Predictors and survival in patients with melanoma brain metastases

Single-cell transcriptomics and functional validation revealed PLEKHA5-L as a promoter of growth and migration in brain metastatic melanoma cells

Background

Melanoma brain metastasis is an lethal event. Investigating the molecules that potentially promoted melanoma metastasis is important for targeted therapy.

Methods

The transcriptional profiles of totaling 7 melanoma samples, including 4 primary and 3 brain metastatic tissues were studied on the single-cell RNA sequencing level, and the expression of PLEKHA5 was examined in tumor clusters. Then PLEKHA5 expression was validated in brain Metastatic model by left ventricular injections in nude mice. The functional effect of PLEKHA5 isoforms (Long or Short) on proliferation and migration of melanoma was studied by RNA interference, overexpression by lentivirus vector, CCK8 test, colony formation test, transwell chamber assay. The targets and signal pathways that was potentially regulated by PLEKHA5 was studied by RNA-sequencing.

Result

PLEKHA5 expression increased in brain metastatic melanoma at single cell level. PLEKH5 was constantly upregulated in brain metastatic tissue of melanoma in animal model. PLEKHA5-L had the potential for melanoma migration and proliferation by upregulating oncogenes such as HRAS, AKT3 etc. PLEKHA5-L also upregulated expression of PD-L1 and ABC transporters that were associated with therapy resistant.

Conclusion

PLEKHA5-L was potential therapeutic target for metastatic melanoma.

The association between graded prognostic assessment and the prognosis of brain metastases after whole brain radiotherapy: a meta-analysis

Introduction

This meta-analysis aims to provide evidence-based medical evidence for formulating rational treatment strategies and evaluating the prognosis of brain metastasis (BM) patients by assessing the effectiveness of the graded prognostic assessment (GPA) model in predicting the survival prognosis of patients with BM after whole-brain radiotherapy (WBRT).

Methods

A comprehensive search was conducted in multiple databases, including the China Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), PubMed, Wanfang database, Cochrane Library, Web of Science, and Embase. Cohort studies that met the inclusion and exclusion criteria were selected. The quality of the included literature was evaluated using the Newcastle-Ottawa Scale, and all statistical analyses were performed with R version 4.2.2. The effect size (ES) was measured by the hazard ratio (HR) of overall survival (OS). The OS rates at 3, 6, 12, and 24 months of patients with BM were compared between those with GPAs of 1.5-2.5, 3.0, and 3.5-4.0 and those with GPAs of 0-1 after WBRT.

Results

A total of 1,797 participants who underwent WBRT were included in this study. The meta-analysis revealed a significant association between GPA and OS rates after WBRT: compared with BM patients with GPA of 0-1, 3-month OS rates after WBRT were significantly higher in BM patients with GPA of 1.5-2.5 (HR = 0.48; 95% CI: 0.40-0.59), GPA of 3 (HR = 0.38; 95% CI: 0.25-0.57), and GPA of 3.5-4 (HR = 0.28; 95% CI: 0.15-0.52); 6-month OS rates after WBRT were significantly higher in BM patients with GPA of 1.5-2.5 (HR = 0.48; 95% CI: 0.41-0.56), GPA of 3 (HR = 0.33; 95% CI: 0.24-0.45), and GPA of 3.5-4 (HR = 0.24; 95% CI: 0.16-0.35); 12-month OS rates after WBRT were significantly higher in BM patients with GPA of 1.5-2.5 (HR = 0.49; 95% CI: 0.41-0.58), GPA of 3 (HR = 0.48; 95% CI: 0.32-0.73), and GPA of 3.5-4 (HR = 0.31; 95% CI: 0.12-0.79); and 24-month OS rates after WBRT were significantly higher in BM patients with GPA of 1.5-2.5 (HR = 0.49; 95% CI: 0.42-0.58), GPA of 3 (HR = 0.49; 95% CI: 0.32-0.74), and GPA of 3.5-4 (HR = 0.38; 95% CI: 0.15-0.94).

Conclusion

BM patients with higher GPAs generally exhibited better prognoses and survival outcomes after WBRT compared to those with lower GPAs.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023422914.

