Molecular profiling of Asian patients with advanced melanoma receiving check-point inhibitor treatment

Melanoma Management: Exploring Staging, Prognosis, and Treatment Innovations

Melanoma, a malignant neoplasm originating from melanocytes, stands as one of the most prevalent cancers globally, ranking fifth in terms of estimated new cases in recent years. Its aggressive nature and propensity for metastasis pose significant challenges in oncology. Recent advancements have led to a notable shift towards targeted therapies, driven by a deeper understanding of cutaneous tumor pathogenesis. Immunotherapy and tyrosine kinase inhibitors have emerged as promising strategies, demonstrating the potential to improve clinical outcomes across all disease stages, including neoadjuvant, adjuvant, and metastatic settings. Notably, there has been a groundbreaking development in the treatment of brain metastasis, historically associated with poor prognosis in oncology but showcasing impressive results in melanoma patients. This review article provides a comprehensive synthesis of the most recent knowledge on staging and prognostic factors while highlighting emerging therapeutic modalities, with a particular focus on neoadjuvant and adjuvant strategies, notably immunotherapy and targeted therapies, including the ongoing trials.

Multidisciplinary approach and treatment of acral and mucosal melanoma

Acral and mucosal melanoma are uncommon variants of melanoma. Acral melanoma has an age-adjusted incidence of approximately 1.8 cases per million individuals per year, accounting for about 2% to 3% of all melanoma cases. On the other hand, mucosal melanoma, with an incidence of 2.2 cases per million per year, makes up around 1.3% of all melanoma cases. These melanomas, in addition to being biologically and clinically distinct from cutaneous melanoma, share certain clinical and pathologic characteristics. These include a more aggressive nature and a less favorable prognosis. Furthermore, they exhibit a different mutational pattern, with KIT mutations being more prevalent in acral and mucosal melanomas. This divergence in mutational patterns may partially account for the relatively poorer prognosis, particularly to immune checkpoint inhibitors. This review explores various aspects of acral and mucosal melanoma, including their clinical presentation, pathologic features, mutational profiles, current therapeutic approaches, outcomes associated with systemic therapy, and potential strategies to address resistance to existing treatments.

Clinical significance of genetic profiling based on different anatomic sites in patients with mucosal melanoma who received or did not receive immune checkpoint inhibitors

BACKGROUND

To date, data on the efficacy of targeted therapies for mucosal melanoma (MM) are limited. In this study, we analyzed genetic alterations according to the primary site of origin, which could provide clues for targeted therapy for MM.

METHODS

We conducted a retrospective cohort study of 112 patients with MM. Targeted sequencing was performed to analyze genetic aberrations. Kaplan-Meier analysis was conducted with the log-rank test to compare the significance among subgroups.

RESULTS

In total, 112 patients with MM were included according to the anatomic sites: 38 (33.9%) in the head and neck, 22 (19.6%) in the genitourinary tract, 21 (18.8%) in the anorectum, 19 (17.0%) in the esophagus, 10 (8.9%) in the uvea, and 2 (1.8%) in the small bowel. The most significantly mutated genes included BRAF (17%), KIT (15%), RAS (15%), TP53 (13%), NF1 (12%), SF3B1 (11%), GNA11 (7%), GNAQ (5%), and FBXW7 (4%). A large number of chromosomal structural variants was found. The anatomic sites of esophagus and small bowel were independent risk factors for progression-free survival (PFS, hazard ratio [HR] 4.78, 95% confidence interval [CI] 2.42-9.45, P < 0.0001) and overall survival (OS, HR 5.26, 95% CI 2.51-11.03, P < 0.0001). Casitas B-lineage lymphoma (CBL) mutants showed significantly poorer PFS and OS. In contrast, MM patients who received immune checkpoint inhibitors (ICIs) had a significantly more favorable OS (HR 0.39, 95% CI 0.20-0.75, P = 0.008).

CONCLUSIONS

Our findings reveal the genetic features of patients with MM, mainly across six anatomic sites, offering a potential avenue for targeted therapies.

BRAF Mutations in Melanoma: Biological Aspects, Therapeutic Implications, and Circulating Biomarkers

Melanoma is an aggressive form of skin cancer resulting from the malignant transformation of melanocytes. Recent therapeutic approaches, including targeted therapy and immunotherapy, have improved the prognosis and outcome of melanoma patients. BRAF is one of the most frequently mutated oncogenes recognised in melanoma. The most frequent oncogenic BRAF mutations consist of a single point mutation at codon 600 (mostly V600E) that leads to constitutive activation of the BRAF/MEK/ERK (MAPK) signalling pathway. Therefore, mutated BRAF has become a useful target for molecular therapy and the use of BRAF kinase inhibitors has shown promising results. However, several resistance mechanisms invariably develop leading to therapeutic failure. The aim of this manuscript is to review the role of BRAF mutational status in the pathogenesis of melanoma and its impact on differentiation and inflammation. Moreover, this review focuses on the mechanisms responsible for resistance to targeted therapies in BRAF-mutated melanoma and provides an overview of circulating biomarkers including circulating tumour cells, circulating tumour DNA, and non-coding RNAs.

