Tumour mutation status and sites of metastasis in patients with cutaneous melanoma

Molecular Underpinnings of Brain Metastases

Brain metastases are the most commonly diagnosed type of central nervous system tumor, yet the mechanisms of their occurrence are still widely unknown. Lung cancer, breast cancer, and melanoma are the most common etiologies, but renal and colorectal cancers have also been described as metastasizing to the brain. Regardless of their origin, there are common mechanisms for progression to all types of brain metastases, such as the creation of a suitable tumor microenvironment in the brain, priming of tumor cells, adaptations to survive spreading in lymphatic and blood vessels, and development of mechanisms to penetrate the blood-brain barrier. However, there are complex genetic and molecular interactions that are specific to every type of primary tumor, making the understanding of the metastatic progression of tumors to the brain a challenging field of study. In this review, we aim to summarize current knowledge on the pathophysiology of brain metastases, from specific genetic characteristics of commonly metastatic tumors to the molecular and cellular mechanisms involved in progression to the central nervous system. We also briefly discuss current challenges in targeted therapies for brain metastases and how there is still a gap in knowledge that needs to be overcome to improve patient outcomes.

Non-coding RNAs in BRAF-mutant melanoma: targets, indicators, and therapeutic potential

Melanoma, a highly aggressive skin cancer, is often driven by BRAF mutations, such as the V600E mutation, which promotes cancer growth through the MAPK pathway and contributes to treatment resistance. Understanding the role of non-coding RNAs (ncRNAs) in these processes is crucial for developing new therapeutic strategies. This review aims to elucidate the relationship between ncRNAs and BRAF mutations in melanoma, focusing on their regulatory roles and impact on treatment resistance. We comprehensively reviewed current literature to synthesize evidence on ncRNA-mediated regulation of BRAF-mutant melanoma and their influence on therapeutic responses. Key ncRNAs, including microRNAs and long ncRNAs, were identified as significant regulators of melanoma development and therapy resistance. MicroRNAs such as miR-15/16 and miR-200 families modulate critical pathways like Wnt signaling and melanogenesis. Long ncRNAs like ANRIL and SAMMSON play roles in cell growth, invasion, and drug susceptibility. Specific ncRNAs, such as BANCR and RMEL3, intersect with the MAPK pathway, highlighting their potential as therapeutic targets or biomarkers in BRAF-mutant melanoma. Additionally, ncRNAs involved in drug resistance, such as miR-579-3p and miR-1246, target processes like autophagy and immune checkpoint regulation. This review highlights the pivotal roles of ncRNAs in regulating BRAF-mutant melanoma and their contribution to drug resistance. These findings underscore the potential of ncRNAs as biomarkers and therapeutic targets, paving the way for innovative treatments to improve outcomes for melanoma patients.

False Positive Rate from Prospective Studies of PET-CT in Cutaneous Malignant Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Cutaneous malignant melanoma (CMM) is increasing in prevalence and possesses the highest mortality rate of any skin cancer. Positron Emission Tomography and Computed Tomography (PET-CT) may be utilised in either radiological staging or surveillance, primarily in stage III-IV disease. False positive (FP) results lead to patient distress, increased costs, and unnecessary follow-up. The FP rate in CMM literature varies widely, altering calculations of positive predictive value and has not undergone pooled meta-analytic.

MATERIALS AND METHODS

A systematic review and meta-analysis of FP results in prospective studies of PET-CT in CMM was performed in accordance with PRISMA guidelines.

RESULTS

The systematic review produced 14 trials for inclusion. Patient-based reporting had the lowest pooled proportion of FP results with 5.8 % (95 % CI = 3.3 % to 8.8 %), lesion-based was highest with 9.1 % (95 % CI = 3.4 % to 17.2 %) and combined was 6.1 % (95 % CI = 4.3 % to 8.1 %). Bias was low to unclear other than for FP reporting. Heterogeneity (I2) was variable across all analyses. FP findings were mainly lymphatic, dermatological, respiratory, or skeletal. Diagnostic information was not provided.

CONCLUSIONS

This study was the first attempt to quantify the pooled proportion of FP results from PET-CT in CMM. A small number of studies (n = 14) were available due to the predominance of retrospective methodology. Due to inconsistent reporting the true proportion of FP results is unclear. Systemic distribution was expected but limited diagnostic information was provided. Repeat meta-analysis using retrospective work should be performed. Future work should be prospective with clearly documented FP proportion, distribution, diagnosis, and follow-up.

Prognostic Role of Clinicopathological Characteristics and Serum Markers in Metastatic Melanoma Patients Treated with BRAF and MEK Inhibitors

Prognostic studies can provide important information about disease biology and improve the use of biomarkers to optimize treatment decisions.

METHODS

A total of 199 patients with advanced melanoma treated with BRAF + MEK inhibitors were included in our single-center retrospective study. We analyzed the risk of progression and death using multivariate Cox proportional hazard models. The predictive effect of prognostic factors on progression-free survival (PFS) was evaluated in ROC analysis.

RESULTS

We found that primary tumor localization, Clark level, pT category, baseline M stage and baseline serum S100B are independent and significant prognostic factors for PFS. The discriminative power of the combination of these factors was excellent for predicting 18 month PFS (AUC 0.822 [95% CI 0.727; 0.916], p < 0.001). Primary tumor localization on the extremities, Clark level V, baseline M1c stage or M1d stage, and elevated baseline serum S100B and LDH levels were independently and significantly associated with unfavorable overall survival (OS).

CONCLUSION

Baseline M stage and serum S100B appear to be independent prognostic factors for both PFS and OS in melanoma patients treated with BRAF + MEK inhibitors. We newly identified significant and independent prognostic effects of primary tumor localization and Clark level on survival that warrant further investigation.

What Is the Timing and Role of Targeted Therapy in Metastatic Melanoma?

ABSTRACT

Melanoma is the most lethal cutaneous malignancy worldwide. The last 15 years have ushered in several regulatory approvals that have dramatically altered the landscape of treatment options for patients with melanoma. Many patients with melanoma harbor activating mutations in the BRAF proto-oncogene, a key component of the mitogen-activated protein kinase (MAPK) intracellular signaling pathway. Therapies targeting BRAF have led to remarkable improvements in both response rates and survival in patients with metastatic disease. In parallel with these developments in MAPK-targeted therapy has been the clinical development of immune checkpoint inhibitors, which also have improved response rates and survival in patients with metastatic disease including randomized trials compared with MAPK-targeted therapy in patients with advanced, BRAF-mutant melanoma. Immune checkpoint inhibitors have become the preferred first-line standard-of-care treatment for patients with newly diagnosed metastatic disease in patients irrespective of BRAF mutational status. Given these developments, it is now less clear how to optimize the use of MAPK-targeted therapy regarding treatment setting and in sequence with immune checkpoint inhibitor.

Endothelial and tumor-intrinsic mechanisms of hepatic melanoma metastasis

The treatment of metastatic cutaneous melanoma was fundamentally improved by the discovery and introduction of immune checkpoint inhibitors, such as anti-PD-1 and anti-CTLA-4 antibodies, and targeted therapy with BRAF and MEK inhibition. Unfortunately, many patients suffer a relapse due to resistance mechanisms that in part are mediated by organ-specific metastatic sites. Especially, brain and liver metastases are negative predictive factors for both treatment modalities. There is still high unmet clinical need to prevent and treat spread to these organs. Therefore, experimental research should focus on mechanisms of hepatic melanoma metastasis to better understand this process and to identify therapeutic targets.