Immunotherapy in patients with brain metastasis: advances and challenges for the treatment and the application of circulating biomarkers

The central nervous system (CNS) is one of the most frequent metastatic sites of various cancers, including lung cancer, breast cancer and melanoma. The development of brain metastases requires a specific therapeutic approach and is associated with high mortality and morbidity in cancer patients. Advances in precision medicine and the introduction in recent years of new drugs, such as immunotherapy, have made it possible to improve the prognosis of these patients by improving survival and quality of life. New diagnostic techniques such as liquid biopsy allow real-time monitoring of tumor evolution, providing molecular information on prognostic and predictive biomarkers of response to treatment in blood or other fluids. In this review, we perform an exhaustive update of the clinical trials that demonstrate the utility of immunotherapy in patients with brain metastases and the potential of circulating biomarkers to improving the results of efficacy and toxicity in this subgroup of patients.

Whole-Body Magnetic Resonance Imaging (MRI) for Staging Melanoma Patients in Direct Comparison to Computed Tomography (CT): Results from a Prospective Positron Emission Tomography (PET)/CT and PET/MRI Study

PURPOSE

The consideration of radiation exposure is becoming more important in metastatic melanoma due to improved prognoses. The aim of this prospective study was to investigate the diagnostic performance of whole-body (WB) magnetic resonance imaging (MRI) in comparison to computed tomography (CT) with ¹⁸F-FDG positron emission tomography (PET)/CT and ¹⁸F-PET/MRI together with a follow-up as the reference standard.

METHODS

Between April 2014 and April 2018, a total of 57 patients (25 females, mean age of 64 ± 12 years) underwent WB-PET/CT and WB-PET/MRI on the same day. The CT and MRI scans were independently evaluated by two radiologists who were blinded to the patients' information. The reference standard was evaluated by two nuclear medicine specialists. The findings were categorized into different regions: lymph nodes/soft tissue (I), lungs (II), abdomen/pelvis (III), and bone (IV). A comparative analysis was conducted for all the documented findings. Inter-reader reliability was assessed using Bland-Altman procedures, and McNemar's test was utilized to determine the differences between the readers and the methods.

RESULTS

Out of the 57 patients, 50 were diagnosed with metastases in two or more regions, with the majority being found in region I. The accuracies of CT and MRI did not show significant differences, except in region II where CT detected more metastases compared to MRI (0.90 vs. 0.68, p = 0.008). On the other hand, MRI had a higher detection rate in region IV compared to CT (0.89 vs. 0.61, p > 0.05). The level of agreement between the readers varied depending on the number of metastases and the specific region, with the highest agreement observed in region III and the lowest observed in region I.

CONCLUSIONS

In patients with advanced melanoma, WB-MRI has the potential to serve as an alternative to CT with comparable diagnostic accuracy and confidence across most regions. The observed limited sensitivity for the detection of pulmonary lesions might be improved through dedicated lung imaging sequences.

Cost Analysis of Adjuvant Whole-Brain Radiotherapy Treatment Versus No Whole-Brain Radiotherapy After Stereotactic Radiosurgery and/or Surgery Among Adults with One to Three Melanoma Brain Metastases: Results from a Randomized Trial

PURPOSE

We aimed to compare Australian health system costs at 12 months for adjuvant whole-brain radiotherapy (WBRT) treatment after stereotactic radiosurgery (SRS) and/or surgery versus observation among adults with one to three melanoma brain metastases. We hypothesized that treatment with adjuvant WBRT and subsequent healthcare would be more expensive than SRS/surgery alone.

METHODS

The analysis was conducted alongside a multicentre, randomized phase III trial. A bespoke cost questionnaire was used to measure healthcare use, including hospitalizations, specialist and primary care visits, imaging, and medicines over 12 months. Mean per-patient costs were calculated based on the quantity of resources used and unit costs, reported in Australian dollars ($AU), year 2018 values. Skewness of cost data was determined using normality tests and censor-adjusted costs reported using the Kaplan-Meier sample average method. The analysis of difference in mean costs at each 2-month time point and at 12 months was performed and checked using Kruskal-Wallis, generalized linear models with gamma distribution and log link, modified Park test, ordinary least squares, and non-parametric bootstrapping.

RESULTS

In total, 89 patients with similar characteristics at baseline were included in the cost analysis (n = 43 WBRT; n = 46 observation). Hospitalization cost was the main cost, ranging from 63 to 89% of total healthcare costs. The unadjusted 12-monthly cost for WBRT was $AU71,138 ± standard deviation 41,475 and for observation $AU69,848 ± 33,233; p = 0.7426. The censor-adjusted 12-monthly cost for WBRT was $AU90,277 ± 36,274 and $AU82,080 ± 34,411 for observation. There was no significant difference in 2-monthly costs between groups (p > 0.30 for all models).

