Neoplastic meningitis following surgical resection of isolated cerebellar metastasis: a potentially preventable complication

The path to leptomeningeal metastasis

The leptomeninges, the cerebrospinal-fluid-filled tissues surrounding the central nervous system, play host to various pathologies including infection, neuroinflammation and malignancy. Spread of systemic cancer into this space, termed leptomeningeal metastasis, occurs in 5-10% of patients with solid tumours and portends a bleak clinical prognosis. Previous, predominantly descriptive, clinical studies have provided few insights. Recent development of preclinical leptomeningeal metastasis models, alongside genomic, transcriptomic and proteomic sequencing efforts, has provided groundwork for mechanistic understanding and identification of long-needed therapeutic targets. Although previously understood as an anatomically isolated compartment, the leptomeninges are increasingly appreciated as a major conduit of communication between the systemic circulation and the central nervous system. Despite the unique nature of the leptomeningeal microenvironment, the general principles of metastasis hold true: cells metastasizing to the leptomeninges must gain access to the new environment, survive within the space and evade the immune system. The study of leptomeningeal metastasis has the potential to uncover novel site-specific metastatic principles and illuminate the physiology of the leptomeningeal space. In this Review, we provide a biology-focused overview of how metastatic cells reach the leptomeninges, thrive in this nutritionally sparse environment and evade the detection of the omnipresent immune system.

The anatomic basis of leptomeningeal metastasis

Leptomeningeal metastasis (LM), or spread of cancer to the cerebrospinal fluid (CSF)-filled space surrounding the central nervous system, is a fatal complication of cancer. Entry into this space poses an anatomical challenge for cancer cells; movement of cells between the blood and CSF is tightly regulated by the blood-CSF barriers. Anatomical understanding of the leptomeninges provides a roadmap of corridors for cancer entry. This Review describes the anatomy of the leptomeninges and routes of cancer spread to the CSF. Granular understanding of LM by route of entry may inform strategies for novel diagnostic and preventive strategies as well as therapies.

Long-term response to sequential anti-HER2 therapies including trastuzumab-deruxtecan in a patient with HER2-positive metastatic breast cancer with leptomeningeal metastases: a case report and review of the literature

The incidence of leptomeningeal metastases (LM) is increasing among breast cancer patients, but their prognosis remains dismal. Many therapeutic options are now available to treat HER2-positive (HER2+) metastatic breast cancer (MBC) involving the central nervous system (CNS). This case report illustrates a long-lasting response of more than 2 years in a patient with HER2+ MBC with LM after sequential administration of systemic and intrathecal (IT) anti-HER2 therapies and highlights that an appropriate treatment of HER2+ LM can result in durable survival.

Collagen deposition within brain metastases is associated with leptomeningeal failure after cavity-directed radiosurgery

Background

Leptomeningeal failure (LMF) represents a devastating progression of disease following resection of brain metastases (BrM). We sought to identify a biomarker at time of BrM resection that predicts for LMF using mass spectrometry-based proteomic analysis of resected BrM and to translate this finding with histochemical assays.

Methods

We retrospectively reviewed 39 patients with proteomic data available from resected BrM. We performed an unsupervised analysis with false discovery rate adjustment (FDR) to compare proteomic signature of BrM from patients that developed LMF versus those that did not. Based on proteomic analysis, we applied trichrome stain to a total of 55 patients who specifically underwent resection and adjuvant radiosurgery. We used competing risks regression to assess predictors of LMF.

Results

Of 39 patients with proteomic data, FDR revealed type I collagen-alpha-1 (COL1A1, P = .045) was associated with LMF. The degree of trichrome stain in each block correlated with COL1A1 expression (β = 1.849, P = .001). In a cohort of 55 patients, a higher degree of trichrome staining was associated with an increased hazard of LMF in resected BrM (Hazard Ratio 1.58, 95% CI 1.11-2.26, P = .01).

Conclusion

The degree of trichrome staining correlated with COL1A1 and portended a higher risk of LMF in patients with resected brain metastases treated with adjuvant radiosurgery. Collagen deposition and degree of fibrosis may be able to serve as a biomarker for LMF.

Leptomeningeal Metastasis from Non-Small Cell Lung Cancer and Current Landscape of Treatments

Leptomeningeal metastasis (LM), also known as leptomeningeal carcinomatosis (LC), is a devastating complication of metastatic cancer that occurs when neoplastic cells invade the meningeal space. Diagnosis of LM remains challenging given the heterogeneous signs and symptoms at presentation and requires thorough neurological examination, cerebrospinal fluid (CSF) analysis, and MRI of the brain and spine with gadolinium. Detecting neoplastic cells in the CSF is the gold standard for diagnosing leptomeningeal metastases; however, it has low sensitivity and may require multiple CSF samples. New emerging technologies, such as liquid biopsy of CSF, have increased sensitivity and specificity for detecting circulating tumor cells in CSF. The management of LM in patients with NSCLC requires an individualized multidisciplinary approach. Treatment options include surgery for ventricular shunt placement, radiation therapy to bulky or symptomatic disease sites, systemic or intrathecal chemotherapy, molecularly targeted agents, and, more recently, immunotherapy. Targeting actionable mutations in LM from NSCLC, such as EGFR tyrosine kinase inhibitors or anaplastic lymphoma kinase gene rearrangement inhibitors, has shown encouraging results in terms of disease control and survival. Although there are limited data regarding the use of immunotherapy in LM, immunotherapy has produced promising results in several case reports. In this review, we focused on the epidemiology, pathophysiology, clinical presentation, diagnosis, and current treatment strategies, with a special emphasis on novel agents, including targeted therapies and immunotherapy of LM in patients with NSCLC.

