Melanoma central nervous system metastases: An update to approaches, challenges, and opportunities

Network-based analysis of heterogeneous patient-matched brain and extracranial melanoma metastasis pairs reveals three homogeneous subgroups

Melanoma, the deadliest form of skin cancer, can metastasize to different organs. Molecular differences between brain and extracranial melanoma metastases are poorly understood. Here, promoter methylation and gene expression of 11 heterogeneous patient-matched pairs of brain and extracranial metastases were analyzed using melanoma-specific gene regulatory networks learned from public transcriptome and methylome data followed by network-based impact propagation of patient-specific alterations. This innovative data analysis strategy allowed to predict potential impacts of patient-specific driver candidate genes on other genes and pathways. The patient-matched metastasis pairs clustered into three robust subgroups with specific downstream targets with known roles in cancer, including melanoma (SG1: RBM38, BCL11B, SG2: GATA3, FES, SG3: SLAMF6, PYCARD). Patient subgroups and ranking of target gene candidates were confirmed in a validation cohort. Summarizing, computational network-based impact analyses of heterogeneous metastasis pairs predicted individual regulatory differences in melanoma brain metastases, cumulating into three consistent subgroups with specific downstream target genes.

Prognostic Value of Baseline 18F-FDG PET/CT to Predict Brain Metastasis Development in Melanoma Patients

To investigate the value of 18F-FDG-PET/CT in predicting the occurrence of brain metastases in melanoma patients, in this retrospective study 201 consecutive patients with pathology-proven melanoma, between 2008 and 2021, were reviewed. Those who underwent 18F-FDG-PET/CT for initial staging were considered eligible. Baseline assessment included histopathology, 18F-FDG-PET/CT, and brain MRI. Also, all patients had serial follow-ups for diagnosing brain metastasis development. Baseline 18F-FDG-PET/CT parameters were analysed using competing risk regression models to analyze their correlation with the occurrence of brain metastases. Overall, 159 patients entered the study. The median follow-up was six years. Among clinical variables, the initial M-stage and TNM-stage were significantly correlated with brain metastasis. Regarding 18F-FDG-PET/CT parameters, regional metastatic lymph node uptake values, as well as prominent SULmax (pSULmax) and prominent SUVmean (pSUVmean), were significantly correlated with the outcome. Cumulative incidences were 10% (6.3-16%), 31% (24.4-38.9%), and 35.2% (28.5-43.5%) after 1, 5, and 10 years. There were significant correlations between pSULmax (p-value < 0.001) and pSULpeak (p-value < 0.001) and the occurrence of brain metastases. The higher these values, the sooner the patient developed brain metastases. Thus, baseline 18F-FDG-PET/CT may have the potential to predict brain metastasis in melanoma patients. Those with high total metabolic activity should undergo follow-up/complementary evaluations, such as brain MRI.

Targeting Translation and the Cell Cycle Inversely Affects CTC Metabolism but Not Metastasis

Melanoma brain metastasis (MBM) is significantly associated with poor prognosis and is diagnosed in 80% of patients at autopsy. Circulating tumor cells (CTCs) are "seeds" of metastasis and the smallest functional units of cancer. Our multilevel approach has previously identified a CTC RPL/RPS gene signature directly linked to MBM onset. We hypothesized that targeting ribogenesis prevents MBM/metastasis in CTC-derived xenografts. We treated parallel cohorts of MBM mice with FDA-approved protein translation inhibitor omacetaxine with or without CDK4/CDK6 inhibitor palbociclib, and monitored metastatic development and cell proliferation. Necropsies and IVIS imaging showed decreased MBM/extracranial metastasis in drug-treated mice, and RNA-Seq on mouse-blood-derived CTCs revealed downregulation of four RPL/RPS genes. However, mitochondrial stress tests and RT-qPCR showed that omacetaxine and palbociclib inversely affected glycolytic metabolism, demonstrating that dual targeting of cell translation/proliferation is critical to suppress plasticity in metastasis-competent CTCs. Equally relevant, we provide the first-ever functional metabolic characterization of patient-derived circulating neoplastic cells/CTCs.

Stereotactic radiosurgery and anti-PD-1 + CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK inhibitors, BRAF inhibitors, or conventional chemotherapy for the management of melanoma brain metastases

BACKGROUND

Immunotherapy and targeted BRAF/MEK inhibitors (i) have revolutionised the systemic management of advanced melanoma. Given the role of stereotactic radiosurgery (SRS) in the local management of brain metastases, we sought to evaluate clinical outcomes in patients with melanoma brain metastases (MBM) treated with SRS and various systemic therapies.