Endotheliale und tumor-intrinsische Mechanismen der hepatischen Melanommetastasierung: Endothelial and tumor-intrinsic mechanisms of hepatic melanoma metastasis

Die Behandlung des metastasierten kutanen Melanoms wurde durch die Entdeckung und Zulassung von Immuncheckpoint‐Inhibitoren (ICI) wie Anti‐PD‐1‐ und Anti‐CTLA‐4‐Antikörpern sowie der zielgerichteten Therapie mit BRAF‐ und MEK‐Inhibition grundlegend verbessert. Allerdings entwickeln viele Patienten Rezidive aufgrund von Resistenzmechanismen, die zum Teil durch Metastasierung in bestimmte Organe verursacht werden. Insbesondere Hirn‐ und Lebermetastasen sind negative prädiktive Faktoren für beide Behandlungsmodalitäten. Bislang gibt es nur begrenzte Möglichkeiten, organspezifische Metastasierung aufzuhalten oder zu behandeln. Daher muss sich die experimentelle Forschung unter anderem Mechanismen der hepatischen Metastasierung des Melanoms widmen, um diesen Prozess besser zu verstehen und therapeutische Ziele ausfindig zu machen.

An update on methods for detection of prognostic and predictive biomarkers in melanoma

The approval of immunotherapy for stage II-IV melanoma has underscored the need for improved immune-based predictive and prognostic biomarkers. For resectable stage II-III patients, adjuvant immunotherapy has proven clinical benefit, yet many patients experience significant adverse events and may not require therapy. In the metastatic setting, single agent immunotherapy cures many patients but, in some cases, more intensive combination therapies against specific molecular targets are required. Therefore, the establishment of additional biomarkers to determine a patient's disease outcome (i.e., prognostic) or response to treatment (i.e., predictive) is of utmost importance. Multiple methods ranging from gene expression profiling of bulk tissue, to spatial transcriptomics of single cells and artificial intelligence-based image analysis have been utilized to better characterize the immune microenvironment in melanoma to provide novel predictive and prognostic biomarkers. In this review, we will highlight the different techniques currently under investigation for the detection of prognostic and predictive immune biomarkers in melanoma.

Predictive accuracy of risk prediction models for recurrence, metastasis and survival for early-stage cutaneous melanoma: a systematic review

OBJECTIVES

To identify prognostic models for melanoma survival, recurrence and metastasis among American Joint Committee on Cancer stage I and II patients postsurgery; and evaluate model performance, including overall survival (OS) prediction.

DESIGN

Systematic review and narrative synthesis.

DATA SOURCES

Searched MEDLINE, Embase, CINAHL, Cochrane Library, Science Citation Index and grey literature sources including cancer and guideline websites from 2000 to September 2021.

ELIGIBILITY CRITERIA

Included studies on risk prediction models for stage I and II melanoma in adults ≥18 years. Outcomes included OS, recurrence, metastases and model performance. No language or country of publication restrictions were applied.

DATA EXTRACTION AND SYNTHESIS

Two pairs of reviewers independently screened studies, extracted data and assessed the risk of bias using the CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies checklist and the Prediction study Risk of Bias Assessment Tool. Heterogeneous predictors prevented statistical synthesis.

RESULTS

From 28 967 records, 15 studies reporting 20 models were included; 8 (stage I), 2 (stage II), 7 (stages I-II) and 7 (stages not reported), but were clearly applicable to early stages. Clinicopathological predictors per model ranged from 3-10. The most common were: ulceration, Breslow thickness/depth, sociodemographic status and site. Where reported, discriminatory values were ≥0.7. Calibration measures showed good matches between predicted and observed rates. None of the studies assessed clinical usefulness of the models. Risk of bias was high in eight models, unclear in nine and low in three. Seven models were internally and externally cross-validated, six models were externally validated and eight models were internally validated.

CONCLUSIONS

All models are effective in their predictive performance, however the low quality of the evidence raises concern as to whether current follow-up recommendations following surgical treatment is adequate. Future models should incorporate biomarkers for improved accuracy.

PROSPERO REGISTRATION NUMBER

CRD42018086784.

Lack of Influence of Non-Overlapping Mutations in BRAF, NRAS, or NF1 on 12-Month Best Objective Response and Long-Term Survival after Checkpoint Inhibitor-Based Treatment for Metastatic Melanoma

BACKGROUND

Non-overlapping somatic mutations in BRAF, NRAS, or NF1 genes occur in 85% of metastatic melanoma patients. It is not known whether these mutations affect immunotherapy outcome.

MATERIALS AND METHODS

Next-Gen sequencing of 324 oncogenes was performed in 73 metastatic melanoma patients. A retrospective review of immunotherapy outcome was performed.

RESULTS

BRAF fusions/internal rearrangements, BRAF V600E, NRAS, NF1 mutations, and triple-negative genotypes occurred in 6.9%, 30.1%, 17.8%, 32.9%, and 12.3% of patients, respectively. Median potential follow-up was 41.0 months. Patients with BRAF fusion/rearrangement had decreased progression-free and overall survival (p = 0.015). The other genotypes each had similar progression-free and overall survival. Patients who achieved a complete best objective response at 12 months (n = 36, 49.3%) were found to have significantly improved survival compared those who failed to achieve remissions (n = 37, 50.7%, p < 0.001).

CONCLUSIONS

The most important determinant of long-term survival was achievement of a complete response by 12 months following immunotherapy. PR and SD were not a stable type of response and generally resulted in progression and death from melanoma. Rare patients with BRAF fusions or rearrangements had decreased progression-free and overall survival following initial immunotherapy. Other BRAF, NRAS, or NF1 mutations were not associated with significant differences in outcome.

Hepatic passaging of NRAS-mutant melanoma influences adhesive properties and metastatic pattern

BACKGROUND

Liver metastasis is a poor prognostic factor for treatment of advanced cutaneous melanoma with either immunotherapy or targeted therapies. In this study we focused on NRAS mutated melanoma, a cohort with high unmet clinical need.

METHODS

WT31 melanoma was repeatedly passaged over the liver after intravenous injections five times generating the subline WT31_P5IV. The colonization of target organs, morphology, vascularization and the gene expression profiles of metastases were analyzed.

RESULTS

After intravenous injection lung metastasis was significantly decreased and a trend towards increased liver metastasis was detected for WT31_P5IV as compared to parental WT31. Besides, the ratio of lung to liver metastases was significantly smaller. Histology of lung metastases revealed reduced proliferation of WT31_P5IV in relation to WT31 while both size and necrotic areas were unaltered. Liver metastases of both sublines showed no differences in vascularization, proliferation or necrosis. To identify tumor-intrinsic factors that altered the metastatic pattern of WT31_P5IV RNA sequencing was performed and revealed a differential regulation of pathways involved in cell adhesion. Ex vivo fluorescence imaging confirmed that initial tumor cell retention in the lungs was significantly reduced in WT31_P5IV in comparison to WT31.

