BRAF-V600E expression in primary nodular melanoma is associated with aggressive tumour features and reduced survival

High-risk histopathologic features in local advanced conjunctival melanoma

PURPOSE

To identify high-risk histopathologic and molecular features of local recurrence, nodal metastasis, distant metastasis (DM) and disease-specific death (DSD) in conjunctival melanoma (CoM).

METHODS

Ninety patients with pathologically diagnosed CoM between 2008 and 2023 were enrolled. Immunohistochemistry staining of BRAFV600E, NRASQ61R, CD117, PD-1 and PD-L1 was performed in 65 and 45 patients, respectively. Cox regression and Kaplan-Meier survival analysis were conducted to identify risk factors for local recurrence, nodal metastasis, DM and DSD.

RESULTS

Pathologically, ulceration (hazard ratio [HR]: 3.170; 95% CI: 1.312-7.659; p = 0.01) and regression (HR: 3.196; 95% CI: 1.094-9.335; p = 0.034) were risk factors for DM. Tumour thickness ≥ 4 mm (HR: 4.889; 95% CI: 1.846-12.946; p = 0.001) and regression (HR: 4.011; 95% CI: 1.464-10.991; p = 0.007) were risk factors for DSD. For patients with tumour thickness < 4 mm, the presence of ulceration indicated a higher risk of nodal metastasis (log-rank p = 0.0011), DM (log-rank p = 0.00051) and DSD (log-rank p = 0.02). Patients with regression (+)/tumour-infiltrating lymphocytes (TILs) (+) had a higher risk for DM (log-rank p = 0.011) and DSD (log-rank p = 0.0032). Molecularly, the positive rate of BRAFV600E, NRASQ61R, CD117, PD-1 and PD-L1 was 40.00% (26/65), 43.08% (28/65), 70.77% (46/65), 46.67% (21/45) and 28.89% (13/45), respectively. Positive BRAFV600E was identified as an independent risk factor for DM (HR: 2.533; 95% CI: 1.046-6.136, p = 0.039). The expression level of BRAFV600E was positively correlated with vascular invasion (p = 0.01), as well as the expression levels of PD-1 (p = 0.038) and PD-L1 (p = 0.049).

CONCLUSIONS

Tumour thickness ≥ 4 mm, ulceration, the coexistence of regression and TILs, and positive BRAFV600E were risk factors for poor prognosis of CoM patients. Besides, expression level of BRAFV600E was positively correlated with the expression levels of PD-1 and PD-L1.

SenNet recommendations for detecting senescent cells in different tissues

Once considered a tissue culture-specific phenomenon, cellular senescence has now been linked to various biological processes with both beneficial and detrimental roles in humans, rodents and other species. Much of our understanding of senescent cell biology still originates from tissue culture studies, where each cell in the culture is driven to an irreversible cell cycle arrest. By contrast, in tissues, these cells are relatively rare and difficult to characterize, and it is now established that fully differentiated, postmitotic cells can also acquire a senescence phenotype. The SenNet Biomarkers Working Group was formed to provide recommendations for the use of cellular senescence markers to identify and characterize senescent cells in tissues. Here, we provide recommendations for detecting senescent cells in different tissues based on a comprehensive analysis of existing literature reporting senescence markers in 14 tissues in mice and humans. We discuss some of the recent advances in detecting and characterizing cellular senescence, including molecular senescence signatures and morphological features, and the use of circulating markers. We aim for this work to be a valuable resource for both seasoned investigators in senescence-related studies and newcomers to the field.

Prognostic and predictive biomarkers in melanoma

Biomarkers help to inform the clinical management of patients with melanoma. For patients with clinically localised primary melanoma, biomarkers can help to predict post-surgical outcome (including via the use of risk prediction tools), better select patients for sentinel lymph node biopsy, and tailor catch-all follow-up protocols to the individual. Systemic drug treatments, including immune checkpoint inhibitor (ICI) therapies and BRAF-targeted therapies, have radically improved the prognosis of metastatic (stage III and IV) cutaneous melanoma patients, and also shown benefit in the earlier setting of stage IIB/C primary melanoma. Unfortunately, a response is far from guaranteed. Here, we review clinically relevant, established, and emerging, prognostic, and predictive pathological biomarkers that refine clinical decision-making in primary and metastatic melanoma patients. Gene expression profile assays and nomograms are emerging tools for prognostication and sentinel lymph node risk prediction in primary melanoma patients. Biomarkers incorporated into clinical practice guidelines include BRAF V600 mutations for the use of targeted therapies in metastatic cutaneous melanoma, and the HLA-A∗02:01 allele for the use of a bispecific fusion protein in metastatic uveal melanoma. Several predictive biomarkers have been proposed for ICI therapies but have not been incorporated into Australian clinical practice guidelines. Further research, validation, and assessment of clinical utility is required before more prognostic and predictive biomarkers are fluidly integrated into routine care.

