Prognostic value of cerebrospinal fluid tumor cell count in leptomeningeal disease from solid tumors.

PURPOSE: Treatment decisions for leptomeningeal disease (LMD) rely on patient risk stratification, since clinicians lack objective prognostic tools. The introduction of rare cell capture technology for identification of cerebrospinal fluid tumor cells (CSF-TCs), such as CNSide assay, improved the sensitivity of LMD diagnosis, but prognostic value is unknown. This study assesses the prognostic value of CSF-TC density in patients with LMD from solid tumors. METHODS: We conducted a retrospective cohort study of patients with newly diagnosed or previously treated LMD from a single institution who had CNSide assay testing for CSF-TCs from 2020 to 2023. Univariable and multivariable survival analyses were conducted with Cox proportional-hazards modeling. Maximally-selected rank statistics were used to determine an optimal cutpoint for CSF-TC density and survival. RESULTS: Of 31 patients, 29 had CSF-TCs detected on CNSide. Median (interquartile range [IQR]) CSF-TC density was 67.8 (4.7-639) TCs/mL. CSF cytology was positive in 16 of 29 patients with positive CNSide (CNSide diagnostic sensitivity = 93.5%, negative predictive value = 85.7%). Median (IQR) survival from time of CSF-TC detection was 176 (89-481) days. On univariable and multivariable analysis, CSF-TC density was significantly associated with survival. An optimal cutpoint for dichotomizing survival by CSF-TC density was 19.34 TCs/mL. The time-dependent sensitivity and specificity for survival using this stratification were 76% and 67% at 6 months and 65% and 67% at 1 year, respectively. CONCLUSIONS: CSF-TC density may carry prognostic value in patients with LMD from solid tumors. Integrating CSF-TC density into LMD patient risk-stratification may help guide treatment decisions.

Prognostic impact of clinical and radiological factors on leptomeningeal metastasis from solid cancers.

PURPOSE: The number of leptomeningeal metastasis (LM) patients has increased in recent years, as the cancer survival rates increased. An optimal prediction of prognosis is essential for selecting an appropriate treatment. The European Association of Neuro-Oncology-European Society for Medical Oncology (EANO-ESMO) guidelines for LM proposed a classification based on the cerebrospinal fluid cytological findings and contrast-enhanced magnetic resonance imaging (MRI) pattern. However, few studies have validated the utility of this classification. This study aimed to investigate the prognostic factors of LM, including the radiological and cytological types. METHODS: We retrospectively analyzed the data of 240 adult patients with suspected LM who had undergone lumbar puncture between April 2014 and September 2021. RESULTS: The most common primary cancer types were non-small-cell lung cancer (NSCLC) (143 (60%)) and breast cancer (27 (11%)). Positive cytology results and the presence of leptomeningeal lesions on contrast-enhanced MRI correlated with decreased survival in all patients. Nodular lesions detected on contrast-enhanced magnetic resonance were a poor prognostic factor in cytology-negative patients, while contrast-enhanced patterns had no prognostic significance in cytology-positive patients. Systemic therapy using cytotoxic agents and molecular-targeted therapy after LM diagnosis correlated with prolonged survival, regardless of the cytology results. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment and systemic chemotherapy after LM improved the survival of EGFR-mutated and wild-type NSCLC patients with positive cytology results. CONCLUSIONS: This study validated the efficacy of prognostication according to the EANO-ESMO guidelines for LM. Systemic therapy after LM diagnosis improves the survival of NSCLC patients.

Comparison of the diagnostic significance of cerebrospinal fluid metagenomic next-generation sequencing copy number variation analysis and cytology in leptomeningeal malignancy.

