarcinoma

The incidence of central nervous system metastasis is known to be high among patients with lung cancer. The frequency of brain metastasis and carcinomatous meningitis during the entire clinical course of non-small cell lung cancer is reported to be about 40% and 5%, respectively. In contrast, the incidence of cranial nerve metastasis is extremely rare, and detailed reports of its clinical course remain limited. Herein, we report 2 patients diagnosed with cranial nerve metastasis of lung adenocarcinoma and treated with radiotherapy and systemic chemotherapy. Both patients had cranial nerve symptoms, and brain magnetic resonance imaging showed cranial nerve enhancement. However, no evidence of carcinomatous meningitis was noted on magnetic resonance imaging and cerebrospinal fluid cytology. Based on these observations, these patients were diagnosed with cranial nerve metastasis of lung adenocarcinoma. Radiotherapy and chemotherapy were performed in both cases. In both cases, neurological symptoms had not worsened and imaging findings did not indicate any deteriorations. Therefore, radiotherapy and systemic chemotherapy should be considered when treating cranial nerve metastasis of lung adenocarcinoma. Early therapeutic intervention may lead to attenuation of the cranial nerve dysfunction resulting from cranial nerve metastasis.

Identification and Characterization of Leptomeningeal Metastases Using SPINE, A Web-Based Collaborative Platform

BACKGROUND AND PURPOSE

Leptomeningeal metastases (LMs) carry a poor prognosis. Existing LM scoring systems show limited reproducibility. We assessed the contribution of education level on the reproducibility of LM scoring using structured planning and implementation of new experiments (SPINE), a novel web-based platform.

METHODS

Stringent radiological definitions of LM and a customized interactive scoring system were implemented in SPINE. Five patients with brain LM and 3 patients with spine, but no brain LM, were selected. Each patient's baseline post-contrast T1-weighted brain MRI was analyzed by three attending neuroradiologists, two neuroradiology fellows, and two radiology residents. Raters identified and characterized all LMs based on: (1) location (cerebrum, cerebellum, brainstem, ventricle, and/or cranial nerves); (2) shape (nodular and/or linear/curvilinear); (3) size (≥ or <5mm in two orthogonal diameters); (4) spatial extension (focal or diffuse). Inter-rater agreement and association of LM with patient survival were investigated.

RESULTS

On average, 6.5 LMs per case were detected. Forty-nine percent of LMs were cerebral, 77.7% were nodular, 86.6% were focal, and 66% were <5 × 5 mm. Agreement on the total number of LMs and the above-mentioned common LM characteristics was higher between attendings (intra-class correlation [ICC] = 0.8-0.94) than fellows (ICC = 0.6-0.82) or residents (ICC = 0.43-0.73). Agreement on ventricular, cranial nerve, and nodular + linear LM was low even between attendings. The number of brainstem LMs showed significant correlation with survival.

CONCLUSION

Structured education using SPINE may improve consistency in LM reporting. Future work should address the impact of the presented approach on the reproducibility of longitudinal analyses directly relevant to the assessment of treatment-response.

Management of leptomeningeal metastases in non-small cell lung cancer

In leptomeningeal metastasis (LM), malignant lung cancer cells reach the sanctuary site of the leptomeningeal space through haematogenous or lymphatic route and thrive in the leptomeninges because of restricted access of chemotherapeutic agents across the blood brain barrier. The incidence of LM is 3%-5% in non-small cell lung cancer (NSCLC) patients; the incidence is higher in patients with anaplastic lymphoma kinase (ALK) gene rearrangement or epidermal growth factor receptor (EGFR) mutations. However, the real-world burden of undiagnosed cases may be higher. LM diagnosis is based on clinical, radiological, and cytological testing. Disease management remains a challenge because of low central nervous system penetration of drugs. The prognosis of NSCLC patients with LM is poor with an overall survival (OS) of 3 months with contemporary treatment and <11 months with novel therapies. Therapy goals in this patient population are to improve or stabilize neurologic status, improve quality of life, and prolong survival while limiting the toxicity of chemotherapeutic regimens. We reviewed therapeutic options for management of LM in NSCLC patients with or without genetic mutations. Radiotherapy, systemic, or intrathecal chemotherapy, and personalized molecularly targeted therapy prolong the OS in patients with LM. Newer third generation EGFR-tyrosine kinase inhibitors have considerable brain penetration property and have been vital in increasing the OS especially in patients with EGFR mutations. Sequential or combination therapy third generation EGFR agents with radiotherapy or chemotherapy might be effective in increasing the quality of life and overall survival.

