Challenges and Advances in Diagnosis and Treatment of Leptomeningeal Disease (LMD)

A Microfluidic, Multi-Antibody Cell Capture Method to Evaluate Tumor Cells in Cerebrospinal Fluid in Patients With Suspected Leptomeningeal Metastases

CONTEXT.—

Leptomeningeal disease (LMD) is a clinical sequela of central nervous system metastasis involving the cerebrospinal fluid (CSF), often seen in late-stage solid tumors. It has a grave prognosis without urgent treatment. Standard of care methodologies to diagnose LMD include CSF cytology, magnetic resonance imaging, and clinical evaluation. These methods offer limited sensitivity and specificity for the evaluation of LMD. Here, we describe the analytic performance characteristics of a microfluidic-based tumor cell enrichment and detection assay optimized to detect epithelial cells in CSF using both contrived samples as well as CSF from patients having suspected or confirmed LMD from carcinomas.

OBJECTIVE.—

To demonstrate the feasibility of using a microfluidic, multi-antibody cell capture assay to identify and quantify tumor cells in CSF.

DESIGN.—

An artificial CSF solution was spiked with 34 different human carcinoma cell lines at different concentrations and assayed for the ability to detect tumor cells to assess analytic accuracy. Two cell lines were selected to assess linearity, intra-assay precision, interinstrument precision, and sample stability. Clinical verification was performed on 65 CSF specimens from patients. Parameters assessed included the number of tumor cells, coefficient of variation percentage, and percentage of tumor cell capture (TCC).

RESULTS.—

Among contrived samples, average tumor cell capture ranged from 50% to 82% (261 of 522; 436 of 531), and coefficients of variation ranged from 7% to 67%. The cell capture assay demonstrated a sensitivity of 92% and a specificity of 95% among clinical samples.

CONCLUSIONS.—

This assay demonstrated the ability to detect and enumerate epithelial cells in contrived and clinical specimens in an accurate and reproducible fashion. The use of cell capture assays in CSF may be useful as a sensitive test for the diagnosis and longitudinal monitoring of LMD from solid tumors.

Longitudinal CSF Tumor Cell Enumeration and Mutational Analysis as a Driver for Leptomeningeal Disease Management

BACKGROUND

Leptomeningeal disease (LMD) is challenging to diagnose and monitor given the poor sensitivity of current gold-standard diagnostics. Cerebrospinal fluid tumor cells (CSF-TCs) have been studied as a biomarker for disease management because oncogene amplification of the primary, metastatic, and CNS metastatic tumors can be heterogeneous. The CNSide platform enumerates CSF-TCs and analyzes oncogene expression via immunocytochemistry (ICC), fluorescent in situ hybridization (FISH), and next-generation sequencing (NGS). We report the utility of this combined enumerative and mutational testing for LMD diagnosis and disease monitoring.

METHODS

A multicenter, retrospective analysis of commercially ordered assays from two health systems between January 2020 and July 2023 included 613 tests on 218 individual patients with suspected or confirmed LMD. To date, this is the largest cohort of patients in LMD literature evaluated using CSF-TCs.

RESULTS

CSF-TCs were detected in 67% (412/613) of samples. The most analyzed cancer types were breast (n = 105) and lung (n = 65). In lung cancer, anaplastic lymphoma kinase (ALK) was detected in 14% (17/118), and c-MET was detected in 61% (78/128). In breast cancer, HER2 was detected in 39% (65/168), and estrogen receptor (ER) was detected in 26% (44/168). Sixty-six patients underwent 2+ longitudinal CSF draws; among these, there were 58 flips in oncogene detection over time, and 30% (20/66) of patients had at least one biomarker change in the CSF.

CONCLUSIONS

Longitudinal combined ICC/FISH/NGS CSF testing demonstrates a wide range in CSF-TC enumeration, which may be correlated with clinical course, and furthermore identifies actionable tumor markers that frequently fluctuate over time. Utilization of this platform would enable timely, personalized LMD-specific chemotherapy.

