Treatment of meningeal carcinomatosis

Current options for the treatment of neoplastic meningitis

Neoplastic meningitis, which is the diffuse involvement of the leptomeninges by infiltrating cancer cells, may be caused by many systemic tumors. The treatment options for neoplastic meningitis disease remain unsatisfactory. In this review article, we discuss the pathogenesis and cytology of neoplastic meningitis and the options for treatment, including intrathecal chemotherapy, systemic chemotherapy, and newer agents such as cytokines and monoclonal antibodies.

Cerebrospinal fluid cytology in patients with cancer: minimizing false-negative results

BACKGROUND

Detection of malignant cells on cytologic examination of the cerebrospinal fluid (CSF) is the diagnostic gold standard for leptomeningeal carcinomatosis. The absence of cells is a primary endpoint for most therapeutic trials. Unfortunately, false-negative results are common. Practical strategies are necessary to remedy this problem.

METHODS

Four physician-dependent variables (CSF sample volume, site of CSF sampling, processing time, and frequency of CSF sampling) were identified, and their contributions to the false-negative rate of CSF cytology were evaluated prospectively in 39 patients with leptomeningeal carcinomatosis. Retrospective data were analyzed to estimate the importance of these variables in daily practice.

RESULTS

False-negative CSF cytology results correlated with small CSF volume (P < 0.001), delayed processing (P < 0.001), not obtaining CSF from a site of symptomatic or radiographically demonstrated disease (P = 0.02), and sampling fewer than two times (P < 0.001). In 1 year, 97% of CSF specimens at the study institution were of inadequate volume; >25% were processed too slowly.

CONCLUSIONS

False-negative CSF cytology results are common, but can be minimized by: 1) withdrawing at least 10.5 mL of CSF for cytologic analysis; 2) processing the CSF specimen immediately; 3) obtaining CSF from a site of known leptomeningeal disease; and 4) repeating this procedure once if the initial cytology is negative.

Primary central nervous system leukemia with a novel chromosomal translocation

A case of central nervous system (CNS) leukemia with normal bone marrow, associated with a novel chromosomal abnormality, is described. A 58 year-old woman complained of hearing disturbance, severe headache and vomiting, and showed signs of meningeal irritation, as well as papilledema and bilateral dysacusis. Immature atypical cells were found in the cerebrospinal fluid (CSF) with elevated pressure, pleocytosis, increased protein and decreased glucose levels. She was diagnosed as having neoplastic meningitis. In spite of intensive investigations, including bone marrow puncture, malignancies were not found in organs other than intra-cranial site. The symptoms and CSF findings were temporarily improved with chemotherapy and irradiation, but she relapsed into neoplastic meningitis. The anaplastic cells in CSF were positive with CD45 by immunocytochemistry, and were positive by peroxidase staining. Thus, the anaplastic cells were considered to be myelocytic leukemic cells. Chromosomal analysis showed that these leukemic cells had a novel chromosomal abnormality: 46XX, 4q+, 10q-, 16q-. There has been no report of leukemic meningitis without bone marrow abnormalities. It is possible that this peculiar abnormal chromosome is related to the primary infiltration of the central nervous system. With this novel chromosomal abnormality, this case is important for considering the mechanism of primary leukemic meningitis.

A rat model of leptomeningeal human neoplastic xenografts

Leptomeningeal (LM) cancer spread from either a primary brain tumor or a systemic cancer is rapidly fatal. Current therapies are ineffective and highly toxic to normal nervous system tissues. A xenograft model of LM neoplasia in nude rats using a diversity of tumor cell types was established in order to evaluate new treatment strategies and to study the pharmacokinetics and biological effects of treatments administered into the subarachnoid space. Consistent leptomeningeal engraftment and progressive tumor growth was seen after intrathecal injection of 9 of 13 tumor cells lines, including 2 melanomas, 2 neuroblastomas, 2 medulloblastomas, 2 gliomas, and 1 breast cancer. Clinical signs ranged from steady weight loss commencing from the day after tumor implantation to absence of any signs for three weeks until the sudden occurrence of major neurological deficits or death. Pathologic examination showed only leptomeningeal tumor growth with some cell lines and severe parenchymal invasion with others. CSF cytology consistently demonstrated tumor cells in animals with LM disease. Cranial magnetic resonance (MR) following intravenous (i.v.) administration of a contrast agent revealed enhancing lesions one week following melanoma tumor implantation. Reliable ventricular puncture was demonstrated by radiography following intraventricular (IVent) injection of an iodinated contrast material. IVent instillation of saline, albumin, or antibodies did not provoke clinical toxicity or an inflammatory response.