Novel Therapeutic Approaches in Neoplastic Meningitis

Central nervous system (CNS) metastasis from systemic cancers can involve the brain parenchyma, leptomeninges, or the dura. Neoplastic meningitis (NM), also known by different terms, including leptomeningeal carcinomatosis and carcinomatous meningitis, occurs due to solid tumors and hematologic malignancies and is associated with a poor prognosis. The current management paradigm entails a multimodal approach focused on palliation with surgery, radiation, and chemotherapy, which may be administered systemically or directly into the cerebrospinal fluid (CSF). This review focuses on novel therapeutic approaches, including targeted and immunotherapeutic agents under investigation, that have shown promise in NM arising from solid tumors.

Radiotherapy for Leptomeningeal Carcinomatosis in Breast Cancer Patients: A Narrative Review

Simple Summary

Leptomeningeal carcinomatosis (LC) is a rare event in breast cancer (BC) patients that carries an abysmal prognosis. Little progress has been made in this field in the last few decades. Despite innovations in radiotherapy (RT), there is no univocal evidence of its impact on survival. Due to the rarity of the diagnosis, only a few prospective trials have evaluated the role of RT for LC in BC. Nonetheless, most BC patients with LC currently receive RT, depending on local protocols and individual convictions. This review presents the current knowledge on the indications and feasibility of RT for LC in BC, focusing on new technologies and perspectives.

Abstract

Leptomeningeal carcinomatosis (LC), defined as the infiltration of the leptomeninges by cancer cells, is a rare oncological event with the most common etiology being breast cancer (BC), lung cancer, and melanoma. Despite innovations in radiotherapy (RT), firm evidence of its impact on survival is lacking, and concerns are related to its possible neurotoxicity. Owing to a paucity of data, the optimal treatment strategy for LC remains unknown. This review discusses current approaches, indications, and contraindications for various forms of RT for LC in BC. A separate section is dedicated to new RT techniques, such as proton therapy. We also summarize ongoing clinical trials evaluating the role of RT in patients with LC.

Surgical and anatomic factors predict development of leptomeningeal disease in patients with melanoma brain metastases

BACKGROUND

Leptomeningeal disease (LMD) is a devastating complication of systemic malignancy, of which there is an unclear etiology. The aim of this study is to determine if surgical or anatomic factors can predict LMD in patients with metastatic melanoma.

METHODS

A retrospective chart review was performed of 1162 patients treated at single institution for melanoma brain metastases (MBM). Patients with fewer than 3 months follow-up or lacking appropriate imaging were excluded. Demographic information, surgical, and anatomic data were collected.

RESULTS

Eight hundred and twenty-seven patients were included in the final review. On multivariate analysis for the entire cohort, female gender, dural-based and intraventricular metastasis, and tumor bordering CSF spaces were associated with increased risk of LMD. Surgical resection was not significant for risk of LMD. On multivariate analysis of patients who have undergone surgical resection of a metastatic tumor, dural-based and intraventricular metastasis, ventricular entry during surgery, and metastasis in the infratentorial space were associated with increased risk of LMD. On multivariate analysis of patients who did not undergo surgery, chemotherapy after initial diagnosis and metastasis bordering CSF spaces were associated with increased risk of LMD.

CONCLUSION

In a single-institution cohort of MBM, we found that surgical resection alone did not result in an increased risk of LMD. Anatomical factors such as dural-based and intraventricular metastasis were significant for developing LMD, as well as entry into a CSF space during surgical resection. These data suggest a strong correlation between anatomic location and tumor cell seeding in relation to the development of LMD.

Malignant Meningitis Associated with Hydrocephalus

Malignant meningitis (MM) is the diffuse involvement of the leptomeninges by infiltrating cancer cells, most frequently from lung and breast cancers. This review is aimed to discuss the current advances in the diagnosis and management of MM, along with management of MM-associated hydrocephalus. We reviewed the literature using PubMed and Google Scholar search engines, focusing on various recent randomized controlled trials and clinical trials on MM. Given the hallmark multifocal involvement, the clinical symptoms and signs are also random and asymmetric. There are three important pillars for establishing a diagnosis of MM: clinical examination, neuroimaging, and CSF cytological findings. Several factors should be considered in decision-making, including performance status, neurological findings (clinical, MRI, and CSF flow dynamic), and evaluation of the primary tumor (nature and systemic dissemination). Response Assessment in Neuro-Oncology (RANO) working group recommended the objective assessment of disease for evaluating the progression and response to therapy. Pillars of current management are mainly focal irradiation and intrathecal or systemic chemotherapy. Symptomatic hydrocephalus is managed with a ventriculoperitoneal shunt, lumboperitoneal shunt, or endoscopic third ventriculostomy as palliative procedures, providing significant improvement in performance scores in the limited survival time of patients with MM. Studies using novel therapeutic approaches, such as new biological or cytotoxic compounds, are ongoing. Despite the use of all the combinations, the overall prognosis remains grim; therefore, decision-making for treatment should predominantly be based on attaining an optimal quality of life.

Neurologic Complications in Patients with Cancer

Neurologic symptoms are commonly seen in patients with cancer and can be among the most challenging to diagnose and manage. It is often difficult to determine if new neurologic symptoms are secondary to direct effects of a malignant lesion, systemic complications of disease, paraneoplastic disorders, or side effects of cancer treatment itself. However, early diagnosis and treatment of each of these conditions can improve patients' quality of life and long-term functional outcomes. In this review, we describe a systematic approach to the diagnosis of new neurologic symptoms in patients with known malignancy. We have categorized the neurologic complications of cancer through a mechanistic approach, with an emphasis on ascertaining underlying pathophysiology to guide treatment choice. This review focuses on the acute neurologic complications of cancer that require hospital admission.

Extraventricular Choroid Plexus Carcinoma with Spinal Metastasis: A Case Report

We report a case of extraventricular choroid plexus carcinoma (CPC) accompanied by spinal metastasis in a pediatric patient. A 15-year-old female patient presented with chronic progressive headache and blurry vision. Magnetic resonance imaging (MRI) revealed an intra-axial mass in the left frontal lobe. A gross total resection was performed, and the histopathological examination revealed the diagnosis of CPC, confirmed with immunohistochemical (IHC) analysis of GFAP, S100, EM, P53 and Ki67. Eleven months later, MRI result identified another mass in the left frontal lobe. Spinal MRI showed drop metastasis to the spine, accompanied by leptomeningeal seeding. This case demonstrated the importance of IHC and spinal MRI in the management of CPC. This case report may provide more insight into extraventricular CPC cases, which is important for the adequate management of patients with CPC in the future.