CONCLUSIONS

Most costs were related to inpatient hospitalizations associated with disease recurrence. Adding WBRT after local SRS/surgery for patients with one to three melanoma brain metastases did not significantly increase health system costs during the first 12 months.

TRIAL REGISTRATION

ACTRN12607000512426, prospectively registered 14 September 2007.

Anatomical and topographical variations in the distribution of brain metastases based on primary cancer origin and molecular subtypes: a systematic review

Background

While it has been suspected that different primary cancers have varying predilections for metastasis in certain brain regions, recent advances in neuroimaging and spatial modeling analytics have facilitated further exploration into this field.

Methods

A systematic electronic database search for studies analyzing the distribution of brain metastases (BMs) from any primary systematic cancer published between January 1990 and July 2020 was conducted using PRISMA guidelines.

Results

Two authors independently reviewed 1957 abstracts, 46 of which underwent full-text analysis. A third author arbitrated both lists; 13 studies met inclusion/exclusion criteria. All were retrospective single- or multi-institution database reviews analyzing over 8227 BMs from 2599 patients with breast (8 studies), lung (7 studies), melanoma (5 studies), gastrointestinal (4 studies), renal (3 studies), and prostate (1 study) cancers. Breast, lung, and colorectal cancers tended to metastasize to more posterior/caudal topographic and vascular neuroanatomical regions, particularly the cerebellum, with notable differences based on subtype and receptor expression. HER-2-positive breast cancers were less likely to arise in the frontal lobes or subcortical region, while ER-positive and PR-positive breast metastases were less likely to arise in the occipital lobe or cerebellum. BM from lung adenocarcinoma tended to arise in the frontal lobes and squamous cell carcinoma in the cerebellum. Melanoma metastasized more to the frontal and temporal lobes.

Conclusion

The observed topographical distribution of BM likely develops based on primary cancer type, molecular subtype, and genetic profile. Further studies analyzing this association and relationships to vascular distribution are merited to potentially improve patient treatment and outcomes.

Long-term Overall Survival and Predictors in Anti-PD-1-naive Melanoma Patients With Brain Metastases Treated With Immune Checkpoint Inhibitors in the Real-world Setting: A Multicohort Study

Long-term survival outcomes among melanoma patients with brain metastases treated with immune checkpoint inhibitors are limited. In this retrospective study at 2 centers, metastatic melanoma patients with radiographic evidence of brain metastases who received anti-programmed death-1 (PD-1) monotherapy or nivolumab in combination with ipilimumab between 2014 and 2017 were included. Overall survival (OS) was assessed in diagnosis-specific graded prognostic assessment (ds-GPA) and melanoma-molecular graded prognostic assessment (molGPA) prognostic risk groups. Baseline clinical covariates were used to identify predictors of OS in univariate/multivariable Cox proportional-hazards models. A total of 84 patients (58 monotherapy, 26 combination) were included with a median duration of follow-up of 43.4 months (maximum: 5.1 y). The median OS [95% confidence interval (CI)] was 3.1 months (1.8, 7) for ds-GPA 0-1, 22.1 months [5.4, not reached (NR)] for ds-GPA 2 and NR (24.9, NR) for ds-GPA 3-4 in the monotherapy cohort [hazard ratio (HR) for ds-GPA 3-4 vs. 0-1: 0.13 (95% CI: 0.052, 0.32); 0.29 (95% CI: 0.12, 0.63) for ds-GPA 2 vs. 0-1]. The median OS was 1.1 months (95% CI: 0.3, NR) for ds-GPA 0-1, 11.8 months (95% CI: 2.9, 23.3) for ds-GPA 2 and 24.4 months (95% CI: 3.4, NR) for ds-GPA 3-4 in the combination cohort [HR for 3-4 vs. 0-1: 0.013 (95% CI: 0.0012, 0.14); HR for ds-GPA 2 vs. 0-1: 0.033 (0.0035, 0.31)]. Predictors associated with longer survival included ds-GPA or molGPA>1 (among prognostic indices), neutrophil-to-lymphocyte ratio (<4 vs. ≥4), while high lactate dehydrogenase, neurological symptoms, and leptomeningeal metastases were associated with shorter survival. Baseline ds-GPA/molGPA>1 and neutrophil-to-lymphocyte ratio <4 were strong predictors of long-term survival to anti-PD-1-based immune checkpoint inhibitors in melanoma brain metastases patients previously naive to anti-PD-1 therapy in a real-world clinical setting treated at independent centers.