CONCLUSION

This study demonstrates that tumor-intrinsic properties influencing the metastatic pattern of NRAS mutated melanoma are strongly affected by hepatic passaging and the hematogenous route tumor cells take. It has implications for the clinical setting as such effects might also occur during metastatic spread or disease progression in melanoma patients.

Academic dermatology in Australia and New Zealand between 2017 and 2022: A cross‐sectional bibliometric analysis

INTRODUCTION

Academic dermatologists in Australia and New Zealand provide high-quality and meaningful contributions to the understanding of disease and therapeutic translational research. Concerns have been raised by the Australian Medical Association regarding the decline of clinical academics in Australia as a whole, however, such trends in scholarly output have not previously been analysed for Australasian dermatologists.

METHODS

A bibliometric analysis of dermatologists in Australia and New Zealand was conducted in January and February 2023. Available Scopus profiles for all dermatologists were used to measure lifetime H index, scholarly output, citation counts and field-weighted citation impact (FWCI) in the last 5 years (2017-2022). Trends in output over time were measured using non-parametric tests. Differences in output between subgroups stratified by gender and academic leadership positions (associate professor or professor) were measured using Wilcoxon rank-sum and one-way ANOVA tests. The scholarly output of recent College graduates was also analysed as a subgroup, comparing the same bibliographic variables in the 5 years preceding and 5 years following awarding of their fellowships.

RESULTS

From the 463 practising dermatologists in Australia and New Zealand, 372 (80%) were successfully matched to Scopus researcher profiles. Of these dermatologists, 167 were male (45%) and 205 (55%) were female, and 31 (8%) held academic leadership positions. Most dermatologists (67%) published at least one paper in the last 5 years. The median lifetime H index was 4, and between 2017 and 2022 median scholarly output was 3, the median citations were 14 and the median FWCI was 0.64. There was a non-significant trend towards fewer publications per year, however, citation count and FWCI decreased significantly. By subgroups, female dermatologists published significantly more papers between 2017 and 2022, and other bibliographic variables were comparable to male dermatologists. However, women were underrepresented in positions of academic leadership-comprising only 32% of this cohort despite representing 55% of dermatologists. Professors were also significantly more likely to have higher bibliographic outcomes than associate professors. Finally, analysis of recent College graduates highlighted a significant decline in bibliometric outcomes pre- and post-fellowship.

CONCLUSION

Overall, our analysis identifies a trend towards decreased research output by dermatologists in Australia and New Zealand in the last 5 years. Strategies to support dermatologists in research endeavours, particularly women and recent graduates, will be essential in maintaining strong scholarly output among Australasian dermatologists and thereby sustaining optimal evidence-based patient care.

Clinical features and response to systemic therapy in NRAS-mutant Chinese melanoma patients

PURPOSE

The prognosis of patients with NRAS-mutant melanoma is rather poor. Immunotherapy and targeted therapy have revolutionized anti-tumor therapy, especially for melanoma. In this study, we retrospectively summarized the real-world experience of systematic treatment for NRAS-mutant melanoma patients in this new era.

PATIENTS AND METHODS

The respective cohort included NRAS-mutant melanoma patients with metastatic or unresectable disease of Sun Yat-sen University Cancer Center (SYSUCC) from January 2018 to July 2022. The data about the clinical features and impact for systemic therapy of NRAS-mutant patients were collected and analyzed.

RESULTS

At data cutoff, 44 patients (19, 11, and 14 for acral, cutaneous, and mucosal ones, respectively) with NRAS-mutant were assessed. In addition, the median time of follow-up was 22.0 months. The immunotherapy-based combined treatment not only significantly improved the progression-free survival (PFS) (P = 0.006, HR 0.322), but was also accompanied by a higher objective response rate (ORR) (18.2%), disease control rate (DCR) (72.7%) than those of cytotoxic therapy or immunotherapy alone for advanced patients as first-line treatment. Nab-paclitaxel combined with anti-PD-1 inhibitor tended to produce better clinical benefit for the first-line treatment, especially for patients with acral melanoma. In addition, the tyrosine kinase inhibitor (TKI) combined with anti-PD-1 inhibitor also seemed to provide longer duration of response (DOR) for some patients. But combined therapy did not prolong the overall survival (OS) of NRAS-mutant patients. The combined therapy was well tolerated. Most adverse events were moderate and controllable.

CONCLUSION

In conclusion, PD-1 inhibitor-based combined therapy increased clinical benefit for advanced patients with NRAS-mutant melanoma.

Factors influencing acceptance, adoption and adherence to sentinel node biopsy recommendations in the Australian Melanoma Management Guidelines: a qualitative study using an implementation science framework

BACKGROUND

Sentinel node biopsy (SN biopsy) is a surgical procedure used to accurately stage patients with primary melanoma at high risk of recurrence. Although Australian Melanoma Management Guidelines recommend SN biopsy be considered in patients with melanomas > 1 mm thick, SN biopsy rates in Australia are reportedly low. Our objective was to identify factors impacting the acceptance, adoption and adherence to the Australian SN biopsy guideline recommendations.

METHODS

Opinions of Australian key informants including clinicians, representatives from melanoma education and training providers, professional associations and colleges, and melanoma advocacy organisations were collected through semi-structured interviews (n = 29) and from publicly released statements (n = 14 news articles). Data analysis involved inductive and deductive thematic analysis using Flottorp's determinants framework.

RESULTS

A complex interplay of contemporary and historical factors was identified as influencing acceptance, adoption and adherence to the SN biopsy guideline recommendations at the individual, guideline, patient, organisational and social levels. Expert and peer opinion leaders have played an important role in facilitating or inhibiting adoption of guideline recommendations, as have financial incentives driven by healthcare-funding policies and non-financial incentives including professional identity and standing. Of critical importance have been the social and knowledge boundaries that exist between different professional groups to whom the guidelines apply (surgeons, dermatologists and primary care practitioners) with adherence to the guideline recommendations having the potential to shift work across professional boundaries, altering a clinician's workflow and revenue. More recently, the emergence of effective immunotherapies and targeted therapies for patients at high risk of recurrence, the emergence of new opinion leaders on the topic (in medical oncology), and patient demands for accurate staging are playing crucial roles in overcoming the resistance to change created by these social and knowledge boundaries.

CONCLUSIONS

Acceptance and adherence to SN biopsy guideline recommendations in Australia over the past 20 years has involved a process of renegotiation and reframing of the evidence for SN biopsy in melanoma by clinicians from different professional groups and networks. This process has helped to refine the evidence for SN biopsy and our understanding of appropriate adoption. New effective systemic therapies have changed the balance towards accepting guideline recommendations.