Objective response to immune checkpoint inhibitor therapy in NRAS-mutant melanoma: A systematic review and meta-analysis

Introduction

NRAS mutations are common in melanoma and confer a worse prognosis. Although most patients with metastatic melanoma receive immune checkpoint inhibitors (ICIs), the impact of NRAS mutational status on their efficacy remains under debate.

Methods

We performed a comprehensive literature search across several large databases. Inclusion criteria were trials, cohorts, and large case series that analyzed the primary outcome of objective response rate by NRAS mutational status in patients with melanoma treated with any line of ICI. At least two reviewers independently screened studies using Covidence software, extracted data, and assessed risk of bias. Standard meta-analysis was performed in R with sensitivity analysis and tests for bias.

Results

Data on 1770 patients from ten articles were pooled for meta-analysis, and the objective response rate to ICIs was calculated to compare NRAS-mutant and NRAS-wildtype melanoma. The objective response rate was 1.28 (95% confidence interval: 1.01-1.64). Sensitivity analysis identified the study by Dupuis et al. with influential impact on the pooled effect size and heterogeneity, favoring NRAS-mutant melanoma.

Discussion

In this meta-analysis evaluating the impact of NRAS mutational status on objective response to ICIs in metastatic melanoma, NRAS-mutant cutaneous melanoma demonstrated an increased likelihood of partial or complete tumor response, relative to NRAS-wildtype cutaneous melanoma. Genomic screening for NRAS mutations in patients with metastatic melanoma may improve predictive ability when initiating ICIs.

Genomic and Transcriptional Profiling of Chinese Melanoma Patients Enhanced Potentially Druggable Targets: A Multicenter Study

BACKGROUND

In contrast to Caucasian melanoma, which has been extensively studied, there are few studies on melanoma in Asian populations. Sporadic studies reported that only 40% of Asian melanoma patients could be druggable, which was much lower than that in Caucasians. More studies are required to refine this conclusion.

METHODS

Chinese melanoma patients (n = 469) were sequentially sequenced by DNA-NGS and RNA-NGS. The genomic alterations were determined, and potentially actionable targets were investigated.

RESULTS

Patients with potential druggable targets were identified in 75% of Chinese melanoma patients by DNA-NGS based on OncoKB, which was much higher than in a previous Asian study. NRG1 fusions were first identified in melanoma. In addition, up to 11.7% (7/60) of patients in the undruggable group could be recognized as actionable by including RNA-NGS analysis. By comparing the fusion detection rate between DNA-NGS and RNA-NGS, all available samples after DNA-NGS detection were further verified by RNA-NGS. The use of RNA-NGS enhanced the proportion of druggable fusions from 2.56% to 17.27%. In total, the use of RNA-NGS increased the druggable proportion from 75% to 78%.

CONCLUSIONS

In this study, we systemically analyzed the actionable landscape of melanoma in the largest Asian cohort. In addition, we first demonstrated how DNA and RNA sequential sequencing is essential in bringing clinical benefits to more patients with melanoma.

Immunotherapy Options for Acral Melanoma, A fast-growing but Neglected Malignancy

Melanoma is the deadliest form of skin cancer. It is classified as cutaneous and non-cutaneous, with the former characterized by developing in sun-exposed areas of the skin, UV-light radiation being its most important risk factor and ordinarily affecting fair skin populations. In recent years, the incidence of melanoma has been increasing in populations with darker complexion, for example, Hispanics, in which acral melanoma is highly prevalent. The WHO estimates that the incidence and mortality of melanoma will increase by more than 60% by 2040, particularly in low/medium income countries. Acral melanoma appears in the palms, soles and nails, and because of these occult locations, it is often considered different from other cutaneous melanomas even though it also originates in the skin. Acral melanoma is very rare in Caucasian populations and is often not included from genetic analysis and clinical trials. In this review, we present the worldwide epidemiology of acral melanoma; we summarize its genetic characterization and point out important signaling pathways for targeted therapy. We also discuss how genetic analyses have shown that acral melanoma carries a sufficient mutational load and neoantigen formation to be targeted by the immune system, arguing for a potential benefit with novel immunotherapeutic strategies, alone or combined with targeted therapy. This is important because chemotherapy remains the first-line treatment in non-developed nations despite a disheartening response. In summary, the increased incidence and mortality of acral melanoma in low/medium income countries calls for increasing our knowledge about its nature and therapeutic options and leveling off the asymmetric research conducted primarily on Caucasian populations.