Whole-Body MRI for the Detection of Recurrence in Melanoma Patients at High Risk of Relapse

Introduction: No standard protocol for surveillance for melanoma patients is established. Whole-body magnetic resonance imaging (whole-body MRI) is a safe and sensitive technique that avoids exposure to X-rays and contrast agents. This prospective study explores the use of whole-body MRI for the early detection of recurrences. Material and Methods: Patients with American Joint Committee on Cancer Staging Manual (seventh edition; AJCC-7) stages IIIb/c or -IV melanoma who were disease-free following resection of macrometastases (cohort A), or obtained a durable complete response (CR) or partial response (PR) following systemic therapy (cohort B), were included. All patients underwent whole-body MRI, including T1, Short Tau Inversion Recovery, and diffusion-weighted imaging, every 4 months the first 3 years of follow-up and every 6 months in the following 2 years. A total body skin examination was performed every 6 months. Results: From November 2014 to November 2019, 111 patients were included (four screen failures, cohort A: 68 patients; cohort B: 39 patients). The median follow-up was 32 months. Twenty-six patients were diagnosed with suspected lesions. Of these, 15 patients were diagnosed with a recurrence on MRI. Eleven suspected lesions were considered to be of non-neoplastic origin. In addition, nine patients detected a solitary subcutaneous metastasis during self-examination, and two patients presented in between MRIs with recurrences. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were, respectively, 58%, 98%, 58%, 98%, and 98%. Sensitivity and specificity for the detection of distant metastases was respectively 88% and 98%. No patient experienced a clinically meaningful (>grade 1) adverse event. Conclusions: Whole-body MRI for the surveillance of melanoma patients is a safe and sensitive technique sparing patients' cumulative exposure to X-rays and contrast media.

A Contemporary Report of Clinical Outcomes in Patients with Melanoma Brain Metastases

Background: Brain metastases are observed in more than 40% of all patients with stage 4 melanoma. In recent years, more extensive use of stereotactic radiation (STRT) and the advent of immune checkpoint inhibitors have positively impacted outcomes in patients with metastatic melanoma.brain metastases. Here, we examined real world clinical outcomes of patients presenting with melanoma brain metastases (MBMs). Methods: This retrospective review evaluated MBMs patients treated at The Ottawa Hospital from April 2000 to July 2017. Clinical, radiologic, pathologic and treatment information were gathered from the electronic medical records. The primary outcome was overall survival. The proportional Cox regression model was employed for survival data, while the Fisher’s exact and Mann–Whitney U tests analyzed the relationship between categorical and continuous data, respectively. Results: This retrospective study included 276 patients. Brain metastases were detected symptomatically in 191 patients (69.2%); the rates of detection by routine screening were 4.6% in the pre-2012 era and 11.7% in the contemporary era (p = 0.029). Median survival was three months. Predictors of overall survival were age, higher lactate dehydrogenase (LDH) values, multiple brain lesions, more extensive extracranial disease, neurological symptoms, infratentorial lesions and treatment type. Multivariable analysis demonstrated that stereotactic radiotherapy (STRT) was associated with a hazard ratio of 0.401 (p < 0.001) for survival; likewise, immune checkpoint inhibitor therapy was associated with a hazard ratio of 0.375 (p < 0.001). Conclusion: The findings from this study as “real world” data are consistent with results of pivotal clinical trials in MBMs patients and support contemporary locoregional and immunotherapy practices.

Thioredoxin, Glutathione and Related Molecules in Tumors of the Nervous System

BACKGROUND

Central Nervous System (CNS) tumors have a poor survival prognosis due to their invasive and heterogeneous nature, in addition to the resistance to multiple treatments.

OBJECTIVE

In this paper, the main aspects of brain tumor biology and pathogenesis are reviewed both for primary tumors of the brain, (i.e., gliomas) and for metastasis from other malignant tumors, namely lung cancer, breast cancer and malignant melanoma which account for a high percentage of overall malignant brain tumors. We review the role of antioxidant systems, namely the thioredoxin and glutathione systems, in the genesis and/or progression of brain tumors.