The clinical characteristic and prognostic factors of leptomeningeal metastasis in patients with non-small-cell lung cancer-a retrospective study from one single cancer institute

Background

Leptomeningeal metastasis (LM) is a detrimental complication of advanced non‐small‐cell lung cancer (NSCLC), and the optimal therapeutic approach for LM patients is in shortage. This retrospective study aimed to investigate the clinical features and prognostic factors of NSCLC patients with LM.

Methods

We retrospectively reviewed the medical records of NSCLC patients with LM at the Shandong Cancer Hospital and Institute between July 2014 and March 2018. Identified cases had pathology‐proven NSCLC with either positive cerebrospinal fluid cytology or leptomeningeal enhancement by MRI.

Results

One hundred and thirty‐six NSCLC patients (58 men, 78 women) with LM were enrolled in the retrospective study; median age was 55 years (range, 29‐89 years). Fifty‐one patients harbored EGFR mutations, ALK rearrangement was detected in 6 patients. Treatment for LM consisted of EGFR‐TKIs alone in 11 patients, whole brain radiotherapy (WBRT) alone in 19 patients, Chemotherapy (ChT) alone in 12 patients, EGFR‐TKIs plus WBRT in 30 patients, WBRT plus ChT in 25 patients, and EGFR‐TKIs plus ChT in 24 patients. The median progression‐free survival was 3.9 months (95% confidence interval [CI]: 3.178‐4.622), and the median overall survival (OS_LM) was 9.8 months (95% CI:7.5‐12.1). Thirty patients who received WBRT plus EGFR‐TKIs achieved longer survival than those who only received WBRT (median 13.6 vs 8.8 months; P = 0.027), but did not add any survival benefit than those only received EGFR‐TKIs (median 13.6 vs 13.9 months; P = 0.352). A multivariate analysis indicated that KPS ≥ 80 (hazard ratio [HR] = 0.592, 95% CI:0.369‐0.95; P = 0.03) and EGFR‐TKIs (HR = 0.507, 95% CI:0.283‐0.908; P = 0.022) after LM diagnosis were independent favourable predictors of survival, whereas smoking (HR = 1.181, 95% CI:1.009‐3.246; P = 0.047) was an independent predictor of poor survival.

Conclusions

Our results suggest that patients with good performance statuses, non‐smoking patients, and the administration of EGFR‐TKIs might improve clinical outcomes in NSCLC patients with LM.

Outcome of Patients with Non-Small Cell Lung Cancer and Brain Metastases Treated with Checkpoint Inhibitors

INTRODUCTION

Although frequent in NSCLC, patients with brain metastases (BMs) are often excluded from immune checkpoint inhibitor (ICI) trials. We evaluated BM outcome in a less-selected NSCLC cohort.

METHODS

Data from consecutive patients with advanced ICI-treated NSCLC were collected. Active BMs were defined as new and/or growing lesions without any subsequent local treatment before the start of ICI treatment. Objective response rate (ORR), progression-free survival, and overall survival (OS) were evaluated. Multivariate analyses were performed by using a Cox proportional hazards model and logistic regression.

RESULTS

A total of 1025 patients were included; the median follow-up time from start of ICI treatment was 15.8 months. Of these patients, 255 (24.9%) had BMs (39.2% active, 14.3% symptomatic, and 27.4% being treated with steroids). Disease-specific Graded Prognostic Assessment (ds-GPA) score was known for 94.5% of patients (35.7% with a score of 0-1, 58.5% with a score of 1.5-2.5, and 5.8% with a score of 3). The ORRs with BM versus without BM were similar: 20.6% (with BM) versus 22.7% (without BM) (p = 0.484). The intracranial ORR (active BM with follow-up brain imaging [n = 73]) was 27.3%. The median progression-free survival times were 1.7 (95% confidence interval [CI]: 1.5-2.1) and 2.1 (95% CI: 1.9-2.5) months, respectively (p = 0.009). Of the patients with BMs, 12.7% had a dissociated cranial-extracranial response and two (0.8%) had brain pseudoprogression. Brain progression occurred more in active BM than in stable BM (54.2% versus 30% [p < 0.001]). The median OS times were 8.6 months (95% CI: 6.8-12.0) with BM and 11.4 months (95% CI: 8.6-13.8) months with no BM (p = 0.035). In the BM subgroup multivariate analysis, corticosteroid use (hazard ratio [HR] = 2.37) was associated with poorer OS, whereas stable BMs (HR = 0.62) and higher ds-GPA classification (HR = 0.48-0.52) were associated with improved OS.

CONCLUSION

In multivariate analysis BMs are not associated with a poorer survival in patients with ICI-treated NSCLC. Stable patients with BM without baseline corticosteroids and a good ds-GPA classification have the best prognosis.