The Underlying Biology and Therapeutic Vulnerabilities of Leptomeningeal Metastases in Adult Solid Cancers

Metastasis to the central nervous system occurs in approximately 20% of patients with advanced solid cancers such as lung cancer, breast cancer, and melanoma. While central nervous system metastases most commonly form in the brain parenchyma, metastatic cancer cells may also reside in the subarachnoid space surrounding the brain and spinal cord to form tumors called leptomeningeal metastases. Leptomeningeal metastasis involves cancer cells that reach the subarachnoid space and proliferate in the cerebrospinal fluid compartment within the leptomeninges, a sequela associated with a myriad of symptoms and poor prognosis. Cancer cells exposed to cerebrospinal fluid in the leptomeninges must contend with a unique microenvironment from those that establish within the brain or other organs. Leptomeningeal lesions provide a formidable clinical challenge due to their often-diffuse infiltration within the subarachnoid space. The molecular mechanisms that promote the establishment of leptomeningeal metastases have begun to be elucidated, demonstrating that it is a biological entity distinct from parenchymal brain metastases and is associated with specific molecular drivers. In this review, we outline the current state of knowledge pertaining to the diagnosis, treatment, and molecular underpinnings of leptomeningeal metastasis.

Is local radiotherapy a viable option for patients with an opening of the ventricles during surgical resection of brain metastases?

Background

Local hypofractionated stereotactic radiotherapy (HFSRT) of the resection cavity is emerging as the standard of care in the treatment of patients with a limited number of brain metastases as it warrants less neurological impairment compared to whole brain radiotherapy. In periventricular metastases surgical resection can lead to an opening of the ventricles and subsequently carries a potential risk of cerebrospinal tumour cell dissemination. The aim of this study was to assess whether local radiotherapy of the resection cavity is viable in these cases.

Methods

From our institutional database we analyzed the data of 125 consecutive patients with resected brain metastases treated in our institution with HFSRT between 2009 and 2017. The incidence of LMD, overall survival (OS), local recurrence (LC) and distant recurrence were evaluated depending on ventricular opening (VO) during surgery.

Results

From all 125 patients, the ventricles were opened during surgery in 14 cases (11.2%). None of the patients with VO and 7 patients without VO during surgery developed LMD (p = 0.371). OS (p = 0.817), LC (p = 0.524) and distant recurrence (p = 0.488) did not differ in relation to VO during surgical resection. However, the incidence of distant intraventricular recurrence was slightly increased in patients with VO (14.3% vs. 2.7%, p < 0.01).

Conclusion

VO during neurosurgical resection did not affect the outcome after HFSRT of the resection cavity in patients with brain metastases. Particularly, the incidence of LMD was not increased in patients receiving local HFSRT after VO. HFSRT can therefore be offered independently of VO as a local treatment of tumor bed after resection of brain metastases.

Outcome after surgery in supratentorial and infratentorial solitary brain metastasis

BACKGROUND

The aim of this retrospective study was to investigate and compare the outcome after surgery in patients with a supratentorial solitary metastasis (SSM) and an infratentorial solitary metastasis (ISM). A worse prognosis has been reported in ISM.

METHODS

Fifty-two patients with a newly diagnosed solitary brain metastasis on MRI were included to identify risk factors affecting the outcome. Key variables included tumor size, staging of the primary tumor, time span of presurgical work-up, and surgical technique. Outcome variables included postoperative complications, tumor recurrence, and mortality. Kaplan-Meier survival analysis was applied.

RESULTS

Thirty patients with a SSM and 22 patients with an ISM underwent gross total resection. The tumor size did not have a statistical significant effect on survival. Presurgical work-up time was similar in SSM and ISM. Postoperative complications were more frequently encountered in ISM. Recurrence rate was comparable in SSM and ISM. Carcinomatous meningitis (CM) was more frequently seen in ISM, and CM was seen more often with the piecemeal resection technique. There was no statistical difference in overall survival between SSM and ISM.

CONCLUSIONS

This study identified factors that play a role in the outcome after surgery in patients with ISM and SSM on MRI. Postoperative complications seemed to be higher in ISM and CM was more often seen in ISM, but the worse prognosis in patients with ISM compared with SSM could not be confirmed.

Leptomeningeal metastasis

Leptomeningeal metastasis (LM) results from dissemination of cancer cells to both the leptomeninges (pia and arachnoid) and cerebrospinal fluid (CSF) compartment. Breast cancer, lung cancer, and melanoma are the most common solid tumors that cause LM. Recent approval of more active anticancer therapies has resulted in improvement in survival that is partly responsible for an increased incidence of LM. Neurologic deficits, once manifest, are mostly irreversible, and often have a significant impact on patient quality of life. LM-directed therapy is based on symptom palliation, circumscribed use of neurosurgery, limited field radiotherapy, intra-CSF and systemic therapies. Novel methods of detecting LM include detection of CSF circulating tumor cells and tumor cell-free DNA. A recent international guideline for a standardization of response assessment in LM may improve cross-trial comparisons as well as within-trial evaluation of treatment. An increasing number of retrospective studies suggest that molecular-targeted therapy, such as EGFR and ALK inhibitors in lung cancer, trastuzumab in HER2+ breast cancer, and BRAF inhibitors in melanoma, may be effective as part of the multidisciplinary management of LM. Prospective randomized trials with standardized response assessment are needed to further validate these preliminary findings.