A Dramatic Clinical Response to Trastuzumab-Deruxtecan in a Patient with HER-2 Low Breast Cancer with Untreated Leptomeningeal Metastasis and Hydrocephalus

Leptomeningeal metastasis (LM) is a rare and challenging manifestation of advanced breast cancer (ABC) with severe morbidity and mortality. Patients with LM may be asymptomatic, or present with non-specific neurologic deficits, thereby possibly delaying diagnosis. Treatment typically requires a multimodal approach for effective management, symptom relief, and quality-of-life improvement. Trastuzumab-deruxtecan (T-DXd), a humanized monoclonal antibody drug conjugate, demonstrated efficacy across diverse breast cancer subtypes expressing variable levels of HER2 proteins. Currently, T-DXd is the standard of care for patients with advanced, pretreated, HER2 low breast cancer. There is limited evidence of the response of brain metastases (BM) and leptomeningeal metastases (LM) to T-DXd in HER2-low patients, with most data extrapolated from HER2-positive breast cancer studies. This case report presents the first documented instance of a patient with debilitating, symptomatic, untreated LM and hydrocephalus demonstrating a rapid and dramatic clinical response to T-DXd. This finding holds crucial clinical relevance, highlighting the potential benefit of initiating effective systemic therapy for LM early in treatment to address both central nervous system (CNS) and non-CNS disease burden, rather than delaying systemic therapy until after radiation therapy.

Clinical Utility of a Circulating Tumor Cell-Based Cerebrospinal Fluid Assay in the Diagnosis and Molecular Analysis of Leptomeningeal Disease in Patients With Advanced Non-Small Cell Lung Cancer

PURPOSE

Leptomeningeal disease (LMD) is associated with significant morbidity and mortality for metastatic non-small cell lung cancer (NSCLC). We describe our clinical experience in evaluating the use of cerebrospinal fluid (CSF)-derived circulating tumor cells (CTCs) for the diagnosis of LMD and the detection of genomic alterations in CSF cell-free DNA (cfDNA).

METHODS

Patients with NSCLC who had CSF collection as part of routine clinical care for suspected LMD were included in the study. CSF was evaluated for CTCs and cfDNA using a commercial assay (CNSide; Biocept, San Diego, CA), and molecular profiling was performed. Molecular testing results from sequencing of tumor tissue and plasma circulating tumor DNA were collected. cMET and human epidermal growth factor receptor 2 (HER2) expression analysis was performed using fluorescence in situ hybridization (FISH).

RESULTS

Twenty-two patients were included (77% female; median age 60 years). Sixty-four percent had sensitizing EGFR mutations, and 32% had an atypical EGFR mutation. Thirteen of the 22 patients (59%) were diagnosed with LMD using the CSF CTC assay. Five of these 13 patients (38%) had negative CSF cytology for LMD, and two patients (15%) had normal magnetic resonance imaging brain imaging. Seven of the 13 patients (54%) had sufficient CTCs to perform molecular profiling. The concordance with tissue next-generation sequencing was 100%, and the driver mutation was identified in all seven patients with the CSF cfDNA assay. cMET expression and HER2 expression via FISH were noted in 11 patients (50%) and four patients (18%) respectively.

CONCLUSION

We detected higher sensitivity to diagnose LMD using CSF CTC-based assay; 38% of LMD cases identified using this assay were missed by standard CSF cytology. CSF molecular testing using CSF cfDNA demonstrated high concordance with tissue-based molecular testing.

Outcomes, responses, and prognostic analyses of intrathecal combined treatment for leptomeningeal metastasis from lung adenocarcinoma

BACKGROUND

Leptomeningeal metastasis (LM) is a severe lung cancer complication, with potentially fatal consequences. The use of intrathecal therapy (IT) combined with systemic therapy has shown promise as a treatment approach for LM. Thus, this study aimed to evaluate the features and responses to IT combined therapy and identify determinants affecting patients with leptomeningeal metastasis resulting from lung adenocarcinoma (LM-LA).

METHODS

A retrospective analysis of medical records from our hospital database was performed, covering from April 2018 to August 2022, for 37 patients diagnosed with LM-LA and treated with IT combined therapy. Patients who received IT combined therapy for LM-LA were evaluated for demographic characteristics, treatment efficacy, survival, and variables that impacted them.

RESULTS

The median overall survival (mOS) of 37 patients was 16.0 months, and the survival rates at 6 and 12 months were 75.7% and 35.1%, respectively. Among the 21 patients with LM-LA who received IT combined with tyrosine kinase inhibitors (TKIs), the mOS was 17.0 months, which was significantly longer than that of patients treated with IT combined with chemotherapy (7.0 months, P = 0.010) and the best supportive care (6.0 months, P = 0.001). However, no significant survival benefit was observed in patients treated with IT combined with TKIs when compared with those treated with IT combined with PD-1 (5.0 months, P = 0.249). Multivariate analysis indicated that the combination of TKIs was an independent favorable prognostic factor for patients with LM-LA.

CONCLUSION

Combination treatment is regarded as an additional option for patients with LM-LA. Compared with other combination therapies in our study, IT combined with TKI therapy provided a better survival outcome for patients with LM-LA.