METHODS

Patients were included if MBM were diagnosed and treated with SRS within 3 months of receiving anti-PD-1+CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK-i, BRAF-i, or conventional chemotherapy. Comparisons between groups were made for overall survival (OS), distant MBM control, local MBM, systemic progression-free survival (sPFS), and neurotoxicity.

RESULTS

In total, 257 patients with 1048 MBM treated over 368 SRS sessions between 2011 and 2020 were identified. On MVA, treatment with anti-PD1+anti-CTLA-4, anti-PD-1, and BRAF/MEK-i improved distant intracranial control over conventional chemotherapy. No significant differences were noted in local control (LC) between groups (p = 0.78). Kaplan-Meier OS at 12 months for anti-PD-1 + CTLA-4 therapy, anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK-i, BRAF-i, and conventional chemotherapy was 68%, 59%, 45%, 62%, 21%, and 15%, respectively (p = <0.0001). The sPFS rates at 12 months were 57%, 53%, 42%, 45%, 14%, and 6% (p = <0.0001). No significant differences were noted in rates of radiation necrosis (p = 0.93).

CONCLUSIONS

This is among the largest series evaluating MBM treated with SRS and various systemic therapy regimens. Our analysis noted significant differences in OS, distant MBM control, and sPFS by systemic therapy. No differences in LC or radiation necrosis risk were noted.

Current Treatment of Melanoma Brain Metastases

Melanoma is a type of skin cancer in which there is a strong correlation between its occurrence and exposure to ultraviolet radiation. Although it is not the most common skin cancer, it has the highest mortality rate of all skin cancers. The prognosis of patients is significantly worsened by melanoma metastasis to the brain, which often occurs in patients with advanced disease. The formation and development of melanoma metastases to the brain involve a very complex process, and their mechanisms are not fully understood. One of the ways for metastatic melanoma cells to survive and develop cancer in the brain environment is the presence of oncogenic BRAF mutation, which occurs in up to 50% of metastatic melanoma cases. Before discovering new methods of treating metastases, the overall survival of patients with this disease was 6 months. Currently, research is being conducted on new drugs using immunotherapy (immune checkpoint inhibitors: anti-PD-1, anti-CTLA-4) and targeted therapy (BRAF and MEK inhibitors) to improve the prognosis of patients. In this article, we summarize the current state of knowledge about the results of treating brain metastases with new systemic therapies.

Brain metastasis localized to the same area of infarction: illustrative case

BACKGROUND

Ischemic stroke and tumor account for a disproportionate share of deaths and disabilities among the elderly. Patients with a tumor who develop recurrent acute neurological deficits after a stroke can be at risk for tumor-related stroke. In contrast, brain metastases (BM) are common causes of neurological symptoms and are associated with a poor prognosis in patients with both malignancy and ischemic stroke.

OBSERVATIONS

The authors report a rare case of metastatic melanoma that manifested in the same region as a previous ischemic infarction. A 22-year-old female presented at our emergency department with right hemiparesis and sensory difficulties. Infarction in the left frontoparietal and basal ganglia regions was found on a computed tomography scan of the brain. A decompressive hemicraniectomy was performed urgently. After 16 years, a biopsy taken from her chin revealed malignant melanoma. Hemorrhagic metastasis on the frontal lobe of the brain was detected with magnetic resonance imaging and was histopathologically confirmed upon resection.

LESSONS

In addition to recurrence, BM may be considered when a person with ischemic stroke and a cancer such as melanoma has new neurological problems in one area that cannot be explained by the stroke.

Epidemiology, management, and treatment outcomes of metastatic spinal melanoma

Metastatic spinal melanoma is a rare and aggressive disease process with poor prognosis. We review the literature on metastatic spinal melanoma, focusing on its epidemiology, management, and treatment outcomes. Demographics of metastatic spinal melanoma are similar to those for cutaneous melanoma, and cutaneous primary tumors tend to be most common. Decompressive surgical intervention and radiotherapy have traditionally been considered mainstays of treatment, and stereotactic radiosurgery has emerged as a promising approach in the operative management of metastatic spinal melanoma. While survival outcomes for metastatic spinal melanoma remain poor, they have improved in recent years with the advent of immune checkpoint inhibition, used in conjunction with surgery and radiotherapy. New treatment options remain under investigation, especially for patients with disease refractory to immunotherapy. We additionally explore several of these promising future directions. Nevertheless, further investigation of treatment outcomes, ideally incorporating high-quality prospective data from randomized controlled trials, is needed to identify optimal management of metastatic spinal melanoma.