Metastatic Complications of Cancer Involving the Central and Peripheral Nervous Systems

Neurologic complications of cancer may involve both the central nervous system and peripheral nervous system manifesting as brain, leptomeningeal, intramedullary, intradural, epidural, plexus, and skull base metastases. Excluding brain involvement, neurologic complications affecting these other sites are relatively infrequent, but collectively they affect more than 25% of patients with metastatic cancer causing significant morbidity and mortality. Early diagnosis and intervention optimize quality of life and improve survival.

Laser Interstitial Thermal Therapy for Posterior Fossa Lesions: An Initial Experience

BACKGROUND

The application of laser interstitial thermal therapy (LITT) for intracranial lesions in the posterior fossa tumors remains challenging due to the smaller size of this compartment as well as the thickness and angle of the occipital bone. In this study, we reviewed our experience with this treatment modality for posterior fossa lesions.

METHODS

We retrospectively reviewed our series of 8 patients with posterior fossa tumors treated with LITT from an Institutional Review Board-approved brain tumor database (2012-2017) of more than 200 cases at our institution.

RESULTS

The 8 patients underwent LITT targeting 3 metastases, 2 pilocytic astrocytomas, 2 zones of radiation necrosis after radiosurgery, and 1 glioblastoma (GBM). The mean preoperative lesion volume was 4.35 cm³. A 6 months postsurgery, the mean lesion volume had decreased from 9.64 cm³ to 5.72 cm³. Two of the tumors (the GBM and a metastatic adenocarcinoma) progressed after 8.5 and 7.5 months, respectively, with mortality after 1.1 and 1.6 years, respectively. Surgical resection was performed in a patient with metastatic adenocarcinoma tumor at 7.7 months after LITT. All other lesions remained stable or were diminished at a median follow-up of 14.8 months (range, 0.4-37.5 months). Magnetic resonance imaging (MRI) on the first postoperative day, showed an increase in mean tumor-related edema volume from 9.45 cm³ to 14.10 cm³. After a postoperative follow-up of at least 1 month, this mean decreased to 8.70 cm³. One case each of transient partial unilateral sixth cranial nerve palsy, superficial wound infection, and a late obstructive hydrocephalus were noted postoperatively. No mortality was associated with the procedure.

CONCLUSIONS

LITT is a safe and feasible treatment modality even in challenging locations like the posterior fossa. However, surgical indications should be tailored for each individual patient based on the size and location of tumor.

Most common sites on MRI of intracranial neoplastic leptomeningeal disease

Neoplastic leptomeningeal disease (LMD) represents infiltration of the leptomeninges by tumor cells. Knowledge of the frequencies of locations of LMD on MRI may assist in early detection, help elucidate the process of leptomeningeal spread of cancer and understand how LMD affects the central nervous system. Our goal was to identify intracranial sites of neoplastic LMD predilection on MRI in patients with cytologically-proven LMD. The presence of FLAIR signal hyperintensity and T1-weighted post-contrast enhancement in the sulci of the supratentorial compartment and cerebellum and enhancement of the cranial nerves (CNs), basal cisterns, pituitary stalk, and ependymal surface of the lateral ventricles, as well as the presence of parenchymal metastasis were recorded. Within each imaging sequence, sites were ordered by prevalence and compared using McNemar's test. The study included 270 patients. Positive MRI findings were present in 185/270 (68.5%) patients. FLAIR signal hyperintensity was significantly more common (p≤0.003) in the cerebellum (n=96) and occipital lobe (n=92) relative to the other lobes. Leptomeningeal enhancement was also significantly more common (p≤0.009) in the cerebellum (n=82) and occipital lobe (n=67) relative to the other lobes. Enhancement was most commonly found involving CN VII/VIII and the ependymal surface of the lateral ventricles compared to other sites. Parenchymal metastases were present in 110 (40.1%) of the patients. In conclusion, neoplastic LMD predominantly involves the cerebellum and occipital lobes, CN VII/VIII, and the ependymal lining of the lateral ventricles. Parenchymal metastases are frequently present in patients with neoplastic LMD.

Effects of Postoperative Radiotherapy on Leptomeningeal Carcinomatosis or Dural Metastasis after Resection of Brain Metastases in Breast Cancer Patients

Purpose

In this retrospective study, we compared the incidence of leptomeningeal carcinomatosis or dural metastasis (LMCDM) in patients who received whole brain radiotherapy (WBRT), partial radiotherapy (PRT), or no radiotherapy (RT) following resection of brain metastases from breast cancer.

Materials and Methods

Fifty-one patients with breast cancer underwent surgical resection for newly diagnosed brain metastases in two institutions between March 2001 and March 2015. Among these, 34 received postoperative WBRT (n=24) or PRT (n=10) and 17 did not.

Results

With a median follow-up of 12.4 months (range, 2.3 to 83.6 months), 22/51 patients developed LMCDM at a median of 8.6 months (range, 4.8 to 51.2 months) after surgery. The 18-months LMCDM-free survival (LMCDM-FS) rates were 77.5%, 30.0%, and 13.6%, in the WBRT, PRT, and no RT groups, respectively (p=0.013). The presence of a tumor adjacent to cerebrospinal fluid flow and no systemic treatment after treatment for brain metastases were also associated with poor LMCDM-FS rate. Multivariate analysis showed that WBRT compared to PRT (p=0.009) and systemic treatment (p < 0.001) were independently associated with reduced incidence of LMCDM.

Conclusion

WBRT improved LMCDM-FS rate after resection of brain metastases compared to PRT in breast cancer patients.

Patterns of Failure after Stereotactic Radiosurgery of the Resection Cavity Following Surgical Removal of Brain Metastases

BACKGROUND

Whole brain radiation treatment (WBRT) is considered standard treatment for BM. However, exposing large volumes of normal brain tissue to irradiation can cause neurotoxicity. This study describes our experience with 100 consecutive patients with brain metastases who were managed with surgical extirpation followed by stereotactic radiosurgery (SRS) to the resection cavity.