Correlation of MRI signal characteristics of intracranial melanoma metastases with BRAF mutation status

BRAF V600 mutations (BRAFmut) are associated with more pigmentation in primary melanomas, but data on melanin content of metastases are limited. This study compares signal characteristics of BRAFmut and BRAF-wildtype (BRAFwt) intracranial melanoma metastases (IMM). MRI brain examinations at first diagnosis of IMM were identified, all performed at 3-Tesla including 1 mm volumetric pre- and postcontrast T1-weighted imaging and susceptibility-weighted imaging (SWI). Individual metastases were assessed by a neuroradiologist, stratified by size (≥10 mm, 'larger', vs. 2-9 mm, 'small'; up to 10 per group); presence of intrinsic T1-hyperintensity (T1H) and, if present, whether confidently attributable to melanin as opposed to haemorrhage; evidence of haemorrhage; presence of central necrosis. A total of 267 IMM in 73 patients were assessed (87 larger IMM, 180 small). The proportion of larger IMM was similar in both groups (31% BRAFmut and 36% BRAFwt). In small IMM, MRI evidence of melanin was more common in BRAFmut patients (42% vs. 26%; P = 0.038). Haemorrhage was more common in larger IMM (51%, vs. 20% of small IMM; P < 0.0001), but did not differ based on BRAF status. Central necrosis was more common in larger IMM (44% vs. 7%; P < 0.0001) and in BRAFmut IMM (23% vs. 11%; P = 0.011). In the BRAFmut cohort, central necrosis was more common in patients without previous anti-BRAF therapy (33% vs. 7%; P = 0.0001). T1H attributable to melanin is only slightly more common in BRAFmut IMM than BRAFwt. Higher rates of central necrosis in BRAFmut patients without previous anti-BRAF therapy suggest that anti-BRAF therapy may affect the patterns of IMM growth.

The Genetics of Early-Stage Melanoma in a Veteran Population

To improve understanding of the genetic signature of early-stage melanomas in Veterans, hotspot mutation profiling using next-generation sequencing (NGS) was performed on melanoma tissue samples from patients at the Iowa City Veterans Affairs Medical Center (VAMC). Genetic analysis identified BRAF (36.3%), TP53 (25.9%), NRAS (19.3%), CDKN2A (11.1%), KIT (8.1%), and BAP1 (7.4%) mutations with the highest prevalence. Although common variants in BRAF were detected at lower rates than what is reported for the general population, 55.6% of cases showed activating mutations in the RAS/RAF pathways. Variants in TP53 and KIT were detected at higher rates than in the general population. Veterans with prior history of melanoma were at significantly higher odds of having TP53 mutation (OR = 2.67, p = 0.04). This suggests that TP53 may be a marker for recurrent melanoma and possibly alternative exposures in the military population. This study provides new information regarding the genetics of melanoma in a Veteran population and early-stage melanomas, highlighting risk factors unique to this population and contributing to the conversation about preventing melanoma deaths in US Military personnel.

Living Bacteria-Based Immuno-Photodynamic Therapy: Metabolic Labeling of Clostridium butyricum for Eradicating Malignant Melanoma

Due to the complexity, aggressiveness, and heterogeneity of malignant melanoma, it is difficult to eradicate the whole tumor through conventional treatment. Herein, a strategy of metabolic engineering labeled anaerobic oncolytic bacteria (Clostridium butyricum) is demonstrated to achieve the ablation of melanoma. In this system, the metabolic substrate of C. butyricum d-alanine (d-Ala) is first conjugated with a photosensitizer (TPApy) showing aggregation-induced emission (AIE). The yielded metabolic substrate of d-Ala-TPAPy can be metabolically incorporated into bacterial peptidoglycan to form engineered C. Butyricum. Once the engineered C. butyricum is injected into melanoma, the bacteria can only proliferate in an anaerobic zone, stimulate the tumor immune microenvironment, and ablate the tumor hypoxia region. Following that, the relatively rich oxygen content in the peripheral area can induce the death of C. butyricum. The photosensitizer (PS) on the bacteria can subsequently exert a photodynamic effect in the oxygen-rich region and further remove the melanoma residue under light irradiation. Prominent in vivo melanoma ablation results revealed that the engineering oncolytic bacteria can provide a promising regime for solid tumor eradication.

MEK inhibitors for pre-treated, NRAS-mutated metastatic melanoma: A multi-centre, retrospective study

BACKGROUND

MEK inhibitors (MEKi) have shown clinical efficacy for NRAS-mutated, metastasized melanoma in randomised controlled trials, yet their clinical use is currently restricted to advanced, pre-treated patients, which is a different situation compared to previous trials. Data on their efficacy in the current real-world use are scarce.

METHODS

In this retrospective, multi-centre study, we evaluated the clinical course of disease of patients treated with MEKi with at least one previous treatment line in five German cancer centres.

RESULTS

Thirty-three patients were included, 19 males (58%) and 14 females (42%), with a median age of 64 years. Ninety-one percent of patients were pre-treated with immune checkpoint inhibitors, 90% of patients had elevated serum lactate dehydrogenase (LDH) levels at treatment initiation, 33% suffered from cerebral metastases and 30% had an Eastern Cooperative Oncology Group performance status of 2 or higher. The response rate was 18.2%; the disease control rate was 48.5%. Median progression-free survival was 2.8 months (95% confidence interval (CI): 1.6-3.9 months), and median overall survival was 7.1 months (95% CI: 5.8-8.3 months). In subgroup analysis, clinical efficacy was similar also in patients with high LDH levels and cerebral metastases, and there was a better outcome in males and in patients treated with trametinib vs. other MEKi, which may be based on selection bias. Overall, the clinical efficacy was similar compared to previous clinical trials in earlier treatment lines.

CONCLUSIONS

MEKi fulfil the need for an in-between treatment to stabilise the course of disease in advanced NRAS-mutated melanoma, but expectations regarding ongoing tumour response should be tempered.

Angiogenic and molecular diversity determine hepatic melanoma metastasis and response to anti-angiogenic treatment

BACKGROUND

Cutaneous melanoma exhibits heterogeneous metastatic patterns and prognosis. In this regard, liver metastasis, which is detected in ~ 10-20% of stage 4 patients, came to the fore of melanoma research, as it recently evolved as decisive indicator of treatment resistance to immune checkpoint inhibition.

METHODS

Hepatic metastases were induced by intrasplenic injection of five different murine melanoma cell lines. The efficiencies of hepatic colonization, morphologic patterns, gene expression profiles and degree of vascularization were analyzed and Sorafenib was applied as anti-angiogenic treatment.

RESULTS

WT31 melanoma showed the highest efficiency of hepatic colonization, while intermediate efficiencies were observed for B16F10 and RET, and low efficiencies for D4M and HCmel12. RNAseq-based gene expression profiles of high and intermediate metastatic melanomas in comparison to low metastatic melanomas indicated that this efficiency predominantly associates with gene clusters involved in cell migration and angiogenesis. Indeed, heterogeneous vascularization patterns were found in the five models. Although the degree of vascularization of WT31 and B16F10 metastases differed, both showed a strong response to Sorafenib with a successful abrogation of the vascularization.

CONCLUSION

Our data indicate that molecular heterogeneity of melanomas can be associated with phenotypic and prognostic features of hepatic metastasis paving the way for organ-specific anti-angiogenic therapeutic approaches.

Genomic and Transcriptomic Underpinnings of Melanoma Genesis, Progression, and Metastasis

Melanoma is a deadly skin cancer with rapidly increasing incidence worldwide. The discovery of the genetic drivers of melanomagenesis in the last decade has led the World Health Organization to reclassify melanoma subtypes by their molecular pathways rather than traditional clinical and histopathologic features. Despite this significant advance, the genomic and transcriptomic drivers of metastatic progression are less well characterized. This review describes the known molecular pathways of cutaneous and uveal melanoma progression, highlights recently identified pathways and mediators of metastasis, and touches on the influence of the tumor microenvironment on metastatic progression and treatment resistance. While targeted therapies and immune checkpoint blockade have significantly aided in the treatment of advanced disease, acquired drug resistance remains an unfortunately common problem, and there is still a great need to identify potential prognostic markers and novel therapeutic targets to aid in such cases.