Identification of germline cancer predisposition variants in pediatric sarcoma patients from somatic tumor testing

Genetic predisposition is an important risk factor for cancer in children and adolescents but detailed associations of individual genetic mutations to childhood cancer are still under intense investigation. Among pediatric cancers, sarcomas can arise in the setting of cancer predisposition syndromes. The association of sarcomas with these syndromes is often missed, due to the rarity and heterogeneity of sarcomas and the limited search of cancer genetic syndromes. This study included 43 pediatric and young adult patients with different sarcoma subtypes. Tumor profiling was undertaken using the Oncomine Childhood Cancer Research Assay (Thermo Fisher Scientific). Sequencing results were reviewed for potential germline alterations in clinically relevant genes associated with cancer predisposition syndromes. Jongmans´ criteria were taken into consideration for the patient selection. Fifteen patients were selected as having potential pathogenic germline variants due to tumor sequencing that identified variants in the following genes: CDKN2A, NF1, NF2, RB1, SMARCA4, SMARCB1 and TP53. The variants found in NF1 and CDKN2A in two different patients were detected in the germline, confirming the diagnosis of a cancer predisposition syndrome. We have shown that the results of somatic testing can be used to identify those at risk of an underlying cancer predisposition syndrome.

Changes In Outcomes And Factors Associated With Survival In Melanoma Patients With Brain Metastases

BACKGROUD

Treatment options for patients with melanoma brain metastasis (MBM) have changed significantly in the last decade. Few studies have evaluated changes in outcomes and factors associated with survival in MBM patients over time. The aim of this study is to evaluate changes in clinical features and overall survival (OS) for MBM patients.

METHODS

Patients diagnosed with MBMs from 1/1/2009-12/31/2013 (Prior Era; PE) and 1/1/2014-12/31/2018 (Current Era; CE) at The University of Texas MD Anderson Cancer Center were included in this retrospective analysis. The primary outcome measure was OS. Log-rank test assessed differences between groups; multivariable analyses were performed with Cox proportional hazards models and recursive partitioning analysis (RPA).

RESULTS

791 MBM patients (PE, n=332; CE, n=459) were included in analysis. Median OS from MBM diagnosis was 10.3 months (95% CI, 8.9 - 12.4) and improved in the CE versus PE (14.4 vs. 10.3 months, P < .001). Elevated serum LDH was the only factor associated with worse OS in both PE and CE patients. Factors associated with survival in CE MBM patients included patient age, primary tumor Breslow thickness, prior immunotherapy, leptomeningeal disease (LMD), symptomatic MBMs, and whole brain radiation therapy (WBRT). Several factors associated with OS in the PE were not significant in the CE. RPA demonstrated that elevated serum LDH and prior immunotherapy treatment are the most important determinants of survival in CE MBM patients.

CONCLUSIONS

OS and factors associated with OS have changed for MBM patients. This information can inform contemporary patient management and clinical investigations.

Melanoma central nervous system metastases: An update to approaches, challenges, and opportunities

Brain metastases are the most common brain malignancy. This review discusses the studies presented at the third annual meeting of the Melanoma Research Foundation in the context of other recent reports on the biology and treatment of melanoma brain metastases (MBM). Although symptomatic MBM patients were historically excluded from immunotherapy trials, efforts from clinicians and patient advocates have resulted in more inclusive and even dedicated clinical trials for MBM patients. The results of checkpoint inhibitor trials were discussed in conversation with current standards of care for MBM patients, including steroids, radiotherapy, and targeted therapy. Advances in the basic scientific understanding of MBM, including the role of astrocytes and metabolic adaptations to the brain microenvironment, are exposing new vulnerabilities which could be exploited for therapeutic purposes. Technical advances including single-cell omics and multiplex imaging are expanding our understanding of the MBM ecosystem and its response to therapy. This unprecedented level of spatial and temporal resolution is expected to dramatically advance the field in the coming years and render novel treatment approaches that might improve MBM patient outcomes.