METHODS

Although overexpression of Thioredoxin Reductase (TrxR) and Thioredoxin (Trx) is often linked to increased malignancy rate of brain tumors, and higher expression of Glutathione (GSH) and Glutathione S-Transferases (GST) are associated to resistance to therapy, several knowledge gaps still exist regarding for example, the role of Peroxiredoxins (Prx), and Glutaredoxins (Grx).

CONCLUSION

Due to their central role in redox homeostasis and ROS scavenging, redox systems are potential targets for new antitumorals and examples of innovative therapeutics aiming at improving success rates in brain tumor treatment are discussed.

Melanoma Brain Metastases in the Era of Target Therapies: An Overview

Malignant melanoma is the third most common type of tumor that causes brain metastases. Patients with cerebral involvement have a dismal prognosis and their treatment is an unmet medical need. Brain involvement is a multistep process involving several signaling pathways such as Janus kinase/signal Transducer and Activator of Transcription (JAK/STAT), Phosphoinositide 3-kinase/Protein Kinase B (PI3K/AKT), Vascular Endothelial Growth Factor and Phosphatase and Tensin Homolog (PTEN). Recently therapy that targets the MAPK signaling (BRAF/MEK inhibitors) and immunotherapy (anti-CTLA4 and anti-PD1 agents) have changed the therapeutic approaches to stage IV melanoma. In contrast, there are no solid data about patients with brain metastases, who are usually excluded from clinical trials. Retrospective data showed that BRAF-inhibitors, alone or in combination with MEK-inhibitors have interesting clinical activity in this setting. Prospective data about the combinations of BRAF/MEK inhibitors have been recently published, showing an improved overall response rate. Short intracranial disease control is still a challenge. Several attempts have been made in order to improve it with combinations between local and systemic therapies. Immunotherapy approaches seem to retain promising activity in the treatment of melanoma brain metastasis as showed by the results of clinical trials investigating the combination of anti-CTL4 (Ipilimumab) and anti-PD1(Nivolumab). Studies about the combination or the sequential approach of target therapy and immunotherapy are ongoing, with immature results. Several clinical trials are ongoing trying to explore new approaches in order to overcome tumor resistance. At this moment the correct therapeutic choices for melanoma with intracranial involvement is still a challenge and new strategies are needed.

Incidence and prognosis of brain metastases in cutaneous melanoma patients: a population-based study

Brain metastases (BM) from cutaneous melanoma are associated with poor prognosis. Population-based data describing the associated factors of incidence and prognosis of BM from melanoma are still lacking. We identified 121 255 melanoma patients diagnosed during 2010-2015 from the Surveillance, Epidemiology, and End Results program, and identified predictive factors for incidence and survival of BM patients by using multivariable logistic and Cox's proportional hazard regression, respectively. We identified 1547 patients with BM at the time of diagnosis of malignant cutaneous melanoma, representing 1.3% of the entire cohort and 35.4% of the subset with metastatic disease. The characteristics associated with higher BM incidence were male sex, age 40-60 years, melanoma location of face/head/neck, histologic type of nodular, higher T-stage, ulceration and extracranial metastases. The median overall survival and median cutaneous melanoma specific survival of patients with BM was 5 and 6 months, respectively. The relative factors of poor survival were older age and more extracranial metastatic sites. In summary, we provided insight into the epidemiology of BM from cutaneous melanoma. These results may provide significant help to improve the screening strategy of BM strategy and update the existing prognosis evaluation system.

Temporal muscle thickness is an independent prognostic marker in melanoma patients with newly diagnosed brain metastases

Objectives

The purpose of this study was to evaluate the prognostic relevance of temporal muscle thickness (TMT) in melanoma patients with newly diagnosed brain metastases.

Methods

TMT was retrospectively assessed in 146 melanoma patients with newly diagnosed brain metastases on cranial magnetic resonance images. Chart review was used to retrieve clinical parameters, including disease-specific graded prognostic assessment (DS-GPA) and survival times.

Results

Patients with a TMT > median showed a statistically significant increase in survival time (13 months) compared to patients with a TMT < median (5 months; p < 0.001; log rank test). A Cox regression model revealed that the risk of death was increased by 27.9% with every millimeter reduction in TMT. In the multivariate analysis, TMT (HR 0.724; 95% 0.642–0.816; < 0.001) and DS-GPA (HR 1.214; 95% CI 1.023–1.439; p = 0.026) showed a statistically significant correlation with overall survival.