BACKGROUND: Diagnosis and monitoring of leptomeningeal malignancy remain challenging, and are usually based on neurological, radiological, cerebrospinal fluid (CSF) and pathological findings. This study aimed to investigate the diagnostic performance of CSF metagenomic next-generation sequencing (mNGS) and chromosome copy number variations (CNVs) analysis in the detection of leptomeningeal malignancy. METHODS: Of the 51 patients included in the study, 34 patients were diagnosed with leptomeningeal malignancies, and 17 patients were diagnosed with central nervous system (CNS) inflammatory diseases. The Sayk's spontaneous cell sedimentation technique was employed for CSF cytology. And a well-designed approach utilizing the CSF mNGS-CNVs technique was explored for early diagnosis of leptomeningeal malignancy. RESULTS: In the tumor group, 28 patients were positive for CSF cytology, and 24 patients were positive for CSF mNGS-CNVs. Sensitivity and specificity of CSF cytology were 82.35% (95% CI: 66.83-92.61%) and 94.12% (95% CI: 69.24-99.69%). In comparison, sensitivity and specificity of CSF mNGS-CNV were 70.59% (95% CI: 52.33-84.29%) and 100% (95% CI: 77.08-100%). There was no significant difference in diagnostic consistency between CSF cytology and mNGS-CNVs (p = 0.18, kappa = 0.650). CONCLUSIONS: CSF mNGS-CNVs tend to have higher specificity compared with traditional cytology and can be used as a complementary diagnostic method for patients with leptomeningeal malignancies.

Detection of genes mutations in cerebrospinal fluid circulating tumor DNA from neoplastic meningitis patients using next generation sequencing.

BACKGROUND: This study profiled the somatic genes mutations and the copy number variations (CNVs) in cerebrospinal fluid (CSF)-circulating tumor DNA (ctDNA) from patients with neoplastic meningitis (NM). METHODS: A total of 62 CSF ctDNA samples were collected from 58 NM patients for the next generation sequencing. The data were bioinformatically analyzed by (Database for Annotation, Visualization and Integrated Discovery) DAVID software. RESULTS: The most common mutated gene was TP53 (54/62; 87.10%), followed by EGFR (44/62; 70.97%), PTEN (39/62; 62.90%), CDKN2A (32/62; 51.61%), APC (27/62: 43.55%), TET2 (27/62; 43.55%), GNAQ (18/62; 29.03%), NOTCH1 (17/62; 27.42%), VHL (17/62; 27.42%), FLT3 (16/62; 25.81%), PTCH1 (15/62; 24.19%), BRCA2 (13/62; 20.97%), KDR (10/62; 16.13%), KIT (9/62; 14.52%), MLH1 (9/62; 14.52%), ATM (8/62; 12.90%), CBL (8/62; 12.90%), and DNMT3A (7/62; 11.29%). The mutated genes were enriched in the PI3K-Akt signaling pathway by the KEGG pathway analysis. Furthermore, the CNVs of these genes were also identified in these 62 samples. The mutated genes in CSF samples receiving intrathecal chemotherapy and systemic therapy were enriched in the ERK1/2 signaling pathway. CONCLUSIONS: This study identified genes mutations in all CSF ctDNA samples, indicating that these mutated genes may be acted as a kind of biomarker for diagnosis of NM, and these mutated genes may affect meningeal metastasis through PI3K-Akt signaling pathway.

Simultaneous primary cancer occurrence of melanoma and pulmonary adenocarcinoma in leptomeningeal metastases: a case report.

BACKGROUND: Leptomeningeal metastasis (LM) is a predominantly late stage, devastating complication of a variety of malignant solid tumors. Diagnosis relies predominantly on neurological, radiographic, and cerebrospinal fluid (CSF) assessments. Recently, liquid biopsy tests derived from CSF has shown to be a feasible, noninvasive promising approach to tumor molecular profiling for proper brain cancer diagnostic treatment, thereby providing an opportunity for CSF-based personalized medicine. However, LM is typically misleadingly assumed to originate from only one primary tumor type. CASE PRESENTATION: In this case report, we provide first evidence of the co-occurrence of LM originating from more than one primary tumor types. DISCUSSION AND CONCLUSIONS: Based on this patient case profile, the co-occurrence of LM from two or more primary tumor types should be accounted for when deriving diagnostic conclusions from liquid biopsy tests.

Standard-dose osimertinib for refractory leptomeningeal metastases in T790M-positive EGFR-mutant non-small cell lung cancer.