The RPL/RPS gene signature of melanoma CTCs associates with brain metastasis

Melanoma brain metastasis (MBM) is linked to poor prognosis and low overall survival. We hypothesized that melanoma circulating tumor cells (CTCs) possess a gene signature significantly expressed and associated with MBM. Employing a multi-pronged approach, we provide first-time evidence identifying a common CTC gene signature for ribosomal protein large/small subunits (RPL/RPS) which associate with MBM onset and progression. Experimental strategies involved capturing, transcriptional profiling and interrogating CTCs, either directly isolated from blood of melanoma patients at distinct stages of MBM progression or from CTC-driven MBM in experimental animals. Second, we developed the first Magnetic Resonance Imaging (MRI) CTC-derived MBM xenograft model (MRI-MBM CDX) to discriminate MBM spatial and temporal growth, recreating MBM clinical presentation and progression. Third, we performed the comprehensive transcriptional profiling of MRI-MBM CDXs, along with longitudinal monitoring of CTCs from CDXs possessing/not possessing MBM. Our findings suggest that enhanced ribosomal protein content/ribogenesis may contribute to MBM onset. Since ribosome modifications drive tumor progression and metastatic development by remodeling CTC translational events, overexpression of the CTC RPL/RPS gene signature could be implicated in MBM development. Collectively, this study provides important insights for relevance of the CTC RPL/RPS gene signature in MBM, and identify potential targets for therapeutic intervention to improve patient care for melanoma patients diagnosed with or at high-risk of developing MBM.

How I treat brain metastases of melanoma

Brain metastases are common in advanced melanoma and cause death in >50% of patients. Until recently, median survival was only ∼4 months. Improved systemic treatment including immune checkpoint inhibitors and combinations of BRAF/MEK inhibitors, however, has significantly improved intracranial tumor response and survival. In addition, advances in radiation therapy have also improved the intracranial outcomes for advanced melanoma patients with brain metastases (MBM). There has long been concern that systemic treatment of the central nervous metastases would be ineffective due to inability of active agents to cross an intact blood-brain barrier. Recent studies have shown, however, that highly active systemic therapy can have significant benefit in these patients. When determining a patient's treatment, the important factors in predicting the likelihood of benefit including the presence of neurologic symptoms, the number and size of brain metastases, performance status/status of extracranial disease, and BRAF mutation status should all be considered. In this review, we will discuss the challenges and treatment options for patients with advanced melanoma and brain metastases.

A distinct pattern of growth and RAC1 signaling in melanoma brain metastasis cells

BACKGROUND

Melanoma, the deadliest of skin cancers, has a high propensity to form brain metastases that are associated with a markedly worsened prognosis. In spite of recent therapeutic advances, melanoma brain lesions remain a clinical challenge, biomarkers predicting brain dissemination are not clear and differences with other metastatic sites are poorly understood.

METHODS

We examined a genetically diverse panel of human-derived melanoma brain metastasis (MBM) and extracranial cell lines using targeted sequencing, a Reverse Phase Protein Array, protein expression analyses, and functional studies in vitro and in vivo.

RESULTS

Brain-specific genetic alterations were not detected; however, MBM cells in vitro displayed lower proliferation rates and MBM-specific protein expression patterns associated with proliferation, DNA damage, adhesion, and migration. MBM lines displayed higher levels of RAC1 expression, involving a distinct RAC1-PAK1-JNK1 signaling network. RAC1 knockdown or treatment with small molecule inhibitors contributed to a less aggressive MBM phenotype in vitro, while RAC1 knockdown in vivo led to reduced tumor volumes and delayed tumor appearance. Proliferation, adhesion, and migration were higher in MBM vs. non-MBM lines in the presence of insulin or brain-derived factors and were affected by RAC1 levels.

CONCLUSIONS

Our findings indicate that despite their genetic variability, MBM engage specific molecular processes such as RAC1 signaling to adapt to the brain microenvironment and this can be used for the molecular characterization and treatment of brain metastases.

Incidence and comparative prognosis of cancers with metastasis to noncommon sites: A population-based study