Conclusion

TMT is an independent predictor of survival in melanoma patients with brain metastases. This parameter may aid in patient selection for clinical trials or to the choice of different treatment options based on the determination of frail patient populations.

Risk factors for development of melanoma brain metastasis and disease progression: a single-center retrospective analysis

Melanoma metastasis to the brain is associated with a poor prognosis. We sought to determine patient demographics and primary tumor factors associated with the development of brain metastasis (BM) and survival. We also investigated whether the BM detection setting (routine screening vs. symptomatic presentation) affected clinical outcomes. A database of melanoma patients seen from 1999 to 2015 at our institution was reviewed to identify patients who developed BM. Patients with BM were matched by initial stage with patients who did not develop BM as a control group. Patient demographics, primary tumor characteristics, and clinical outcomes were analyzed. A total of 123 patients with BM were matched by initial presenting stage to 237 patients without BM. The characteristics of the primary melanoma tumor associated with BM development included location on the scalp (P=0.030), nodular histologic type (P=0.020), and Breslow depth more than 4 mm (P=0.048), whereas location on the leg was associated with decreased BM risk (P=0.006). In patients with BM, time to first recurrence for melanomas of the scalp was significantly shorter (10.8 vs. 24.8 months, P=0.007) than nonscalp head and neck tumors. Patient stage, tumor depth, nodular type, and ulceration were also associated with worse clinical outcomes. There were no differences in the clinical outcomes between patients whose BM were detected upon routine screening versus those detected upon symptomatic presentation. In summary, factors predictive of development of BM included primary scalp location, nodular type, and depth. In BM patients, scalp location, stage, tumor depth, nodular type, and ulceration, but not detection setting, were associated with worse clinical outcomes.

Brain metastasis: Unique challenges and open opportunities

The metastasis of cancer to the central nervous system (CNS) remains a devastating clinical reality, carrying an estimated survival time of less than one year in spite of recent therapeutic breakthroughs for other disease contexts. Advances in brain metastasis research are hindered by a number of factors, including its complicated nature and the difficulty of modeling metastatic cancer growth in the unique brain microenvironment. In this review, we will discuss the clinical challenge, and compare the merits and limitations of the available models for brain metastasis research. Additionally, we will specifically address current knowledge on how brain metastases take advantage of the unique brain environment to benefit their own growth. Finally, we will explore the distinctive metabolic and chemical characteristics of the brain and how these paradoxically represent barriers to establishment of brain metastasis, but also provide ample supplies for metastatic cells' growth in the brain. We envision that multi-disciplinary innovative approaches will open opportunities for the field to make breakthroughs in tackling unique challenges of brain metastasis.

Treatment of brain metastases in the modern genomic era

Development of brain metastasis (BM) portends a dismal prognosis for patients with cancer. Melanomas and carcinomas of the lung, breast, and kidney are the most common malignancies to metastasize to the brain. Recent advances in molecular genetics have enabled the identification of actionable, clinically relevant genetic alterations within primary tumors and their corresponding metastases. Adoption of genotype-guided treatment strategies for the management of systemic malignancy has resulted in dramatic and durable responses. Unfortunately, despite these therapeutic advances, central nervous system (CNS) relapses are not uncommon. Although these relapses have historically been attributed to limited blood brain barrier penetration of anti-neoplastic agents, recent work has demonstrated genetic heterogeneity such that metastatic sites, including BM, harbor relevant genetic alterations that are not present in primary tumor biopsies. This improved insight into molecular mechanisms underlying site specific recurrences can inform strategies for targeting these oncogenic drivers. Thus, development of rational, genomically guided CNS-penetrant therapies is crucial for ongoing therapeutic success.

Linear accelerator-based stereotactic radiosurgery in 140 brain metastases from malignant melanoma

BACKGROUND

To retrospectively access outcome and prognostic parameters of linear accelerator-based stereotactic radiosurgery in brain metastases from malignant melanoma.

METHODS

Between 1990 and 2011 140 brain metastases in 84 patients with malignant melanoma (median age 56 years) were treated with stereotactic radiosurgery. At initial stereotactic radiosurgery 48 % of patients showed extracerebral control. The median count of brain metastases in a single patient was 1, the median diameter was 12 mm. The median dose applied was 20 Gy/80 % isodose enclosing.