METHODS

Patients with 1-3 brain metastases (BM), who underwent resection of 1-2 BM between June 2005 and December 2013, were treated with SRS directed to the tumor cavity and for any synchronous BM. Local and distant treatment failures were determined based on neuroimaging. Kaplan-Meier curves were generated for local and distant failure rates and overall survival.

RESULTS

One hundred and two resection cavities were treated with SRS in 100 consecutive patients. Thirty-two additional synchronous metastases were treated in 27 patients during the same session. The median overall survival was 18.9 months. Local control rate at 1 year was 84%. Longer delays between surgery and SRS were associated with increased risk of local failure (hazard ratio, -1.46; P = 0.02). Distant progression occurred in 44% of the patients at a mean of 8.8 ± 6.6 months after SRS treatment. Ten cases of leptomeningeal spread occurred around the resection cavities (9.8%). Central nervous system failure was not significantly associated with survival. Multivariate Cox regression analysis showed that recursive partitioning analysis and active systemic disease were significantly associated with survival.

CONCLUSION

The strategy described provides acceptable local disease control when compared with WBRT following surgery. This approach can delay and even annul WBRT in the majority of selected BM patients, especially recursive partitioning analysis class I patients. SRS should be scheduled as soon as possible after surgery.

Risk factors for leptomeningeal carcinomatosis in patients with brain metastases who have previously undergone stereotactic radiosurgery

Our objective was to explore the hypothesis that the risk of leptomeningeal dissemination (LMD) in patients who underwent stereotactic radiosurgery (SRS) for brain metastases is influenced by the site of the primary cancer, the addition of whole brain radiation therapy (WBRT), surgical resection, and control over their systemic disease. We conducted a retrospective cohort analysis of 805 patients who were treated with SRS for brain metastases between 1999 and 2012 at the Wake Forest Baptist Medical Center, and excluded all patients with evidence of LMD before SRS. The primary outcome was LMD. Forty-nine of 795 patients developed LMD with a cumulative incidence of 6.2% (95% Confidence Interval (CI), 4.7-8.0). Median time from SRS to LMD was 7.4 months (Interquartile Range (IQR), 3.3-15.4). A colorectal primary site (Hazard Ratio (HR), 4.5; 95% CI 2.5-8.0; p < 0.0001), distant brain failure (HR, 2.0; 95% CI 1.2-3.2; p = 0.007), breast primary site (HR, 1.6; 95% CI 1.0-2.7; p = 0.05), the number of intracranial metastases at time of initial SRS (HR, 1.1; 95% CI 1.0-1.2; p = 0.02), and age (by 5-year interval) (HR, 0.9; 95% CI 0.8, 0.9; p = 0.0006) were independent factors associated with LMD. There was no evidence that surgical resection before SRS altered the risk of LMD (HR, 1.1; 95 % CI 0.6-2.0, p = 0.78). In patients who underwent SRS for brain metastases, a colorectal or breast primary site, distant brain failure, younger age, and an increased number of intracranial metastases were independently associated with LMD. Given its relative rarity as an outcome, multi-institutional prospective studies will likely be necessary to validate and quantify these relationships.

Carcinomatous meningitis: Leptomeningeal metastases in solid tumors

Leptomeningeal metastasis (LM) results from metastatic spread of cancer to the leptomeninges, giving rise to central nervous system dysfunction. Breast cancer, lung cancer, and melanoma are the most frequent causes of LM among solid tumors in adults. An early diagnosis of LM, before fixed neurologic deficits are manifest, permits earlier and potentially more effective treatment, thus leading to a better quality of life in patients so affected. Apart from a clinical suspicion of LM, diagnosis is dependent upon demonstration of cancer in cerebrospinal fluid (CSF) or radiographic manifestations as revealed by neuraxis imaging. Potentially of use, though not commonly employed, today are use of biomarkers and protein profiling in the CSF. Symptomatic treatment is directed at pain including headache, nausea, and vomiting, whereas more specific LM-directed therapies include intra-CSF chemotherapy, systemic chemotherapy, and site-specific radiotherapy. A special emphasis in the review discusses novel agents including targeted therapies, that may be promising in the future management of LM. These new therapies include anti-epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors erlotinib and gefitinib in nonsmall cell lung cancer, anti-HER2 monoclonal antibody trastuzumab in breast cancer, anti-CTLA4 ipilimumab and anti-BRAF tyrosine kinase inhibitors such as vermurafenib in melanoma, and the antivascular endothelial growth factor monoclonal antibody bevacizumab are currently under investigation in patients with LM. Challenges of managing patients with LM are manifold and include determining the appropriate patients for treatment as well as the optimal route of administration of intra-CSF drug therapy.

Incidence and risk factors for leptomeningeal carcinomatosis in breast cancer patients with parenchymal brain metastases

OBJECTIVE

The objective of study is to evaluate the incidence of leptomeningeal carcinomatosis (LMC) in breast cancer patients with parenchymal brain metastases (PBM) and clinical risk factors for the development of LMC.

METHODS

We retrospectively analyzed 27 patients who had undergone surgical resection (SR) and 156 patients with whole brain radiation therapy (WBRT) as an initial treatment for their PBM from breast cancer in our institution and compared the difference of incidence of LMC according to clinical factors. The diagnosis of LMC was made by cerebrospinal fluid cytology and/or magnetic resonance imaging.

RESULTS

A total of 27 patients (14%) in the study population developed LMC at a median of 6.0 months (range, 1.0-50). Ten of 27 patients (37%) developed LMC after SR, whereas 17 of 156 (11%) patients who received WBRT were diagnosed with LMC after the index procedure. The incidence of LMC was significantly higher in the SR group compared with the WBRT group and the hazard ratio was 2.95 (95% confidence interval; 1.33-6.54, p<0.01). Three additional factors were identified in the multivariable analysis : the younger age group (<40 years old), the progressing systemic disease showed significantly increased incidence of LMC, whereas the adjuvant chemotherapy reduce the incidence.