Biology of cancer; from cellular and molecular mechanisms to developmental processes and adaptation

Cancer research has been largely focused on the cellular and molecular levels of investigation. Recent data show that not only the cell but also the extracellular matrix plays a major role in the progression of malignancy. In this way, the cells and the extracellular matrix create a specific local microenvironment that supports malignant development. At the same time, cancer implies a systemic evolution which is closely related to developmental processes and adaptation. Consequently, there is currently a real gap between the local investigation of cancer at the microenvironmental level, and the pathophysiological approach to cancer as a systemic disease. In fact, the cells and the matrix are not only complementary structures but also interdependent components that act synergistically. Such relationships lead to cell-matrix integration, a supracellular form of biological organization that supports tissue development. The emergence of this supracellular level of organization, as a structure, leads to the emergence of the supracellular control of proliferation, as a supracellular function. In humans, proliferation is generally involved in developmental processes and adaptation. These processes suppose a specific configuration at the systemic level, which generates high-order guidance for local supracellular control of proliferation. In conclusion, the supracellular control of proliferation act as an interface between the downstream level of cell division and differentiation, and upstream level of developmental processes and adaptation. Understanding these processes and their disorders is useful not only to complete the big picture of malignancy as a systemic disease, but also to open new treatment perspectives in the form of etiopathogenic (supracellular or informational) therapies.

BRAF and NRAS Mutation Status and Response to Checkpoint Inhibition in Advanced Melanoma

PURPOSE

Little is known about the effect of specific gene mutations on efficacy of immune checkpoint inhibitors in patients with advanced melanoma.

MATERIALS AND METHODS

All patients with advanced melanoma treated with first-line anti-PD-1 or ipilimumab-nivolumab between 2012 and 2021 in the nationwide Dutch Melanoma Treatment Registry were included in this cohort study. Objective response rate, progression-free survival (PFS), and overall survival (OS) were analyzed according to BRAF and NRAS status. A multivariable Cox model was used to analyze prognostic factors associated with PFS and OS.

RESULTS

In total, 1764 patients received anti-PD-1 and 759 received ipilimumab-nivolumab. No significant differences in PFS were found in the anti-PD-1 cohort. In the ipilimumab-nivolumab cohort, median PFS was significantly higher for BRAF-mutant melanoma (9.9 months; 95% CI, 6.8 to 17.2) compared with NRAS-mutant (4.8 months; 95% CI, 3.0 to 7.5) and double wild-type (5.3 months; 95% CI, 3.6 to 7.1). In multivariable analysis, BRAF-mutant melanoma was significantly associated with a lower risk of progression or death in the ipilimumab-nivolumab cohort. Median OS was significantly higher for BRAF-mutant melanoma compared with NRAS-mutant and double wild-type melanoma for both immune checkpoint inhibitor regimens.

CONCLUSION

Ipilimumab-nivolumab-treated patients with BRAF-mutant melanoma display improved PFS and OS compared with patients with NRAS-mutant and double wild-type melanoma. BRAF mutation status is a factor to consider while choosing between mono and dual checkpoint inhibition in advanced melanoma.

Next-generation sequencing in advanced Chinese melanoma reveals therapeutic targets and prognostic biomarkers for immunotherapy

Limited studies have interrogated the genomic landscape of Chinese melanoma in which acral and mucosal melanoma are the mainstay. In this study, we carried out a retrospective analysis on 81 Chinese melanoma patients (15 acral, 25 mucosal and 41 cutaneous melanoma). With the identification of 1114 mutations spanning 248 genes, we summarized that the mutation spectrum varied significantly by subtypes. Acral melanoma and mucosal melanoma had significantly more CNVs. MYC amplification was one of the most commonly detected CNVs, other frequent CNVs in mucosal melanoma included NBN and KDR, which were associated with the poor survival of melanoma patients. A generally low TMB, with a median of only 5.1 mut/Mb, was observed in three groups including cutaneous melanoma. Additionally, over 50% variants in DNA damage repair pathway were detected in all three subtypes, most of which were HRD related genes. Patients with alterations of HRD related genes had a longer survival time after immunotherapy. This study revealed a molecular profiling of Chinese patients with advanced melanoma, and proposed the high variant rate in DDR pathway as a biomarker of immunotherapy, which might provide therapeutic targets and guidance in making clinical decision for different Chinese melanoma.

Immunotherapy in Acral and Mucosal Melanoma: Current Status and Future Directions

Acral and mucosal melanomas are extremely rare in Caucasians; however, they are the predominant melanoma subtypes in Asians and other non-Caucasian populations. Acral and mucosal melanomas share many clinicopathological features, including aggressive phenotypes, similar genetic landscapes, and grim prognoses. In spite of advances in melanoma management, patients with acral and mucosal melanomas show limited benefit from current therapies. The rarity of these subtypes of melanoma is a significant factor contributing to the poor understanding of these pathological subtypes and the lack of effective interventions. Furthermore, the mechanisms contributing to disparities between different types of melanoma remain largely unclear. Herein, we comprehensively review current knowledge on the clinicopathological characteristics and mutational landscapes of acral and mucosal melanomas, as well as providing an overview of current therapies for patients with these aggressive melanoma subtypes, focusing on available immunotherapeutic interventions. We also discuss pathological differences between different melanoma subtypes and summarize current knowledge on melanoma disparities between Asians and Caucasians. Finally, we discuss emerging immunotherapeutic strategies for the treatment of acral and mucosal melanomas, focusing on combination therapies with immune checkpoint inhibitors. Unraveling the unique features of acral and mucosal melanomas is key for their early diagnosis and for the development of effective therapies.

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.