BACKGROUND: Osimertinib demonstrated promising efficacy for refractory leptomeningeal metastases (LM) in preclinical data and a clinical study at 160 mg, but there is limited data for the standard 80 mg dose. METHODS: T790M-positive patients with suspected LM after classical epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) failure were enroled. RESULTS: We investigated 13 patients (5 definitive and 8 possible LM cases). In two of the five definitive cases with T790M in and outside the central nervous system (CNS), osimertinib was effective for both lesions, with cerebrospinal fluid (CSF) clearance of cancer cells and sensitive/T790M mutations. In three definitive cases with extra-CNS T790M without CSF T790M, cancer cells and sensitive mutations in the CSF persisted after osimertinib initiation. The median progression-free survival of all 13 patients was 7.2 months. Osimertinib was generally well-tolerated despite poor performance status, but interstitial lung disease (grade 2) was confirmed in one patient. Based on 25 samples from 13 patients, the osimertinib CSF penetration rate was 2.5±0.3%. CONCLUSIONS: Osimertinib 80 mg is a useful therapeutic option for refractory LM after classical EGFR-TKI failure. It appears more effective in CSF T790M-positive cases.

Unique genetic profiles from cerebrospinal fluid cell-free DNA in leptomeningeal metastases of EGFR-mutant non-small-cell lung cancer: a new medium of liquid biopsy.

Background: Leptomeningeal metastases (LM) are more frequent in non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. Due to limited access to leptomeningeal lesions, the purpose of this study was to explore the potential role of cerebrospinal fluid (CSF) as a source of liquid biopsy in patients with LM. Patients and methods: Primary tumor, CSF, and plasma in NSCLC with LM were tested by next-generation sequencing. In total, 45 patients with suspected LM underwent lumbar puncture, and those with EGFR mutations diagnosed with LM were enrolled. Results: A total of 28 patients were enrolled in this cohort; CSF and plasma were available in 26 patients, respectively. Driver genes were detected in 100% (26/26), 84.6% (22/26), and 73.1% (19/26) of samples comprising CSF cell-free DNA (cfDNA), CSF precipitates, and plasma, respectively; 92.3% (24/26) of patients had much higher allele fractions in CSF cfDNA than the other two media. Unique genetic profiles were captured in CSF cfDNA compared with those in plasma and primary tissue. Multiple copy number variations (CNVs) were mainly identified in CSF cfDNA, and MET copy number gain identified in 47.8% (11/23) of patients was the most frequent one, while other CNVs included ERBB2, KRAS, ALK, and MYC. Moreover, loss of heterozygosity (LOH) of TP53 was identified in 73.1% (19/26) CSF cfDNA, which was much higher than that in plasma (2/26, 7.7%; P < 0.001). There was a trend towards a higher frequency of concomitant resistance mutations in patients with TP53 LOH than those without (70.6% versus 33.3%; P = 0.162). EGFR T790M was identified in CSF cfDNA of 30.4% (7/23) of patients who experienced TKI progression. Conclusion: CSF cfDNA could reveal the unique genetic profiles of LM and should be considered as the most representative liquid biopsy medium for LM in EGFR-mutant NSCLC.

EpCAM-based assays for epithelial tumor cell detection in cerebrospinal fluid.

The diagnosis of leptomeningeal metastases (LM) of solid tumors is complicated due to low sensitivities of both magnetic resonance imaging (MRI) and cytology. MRI has a sensitivity of 76% for the diagnosis of LM and cerebrospinal fluid (CSF) cytology has a sensitivity of 44-67% at first lumbar puncture which increases to 84-91% upon second CSF sampling. Epithelial cell adhesion molecule (EpCAM) is expressed by solid tumors of epithelial origin like non-small-cell lung cancer, breast cancer or ovarium cancer. Recently, a CELLSEARCH® assay and flow cytometry laboratory techniques have been developed to detect circulating tumor cells (CTCs) of epithelial origin in CSF. These laboratory techniques are based on capture antibodies labelled with different fluorescent tags against EpCAM. In this review, we provide an overview of the available laboratory techniques and diagnostic accuracy for tumor cell detection in CSF. The reported sensitivities of the EpCAM-based CTC assays for the diagnosis of LM across the different studies are highly promising and vary between 76 and 100%. An overview of the different EpCAM-based techniques for the enumeration of CTCs in the CSF is given and a comparison is made with CSF cytology for the diagnoses of LM from epithelial tumors.

The Utility of Liquid Biopsy in Central Nervous System Malignancies.