CONCLUSION

There is an increased risk of LMC after SR for PBM from breast cancer compared with WBRT. The young age (<40) and systemic burden of cancer in terms of progressing systemic disease without adjuvant chemotherapy could be additional risk factors for the development of LMC.

Risk for leptomeningeal seeding after resection for brain metastases: implication of tumor location with mode of resection

Object

Surgical spillage has been one of the causative factors for the development of leptomeningeal seeding (LMS) after resection of brain metastases. In this paper, the authors' goal was to define the factors related to the development of LMS and to evaluate the difference according to tumor location.

Methods

The authors retrospectively analyzed 242 patients who had undergone resection for brain metastases. The factors investigated included tumor location with proximity to the CSF pathway (that is, contacting, involved with, or separated from the CSF pathway), the method of resection, and the use of the Cavitron Ultrasonic Surgical Aspirator (CUSA).

Results

A total of 39 patients (16%) developed LMS at a median of 6.0 months (range 1–42 months) after resection. The risk of developing LMS was significantly higher in patients whose tumors were resected piecemeal than in those whose tumors were removed en bloc, with a hazard ratio (HR) of 4.08 (p < 0.01). The incidence of LMS was significantly higher in patients in whom the CUSA was used, and the HR was 2.64 (p < 0.01). The proximity of tumor to the CSF pathway in the involved group conferred an increased risk of LMS compared with the separated group (HR 11.36, p < 0.01). The risk of piecemeal resection for LMS was significant only in involved lesions (p < 0.01), and the use of the CUSA in both contact and involved lesions increased the incidence of LMS (p < 0.01 and p < 0.03, respectively).

Conclusions

The authors suggest that piecemeal resection using the CUSA should be limited because of the risk of postsurgical LMS, especially when the tumor is in contact with the CSF pathway.

The Louisiana State University Experience in the Management of Single Small Cerebellar Metastasis

BACKGROUND:

Cerebellar metastasis is often believed to be a more immediately life-threatening complication than brain metastasis in other locations. It is considered a negative prognostic factor in patients with systemic cancers. Despite its clinical importance and technological advances, the survival outcomes of patients with single small cerebellar metastases are rarely studied.

OBJECTIVE:

To retrospectively evaluate our experience in the management of patients with single small cerebellar metastasis and compare the treatment modalities.

MATERIAL AND METHODS:

A total of 35 patients with single small cerebellar metastasis were included in this retrospective analysis. Of the 35 patients, 24 had surgery followed by whole-brain radiation therapy and 11 had Gamma Knife radiosurgery alone.

RESULTS:

The median survival for the whole cohort was 5.6 months after the intervention. No significant differences were noted in median survival between the surgery plus whole-brain radiation therapy and the Gamma Knife radiosurgery alone groups (6.3 months: 95% confidence interval [CI], 4.0-8.6; vs 5.0 months: 95% CI, 1.9-8.1; P = .9). There was no difference in the median time to local progression, distance progression, and overall progression between the 2 groups. Patients with hydrocephalus had a significantly lower survival rate (median, 3.3 months; 95% CI, 0.0-6.6) compared with those without hydrocephalus (median, 6.9 months; 95% CI, 4.4-9.8; P = .02). In the Cox regression model, the significant predictor of survival was hydrocephalus (P = .01; hazard ratio, 3.5; 95% CI, 1.3-9.1) after propensity score adjustment.

CONCLUSION:

Treatment with Gamma Knife radiosurgery alone and surgery plus whole-brain radiation therapy were both efficacious in patients with single small cerebellar metastasis. Overall survival was nearly identical in both treatment groups.

Melanoma leptomeningeal dissemination following frontoparietal metastasis surgery: Case report and review of the literature

We present the case of a patient with a solitary left frontoparietal brain metastasis of melanoma previously treated with surgery. Three months later, the patient was admitted to the emergency room in a confusional state with meningeal signs. A cerebrospinal fluid (CSF) test and magnetic resonance imaging findings suggested a subarachnoid haemorrhage (SAH) and/or meningeal carcinomatosis. The results of a cytological examination of the CSF showed neoplastic epithelial cells consistent with metastatic melanoma cells. Resection of metastatic posterior fossa lesions is often cited as a risk factor for leptomeningeal dissemination, however, when the resection is limited to the anterior fossa, this complication is relatively rare. In contrast, SAH may be a complication of leptomeningeal dissemination and responsible for acute meningeal syndrome. Treatment with high doses of corticoids did not show any improvement, and intrathecal chemotherapy was not possible due to the patient's poor functional status. She succumbed 1 week after admission.

Known and emerging biomarkers of leptomeningeal metastasis and its response to treatment

Leptomeningeal metastasis (LM) is the metastatic dissemination of malignant cells to the leptomeninges and the subarachnoid space of the CNS, affecting approximately 8% of all cancer patients. Cerebrospinal fluid cytology is currently the gold standard for diagnosis of LM and assessment of treatment response, but it has relatively low sensitivity. Thus, specific biomarkers of LM may allow for earlier diagnosis and treatment. This article reviews known tumor markers for LM and describes recent work to find LM-specific markers, such as angiogenesis-related proteins. Novel methods of protein profiling that may aid this search are also described; these methods still need to be standardized and validated to gain widespread acceptance. Nevertheless, we anticipate that future biomarkers will have not only the potential to detect LM, but to predict its progression and response to treatment.

The role of intra-cerebrospinal fluid treatment and prophylaxis in patients with solid tumors

Metastasis to the central nervous system (CNS), including neoplastic meningitis (NM), is a devastating complication of systemic cancer. With the improved survival of cancer patients, the incidence of CNS metastasis is rising, especially among those with breast or lung carcinoma. New therapies that effectively treat these primary tumors outside of the CNS have underscored the significance of CNS metastases; they have become a significant clinical issue and a therapeutic challenge. This review discusses clinical situations in which treatment or chemoprophylaxis of CNS metastases and NM from breast or lung cancer may play an important role. Potential clinical trials to assess these assumptions also will be proposed.