Assessment of RAS-RAF-MAPK Pathway Mutation Status in Healthy Skin, Benign Nevi, and Cutaneous Melanomas: Pilot Study Using Droplet Digital PCR

In the present study, we employed the ddPCR and IHC techniques to assess the prevalence and roles of RAS and RAF mutations in a small batch of melanoma (n = 22), benign moles (n = 15), and normal skin samples (n = 15). Mutational screening revealed the coexistence of BRAF and NRAS mutations in melanomas and nevi and the occurrence of NRAS G12/G13 variants in healthy skin. All investigated nevi had driver mutations in the BRAF or NRAS genes and elevated p16 protein expression, indicating cell cycle arrest despite an increased mutational burden. BRAF V600 mutations were identified in 54% of melanomas, and NRAS G12/G13 mutations in 50%. The BRAF mutations were associated with the Breslow index (BI) (p = 0.029) and TIL infiltration (p = 0.027), whereas the NRAS mutations correlated with the BI (p = 0.01) and the mitotic index (p = 0.04). Here, we demonstrate that the "young" ddPCR technology is as effective as a CE-IVD marked real-time PCR method for detecting BRAF V600 hotspot mutations in tumor biopsies and recommend it for extended use in clinical settings. Moreover, ddPCR was able to detect low-frequency hotspot mutations, such as NRAS G12/G13, in our tissue specimens, which makes it a promising tool for investigating the mutational landscape of sun-damaged skin, benign nevi, and melanomas in more extensive clinical studies.

Phase Ib study of anlotinib in combination with anti-PD-L1 antibody (TQB2450) in patients with advanced acral melanoma

BACKGROUND

Acral melanoma, the most common subtype of melanoma in Asians, is often diagnosed at an advanced stage and responds poorly to current programmed cell death protein 1 (PD-1) inhibitors.

OBJECTIVES

To evaluate the safety and efficacy of TQB2450 and anlotinib in patients with advanced acral melanoma in a phase Ib study (NCT03991975).

METHODS

Patients received TQB2450 (1200 mg every 3 weeks) and anlotinib (10 mg or 12 mg once daily, 2-week on/1-week off) in the dose-escalation and dose-expansion phases. The primary endpoints were dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and objective response rate (ORR).

RESULTS

Nineteen patients were enrolled between June 2019 and June 2022. The majority of patients (16 of 19 patients) received anlotinib and TQB2450 as first-line treatment. No DLTs were observed, and MTD was not reached. Eighteen (94.7%) out of 19 patients experienced treatment-related adverse events (TRAEs), but most were grade 1 or 2. Grade 3 or greater TRAEs occurred in seven patients (36.8%). The ORR was 26.3% (two complete responses and three partial responses). The disease control rate was 73.7%. The median duration of response was 30.3 months [95% confidence interval (CI): 5.8-NA]. The median progression-free survival (PFS) was 5.5 months (95% CI: 2.8-NA), and median overall survival was 20.3 months (95% CI: 14.8-NA). Whole-exome sequencing suggested that acquired drug resistance might be attributed to activation of the MAPK signalling pathway and transformation to an immunosuppressive tumour environment.

CONCLUSIONS

TQB2450 combined with anlotinib showed favourable tolerance and promising anti-tumour activity with a prolonged PFS compared with anti-PD1 monotherapy in patients with advanced acral melanoma.

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.

