Intrathecal liposomal cytarabine in combination with temozolomide in low-grade oligoastrocytoma with leptomeningeal dissemination

Leptomeningeal dissemination of low-grade neuroepithelial CNS tumors in adults: a 15-year experience

Background

Leptomeningeal dissemination (LD) in adults is an exceedingly rare complication of low-grade neuroepithelial CNS tumors (LGNs). We aimed to determine relative incidence, clinical presentation, and predictors of outcome.

Methods

We searched the quality control database of the Section of Neuro-Oncology, Yale Cancer Center, for patients with LGN (WHO grade I/II) seen between 2002 and 2017. For cases complicated by LD, we recorded demographics, clinical signs, histopathological diagnosis, and imaging findings. A comprehensive literature review was performed.

Results

Eleven consecutive patients with LD were identified, representing 2.3% of individuals with LGN seen at our institution between 2002 and 2017 (n = 475). Ependymoma was the predominant histological entity. Mean time interval from diagnosis of LGN to LD was 38.6 ± 10 months. Symptoms were mostly attributed to communicating hydrocephalus. Tumor deposits of LD were either nodular or linear with variable enhancement (nonenhancing lesions in 4 of 11 patients). Localized (surgery, radiosurgery, involved-field, or craniospinal radiation therapy) or systemic treatments (chemotherapy) were provided. All patients progressed radiographically. Median overall survival after LD was 102 months. Survival was prolonged when a combination of localized and systemic therapies was administered (188.5 vs 25.5 months; P = .03). Demographics and tumor spectrum reported in the literature were similar to our cohort.

Conclusions

LD is a rare complication of LGNs. A high level of suspicion is required for timely diagnosis as early symptoms are nonspecific and commonly do not occur until years after initial tumor diagnosis. Repeated aggressive treatment appears to be beneficial in improving survival.

Challenges in drug delivery to tumors of the central nervous system: an overview of pharmacological and surgical considerations

The majority of newly diagnosed brain tumors are treated with surgery, radiation, and the chemotherapeutic temozolomide. Development of additional therapeutics to improve treatment outcomes is complicated by the blood-brain barrier (BBB), which acts to protect healthy tissue from chemical insults. The high pressure found within brain tumors adds a challenge to local delivery of therapy by limiting the distribution of bolus injections. Here we discuss various drug delivery strategies, including convection-enhanced delivery, intranasal delivery, and intrathecal delivery, as well as pharmacological strategies for improving therapeutic efficacy, such as blood-brain barrier disruption.

Neoplastic meningitis from solid tumors: new diagnostic and therapeutic approaches

Neoplastic meningitis is a result of the spread of malignant cells to the leptomeninges and subarachnoid space and their dissemination within the cerebrospinal fluid. This event occurs in 4%-15% of all patients with solid tumors and represents an important prognostic factor for poor survival. Neoplastic meningitis should be diagnosed in the early stages of disease to prevent important neurological deficits and to provide the most appropriate treatment. Despite new diagnostic approaches developed in recent years, such as positron emission tomography-computed tomography and new biological markers, the combination of magnetic resonance imaging without and with gadolinium enhancement and cytology still has the greatest diagnostic sensitivity. Recently, no new randomized studies comparing intrathecal (i.t.) with systemic treatment have been performed, yet there have been a few small phase II studies and case reports about new molecularly targeted substances whose successful i.t. or systemic application has been reported. Trastuzumab, gefitinib, and sorafenib are examples of possible future treatments for neoplastic meningitis, in order to better individualize therapy thus allowing better outcomes. In this review, we analyze the most recent and interesting developments on diagnostic and therapeutic approaches.

Biology and therapy of neoplastic meningitis

Neoplastic meningitis (NM) occurs in 5% to 8% of cancer patients, commonly as an end-stage process in previously metastatic disease. As newer therapeutics extend patient survival by maintaining long-term control of systemic malignancies, the incidence of NM is likely to rise. This can be expected both because of a change in the natural history of the underlying disease and the generally poor penetrance of many newer anticancer drugs into the central nervous system, thereby creating a sanctuary site for malignant cells. Currently available treatments have provided limited benefit in overall survival in NM, although long-term survival does occur. Because of the morbidity occasionally associated with treatment, prognostic indicators are being analyzed to identify patients who may benefit from systemic and/or intrathecal therapy before making the decision to initiate treatment. Additionally, because of the relative insensitivity of traditional cerebrospinal fluid analysis, new markers of NM are being investigated. This endeavor is being aided by ongoing research into the underlying biology of the metastatic process.