Comparative risk of leptomeningeal dissemination of cancer after surgery or stereotactic radiosurgery for a single supratentorial solid tumor metastasis

OBJECTIVE

To test the hypothesis that differential risks of developing leptomeningeal disease (LMD) exist in patients having a single supratentorial brain metastasis resected via a piecemeal or en bloc approach or treated with stereotactic radiosurgery (SRS).

METHODS

Between 1993 and 2006, 827 patients with a supratentorial brain metastasis underwent resection or SRS at The University of Texas M.D. Anderson Cancer Center. The primary outcome was the incidence of LMD.

RESULTS

Resection was performed piecemeal in 191 patients and en bloc in 351 patients; 285 patients received SRS. LMD occurred in 33 patients, 29 in the resection group and 4 in the SRS group. Risk of LMD was significantly higher with piecemeal tumor resection than with other procedures (SRS: hazard ratio [HR] for piecemeal, 5.8; 95% confidence interval [CI], 1.9-17.2; P = 0.002; en bloc, HR for piecemeal, 2.7; 95% CI, 1.3-5.6; P = 0.009). The difference between piecemeal and en bloc was particularly pronounced in patients with a melanoma primary (HR, 8.4; 95% CI, 1.8-39.2; P = 0.007). The risk of LMD was not significantly different between en bloc resection and SRS (HR for en bloc, 2.1; 95% CI, 0.7-6.4; P = 0.21). Similar results were obtained when comparing effects of SRS and both resection approaches after limiting the sample to patients with tumors in a specific volume range.

CONCLUSION

Piecemeal resection of a supratentorial brain metastasis carries a higher risk of LMD than en bloc resection or SRS. Further assessment of the role of the 2 surgical resection approaches and SRS in a controlled prospective setting with large numbers of patients is warranted.

Brain metastases: current management and new developments

PURPOSE OF REVIEW

To review the state-of-the-art and new developments in the management of patients with brain metastases.

RECENT FINDINGS

Treatment decisions are based on prognostic factors to maximize neurologic function and survival, while avoiding unnecessary therapies. Whole-brain radiotherapy (WBRT) is the treatment of choice for patients with unfavorable prognostic factors. Stereotactic radiosurgery (SRS) or surgery is indicated for patients with favorable prognostic factors and limited brain disease. In single brain metastasis, the addition of either stereotactic radiosurgery or surgery to WBRT improves survival. The omission of WBRT after surgery or radiosurgery results in a worse local and distant control, though it does not affect survival. The incidence of neurocognitive deficits in long-term survivors after WBRT remains to be defined. New approaches to avoid cognitive deficits following WBRT are being investigated. The role of chemotherapy is limited. Molecularly targeted therapies are increasingly employed. Prophylaxis with WBRT is the standard in small-cell lung cancer.

SUMMARY

Many questions need future trials: the usefulness of new radiosensitizers; the role of local treatments after surgery; and the impact of molecularly targeted therapies on subgroups of patients with specific molecular profiles. Quality of life and cognitive functions are recognized as major endpoints in clinical trials.

Comparative risk of leptomeningeal disease after resection or stereotactic radiosurgery for solid tumor metastasis to the posterior fossa

Object

The authors tested the hypothesis that patients with metastatic posterior fossa lesions (MPFLs) treated with resection have a higher risk of leptomeningeal disease (LMD) than those with MPFLs treated with stereotactic radiosurgery (SRS).

Methods

Between 1993 and 2004, 379 patients with MPFLs were treated with resection or SRS at The University of Texas M. D. Anderson Cancer Center. The authors' primary study outcome was the incidence of LMD, as diagnosed with cerebrospinal fluid cytological analysis and/or neuroimaging.

Results

Resection was performed in 260 patients, whereas 119 patients underwent SRS. The median patient age was 56 years, 51% of patients were male, and 93% had a Karnofsky Performance Scale score $ 70. The most common primary cancers were those of the lung, breast, and kidney, as well as melanoma. Leptomeningeal dissemination of cancer occurred in 33 patients: 26 in the resection group and 7 in the SRS group (resection group: rate ratio [RR] 2.06, 95% confidence interval [CI] 0.89–4.75, p = 0.09). Piecemeal tumor resection (137 cases) was associated with a significantly higher risk of LMD than en bloc resection (123 cases; RR 3.4, 95% CI 1.43–8.12, p = 0.006) or SRS (RR 3.37, 95% CI 1.41–8.04, p = 0.006), and there was no significant difference in the risk for LMD between en bloc resection and SRS (en bloc resection: RR 0.98, 95% CI 0.34–2.81, p = 0.98). The multivariate RR and significance associated with piecemeal resection, however, were consistent, with a strong effect (RR 2.45, 95% CI 1.19–5.02, p = 0.02) and no indication of biases associated with tumor size, location, or cystic/necrotic appearance.

Conclusions

There is an increased risk of LMD after piecemeal resection of an MPFL. This increase, although clinically and statistically significant, is not as alarming as previously reported and is absent when en bloc removal is achieved. Further assessment of the role of resection in a controlled prospective setting is warranted.

Leptomeningeal metastases from solid malignancy: a review

Leptomeningeal metastases (LMM) consist of diffuse involvement of the leptomeninges by infiltrating cancer cells. In solid tumors, the most frequent primary sites are lung and breast cancers, two tumors where the incidence of LMM is apparently increasing. Careful neurological examination is required to demonstrate multifocal involvement of the central nervous system (CNS), cranial nerves, and spinal roots, which constitute the clinical hallmark of the disease. Cerebro-spinal fluid (CSF) analysis is almost always abnormal but only a positive cytology or demonstration of intrathecal synthesis of tumor markers is diagnostic. T1-weighted gadolinium-enhanced sequence of the entire neuraxis (brain and spine) plays an important role in supporting the diagnosis, demonstrating the involved sites and guiding treatment. Radionuclide CSF flow studies detect CSF compartmentalization and are useful for treatment planning. Standard therapy relies mainly on focal irradiation and intrathecal or systemic chemotherapy. Studies using other therapeutic approaches such as new biological or cytotoxic compounds are ongoing. The overall prognosis remains grim and quality of life should remain the priority when deciding which treatment option to apply. However, a sub-group of patients, tentatively defined here, may benefit from an aggressive treatment.