Oncogenic BRAF and p53 Interplay in Melanoma Cells and the Effects of the HDAC Inhibitor ITF2357 (Givinostat)

Oncogenic BRAF mutations have been widely described in melanomas and promote tumour progression and chemoresistance. We previously provided evidence that the HDAC inhibitor ITF2357 (Givinostat) targets oncogenic BRAF in SK-MEL-28 and A375 melanoma cells. Here, we show that oncogenic BRAF localises to the nucleus of these cells, and the compound decreases BRAF levels in both the nuclear and cytosolic compartments. Although mutations in the tumour suppressor p53 gene are not equally frequent in melanomas compared to BRAF, the functional impairment of the p53 pathway may also contribute to melanoma development and aggressiveness. To understand whether oncogenic BRAF and p53 may cooperate, a possible interplay was considered in the two cell lines displaying a different p53 status, being p53 mutated into an oncogenic form in SK-MEL-28 and wild-type in A375 cells. Immunoprecipitation revealed that BRAF seems to preferentially interact with oncogenic p53. Interestingly, ITF2357 not only reduced BRAF levels but also oncogenic p53 levels in SK-MEL-28 cells. ITF2357 also targeted BRAF in A375 cells but not wild-type p53, which increased, most likely favouring apoptosis. Silencing experiments confirmed that the response to ITF2357 in BRAF-mutated cells depends on p53 status, thus providing a rationale for melanoma-targeted therapy.

Nodular melanoma in an African American Japanese male

Nodular melanoma (NM) is the third most common subtype of melanoma among African Americans trailing behind acral lentiginous melanoma and superficial spreading melanoma. This case of NM in an African American Japanese male was selected due to the rare occurrence of NM in people of color.

TMB and BRAF mutation status are independent predictive factors in high-risk melanoma patients with adjuvant anti-PD-1 therapy

BACKGROUND

High tumor mutational burden (TMB) is associated with a favorable outcome in metastatic melanoma patients treated with immune checkpoint inhibitors. However, data are limited in the adjuvant setting. As BRAF mutated patients have an alternative with targeted adjuvant therapy, it is important to identify predictive factors for relapse and recurrence-free survival (RFS) in patients receiving adjuvant anti-PD-1 antibodies.

METHODS

We evaluated 165 melanoma patients who started adjuvant anti-PD-1 antibody therapy at our center between March 2018 and September 2019. The initial tumor stage was assessed at the beginning of therapy according to the 8th edition of the AJCC Cancer Staging Manual. Tumor and normal tissue of the high-risk stages IIIC/D/IV were sequenced using a 700 gene NGS panel.

RESULTS

The tumor stages at the beginning of adjuvant anti-PD-1 therapy were as follows: N = 80 stage IIIA/B (48%), N = 85 stage IIIC/D/IV (52%). 72/165 patients (44%) suffered a relapse, 44/72 (61%) with only loco regional and 28/72 (39%) with distant metastases. Sequencing results were available from 83 to 85 patients with stage IIIC/D/IV. BRAF mutation status (HR 2.12, 95% CI 1.12-4.08; p = 0.022) and TMB (HR 7.11, 95% CI 2.19-23.11; p = 0.001) were significant and independent predictive factors for relapse-free survival (RFS).

CONCLUSION

BRAF mutation status and TMB were independent predictive factors for RFS. Patients with BRAF V600E/K mutation and TMB high had the best outcome. A classification based on BRAF mutation status and TMB is proposed to predict RFS in melanoma patients with adjuvant anti-PD-1 therapy.

Metastatic multifocal melanoma of multiple organ systems: A case report

BACKGROUND

Malignant melanoma is becoming more common among middle-aged individuals all over the world. Melanoma metastasis can be found in various organs, although metastases to the spleen and stomach are rare. Herein we present a rare metastatic multifocal melanoma, clinically and histologically mimicking lymphoma, with metastases of multiple organs.

CASE SUMMARY

A 46-year-old Caucasian male with a history of nodular cutaneous malignant melanoma was presented with nausea, general weakness, shortness of breath, abdominal enlargement, and night sweating. The abdominal ultrasound revealed enlarged liver and spleen with multiple lesions. Computed tomography demonstrated multiple lesions in the lungs, liver, spleen, subcutaneous tissue, bones and a pathological lymphadenopathy of the neck. Trephine biopsy and the biopsy from the enlarged lymph node were taken. Tumor cells showed diffuse or partial positivity for melanocytic markers, such as microphthalmia - associated transcription factor, S100, HMB45 and Melan-A. The tumor harbored BRAF V600E mutation, demonstrated by immunohistochemical labelling for BRAF V600E and detected by real-time polymerase chain reaction test. Having combined all the findings, a diagnosis was made of a metastatic multifocal melanoma of the stomach, duodenum, liver, spleen, lungs, lymph nodes and bones. The patient refused treatment and died a week later.

CONCLUSION

This case report highlights the clinical relevance of rare metastatic multifocal melanoma of multiple organ systems.