Discovery of novel ibrutinib analogues to treat malignant melanoma

A series of novel ibrutinib analogues was synthesized, and their proliferation inhibitory activities against various B lymphoma cell lines (DaudiB and Raji) and solid tumor cells (B16, CT26, HepG2 and 4T1) were evaluated. The most potent compound, YL7, exhibited strong antiproliferative activity in all cell lines, and its IC50 value in B16 cells was almost 9-fold better than that of ibrutinib. Mechanism of action studies showed that YL7 inhibited proliferation and migration and induced G1 cell cycle arrest, apoptosis and autophagy in B16 cells. Further assessment of in vivo antitumor efficacies demonstrated that YL7 significantly inhibited the growth of B16 melanoma. These preliminary studies suggest that it is reasonable to modify the structure of ibrutinib for antimelanoma treatment.

Prognostic Roles of BRAF, KIT, NRAS, IGF2R and SF3B1 Mutations in Mucosal Melanomas

BACKGROUND

The prognostic value of commonly recurrent mutations remains unclear in mucosal melanomas.

METHODS

Clinicopathologic parameters of 214 cases of mucosal melanomas diagnosed in 1989-2020 in several clinical institutions were analyzed. NRAS, KIT, BRAF, IGF2R and SF3B1 mutational analyses by Sanger sequencing and next generation sequencing-based assay were performed in a subset of cases.

RESULTS

Of the triple (BRAF, NRAS, NF1)-negative cases, APC, KIT and KRAS are detected mainly in sinonasal, vulvovaginal and anorectal melanomas, respectively. NRAS, KIT, BRAF, IGF2R and SF3B1 mutations are detected in 19% (37/198), 22% (44/197), 12% (25/201), 16% (22/138) and 15% (20/133) of cases, respectively. In univariate analyses, advanced stage (p = 0.016), 65 years or older (p = 0.048) and presence of ulceration (p = 0.027) are significantly correlated with worse overall survival (OS), respectively. NRAS mutation significantly correlates with worse OS (p = 0.028) and worse melanoma-specific survival (MSS) (p = 0.03) for all cases of mucosal melanomas. In multivariate analyses, NRAS mutation remains as an independent predictor of worse OS (p = 0.036) and worse MSS (p = 0.024).

CONCLUSION

NRAS mutation is a predictor of worse survival, independent of stage in mucosal melanomas. The significance of frequently mutated IGF2R in mucosal melanomas remains unclear.

An Approach to Cell Motility as a Key Mechanism in Oncology

Motility is an inherent characteristic of living cells manifesting cell migration, a fundamental mechanism of survival and development [...].

Current Perspectives and Novel Strategies of NRAS-Mutant Melanoma

Melanoma is the deadliest cutaneous cancer. Activating mutations in NRAS are found in 20% of melanomas. NRAS-mutant melanoma is more aggressive and, therefore, has poorer outcomes, compared to non-NRAS-mutant melanoma. Despite promising preclinical data, to date immune checkpoint inhibitors remain the standard of care for locally advanced unresectable or metastatic NRAS melanoma. Data for efficacy of immunotherapy for NRAS melanoma mainly come from retrospective cohorts with divergent conclusions. MEK inhibitors have been the most developed targeted therapy approach. Although associated with an increase in progression-free survival, MEK inhibitors do not provide any benefit in terms of overall survival. Combination strategies with PI3K-AKT-mTOR pathway and CDK4/6 inhibitors seem to increase MEK inhibitors' benefit. Nevertheless, results from clinical trials are still prelaminar. A greater comprehension of the biology and intracellular interactions of NRAS-mutant melanoma will outline novel impactful strategies which could improve prognosis of these subgroup of patients.

High BRAF variant allele frequencies are associated with distinct pathological features and responsiveness to target therapy in melanoma patients

Background

BRAF mutant melanoma patients are commonly treated with anti-BRAF therapeutic strategies. However, many factors, including the percentage of BRAF-mutated cells, may contribute to the great variability in patient outcomes.

Patients and methods

The BRAF variant allele frequency (VAF; defined as the percentage of mutated alleles) of primary and secondary melanoma lesions, obtained from 327 patients with different disease stages, was assessed by pyrosequencing. The BRAF mutation rate and VAF were then correlated with melanoma pathological features and patients’ clinical characteristics. Kaplan–Meier curves were used to study the correlations between BRAF VAF, overall survival (OS), and progression-free survival (PFS) in a subset of 62 patients treated by anti-BRAF/anti-MEK therapy after metastatic progression.

Results

A highly heterogeneous BRAF VAF was identified (3%-90%). Besides being correlated with age, a higher BRAF VAF level was related to moderate lymphocytic infiltration (P = 0.017), to melanoma thickness according to Clark levels, (level V versus III, P = 0.004; level V versus IV, P = 0.04), to lymph node metastases rather than cutaneous (P = 0.04) or visceral (P = 0.03) secondary lesions. In particular, a BRAF VAF >25% was significantly associated with a favorable outcome in patients treated with the combination of anti-BRAF/anti-MEK drug (OS P = 0.04; PFS P = 0.019), retaining a significant value as an independent factor for the OS and the PFS in the multivariate analysis (P = 0.014 and P = 0.003, respectively).

Conclusion

These results definitively support the role of the BRAF VAF as a potential prognostic and predictive biomarker in melanoma patients in the context of BRAF inhibition.

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In melanoma the response to anti-BRAF targeted therapies is heterogeneous and influenced by several features.

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The role of the BRAF VAF as provider of sensitivity to target therapies is debated.

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We found that high BRAF VAFs are associated with patient age, melanoma thickness, non-brisk TILs and lymph node metastases.

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We proved the independent prognostic value of high BRAF VAFs in melanoma patients treated with targeted therapies.

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The quantitative evaluation of BRAF mutations allows stratifying melanoma patients to the BRAF/MEK targeted treatment.

HYPONATREMIA - A COMMON PROBLEM WITH AN UNCOMMON ETIOLOGY

Hyponatremia is a common abnormality found in patients admitted in an internal medicine department of an emergency hospital. Sometimes its cause is quite easy to find (in our clinic especially drug-induced due to thiazide or various antidepressant medication in geriatric population), but in other situations it proved to be a challenging diagnosis in what concerns etiology. It is not frequently found in young patients and if this situation occurs a tight diagnosis protocol is always recommended.

BRAF Gene and Melanoma: Back to the Future

As widely acknowledged, 40-50% of all melanoma patients harbour an activating BRAF mutation (mostly BRAF V600E). The identification of the RAS-RAF-MEK-ERK (MAP kinase) signalling pathway and its targeting has represented a valuable milestone for the advanced and, more recently, for the completely resected stage III and IV melanoma therapy management. However, despite progress in BRAF-mutant melanoma treatment, the two different approaches approved so far for metastatic disease, immunotherapy and BRAF+MEK inhibitors, allow a 5-year survival of no more than 60%, and most patients relapse during treatment due to acquired mechanisms of resistance. Deep insight into BRAF gene biology is fundamental to describe the acquired resistance mechanisms (primary and secondary) and to understand the molecular pathways that are now being investigated in preclinical and clinical studies with the aim of improving outcomes in BRAF-mutant patients.