Leptomeningeal metastases from solid tumors (meningeal carcinomatosis)

Leptomeningeal metastases (LM) are increasingly recognized as a devastating complication of solid tumors. Improved treatment of primary malignancy and advances in diagnostic imaging have led to an apparent increase in the number of patients diagnosed with LM. Unfortunately, therapeutic options remain limited. Radiotherapy is used to treat bulky tumor and provide symptomatic relief. Intrathecal chemotherapy benefits a selected subset of patients. The challenge to the future is to delineate the molecular mechanisms underlying LM and to develop novel therapeutic or prophylactic modalities to combat LM.

Posterior fossa metastases: risk of leptomeningeal disease when treated with stereotactic radiosurgery compared to surgery

INTRODUCTION

Leptomeningeal disease (LMD) represents a diffuse form of central nervous system metastatic disease that is often associated with poor quality of life and prognosis. Our objective was to compare the incidence of LMD in patients with posterior fossa metastases (PFM) following stereotactic radiosurgery (SRS) versus surgical resection.

METHODS

The medical records of 93 patients aged 57.9 +/- 10.8 years (mean +/- SD) with PFM treated at the Cleveland Clinic from 1995 to 2001 were analyzed retrospectively. Treatments consisted of surgery with whole brain radiation therapy (WBRT) or SRS with or without WBRT. The impact of age, Karnofsky performance status (KPS) at presentation, Radiation Therapy Oncology Group, recursive partitioning analysis (RPA) class, status of extracranial disease, number, size, volume, pathology of brain metastases and steroid use were studied using univariate and multivariate analyses.

RESULTS

There were 80 evaluable patients (10 lost to follow-up and three excluded for supratentorial surgery with subsequent LMD). LMD occurred after the surgical removal of the PFM in 9 of 18 patients (50%), whereas LMD occurred after SRS in 4 of 62 patients (6.5%) (p = 0.0028). Multivariate analysis also showed that patients who had surgery were more likely to develop LMD compared to patients treated with SRS (p = 0.0024). Patients had a median KPS decline of 30 points after LMD was diagnosed. There was no statistically significant difference in survival of patients with LMD and the rest of the patients (13.5 vs. 11.7 months, p = 0.7659). Patients treated surgically had significantly larger lesions (3.43 +/- 0.74 vs. 1.96 +/- 0.95 cm maximum diameter, p < 0.0001). All surgical patients belonged to RPA class II at diagnosis. Their survival was not different from the RPA class II patients in the SRS group. Surgery and SRS had comparable complication rates (8.1% vs. 5.6%, p = 0.99), although the surgical complications were more serious (e.g. hemorrhage, CSF leak). The duration of steroid use was longer after SRS compared to surgery (2.1 +/- 3.6 vs. 1.3 +/- 2.4 months); however, the difference was not statistically significant. Myopathy and psychosis in one patient after SRS, were the only steroid-related complications. There was no statistically significant association between the primary tumor type and the presence of LMD.

CONCLUSIONS

In this retrospective analysis of patients with PFM, SRS was associated with a lower incidence of LMD than was surgery. Although LMD was associated with rapid and considerable decline in the quality of life, it did not influence the overall survival. SRS was associated with less serious complications than surgery. Surgery in this study was performed on patients with larger lesion sizes and a trend toward poorer initial performance status, which could bias these results. A prospective study directly comparing surgery and SRS and further evaluating the significance of LMD in PFM is warranted.

Leptomeningeal metastases

LM is an increasingly common neurologic complication of cancer with variable clinical manifestations. Although there are no curative treatments, currently available therapies can preserve neurologic function and potentially improve quality of life. Further research into the mechanisms of leptomeningeal metastasis will elucidate molecular and cellular pathways that may allow identification of potential targets to interrupt this process early or to prevent this complication. Animal models are needed to further define the pathophysiology of LM and to provide an experimental system to test novel treatments [242-245]. There is an urgent need to develop new drug-based or radiation-based treatments for patients with LM. Randomized clinical trials are the appropriate study design to determine the efficacy of new treatments for LM. However, surrogate markers for response must be developed to facilitate the identification of effective regimens. Survival is not the optimal end point for such studies as most patients who develop this complication already have advanced, incurable cancer. Prevention of or delay in neurologic progression is one objective that has been utilized in recent randomized trials in patients with LM, and this end point deserves further attention. Although the development of LM represents a poor prognostic marker in patients with cancer it is important for physicians to recognize the symptoms and signs of the disease and establish the diagnosis as early in the disease course as possible. This may provide an opportunity for effective intervention that can improve quality of life, prevent further neurologic deterioration and, for a subset of patients, improve survival.

The pathogenesis of neoplastic meningitis

Neoplastic meningitis (NM) is a dreaded metastatic complication occurring in 5% to 10% of cancer patients. Survival is limited, usually ranging from 4 to 16 weeks. The pathogenesis of NM has not been extensively investigated but can be considered from the anatomic and molecular biologic standpoints. Malignant cells reach the cerebrospinal fluid (CSF) and meninges by direct invasion from tumors located near or within the central nervous system (CNS), or via the bloodstream or other pathways that contact the CNS. Symptoms of NM are caused by malignant cells invading and damaging nervous tissue, obstructing the vascular supply to nervous tissue, or obstructing CSF pathways. The molecular changes responsible for the development of NM are not well delineated, but it is likely that they involve changes in molecules responsible for tumor cell adhesion, migration, and proliferation. An understanding of the pathogenesis of NM will allow for its earliest possible diagnosis and ultimately lead to therapies targeted at the underlying molecular causes of this devastating condition.