A biomarker panel predicts recurrence-free survival in ulcerated primary cutaneous melanoma

BACKGROUND

Ulceration is an independent adverse prognostic factor in cutaneous malignant melanoma (CMM). There is, however, a need for additional prognostic markers to identify patients with ulcerated stage I-II CMM who have a high-risk for recurrence. The aim of this study was to examine the prognostic impact of BRAF mutation, proliferation and presence of tumour infiltrating lymphocytes (TILs) in primary ulcerated CMM.

MATERIAL AND METHODS

We have used a consecutive cohort consisting of 71 primary ulcerated CMM (T1b-T4b). BRAF mutation was detected using Cobas test and pyrosequencing. Protein expression of the proliferation marker Ki67 was analysed using immunohistochemistry. Presence of TILs was evaluated in representative hematoxylin-eosin stained formalin-fixed paraffin-embedded tumour sections.

RESULTS

Proportion of BRAF mutated alleles, proliferation and presence of TILs all had a statistically significant impact on recurrence free survival in univariate analyses (HR 2.44, 95% CI 1.23-4.84, p = 0.011; HR 2.66, 95% CI 1.32-5.35, p = 0.006 respectively HR 0.48, 95% CI 0.24-0.98, p = 0.045). A trend test found a statistically significant decrease in the proportion of recurrence by including the three favourable factors (BRAF wildtype/low proportion of BRAF mutated alleles, low proliferation and high presence of TILs) (p = 0.0004). When at least two out of three factors were present there was a statistically significant association with longer recurrence free survival in the multivariate analysis (HR 0.30, 95% CI 0.15-0.61, p = 0.001) when adjusted for Breslow thickness, an established independent prognostic marker for CMM.

CONCLUSION

Thus, this panel of markers could be an interesting novel concept for predicting the clinical outcome in patients with high-risk stage I-II ulcerated CMM.

Prognostic Value of Lymph Node Ratio in Cutaneous Melanoma: A Systematic Review

The prognosis of cutaneous melanoma (CM) is based on the histological characteristics of the primary tumor, such as Breslow depth, ulceration, and mitotic rate. The lymph node ratio (LNR) is the ratio of the involved lymph nodes (LNs) divided by the total number of LNs removed during regional LN dissection. LNR is a prognostic factor for many solid tumors; however, controversies exist regarding CM. This study sought to analyze the role of LNR as a prognostic factor in CM.

An extensive literature search was conducted using PubMed, Google Scholar, Medline, and the Cochrane Central Registry of Controlled Trials from January 1966 to July 2015. The keywords included in the search were CM and inclusion of the ratio of positive to the total number of LNs as a prognostic factor. The outcomes analyzed included the number of patients with positive LNs, type of survival analysis, and results from the multivariate analysis.

A total of 11 studies involving 12,011 patients with positive LNs were evaluated. No previous randomized controlled trials, meta-analyses, or systematic reviews were identified in the Cochrane database on the prognostic value of LNR in CM. The primary electronic database search resulted in 333 full-text articles. The LN location examined was the cervical, axillary, and inguinal regions in all studies except for one that examined only the inguinal region. All studies except three studied the prognostic value of the LNR as a categorical variable rather than a continuous variable. LNR was categorized as A (≤0.1), B (0.11-0.25), and C (>0.25). All studies identified LNR as an independent predictor of overall survival (OS), disease-free survival (DFS), or disease-specific survival (DSS). The hazard ratio (HR) and confidence interval (CI) associated with either DFS or OS were available only in a few studies. Moreover, pooled HR for OS was 2.08 (95% CI: 1.48 2.92), for DFS was 1.364 (95% CI: 0.92-2.02), and for DSS was 1.643 (95% CI: 0.89-3.0).

The LNR provides superior prognostic stratification among patients with CM. Additional adequately powered prospective studies are needed to further define the role of LNR and be included in the staging system of CM and direct adjuvant therapy.

Durable Response to Vemurafenib and Cobimetinib for the Treatment of BRAF-Mutated Metastatic Melanoma in Routine Clinical Practice

Background

The combination of BRAF and MEK inhibitors delays the onset of resistance and provides more sustained and dramatic responses in comparison with a BRAF inhibitor in monotherapy. The objective of the study was to evaluate the effectiveness of the combination therapy with vemurafenib/cobimetinib in terms of durability, and to describe differential characteristics in patients associated to durable responses in real-world settings.