A Case of MRI-Negative Leptomeningeal Disease From Non-small Cell Lung Cancer

Leptomeningeal disease (LMD) is a rare complication of advanced non-small cell lung cancer (NSCLC), associated with a poor prognosis. We report the case of a 55-year-old man, who presented with a metastatic NSCLC with limited brain and abdominal metastases. He was treated with both chemoimmunotherapy and stereotactic radiotherapy (SRT) to the brain. Despite treatment, the patient experienced progressive neurological symptoms not in keeping with the extent of disease seen on imaging of the brain. Due to this incongruence between symptoms and radiologic findings, he underwent a lumbar puncture, which had positive cytology for LMD. He had a rapid progression of symptoms and died six days after the discovery of LMD. We review the available literature regarding the prevalence of MRI-negative LMD from a solid primary malignancy.

Comparative evaluation of the diagnostic and prognostic performance of CNSide™ versus standard cytology for leptomeningeal disease

Background

This retrospective study compares the real-world performance of cerebrospinal fluid (CSF) CNSide™ versus cytology in leptomeningeal disease (LMD).

Methods

Consecutive patients with suspected LMD who underwent lumbar punctures for CSF cytology and CNSide™ from January 2020 to December 2022 were reviewed. LMD was classified by EANO criteria. Descriptive statistics, confusion matrix, Kaplan-Meier curves, and Cox proportional regression were used.

Results

Median age for 87 evaluable patients was 63 years (range: 23-93); 82 (94%) met EANO criteria for possible/probable/confirmed LMD (EANO/LMD). The commonest primary cancers were breast (36,44.0%) and lung (34,41.5%). Primary lung harbored actionable mutations in 18 (53.0%); primary breast expressed hormone receptors in 27 (75%), and HER2 amplification in 8 (22%). Uncontrolled systemic disease was detected in 35 (40%), while 25 (46%) received systemic therapy with medium/high CNS penetrance at LMD diagnosis. The median time from initial cancer to LMD diagnosis was 31 months (range: 13-73). LMD was confirmed by CSF cytology in 23/82 (28%), all identified by CNSide™. CNSide™ identified 13 additional cases (36/82, 43.9%), increasing diagnostic yield by 56.5%. Median overall survival (mOS) was 31 weeks (95%CI: 21-43), significantly worse for CNSide™ positive versus negative: 4.0 versus 16.0 weeks, respectively (HR = 0.50, P = .010). While survival since LMD diagnosis did not differ by histology, time to LMD diagnosis from initial cancer diagnosis was longer for breast (48.5 months, IQR: 30.0-87.5) versus lung (8 months, IQR:0.5-16.0) cohorts. mOS was longer for patients eligible for intrathecal chemotherapy (HR: 0.189, 95%CI: 0.053-0.672, P = .010).

Conclusions

This retrospective, real-world analysis of CNSide™ showed increased sensitivity versus cytology and provided clinically relevant molecular CSF analyses.

Leptomeningeal Metastases in Melanoma Patients: An Update on and Future Perspectives for Diagnosis and Treatment

Leptomeningeal disease (LMD) is a devastating complication of cancer with a particularly poor prognosis. Among solid tumours, malignant melanoma (MM) has one of the highest rates of metastasis to the leptomeninges, with approximately 10-15% of patients with advanced disease developing LMD. Tumour cells that metastasise to the brain have unique properties that allow them to cross the blood-brain barrier, evade the immune system, and survive in the brain microenvironment. Metastatic colonisation is achieved through dynamic communication between metastatic cells and the tumour microenvironment, resulting in a tumour-permissive milieu. Despite advances in treatment options, the incidence of LMD appears to be increasing and current treatment modalities have a limited impact on survival. This review provides an overview of the biology of LMD, diagnosis and current treatment approaches for MM patients with LMD, and an overview of ongoing clinical trials. Despite the still limited efficacy of current therapies, there is hope that emerging treatments will improve the outcomes for patients with LMD.

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.

CEACAM6 serves as a biomarker for leptomeningeal metastasis in lung adenocarcinoma

BACKGROUND AND AIMS

Diagnosis of leptomeningeal metastasis (LM) is challenging. In our previous study, CEACAM6 mRNA was found to be highly expressed in the circulating tumor cells of cerebrospinal fluid (CSF) from patients with lung adenocarcinoma with LM (LUAD-LM). The aim of this study was to identify whether CEACAM6 could be used as a biomarker for LUAD-LM.