Primary tumors have common sites of metastasis such as lymph nodes, bones, liver, lungs, and brain; however, they can also metastasize to other uncommon sites such as adrenals, bone marrow, and skin among others. Our study aimed to investigate the relationship between uncommon sites of metastasis at the time of diagnosis and median survival in a number of primary tumors using the Surveillance, Epidemiology, and End Results (SEER) database. This retrospective cohort study conducted between September-October 2021 included patient-level SEER data for 2016-2018 using SEER Research Data, 9 Registries, Nov 2020 Sub (1975-2018). Descriptive analysis for complete cohort and median survival for each primary within the cohort was performed using R software. A total of 25,345 patients (females, 51.4%) were diagnosed with primary tumors with metastasis to uncommon sites at the time of diagnosis; the mean age at diagnosis was 68 years. Lung and bronchus primaries constituted the largest proportion of cohort (41.9%) that metastasized to uncommon sites, followed by nonHodgkin lymphoma-nodal (7.4%), pancreas (6.6%), stomach (3.7%), and ovarian (3.4%). The incidence of metastasis to uncommon sites was most common in respiratory cancers in ages 61-80 years (25%) and least in breast primaries in ages 18-40 years (0.1%), and was higher in Whites compared to other races. Regarding median survival, liver cancer with metastasis to uncommon sites had the worst prognosis (1 month), whereas small intestine tumors were associated with a better prognosis, median survival of 13 months. In this cohort study, the lung and bronchus cancers were the most common primaries metastasized to uncommon sites at diagnosis. The liver tumor had the worst survival compared to other tumors. These findings will help redirect the available screening tools to improve survival in patients with primary tumors with metastasis at diagnosis and may also play an essential role in future research and achieve a better prognosis for cancer patients.

Functionalization of Nanomaterials for Skin Cancer Theranostics

Skin cancer has drawn attention for the increasing incident rates and high morbidity worldwide. Timely diagnosis and efficient treatment are of paramount importance for prompt and effective therapy. Thus, the development of novel skin cancer diagnosis and treatment strategies is of great significance for both fundamental research and clinical practice. Recently, the emerging field of nanotechnology has profoundly impact on early diagnosis and better treatment planning of skin cancer. In this review, we will discuss the current encouraging advances in functional nanomaterials for skin cancer theranostics. Challenges in the field and safety concerns of nanomaterials will also be discussed.

A 41-Year-Old Woman with a Late Cerebral Metastasis 16 Years After an Initial Diagnosis of Cutaneous Melanoma

Patient: Female, 41-year-old

Final Diagnosis: Melanoma brain metastasis

Symptoms: Intrercranial hemorraghe

Medication:—

Clinical Procedure: —

Specialty: Neurosurgery

Targeted therapy strategies for melanoma brain metastasis

Melanoma is the most aggressive of the common forms of skin cancer. Metastasis to the central nervous system is one of the most common and deadly complications of this disease. Historically, melanoma patients with brain metastases had a median survival of less than 6 months. However, outcomes of melanoma patients have markedly improved over the last decade due to new therapeutic approaches, including immune and targeted therapies. Targeted therapies leverage the high rate of driver mutations in this disease, which result in the activation of multiple key signaling pathways. The RAS-RAF-MEK-ERK pathway is activated in the majority of cutaneous melanomas, most commonly by point mutations in the Braf serine-threonine kinase. While most early targeted therapy studies excluded melanoma patients with brain metastases, subsequent studies have shown that BRAF inhibitors, now generally given concurrently with MEK inhibitors, achieve high rates of tumor response and disease control in Braf-mutant melanoma brain metastases (MBMs). Unfortunately, the duration of these responses is generally relatively short- and shorter than is observed in extracranial metastases. This review will summarize current data regarding the safety and efficacy of targeted therapies for MBMs and discuss rational combinatorial strategies that may improve outcomes further.

Novel human melanoma brain metastasis models in athymic nude fox1nu mice: Site-specific metastasis patterns reflecting their clinical origin

BACKGROUND

Malignant melanomas frequently metastasize to the brain, but metastases in the cerebellum are underrepresented compared with metastases in the cerebrum.

METHODS

We established animal models by injecting intracardially in athymic nude fox1nu mice two human melanoma cell lines, originating from a cerebral metastasis (HM19) and a cerebellar metastasis (HM86).

RESULTS

Using magnetic resonance imaging (MRI), metastases were first detected after a mean of 34.5 days. Mean survival time was 59.6 days for the mice in the HM86 group and significantly shorter (43.7 days) for HM19-injected animals (p < 0.001). In the HM86 group, the first detectable metastasis was located in the cerebellum in 15/55 (29%) mice compared with none in the HM19 group (p < 0.001). At sacrifice, cerebellar metastases were found in 34/55 (63%) HM86-injected mice compared with 1/53 (2%) in the HM19-injected (p < 0.001) mice. At that time, all mice in both groups had detectable metastases in the cerebrum. Comparing macroscopic and histologic appearances of the brain metastases with their clinical counterparts, the cell line-based tumors had kept their original morphologic characteristics.

CONCLUSIONS

The present work demonstrates that human brain-metastatic melanoma cells injected intracardially in mice had retained inherent characteristics also in reproducing interaction with subtle microenvironmental brain tissue compartment-specific features. The models offer new possibilities for investigating tumor- and host-associated factors involved in determining tissue specificity of brain metastasis.