Comprehensive upstream and downstream regulatory analyses identify miR-675-3p as a potential prognostic biomarker in melanoma

This study assessed miR-675-3p-related regulatory mechanisms in melanoma and the clinical relevance of such regulatory activities. We downloaded miRNA mature strand expression RNA-Seq, phenotypic, and DNA methylation data pertaining to the TCGA Melanoma cohort. Differentially expressed miRNAs (DEMs) between metastatic and primary melanoma patient tissues were then identified, and miR-675-3p expression in melanoma patient peripheral blood was confirmed using the GSE20994 GEO dataset, while its expression in melanoma cell lines was evaluated via qRT-RCR. The clinical and prognostic implications of miR-675-3p in melanoma were assessed, and miR-675-3p target genes were identified using bioinformatics tools. Functional roles of this miRNA were explored via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. We identified 3 and 22 miRNAs that were up- and downregulated, respectively, in metastatic melanoma samples relative to primary melanoma samples. Upregulation of miR-675-3p was associated with poorer overall patient survival, tumor histologic grade, and Clark's level. Consistently, miR-675-3p was also overexpressed in the peripheral blood of melanoma patients relative to healthy controls, and in melanoma cell lines relative to control cells. Gene regulatory networks indicated that 32 transcription factors control miR-675-3p expression, and that it, in turn, regulates 10 target genes. KEGG analyses indicated that these genes were associated with cell cycle, transcriptional misregulation in cancer, TGF-beta signaling, and HIF-1 signaling pathways. Gain-of-function assays revealed that miR-675-3p could promote cell proliferation via accelerating cell cycle progression. Western blotting results indicated that miR-675-3p could active TGF-beta and HIF-1 signaling. Through upstream and downstream analyses of miR-675-3p-related regulatory activity, we confirmed that this miRNA participates in key melanoma-related processes and offers value as a prognostic biomarker in melanoma patients.

The mutational landscape of melanoma brain metastases presenting as the first visceral site of recurrence

Brain metastases are a major cause of melanoma-related mortality and morbidity. We undertook whole-exome sequencing of 50 tumours from patients undergoing surgical resection of brain metastases presenting as the first site of visceral disease spread and validated our findings in an independent dataset of 18 patients. Brain metastases had a similar driver mutational landscape to cutaneous melanomas in TCGA. However, KRAS was the most significantly enriched driver gene, with 4/50 (8%) of brain metastases harbouring non-synonymous mutations. Hotspot KRAS mutations were mutually exclusive from BRAFV600, NRAS and HRAS mutations and were associated with a reduced overall survival from the resection of brain metastases (HR 10.01, p = 0.001). Mutations in KRAS were clonal and concordant with extracranial disease, suggesting that these mutations are likely present within the primary. Our analyses suggest that KRAS mutations could help identify patients with primary melanoma at higher risk of brain metastases who may benefit from more intensive, protracted surveillance.

Cutaneous melanoma dissemination is dependent on the malignant cell properties and factors of intercellular crosstalk in the cancer microenvironment (Review)

The incidence of cutaneous malignant melanoma has been steadily increasing worldwide for several decades. This phenomenon seems to follow the trend observed in many types of malignancies caused by multiple significant factors, including ageing. Despite the progress in cutaneous malignant melanoma therapeutic options, the curability of advanced disease after metastasis represents a serious challenge for further research. In this review, we summarise data on the microenvironment of cutaneous malignant melanoma with emphasis on intercellular signalling during the disease progression. Malignant melanocytes with features of neural crest stem cells interact with non‑malignant populations within this microenvironment. We focus on representative bioactive factors regulating this intercellular crosstalk. We describe the possible key factors and signalling cascades responsible for the high complexity of the melanoma microenvironment and its premetastatic niches. Furthermore, we present the concept of melanoma early becoming a systemic disease. This systemic effect is presented as a background for the new horizons in the therapy of cutaneous melanoma.

Preclinical discovery and clinical development of encorafenib for the treatment of melanoma

INTRODUCTION

Nearly 50% of patients with metastatic melanoma harbor a BRAFV600-mutation, which can be targeted with the use of BRAF and MEK inhibitors, either in the front-line or treatment-refractory setting. Encorafenib is the newest BRAF-inhibitor to have received FDA-approval in combination with the MEK inhibitor binimetinib.

AREAS COVERED

The authors provide an overview of the preclinical development and the clinical trials that led to the use of encorafenib in BRAFV600-mutant melanoma. They also give discussion on its current use in clinical practice, providing their expert perspectives on the subject.

EXPERT OPINION

Preclinical research has provided strong rationale for upgrading encorafenib investigation into clinical development/testing. However, there is not yet enough data to determine where encorafenib may fit in comparison to other drugs in the same class, and ongoing trials will further define its role in the treatment of melanoma. Of note, there are ongoing studies that further explore the role of encorafenib + binimetinib such as in combination regimens with immunotherapy drugs, and in brain metastases.

Quantitative and Spatial Analysis of CD8+/PD-1 Tumor-Infiltrating Lymphocytes as a Predictive Biomarker for Clinical Response of Melanoma In-Transit Metastases to Topical Immunotherapy

Background

Melanoma in-transit metastases (ITMs) are a challenge to treat and associated with systemic disease and poor prognosis. Topical diphencyprone (DPCP), a potent contact sensitizer, is an established treatment for melanoma ITMs. This exploratory study investigated the utility of BRAF mutation status, CD8, PD-1, PD-L1, and TILs distribution as biomarkers for response of ITMs to topical immunotherapy (DPCP).

Methods

The ITM deposits of 40 patients treated with DPCP were subjected to biomarker analysis for BRAF status, CD8 and PD-1 expression on tumor-infiltrating lymphocytes (TILs), and tumor PD-L1 expression. Response to DPCP and overall survival (OS) were compared by biomarker status.

Results

After 12 weeks, 10 patients (25%) had a complete response, 12 patients (30%) had a partial response, and 18 patients (45%) had no response. No significant association was found between any individual biomarker and response to DPCP or OS. The BRAF mutation rate was 25% (10/40). All the patients with a complete response had BRAF wild-type tumor. Peritumoral CD8+ T-cells were associated with complete response (P = 0.041). Both CD8+ and PD-1 expressions were highly correlated (P < 0.0001), and the highest levels of PD-1 expression were detected at the peritumoral interface (P = 0.0004). Only two cases were PD-L1-positive, and both had a complete response to DPCP (P = 0.043).

Conclusion

Patients who have BRAF wild-type tumor are more likely to experience a complete response to DPCP. Peritumoral TILs and PD-1 expressions may predict a better response to DPCP. Expression of PD-L1 may be associated with a complete response to DPCP. A larger prospective study is required.