PURPOSE OF REVIEW: Liquid biopsy is a sampling of tumor cells or tumor nucleotides from biofluids. This review explores the roles of liquid biopsy for evaluation and management of patients with primary and metastatic CNS malignancies. RECENT FINDINGS: Circulating tumor cell (CTC) detection has emerged as a relatively sensitive and specific tool for diagnosing leptomeningeal metastases. Circulating tumor DNA (ctDNA) detection can effectively demonstrate genetic markup of CNS tumors in the cerebrospinal fluid, though its role in managing CNS malignancies is less well-defined. The value of micro RNA (miRNA) detection in CNS malignancies is unclear at this time. Current standard clinical tools for the diagnosis and monitoring of CNS malignancies have limitations, and liquid biopsy may help address clinical practice and knowledge gaps. Liquid biopsy offers exciting potential for the diagnosis, prognosis, and treatment of CNS malignancies, but each modality needs to be studied in large prospective trials to better define their use.

Leptomeningeal Metastases.

OPINION STATEMENT: Treatment options for leptomeningeal metastases are expanding with greater tolerability and efficacy than in the past. Improved knowledge of molecular subtypes of some cancers can guide in choosing more effective therapeutic options; however, physicians should be mindful that these molecular types can be different in the central nervous system compared to the rest of the body. This is particularly true in breast and lung cancer, in which some patients now can live for many months or even years after diagnosis of leptomeningeal metastases. Options for intrathecal therapies are expanding, but physicians should be mindful that this is a passive delivery system that relies on normal CSF flow, so therapies will not penetrate bulky or parenchymal disease sites, especially in the presence of abnormal CSF flow. When chemotherapeutic options are lacking or unsuccessful, focal radiosurgery which can provide symptomatic relief and proton craniospinal radiation remain effective options. Hopefully more formal studies will be conducted in the future to verify which treatments are indeed most effective for particular types of cancer.

Cerebrospinal Fluid Dissemination and Neoplastic Meningitis in Primary Brain Tumors.

BACKGROUND: Neoplastic meningitis, also known as leptomeningeal disease, affects the entire neuraxis. The clinical manifestations of the disease may affect the cranial nerves, cerebral hemispheres, or the spine. Because of the extent of disease involvement, treatment options and disease staging should involve all compartments of the cerebrospinal fluid (CSF) and subarachnoid space. Few studies of patients with primary brain tumors have specifically addressed treatment for the secondary complication of neoplastic meningitis. Therapy for neoplastic meningitis is palliative in nature and, rarely, may have a curative intent. METHODS: A review of the medical literature pertinent to neoplastic meningitis in primary brain tumors was performed. The complication of neoplastic meningitis is described in detail for the various types of primary brain tumors. RESULTS: Treatment of neoplastic meningitis is complicated because determining who should receive aggressive, central nervous system (CNS)-directed therapy is difficult. In general, the therapeutic response of neoplastic meningitis is a function of CSF cytology and, secondarily, of the clinical improvement in neurological manifestations related to the disease. CSF cytology may manifest a rostrocaudal disassociation; thus, consecutive, negative findings require that both lumbar and ventricular cytological testing are performed to confirm the complete response. Based on data from several prospective, randomized trials extrapolated to primary brain tumors, the median rate of survival for neoplastic meningitis is several months. Oftentimes, therapy directed at palliation may improve quality of life by protecting patients from experiencing continued neurological deterioration. CONCLUSIONS: Neoplastic meningitis is a complicated disease in which response to therapy varies by histology. Thus, survival rates after CNS-directed therapy will differ by the underlying primary tumor. Optimal therapy of neoplastic meningitis is poorly defined, and few guidelines exist to guide clinicians on the most appropriate choice of therapy.

Evaluating EFEMP1 in Cerebrospinal Fluid and Serum as a Potential Diagnosis Biomarker for Meningiomas.

BACKGROUND: The aim of this study was to determine the cerebrospinal fluid (CSF) and serum levels of EGF containing fibulin-like extracellular matrix protein 1 (EFEMP1) in the patients with meningiomas and explore its potential as a biomarker. METHODS: Forty-five patients with meningioma, 11 of whom underwent meningioma resection, as well as 30 healthy controls were enrolled in this study. CSF and blood samples were collected preoperatively and postoperatively. Expression levels of EFEMP1 were measured by enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curves were used to evaluate its discriminant ability. RESULTS: CSF EFEMP1 levels were significantly higher in the CSF samples (p < 0.0001) and serum samples (p = 0.0056) of meningioma patients compared to controls. To distinguish meningioma patients from controls by CSF and serum EFEMP1 levels, ROC/AUC analysis indicated an AUC of 0.945 (sensitivity 0.933; specificity 0.833) and an AUC of 0.674 (sensitivity 0.867; specificity 0.400), respectively. Moreover, the postoperative CSF levels of EFEMP1 were significantly decreased compared to the preoperative levels (p < 0.0001). CONCLUSIONS: The present study suggested that elevated EFEMP1 levels might be a novel diagnostic biomarker for meningioma patients.