MATERIALS AND METHODS

The level of CEACAM6 was determined by enzyme-linked immunosorbent assay (ELISA) in CSF from 40 LUAD-LM and 44 normal controls, and additional serum samples from 138 LUAD patients, including 12 LUAD-LM patients, and 30 healthy controls. Carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA 21-1) and neuron-specific enolase (NSE) levels in the CSF and sera were detected by chemiluminescent immunoassay. Receiver operating characteristic curve was plotted to evaluate the diagnostic performance for LUAD-LM.

RESULTS

CSF CEACAM6 level was higher in LUAD-LM than that in normal controls. In serum, LUAD patients had a higher level of CAECAM6 than healthy controls, and LM patients had the highest level among them. Serum CEACAM6 had a higher AUC than CEA in differentiating LM from non-LM in LUAD patients (0.95 vs. 0.64, p < 0.001).

CONCLUSION

CEACAM6 may serve as a potential biomarker in diagnosing LUAD-LM.

Solitary Leptomeningeal Metastasis from Lung Cancer: A Case Report

Leptomeningeal metastasis (LM) is a rare but devastating cancer complication. LM occurs when cancer spreads into the leptomeningeal layer or cerebrospinal fluid. Intracranial magnetic resonance (MR) images of LM are characterized by the diffuse enhancement of the leptomeninges along the cerebral sulci, cerebellar folia, and cranial nerves. Here, we report an extremely rare case of LM with an atypical MR image revealing tumor mass confinement to the arachnoid membrane. The case involves an 85-year-old man who was referred to our hospital with a three-day history of dysarthria. Radiological examination revealed a solid lesion with heterogeneous enhancement and a cystic component in the extra-axial region of the right parietal lobe. Upon subsequent general examination, multiple lung cancer metastases were suspected. The patient underwent gross total resection of the brain mass in the right parietal region. Although the tumor slightly adhered to the dura mater, it was sharply demarcated from the surrounding parenchyma and pia mater. Based on pathological examination, the tumor was diagnosed as small cell lung cancer metastasis. This metastatic brain tumor was exclusively confined to the arachnoid membrane and, except for a few blood vessels, the dura mater was not infiltrated by metastatic tumor cells. To our knowledge, this is the first reported case of LM in which the tumor mass is confined only to the arachnoid membrane. Thus, in cases with atypical MR images, a general examination considering the possibility of LM is important for prompt and accurate diagnosis.

Development of Two Diagnostic Prediction Models for Leptomeningeal Metastasis in Patients With Solid Tumors

Objectives

For accurate diagnosis of leptomeningeal metastasis (LM) and to avoid unnecessary examinations or lumber puncture (LP), we develop two diagnostic prediction models for patients with solid tumors.

Study Design, Setting, and Participants

This is a retrospective cohort study launched at the Second Affiliated Hospital of Dalian Medical University. In total, 206 patients who had been admitted between January 2005 and December 2021 with a solid tumor and clinical suspicion of LM were enrolled to develop model A. In total, 152 patients of them who underwent LPs for cytology and biochemistry were enrolled to develop model B.

Model Development

Diagnostic factors included skull metastasis, active brain metastasis, progressed extracranial disease, number of extracranial organs involved, number of symptoms, cerebrospinal fluid (CSF) protein, and CSF glucose. The outcome predictor was defined as the clinical diagnosis of LM. Logistic least absolute shrinkage and selection operator (LASSO) regression was used to identify relevant variables and fit the prediction model. A calibration curve and the concordance index (c-index) were used to evaluate calibration and discrimination ability. The n-fold cross-validation method was used to internally validate the models. The decision curve analysis (DCA) and the interventions avoided analysis (IAA) were used to evaluate the clinical application.

Results

The area under the curve (AUC) values of models A and B were 0.812 (95% CI: 0.751–0.874) and 0.901 (95% CI: 0.852–0.949). Respectively, compared to the first magnetic resonance imaging (MRI) and first LP, models A and B showed a higher AUC (model A vs. first MRI: 0.812 vs. 0.743, p = 0.087; model B vs. first LP: 0.901 vs. 0.800, p = 0.010). The validated c-indexes were 0.810 (95% CI: 0.670–0.952) and 0.899 (95% CI: 0.823–0.977). The calibration curves show a good calibrated ability. The evaluation of clinical application revealed a net clinical benefit and a reduction of unnecessary interventions using the models.

Conclusions

The models can help improve diagnostic accuracy when used alone or in combination with conventional work-up. They also exhibit a net clinical benefit in medical decisions and in avoiding unnecessary interventions for patients with LM. Studies focused on external validation of our models are necessary in the future.