Re-thinking therapeutic development for CNS metastatic disease

There has been unprecedented progress in the development of systemic therapies for patients with metastatic melanoma over the last decade. There is now tremendous potential and momentum to further and markedly reduce the impact of this disease. However, developing more effective treatments for metastases to the CNS remains a critical challenge for patients with melanoma. Melanoma patients with active CNS metastases have largely been excluded from both early-phase and registration trials for all currently approved targeted and immune therapies for this disease. While this exclusion has generally been justified in clinical research due to concerns about poor prognosis, lack of CNS penetration of agents and/or risk of toxicities, recent post-approval trials have shown the feasibility, safety and clinical benefit of clinical investigation in these patients. These trials have also identified key areas for which more effective strategies are needed. In parallel, recent translational and preclinical research has provided insights into novel immune, molecular and metabolic features of melanoma brain metastases that may mediate the aggressive biology and therapeutic resistance of these tumors. Together, these advances suggest the need for new paradigms for therapeutic development for melanoma patients with CNS metastasis.

Nanocarrier-Based Drug Delivery for Melanoma Therapeutics

Melanoma, as a tumor cell derived from melanocyte transformation, has the characteristics of malignant proliferation, high metastasis, rapid recurrence, and a low survival rate. Traditional therapy has many shortcomings, including drug side effects and poor patient compliance, and so on. Therefore, the development of an effective treatment is necessary. Currently, nanotechnologies are a promising oncology treatment strategy because of their ability to effectively deliver drugs and other bioactive molecules to targeted tissues with low toxicity, thereby improving the clinical efficacy of cancer therapy. In this review, the application of nanotechnology in the treatment of melanoma is reviewed and discussed. First, the pathogenesis and molecular targets of melanoma are elucidated, and the current clinical treatment strategies and deficiencies of melanoma are then introduced. Following this, we discuss the main features of developing efficient nanosystems and introduce the latest reports in the literature on nanoparticles for the treatment of melanoma. Subsequently, we review and discuss the application of nanoparticles in chemotherapeutic agents, immunotherapy, mRNA vaccines, and photothermal therapy, as well as the potential of nanotechnology in the early diagnosis of melanoma.

Melanoma brain metastases - Interdisciplinary management recommendations 2020

Melanoma brain metastases (MBM) are common and associated with a particularly poor prognosis; they directly cause death in 60-70% of melanoma patients. In the past, systemic treatments have shown response rates around 5%, whole brain radiation as standard of care has achieved a median overall survival of approximately three months. Recently, the combination of immune checkpoint inhibitors and combinations of MAP-kinase inhibitors both have shown very promising response rates of up to 55% and 58%, respectively, and improved survival. However, current clinical evidence is based on multi-cohort studies only, as prospectively randomized trials have been carried out rarely in MBM, independently whether investigating systemic therapy, radiotherapy or surgical techniques. Here, an interdisciplinary expert team reviewed the outcome of prospectively conducted clinical studies in MBM, identified evidence gaps and provided recommendations for the diagnosis, treatment, outcome evaluation and monitoring of MBM patients. The recommendations refer to four distinct scenarios: patients (i) with 'brain-only' disease, (ii) with oligometastatic asymptomatic intra- and extracranial disease, (iii) with multiple asymptomatic metastases, and (iv) with multiple symptomatic MBM or leptomeningeal disease. Changes in current management recommendations comprise the use of immunotherapy - preferably combined anti-CTLA-4/PD-1-immunotherapy - in asymptomatic MBM minus/plus stereotactic radiosurgery which remains the mainstay of local brain therapy being safe and effective. Adjuvant whole-brain radiotherapy provides no clinical benefit in oligometastatic MBM. Among the systemic therapies, combined MAPK-kinase inhibition provides, in BRAF^V600-mutated patients with rapidly progressing or/and symptomatic MBM, an alternative to combined immunotherapy.

Leptomeningeal disease in melanoma patients: An update to treatment, challenges, and future directions

In February 2018, the Melanoma Research Foundation and the Moffitt Cancer Center hosted the Second Summit on Melanoma Central Nervous System Metastases in Tampa, Florida. The meeting included investigators from multiple academic centers and disciplines. A consensus summary of the progress and challenges in melanoma parenchymal brain metastases was published (Eroglu et al., Pigment Cell & Melanoma Research, 2019, 32, 458). Here, we will describe the current state of basic, translational, clinical research, and therapeutic management, for melanoma patients with leptomeningeal disease. We also outline key challenges and barriers to be overcome to make progress in this deadly disease.