Metastatic Breast Carcinoma in Cerebrospinal Fluid: A Cytopathological Review of 15 Cases.

The incidence of metastatic carcinoma to the meninges ("meningeal carcinomatosis" [MC]) is increasing due to longer survival of patients and improved imaging techniques. Currently, MC is best diagnosed by cytopathological evaluation of cerebrospinal fluid (CSF). Breast primaries are the commonest cause of MC; although cytopathological features thereof have not been, as yet, fully characterized. In this study of meningeal mammary carcinomatosis, relevant clinicopathological data and archived cytopathological preparations of all "suspicious" and "positive" CSF specimens (1992-2015), from patients with a history of breast carcinoma, were retrieved and reviewed. Twenty-three "positive" CSF specimens, derived from 15 patients formed the basis of this study. All specimens were processed as Cytospin preparations, and stained by Papanicolaou and Diff-Quik techniques. All patients were female, with a mean age of 57 (range: 32-85) years. Mean interval between initial diagnosis of breast carcinoma and "positive" CSF was 32 (range 6-84) months. All 23 specimens (100%) were "cellular" (>10 carcinoma cells). Eighteen (78%) specimens showed only isolated nonclustered cells, and 5 (22%) specimens showed both cell clusters and isolated cells. In most "positive" cases, metastatic breast carcinoma cells showed variation in cell size, with hyperchromatic nuclei, irregular nuclear membranes, prominent nucleoli and cytoplasmic vacuolization. The background in some CSF samples showed red blood cells and fibrin admixed with rare lymphocytes and histiocytes. One specimen showed necrotic debris. Papanicolaou and Diff-Quik-stained Cytospin preparations were equally diagnostic, as the aforementioned findings were present in both types of preparation.

Proteomic Biomarker Identification in Cerebrospinal Fluid for Leptomeningeal Metastases with Neurological Complications.

Leptomeningeal metastases (LM) from solid tumours, lymphoma and leukaemia are characterized by multifocal neurological deficits with a high mortality rate. Early diagnosis and initiation of treatment are essential to kerb neurological deterioration. However, this is not always possible as 25% of cerebrospinal fluid samples produce false-negative results at first cytological examination. The identification of biomarkers that allow stratification of individuals according to risk for developing LM would be a major benefit. Proteomic-based approaches are now in increasing use for this purpose, and these are reviewed in this chapter with a focus on cerebrospinal fluid (CSF) analyses. The construction of a CSF proteome disease database would also facilitate analysis of other neurological disorders.

Tumor DNA in cerebral spinal fluid reflects clinical course in a patient with melanoma leptomeningeal brain metastases.

Cerebral spinal fluid (CSF) from brain tumor patients contains tumor cellular and cell-free DNA (cfDNA), which provides a less-invasive and routinely accessible method to obtain tumor genomic information. In this report, we used droplet digital PCR to test mutant tumor DNA in CSF of a patient to monitor the treatment response of metastatic melanoma leptomeningeal disease (LMD). The primary melanoma was known to have a BRAF (V600E) mutation, and the patient was treated with whole brain radiotherapy and BRAF inhibitors. We collected 9 CSF samples over 6 months. The mutant cfDNA fraction gradually decreased from 53 % (time of diagnosis) to 0 (time of symptom alleviation) over the first 6 time points. Three months after clinical improvement, the patient returned with severe symptoms and the mutant cfDNA was again detected in CSF at high levels. The mutant DNA fraction corresponded well with the patient's clinical response. We used whole exome sequencing to examine the mutation profiles of the LMD tumor DNA in CSF before therapeutic response and after disease relapse, and discovered a canonical cancer mutation PTEN (R130*) at both time points. The cellular and cfDNA revealed similar mutation profiles, suggesting cfDNA is representative of LMD cells. This study demonstrates the potential of using cellular or cfDNA in CSF to monitor treatment response for LMD.