Carcinomatous meningitis in solid tumours

Carcinomatous meningitis (CM) is an uncommon but devastating complication of malignancy. The management is controversial and clear recommendations cannot be made because: 1) Most series include patients with CM that has arisen from different primary malignancies which are associated with different median survival intervals. 2) There have been no prospective randomised investigations of treatment modalities in patients with CM from a particular tumour type. 3) The definition of response varies from one report to another so that some response rates refer to cytological changes in the CSF while others take clinical, cytological and biochemical parameters into account. 4) Reports include patients with and without parenchymal metastases and the natural history of carcinomatous meningitis in the two situations may differ. The median survival of solid tumour carcinomatous meningitis (excluding leukaemia and lymphoma) is approximately 2-3 months and patients with breast cancer have the longest survival (median 3 months). Currently patients are treated with radiotherapy to part or all of the neuraxis with either intrathecal or intravenous chemotherapy but the relative contribution of these modalities to survival or quality of life remains unknown. Approximately 50% of patients with carcinomatous meningitis die from other causes, including systemic disease. The two most important endpoints for the patient, neurological improvement and overall survival, are seldom used in isolation in the literature. Many reports have focused on surrogate markers of response, namely biochemical and cytological data points but the correlation between clinical status and these parameters is poor because of differences between lumbar and ventricular CSF and disturbances of CSF flow in CM. The current literature does not provide clear guidelines for the treatment of this condition. Multicentre, prospective, randomised trials should be conducted that address questions of most relevance to the patient, namely neurological status and overall survival.

Distribution of intrathecally administered ACNU in mongrel dogs: pharmacokinetics and quantitative autoradiographic study

The pharmacokinetics of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) in the cerebrospinal fluid (CSF), were determined in dogs after ventriculolumbar perfusion (VLP, n = 6), and bolus injection into the ventricle (VB, n = 2), cisterna magna (MB, n = 5), and lumbar cistern (LB, n = 3), by high-performance liquid chromatography. The VLP method introduced effective amounts of ACNU into the lumbar cistern for cell kill in vitro. That is, the areas under the time concentration curve (AUC) of ACNU in the lumbar CSF for those receiving a 1.5 mg perfusion of ACNU were 481, 791, and 520 micrograms.min/ml and those receiving a 5 mg perfusion were 1,081, 2,048, and 1,215 micrograms.min/ml, respectively. These values were superior to 3-log cell kill condition of 9L gliosarcoma and 1.5-log cell kill of HU-126 human glioma cell line. Among the groups to which 5 mg of ACNU was administered, the VLP method attained significantly higher AUC values in the lumbar CSF than MB method. Quantitative autoradiography using an imaging plate system was performed in the VLP group (n = 2), VB group (n = 1), MB group (n = 2), and LB group (n = 2) using a 10 microCi/kg [ethylene-14C] ACNU dose which is thought to be related to the alkylating activity of ACNU. The VLP method attained a stable and abundant distribution of ACNU in the neural axis from the ventricular cavity to the lumbar cistern, but the cerebral convexity surface was devoid of a significant level of ACNU. When the MB method was used, the pharmacokinetic data varied in the cisterna magna and lumbar region, and again no significant level of ACNU was detected in the ventricular cavity. With the LB method, although a rich distribution was detected in the spinal cord, the concentration decreased abruptly at the upper cervical level. The VB method was unsatisfactory for obtaining an effective amount of ACNU in the lumbar region. The research and testing to date indicate that the VLP method is the procedure of choice in the treatment of meningeal dissemination.