Melanoma brain metastases: review of histopathological features and immune-molecular aspects

Patients with melanoma brain metastases (MBM) have a dismal prognosis, but the unprecedented advances in systemic therapy alone or in combination with local therapy have now extended the 1-year overall survival rate from 20–25% to nearing 80–85%, mainly in asymptomatic patients. The histopathological and molecular characterization of MBM and the understanding of the microenvironment are critical to more effectively manage patients with advanced melanoma and to design biologically driven clinical trials. This review aims to give an overview of the main histopathological features and the immune-molecular aspects of MBM.

Cumulative Incidence and Predictors of CNS Metastasis for Patients With American Joint Committee on Cancer 8th Edition Stage III Melanoma

PURPOSE

Improved understanding of the incidence, risk factors, and timing of CNS metastasis is needed to inform surveillance strategies for patients with melanoma.

PATIENTS AND METHODS

Clinical data were extracted from the databases of 2 major melanoma centers in the United States and Australia for 1,918 patients with American Joint Committee on Cancer (AJCC) 8th edition stage III melanoma, diagnosed from 1998-2014, who had (negative) baseline CNS imaging within 4 months of diagnosis. The cumulative incidence of CNS metastasis was calculated in the presence of the competing risk of death, from stage III presentation and at benchmark time points 1, 2, and 5 years postdiagnosis.

RESULTS

At a median follow-up of 70.2 months, distant recurrence occurred in 711 patients (37.1%). The first site of distant metastasis was CNS only for 3.9% of patients, CNS and extracranial (EC) for 1.8%, and EC only for 31.4%. Overall, 16.7% of patients were diagnosed with CNS metastasis during follow-up. The cumulative incidence of CNS metastasis was 3.6% (95% CI, 2.9% to 4.6%) at 1 year, 9.6% (95% CI, 8.3% to 11.0%) at 2 years, and 15.8% (95% CI, 14.1% to 17.6%) at 5 years. The risk of CNS metastasis was significantly influenced by patient sex, age, AJCC stage, primary tumor site, and primary tumor mitotic rate in multivariable and conditional analyses. High primary tumor mitotic rate was significantly associated with increased risk of CNS metastasis at diagnosis and all subsequent time points examined.

CONCLUSION

Similar rates of CNS metastasis were observed in 2 large, geographically distinct cohorts of patients with stage III melanoma. The results highlight the importance of primary tumor mitotic rate. Furthermore, they provide a framework for developing evidence-based surveillance strategies and evaluating the impact of contemporary adjuvant therapies on the risk of CNS metastasis development.

CAR-T Engineering: Optimizing Signal Transduction and Effector Mechanisms

The adoptive transfer of genetically engineered T cells expressing a chimeric antigen receptor (CAR) has shown remarkable results against B cell malignancies. This immunotherapeutic approach has advanced and expanded rapidly from preclinical models to the recent approval of CAR-T cells to treat lymphomas and leukemia by the Food and Drug Administration (FDA). Ongoing research efforts are focused on employing CAR-T cells as a therapy for other cancers, and enhancing their efficacy and safety by optimizing their design. Here we summarize modifications in the intracellular domain of the CAR that gave rise to first-, second-, third- and next-generation CAR-T cells, together with the impact that these different designs have on CAR-T cell biology and function. Further, we describe how the structure of the antigen-sensing ectodomain can be enhanced, leading to superior CAR-T cell signaling and/or function. Finally we discuss how tissue-specific factors may impact the clinical efficacy of CAR-T cells for bone and the central nervous system, as examples of specific indications that may require further CAR signaling optimization to perform in such inhospitable microenvironments.

Systemic Analysis of the Prognosis-Related RNA Alternative Splicing Signals in Melanoma