BRAF in malignant melanoma progression and metastasis: potentials and challenges

Recent advances in gene sequencing have shown that activated BRAF mutations are present in more than 50% of malignant melanomas and contribute to constitutive signals in the MAPK pathway. Besides the importance of its mutations in cell proliferation, BRAF is associated with lymph node, brain and liver metastasis, along with the loss of PTEN expression and ATG5. Knowledge of this genetic alteration has led to the development of personalized and targeted therapy strategies which block different pathways driving melanoma pathogenesis. Several targeted therapy agents such as vemurafenib, dabrafenib and encorafenib have been approved by the FDA as BRAF inhibitors, as well as other immunotherapies such as anti-CTLA-4 (ipilimumab). However, one of the main challenges is acquired resistance via reactivation of MAPK via CRAF/COT overexpression. Resistance to current BRAF inhibitors is a clinical challenge and one of the strategies to overcome this phenomenon is combination treatment, with the most recently approved combination being BRAF/MEK inhibitors (dabrafenib and trametinib) and BRAF or MEK inhibitors with immunocheckpoint blockers. This review delineates the current role of BRAF in melanoma progression and metastasis. It discusses targeted therapies and resistance mechanisms to BRAF inhibitors, and illustrates strategies to overcome this mechanism with recently approved agents.

Melanoma Radiological Surveillance: A Review of Current Evidence and Clinical Challenges

Melanoma is a common cancer in both young and older populations in many western countries. Rates of melanoma diagnosis worldwide are increasing. With the introduction of both targeted and immunotherapies there have been dramatic improvements in the care of patients with metastatic melanoma. With these new therapies being increasingly offered to patients with stage III metastatic melanoma and stage IV disease, radiological surveillance of melanoma has become a widely used method of monitoring melanoma patients for early locoregional and distant metastasis. However, concerns have been raised about risk of false positive results, which patients to consider radiological surveillance for, and at what intervals to do so. To date, there are no published review articles on the topic of radiological surveillance in melanoma patients identified in the MEDLINE database. A comprehensive literature review was performed by searching the MEDLINE database to review all published works on this topic. This article aims to present an extensive review of literature surrounding radiological surveillance in melanoma patients, a discussion of controversies, and recommendations for surveillance modalities.

Activated Hgf-Met Signaling Cooperates with Oncogenic BRAF to Drive Primary Cutaneous Melanomas and Angiotropic Lung Metastases in Mice

Oncogenic mutations in the BRAF kinase gene represent the most frequent genomic driver in acquired melanocytic nevi and in cutaneous melanomas. It is currently thought that oncogene-induced senescence and cell cycle arrest limit the ability of oncogenic BRAF to promote melanocyte proliferation in benign nevi. The molecular and cellular mechanisms that allow an oncogenic BRAF mutation to fully transform melanocytes into invasively growing melanoma cells that are able to metastasize systemically are only partially understood. In this study, we show in a genetic mouse model that constitutively enhanced Hgf-Met signaling cooperates with oncogenic BRAF to drive tumor development and metastatic spread. Activation of oncogenic BRAF in mice with transgenic Hgf overexpression and an oncogenic CDK4 germline mutation accelerated and increased the development of primary cutaneous melanomas. Primary melanomas showed considerable phenotypic heterogeneity with frequent signs of dedifferentiation. BRAF activation in Hgf-CDK4 mice also increased the number of lung metastases. Melanoma cells showed a pronounced angiotropic growth pattern both at the invasive front in primary tumors and in metastatic lesions of the lung. Taken together, our work supports the notion that activated Hgf-Met signaling and oncogenic BRAF can cooperate in melanoma pathogenesis.

STAT3 Relays a Differential Response to Melanoma-Associated NRAS Mutations

Melanoma patients carrying an oncogenic NRAS mutation represent 20% of all cases and present worse survival, relapse rate and therapy response than patients with wild type NRAS or with BRAF mutations. Nevertheless, no efficient targeted therapy has emerged so far for this group of patients in comparison with the classical combination of BRAF and MEK inhibitors for the patient group carrying a BRAF mutation. NRAS key downstream actors should therefore be identified for drug targeting, possibly in combination with MEK inhibitors. Here, we investigated the influence of different melanoma-associated NRAS mutations (codon 12, 13 or 61) on several parameters such as oncogene-induced senescence, cell proliferation, migration or colony formation in immortalized melanocytes and in melanoma cell lines. We identified AXL/STAT3 axis as a main regulator of NRASQ61-induced oncogene-induced senescence (OIS) and observed that NRASQ61 mutations are not only more tumorigenic than NRASG12/13 mutations but also associated to STAT3 activation. In conclusion, these data bring new evidence of the potential tumorigenic role of STAT3 in NRAS-mutant melanomas and will help improving current therapy strategies for this particular patient group.

Principles of Targeted Therapy for Melanoma

Targeted BRAF and MEK inhibition has become an appropriate first-line treatment of BRAF-mutant advanced cutaneous melanoma. The authors present an overview of the MAPK pathway as well as the other major pathways implicated in melanoma development. Melanoma brain metastases are a devastating complication of melanoma that can be traced to derangements in cell signaling pathways, and the current evidence for targeted therapy is reviewed. Finally, activating KIT mutations are rarely found to cause melanomas and may provide an actionable target for therapy. The authors review the current evidence for targeted KIT therapy and summarize the ongoing clinical trials.

Dynamic and unpredictable changes in mutant allele fractions of BRAF and NRAS during visceral progression of cutaneous malignant melanoma

Background

Data indicate that primary cutaneous melanomas are characterized by clonal heterogeneity associated with oncogenic drivers. Less data are available on the clonal changes occurring during melanoma progression. We therefore wished to analyse these changes in skin melanomas in common sites of visceral metastases as compared to the primary tumor.

Methods

An autopsy cohort of 50 patients with BRAF- and NRAS-mutant cutaneous metastatic melanomas including 139 visceral metastases was analysed for mutant allele fractions (MAF), determined by pyrosequencing and corrected for tumor/normal ratio. MAF levels were also classified as high (> 40%), medium (15–40%) or low (< 15%).

Results

Contrary to NRAS mutant cases, in BRAF-mutant melanomas MAFs were found to be significantly increased in visceral metastases compared to the primary due to the significantly higher levels in lung-, adrenal gland-, intestinal- and kidney metastases. The incidence of the three MAF variants in BRAF-mutant primaries was similar, whereas the high MAF cases were found to be increased in metastases. On the other hand, medium MAF levels were more common in case of NRAS-mutant tumors. Only 31.3% of BRAF mutant- and 50% of NRAS mutant cases maintained the MAF profile of the primary in metastasis. In the majority of multiple metastatic tumors, (BRAF:71.8%, NRAS:75%) metastases were relatively homogeneous regarding MAF. However, in 6/32(18.7%) of BRAF mutant cases low MAF primaries switched to high MAF in metastases. In heterogeneous BRAF mutant metastatic cases low to high or high to low MAF conversions occurred in a further 4/32(12.5%) cases in individual metastases as compared to the primary tumors. At lower frequency, in NRAS mutant tumor such changes also observed (2/12,16.7%).

Conclusion

We provided evidence for the selection of BRAF-mutant melanoma cells during metastatic progression to the lung, intestine, adrenal gland and kidney. Our findings suggest that in visceral metastases of malignant melanoma BRAF- or NRAS-MAFs are rather heterogeneous and cannot be predicted from data of the primary tumor. These data may have clinical significance when using targeted therapies.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5990-9) contains supplementary material, which is available to authorized users.