Intrathecal chemotherapy with ACNU for meningeal gliomatosis

ACNU [1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride], one of the chloroethylnitrosoureas (CENUs), is believed to be effective against malignant glioma when intravenously or intrathecally administered. A rat model with meningeal gliomatosis (MG) induced by an intracisternal inoculation of rat C6 or 9L glioma cells was intrathecally and intravenously treated with ACNU in order to test the feasibility of intrathecal chemotherapy with ACNU in the treatment of meningeal gliomatosis. The median survival time (MST) of the animals was significantly prolonged when ACNU was intrathecally administered at dosages of 0.5 to 1.5 mg kg-1 in the early stages of MG, i.e. within 3 days after the tumour inoculation, whereas intravenous therapy with ACNU at a dose of 15 mg kg-1 did not exhibit any efficacy in the rats inoculated with C6 glioma cells (C6-MG). Intrathecal ACNU, however, at dosages of up to 1.5 mg kg-1 failed to demonstrate any therapeutic effect in the late stage of MG, i.e. 5 days after the tumour inoculation, except in the rats inoculated with 9L brain tumour cells (9L-MG). Intravenous chemotherapy with ACNU at a dose of 15 mg kg-1 extended the MST of the 9L-MG rats more significantly in the late stage of MG than in its early stage. This points to the feasibility of intrathecal ACNU in the treatment of meningeal gliomatosis in its early stages, but not in its late stages in which intravenous ACNU might be more effective than intrathecal treatment against MG of which the parenchyma has already been deeply invaded by the tumour.

Serial lumbar and ventricular cerebrospinal fluid biochemical marker measurements in patients with leptomeningeal metastases from solid and hematological tumors

This study presents results of investigations of lumbar and ventricular cerebrospinal fluid (CSF) biochemical markers (Beta-glucuronidase (B-gluc), Beta-2-microglobulin (B2-m), and carcinoembrionic antigen (CEA] in 28 patients with five different tumor types with leptomeningeal metastasis diagnosed by CSF cytology and/or autopsy. All received methotrexate and radiotherapy at some stage. Decadron or other symptomatic treatments were not used. Measurements of the concentrations of B-gluc, B2-m and CEA were evaluated with the aim of correlating the results of these measurements to site of disease, of monitoring response and early relapse of leptomeningeal disease, and of establishing the duration of survival. In almost all our patients the results of ventricular CSF B-gluc, B2-m and CEA measurements were lower than those obtained from lumbar CSF. The markers did not correlate with site of disease or CSF cytology. A clear relationship was found between pretreatment lumbar CSF B2-m and CEA levels, response to therapy and survival. The markers are also useful for monitoring response. The findings of this study indicate that B2-m and CEA levels have a prognostic value with regard to response to therapy and time of survival.

Early and delayed neurotoxicity of mitoxantrone and doxorubicin following subarachnoid injection

Doxorubicin (DXR) and Mitoxantrone (MXN) were administered into the subarachnoid space of mice or the ventricular system of rats. The maximal non-toxic systemic single dose (zero mortality = LDo) of DXR or MXN was used as reference for planning drug doses for CSF administration. LDo in mice were: 8 mg/kg DXR and 6 mg/kg MXN; in rats: 6 mg/kg DXR and 4.5 mg/kg MXN. Signs of neurotoxicity were remarkably similar in DXR or MXN treatment animals and included: head tremor, atactic-dystonic posture and circling behavior. The toxicity was dose dependent. Doses of greater than or equal to 10% the LDo caused early appearance of clinical signs: a dose of 10% LDo caused neurotoxicity in 90% of DXR treated mice and in only 15% of MXN-treated animals. Treatment with 25% LDo MXN caused neurotoxicity in 30% of treated animals. Doses of less than or equal to 5% the LDo caused a delayed onset of DXR neurotoxicity in one third of treated mice (after 60-90 days). In rats, neurotoxicity was of an early onset and augmented severity following doses of greater than or equal to 5% LDo. Abnormal histopathological findings were detected only in symptomatic animals with early toxicity and were usually restricted to superficial cortical layers in mice or the basal surface of the brainstem in rats. Brains of mice with delayed toxicity were unremarkable. The levels of monoamine neurotransmitters and their metabolites (DA, DOPAC, HVA, NE, 5HT) in the striatum, cortex and cerebellum of mice with early and delayed DXR neurotoxicity did not differ from normal brains.(ABSTRACT TRUNCATED AT 250 WORDS)