BACKGROUND Alternative splicing (AS), the mechanism underlying the occurrence of protein diversity, may result in cancer genesis and development when it becomes out of control, as suggested by a growing number of studies. However, systemically analyze of AS events at the genome-wide level for skin cutaneous melanoma (SKCM) is still in a preliminary phase. This study aimed to systemically analyze the bioinformatics of the AS events at a genome-wide level using The Cancer Genome Atlas (TCGA) SKCM data. MATERIAL AND METHODS The SpliceSeq tool was used to analyze the AS profiles for SKCM clinical specimens from the TCGA database. The association between AS events and overall survival was analyzed by Cox regression analysis. AS event intersections and a gene interaction network were established by UpSet plot. A multivariate survival model was used to establish a feature genes prognosis model. RESULTS A total of 103 SKCM patients with full clinical parameters available were included in this study. We established an AS network that investigated the relationship between AS events and clinical prognosis information. Furthermore, 4 underlying feature genes of SKCM (MCF2L, HARS, TFR2, and RALGPS1) were found in the AS network. We performed function analysis as well as correlation analysis of AS events with gene expression. Using the multivariate survival model, we further confirmed the 4 genes that impacted the classifying SKCM prognosis at the level of AS events as well as gene expression, especially in wild-type SKCM. CONCLUSIONS AS events could be ideal indicators for SKCM prognosis. The key feature gene MCF2L played an important role in wild-type SKCM.

Supportive roles of brain macrophages in CNS metastases and assessment of new approaches targeting their functions

Metastases to the central nervous system (CNS) occur frequently in adults and their frequency increases with the prolonged survival of cancer patients. Patients with CNS metastases have short survival, and modern therapeutics, while effective for extra-cranial cancers, do not reduce metastatic burden. Tumor cells attract and reprogram stromal cells, including tumor-associated macrophages that support cancer growth by promoting tissue remodeling, invasion, immunosuppression and metastasis. Specific roles of brain resident and infiltrating macrophages in creating a pre-metastatic niche for CNS invading cancer cells are less known. There are populations of CNS resident innate immune cells such as: parenchymal microglia and non-parenchymal, CNS border-associated macrophages that colonize CNS in early development and sustain its homeostasis. In this study we summarize available data on potential roles of different brain macrophages in most common brain metastases. We hypothesize that metastatic cancer cells exploit CNS macrophages and their cytoprotective mechanisms to create a pre-metastatic niche and facilitate metastatic growth. We assess current pharmacological strategies to manipulate functions of brain macrophages and hypothesize on their potential use in a therapy of CNS metastases. We conclude that the current data strongly support a notion that microglia, as well as non-parenchymal macrophages and peripheral infiltrating macrophages, are involved in multiple stages of CNS metastases. Understanding their contribution will lead to development of new therapeutic strategies.

Intracranial antitumor activity with encorafenib plus binimetinib in patients with melanoma brain metastases: A case series

Background

Sixty percent of patients with stage IV melanoma may develop brain metastases, which result in significantly increased morbidity and a poor overall prognosis. Phase 3 studies of melanoma usually exclude patients with untreated brain metastases; therefore, clinical data for intracranial responses to treatments are limited.

Methods

A multicenter, retrospective case series investigation of consecutive BRAF‐mutant patients with melanoma brain metastases (MBMs) treated with a combination of BRAF inhibitor encorafenib and MEK inhibitor binimetinib was conducted to evaluate the antitumor response. Assessments included the intracranial, extracranial, and global objective response rates (according to the modified Response Evaluation Criteria in Solid Tumors, version 1.1); the clinical benefit rate; the time to response; the duration of response; and safety.

Results

A total of 24 patients with stage IV BRAF‐mutant MBMs treated with encorafenib plus binimetinib in 3 centers in the United States were included. Patients had received a median of 2.5 prior lines of treatment, and 88% had prior treatment with BRAF/MEK inhibitors. The intracranial objective response rate was 33%, and the clinical benefit rate was 63%. The median time to a response was 6 weeks, and the median duration of response was 22 weeks. Among the 21 patients with MBMs and prior BRAF/MEK inhibitor treatment, the intracranial objective response rate was 24%, and the clinical benefit rate was 57%. Similar outcomes were observed for extracranial and global responses. The safety profile for encorafenib plus binimetinib was similar to that observed in patients with melanoma without brain metastases.

Conclusions

Combination therapy with encorafenib plus binimetinib elicited intracranial activity in patients with BRAF‐mutant MBMs, including patients previously treated with BRAF/MEK inhibitors. Further prospective studies are warranted and ongoing.

All clinical trials to date with encorafenib and binimetinib (US Food and Drug Administration–approved in June 2018 for BRAF‐mutated metastatic melanoma) have excluded untreated melanoma brain metastases. This case series provides the first clinical evidence of intracranial activity of the combination of encorafenib plus binimetinib in patients with BRAF‐mutant melanoma with active brain metastases. Intracranial clinical activity is observed for the first time in patients previously treated with BRAF/MEK inhibitors, a population that has not been previously investigated.