BRAF immunohistochemistry predicts sentinel lymph node involvement in intermediate thickness melanomas

Background

Sentinel node biopsy (SNB) is an important step in melanoma staging and prognostication. It is commonly performed for patients with intermediate thickness melanomas, based on clinicopathological features. However, only 20–25% of patients eventually demonstrate nodal involvement. The aim of this study was to evaluate whether tissue biomarkers with links to melanoma biology, together with clinicopathological parameters, could aid in the prediction of sentinel node involvement and improve selection of patients for SNB. In addition, we examined the role of these clinical or biological markers in disease outcome.

Methods

We collected a case-control cohort of 140 intermediate thickness (Breslow 0,9–4,0mm) melanoma patients with or without SNB involvement matched for age, gender, Breslow thickness and location. From this cohort, we tested the predictive value of common clinicopathological parameters (ulceration, mitotic count and tumor regression) and FMNL-2, ezrin and BRAF V600E immunoreactivity, for sentinel node involvement and survival. We further analyzed the correlations in the superficial spreading melanoma subtype.

Results

Based on our case control analysis, of the markers, BRAF V600E status (p = 0.010) and mitotic count (p = 0.036) correlated with SNB involvement. SNB status was a strong independent prognosticator for recurrence free survival (RFS p<0.001), melanoma specific survival (MSS p = 0.000) and overall survival (OS p = 0.029). In the superficially spreading melanoma subgroup, BRAF V600E positivity indicated poorer RFS (p = 0.039) and OS (p = 0.012). By combining the Breslow thickness, mitotic count and BRAF immunohistochemistry, we identified a group of superficially spreading melanomas with an excellent survival probability independent of SNB status.

Conclusions

These results demonstrate that BRAF immunohistochemistry could serve as a useful addition to a marker panel for selecting intermediate thickness melanoma patients for SNB.

New Era in the Management of Melanoma Brain Metastases

The remarkable advances in the systemic therapy of metastatic melanoma have now extended the 1-year overall survival rate from 25% to nearing 85%. Systemic treatment in the form of BRAF-targeted therapy and immunotherapy is slowly but surely proving its efficacy in the treatment of metatstatic brain metastases (MBM). Single-agent BRAF inhibitors provide an intracranial response rate of 25% to 40%, whereas the combination of BRAFi/MEKi leads to responses in up to 58%. However, the durability of responses induced by BRAFi/MEKi seems to be even shorter than in extracranial disease. On the other hand, single-agent ipilimumab provides comparable clinical benefit in MBMs as it does in extracranial metastases. Single-agent PD-1 anitbodies induce response rates of approximately 20%, and those responses appear durable. Similarly the combination of CTLA-4+ PD-1 antibodies induces durable responses at an impressive rate of 55% and is safe to administer. Although the local treatment approaches with radiation and surgery remain important and are critically needed in the management of MBM, systemic therapy offers a new dimension that can augment the impact of those therapies and come at a potentially lower cost of neurocognitive impairment. Considerations for combining those modalities are direly needed, in addition to considering novel systemic combinations that target mechanisms specific to MBM. In this report, we will discuss the underlying biology of melanoma brain metastases, the clinical outcomes from recent clinical trials of targeted and immunotherapy, and their impact on clinical practice in the context of existing local therapeutic modalities.

Older melanoma patients aged 75 and above retain responsiveness to anti-PD1 therapy: results of a retrospective single-institution cohort study

INTRODUCTION

The utility of immunotherapy in elderly melanoma patients is debated. We aimed in this study to evaluate the efficacy and tolerability of immunotherapy among elderly patients.

METHOD

This is a retrospective single-institution cohort study. Patients aged 75 years and above who had been treated with nivolumab, pembrolizumab or ipilimumab for advanced or metastatic melanoma, were included. Patients and disease characteristics were collected using electronic medical records. Objective response was determined according to the immune-related response criteria. Drug-related toxicities (DRT) were graded according to the CTCAE v4.03.

RESULTS

99 patients were included with a mean age of 80 years (SD = 4). One patient received nivolumab and ipilimumab combination, but died because of drug-related diverticulitis. Median PFS on pembrolizumab, nivolumab or ipilimumab were equal to 11.9 (95% CI 5.4-18.4), 1.4 (95% CI 0.01-2.8), and 2.8 months (95% CI 2.6-3), respectively, while objective response rates were equal to 51.6, 12.5, and 17.3%, respectively. Median OS was not reached in patients who received only pembrolizumab, 8.7 months in the ipilimumab only group, and 23 months in patients receiving several immune therapies sequentially. Pembrolizumab, nivolumab, and ipilimumab grade 3-4 DRT rates were equal to 24.2, 62.5, and 32.7% respectively, while discontinuation rates were equal to 43.5, 62.5, and 28.8%, respectively.

CONCLUSIONS

Our study suggests that immunotherapy is effective and well tolerated in the elderly. The PFS on pembrolizumab was greater than expected, a finding that needs to be investigated further.

Expression of HMB45, MelanA and SOX10 is rare in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) and melanoma are frequent entities in routine diagnostics. Whereas the differential diagnosis is usually straight forward based on histomorphology, it can be challenging in poorly differentiated tumors as melanoma may mimic various histological patterns. Distinction of the two entities is of outmost importance as both are treated differently. HMB45 and MelanA are recommended immunohistological markers for melanoma in this scenario. SOX10 has been described as an additional marker for melanoma. However, comprehensive large-scale data about the expression of melanoma markers in NSCLC tumor tissue specimen are lacking so far.

METHODS

Therefore, we analyzed the expression of these markers in 1085 NSCLC tumor tissue samples. Tissue microarrays of NSCLC cases were immunohistochemically stained for HMB45, MelanA, and SOX10. Positivity of a marker was defined as ≥1% positive tumor cells.

RESULTS

In 1027 NSCLC tumor tissue samples all melanoma as well as conventional immunohistochemical markers for NSCLC could be evaluated. HMB45, MelanA, and SOX10 were positive in 1 (< 1%), 0 (0%) and 5 (< 1%) cases. The HMB45 positive case showed co-expression of SOX10 and was classified as large cell carcinoma. Three out of five SOX10 positive cases were SqCC and one case was an adenosquamous carcinoma.

CONCLUSIONS

Expression of HMB45, MelanA and SOX10 is evident but exceedingly rare in NSCLC cases. Together with conventional immunomarkers a respective marker panel allows a clear-cut differential diagnosis even in poorly differentiated tumors.

MEK inhibitors for the treatment of NRAS mutant melanoma

Melanoma is increasing rapidly in incidence and prevalence, especially in younger females and older males. Treatment options have expanded beyond high-dose interleukin 2 and adoptive T-cell therapy to include inhibitors of immune checkpoints programmed death 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and small molecular inhibitors of pathways activated in melanoma, in particular the mitogen-activated protein kinase (MAPK) pathway. PD-1/CTLA-4 inhibitors and inhibitors of MAPK such as BRAF/MEK inhibitors have significantly improved survival in both the metastatic and, more recently, adjuvant settings. In this review, we discuss the preclinical data, clinical development, and potential use of novel MEK inhibitor binemetinib, particularly in the setting of NRAS mutant melanoma.