SHP-1 promoter 2 methylation in cerebrospinal fluid for diagnosis of leptomeningeal epithelial-derived malignancy (carcinomatous meningitis).

Current diagnostic methods for leptomeningeal metastasis (LM) from epithelial-derived malignancy (EDM) have limited sensitivity. Here, we explored SHP-1 promoter 2 methylation (SHP1P2)-an epithelial-specific methylation marker previously proven as risk stratification and potential diagnostic marker in non-small cell lung cancer-for EDM with LM. We prospectively recruited 136 patients who were diagnosed EDM with LM (n = 25), EDM without LM (n = 14), non-EDM with LM (n = 8), and benign meningeal diseases (n = 89). The primary cancer sites for EDM with LM were lung (n = 17), breast (n = 5), and colon (n = 3). We performed quantitative analyses of cell-free (cfSHP1P2) and whole fraction (wSHP1P2) from cerebrospinal fluid (CSF); results were correlated with the clinicopathological data, including CSF cytology. Median cfSHP1P2 and wSHP1P2 were 3.08 [range: 0-163.5] and 9.35 [0.69-91.63] ng/ml, respectively, in EDM with LM; 0 [0-0.08] and 0.23 [0-7.84] ng/ml in EDM without LM; and were undetectable in most cases of benign meningeal diseases and non-EDM with LM. The cut-off values of 0.22 ng/ml for methylated cfSHP1P2 and 0.59 ng/ml for wSHP1P2 were the best to discriminate EDM with LM from EDM without LM (sensitivity: 79-100 %; specificity: 83-100 %), as well as from other benign conditions (sensitivity: 85-100 % specificity: 78-100 %). CSF cytology yielded 76 % sensitivity for diagnosing EDM with LM. Further validation of CSF SHP1P2 methylation detection as a role of adjunctive tool for LM from EDM should be interested based on our study.

Leptomeningeal metastasis from solid tumors: a diagnostic and therapeutic challenge.

Leptomeningeal metastasis (LM) is a severe complication in the natural history of malignancies that occurs in 4-15 % of patients (pts) with solid tumors. Clinical presentation, cerebrospinal fluid cytology (CSF), and gadolinium magnetic resonance imaging (gdMRI) of the brain and spine are the methods routinely used to diagnose LM. Treatment encompasses involved-field radiotherapy of bulky or symptomatic disease sites and chemotherapy; however, no standard therapy has been established yet. We collected and reviewed retrospectively the clinical, pathological, radiological findings as well as the outcomes of 50 consecutive patients with LM from solid tumors to determine whether the diagnostic modalities and therapeutic procedures affected the outcomes. The results of this study confirm the role of gdMRI in the diagnosis of LM in clinical practice and suggest that an aggressive treatment may improve survival in patients with this debilitating and increasingly frequent neurological complication.

Final results of a multicenter trial addressing role of CSF flow cytometric analysis in NHL patients at high risk for CNS dissemination.

This prospective study compared diagnostic and prognostic value of conventional cytologic (CC) examination and flow cytometry (FCM) of baseline samples of cerebrospinal fluid (CSF) in 174 patients with newly diagnosed aggressive non-Hodgkin lymphoma (NHL). FCM detected a neoplastic population in the CSF of 18 of 174 patients (10%), CC only in 7 (4%; P < .001); 11 patients (14%) were discordant (FCM(+)/CC(-)). At a median follow-up of 46 months, there were 64 systemic progressions and 10 CNS relapses, including 2 patients with both systemic and CNS relapses. Two-year progression-free and overall survival were significantly higher in patients with FCM(-) CSF (62% and 72%) compared with those FCM(+) CSF (39% and 50%, respectively), with a 2-year CNS relapse cumulative incidence of 3% (95% confidence interval [CI], 0-7) versus 17% (95% CI, 0-34; P = .004), respectively. The risk of CNS progression was significantly higher in FMC(+)/CC(-) versus FCM(-)/CC(-) patients (hazard ratio = 8.16, 95% CI, 1.45-46). In conclusion, FCM positivity in the CSF of patients with high-risk NHL is associated with a significantly higher CNS relapse risk and poorer outcome. The combination of IV drugs with a higher CNS bioavailability and intrathecal chemotherapy is advisable to prevent CNS relapses in FCM(+) patients.