RESULTS

The median follow-up was 7 months and the median overall survival 9 months. The 6-, 12- and 24 month overall survival rates were 71 %, 39 % and 25 % respectively. Cerebral follow-up imaging showed complete remission in 20 brain metastases, partial remission in 39 brain metastases, stable disease in 54 brain metastases, progressive disease in 24 brain metastases and pseudo-progression in 3 brain metastases. Median intracerebral control was 5.3 months and the 6- and 12-month intracerebral progression-free survival rates 48 % and 38 %, respectively. Upon univariate analysis, extracerebral control (log-rank, p < 0.001), the response to stereotactic radiosurgery (log-rank, p < 0.001), the number of brain metastases (log-rank, p = 0.007), the recursive partitioning analysis class (log-rank, p = 0.027) and the diagnosis-specific graded prognostic assessment score (log-rank, p = 0.011) were prognostic for overall survival. The most common clinical side effect was headache common toxicity criteria grade I. The most common radiological finding during follow-up was localized edema within the stereotactic radiosurgery high dose region.

CONCLUSION

Stereotactic radiosurgery is a well-tolerated and effective treatment option for brain metastases in malignant melanoma and was able to achieve local remissions in several cases. Furthermore, especially patients with controlled extracerebral disease and a low count of brain metastases seem to benefit from this treatment modality. Prospective trials analysing the effects of combined stereotactic radiosurgery and new systemic agents are warranted.

DNA methylation and gene deletion analysis of brain metastases in melanoma patients identifies mutually exclusive molecular alterations

BACKGROUND

The brain is a common target of metastases for melanoma patients. Little is known about the genetic and epigenetic alterations in melanoma brain metastases (MBMs). Unraveling these molecular alterations is a key step in understanding their aggressive nature and identifying novel therapeutic targets.

METHODS

Genome-wide DNA methylation analyses of MBMs (n = 15) and normal brain tissues (n = 91) and simultaneous multigene DNA methylation and gene deletion analyses of metastatic melanoma tissues (99 MBMs and 43 extracranial metastases) were performed. BRAF and NRAS mutations were evaluated in MBMs by targeted sequencing.

RESULTS

MBMs showed significant epigenetic heterogeneity. RARB, RASSF1, ESR1, APC, PTEN, and CDH13 genes were frequently hypermethylated. Deletions were frequently detected in the CDKN2A/B locus. Of MBMs, 46.1% and 28.8% had BRAF and NRAS missense mutations, respectively. Compared with lung and liver metastases, MBMs exhibited higher frequency of CDH13 hypermethylation and CDKN2A/B locus deletion. Mutual exclusivity between hypermethylated genes and CDKN2A/B locus deletion identified 2 clinically relevant molecular subtypes of MBMs. CDKN2A/B deletions were associated with multiple MBMs and frequently hypermethylated genes with shorter time to brain metastasis.

CONCLUSIONS

Melanoma cells that colonize the brain harbor numerous genetically and epigenetically altered genes. This study presents an integrated genomic and epigenomic analysis that reveals MBM-specific molecular alterations and mutually exclusive molecular subtypes.

Current management of advanced melanoma: a transformed landscape

The prognosis for patients with stage IV melanoma has historically been extremely poor and there have until recently been no effective treatment options. The last 3 years have seen a seismic shift in the management of these patients with the entry to the clinic of a number of novel agents with proven efficacy. These agents fall into two main classes: molecular-targeted therapy and immunotherapy. Molecular therapies have primarily targeted the mitogen-activated protein kinase pathway, most notably with oral inhibitors targetting oncogenic BRAF. Immunotherapy agents such as ipilimumab, and more recently antibodies against PD-1 boost the host immune response against the melanoma. It is important for surgeons to be aware of these advances for a number of reasons. Firstly, to be able to inform their patients of the general options available in the event of disease progression. Secondly, these agents are currently being assessed in the adjuvant setting and are likely to demonstrate efficacy for earlier stages of disease. Finally, it is important for surgeons to be able to advocate on their patients' behalf to minimize the lag time between publication of these promising results and the availability of these agents in the clinic. Furthermore, patients with advanced melanoma should be offered participation in clinical trials in order to refine the indications for these agents to maximize their chance of benefit.