Patients and Methods

Retrospective, observational, cross-sectional, multicenter study involving 41 patients with advanced melanoma harboring a BRAF^V600 mutation who initiated a combination therapy with vemurafenib/cobimetinib between May 2018 and March 2019. Participants were differentiated regarding the durability of the response: durable (complete response, CR, or a partial response, PR, for at least 12 months) and non-durable (stable disease, SD, progressive disease, PD, or CR/PR <12 months). Secondary endpoints included treatment adherence, labor productivity, anxiety/depression, and safety profile.

Results

During the combination therapy, 12 patients (29.3%) had a CR, 19 a PR (46.3%), 5 showed SD (12.2%), and 5 had PD. A total of 12 patients (29.3%) were considered as achieving a durable response and 29 (70.7%) as a non-durable one. Practically all sociodemographic and clinical characteristics were similar between patients. Body mass index was the only differential factor (with higher body mass index achieving a non-durable response). The treatment adherence was 100% in patients with durable response and 66.7% in those with non-durable.

Conclusion

The combination treatment with vemurafenib/cobimetinib results in an important impact on long-term survival, leading to a steady CR in one-third of the patients.

Sex-Based Differences in Treatment with Immune Checkpoint Inhibition and Targeted Therapy for Advanced Melanoma: A Nationwide Cohort Study

Simple Summary

Melanoma is a malignant form of skin cancer. The overall survival of patients with advanced stages of disease were initially low. Fortunately, in recent years systemic treatment with immunotherapy has prolonged survival. We set out to answer the question whether men and women with advanced melanoma differ in prognostic factors, tumor-response to immunotherapy, and treatment-related adverse events. All patients in the Netherlands were registered between July 2013 and July 2018. We showed that although clinical and tumor characteristics differ, the safety profile of immunotherapy is comparable. Furthermore, overall, a 10% survival advantage for women was seen. Following immunotherapy there was no survival difference.

Abstract

Recent meta-analyses show conflicting data on sex-dependent benefit following systemic treatment for advanced melanoma patients. We examined the nationwide Dutch Melanoma Treatment Registry (July 2013–July 2018), assessing sex-dependent differences in advanced melanoma patients (stage IIIC/IV) with respect to clinical characteristics, mutational profiles, treatments initiated, grade 3–4 adverse events (AEs), treatment responses, and mortality. We included 3985 patients, 2363 men (59%) and showed that although men and women with advanced melanoma differ in clinical and tumor characteristics, the safety profile of immune checkpoint inhibition (ICI) is comparable. The data suggest a 10% survival advantage for women, mainly seen in patients ≥60 years of age and patients with BRAF V600 mutant melanoma. Following ICI there was no survival difference.

The human melanoma proteome atlas-Defining the molecular pathology

The MM500 study is an initiative to map the protein levels in malignant melanoma tumor samples, focused on in-depth histopathology coupled to proteome characterization. The protein levels and localization were determined for a broad spectrum of diverse, surgically isolated melanoma tumors originating from multiple body locations. More than 15,500 proteoforms were identified by mass spectrometry, from which chromosomal and subcellular localization was annotated within both primary and metastatic melanoma. The data generated by global proteomic experiments covered 72% of the proteins identified in the recently reported high stringency blueprint of the human proteome. This study contributes to the NIH Cancer Moonshot initiative combining detailed histopathological presentation with the molecular characterization for 505 melanoma tumor samples, localized in 26 organs from 232 patients.

Biomarkers for Diagnosis, Prognosis and Response to Immunotherapy in Melanoma

Simple Summary

Cutaneous Melanoma is a form of skin cancer characterized by an elevated mutational load that favors high spread to distant organs and resistance to therapies. The identification of biomarkers, able to dissect normal and pathogenic biological processes and response to therapeutic intervention, is necessary to describe melanoma as accurately as possible, having a positive impact on early diagnosis, in turn selecting the best therapeutic option. Recently, a great number of new biomarkers were evaluated, in order to identify those patients who may have clinical benefit from a therapeutic choice, particularly for immunotherapy. At present, these new biomarkers wait to be validated before clinical use. Hence, the requirement to look at and periodically update the advances in this field.

Abstract

Cutaneous Melanoma classification is constantly looking for specific and sensitive biomarkers capable of having a positive effect on diagnosis, prognosis and risk assessment, eventually affecting clinical outcome. Classical morphological, immunohistochemical and the well-known BRAF and NRAS genetic biomarkers do not allow the correct categorization of patients, being melanoma conditioned by high genetic heterogeneity. At the same time, classic prognostic methods are unsatisfactory. Therefore, new advances in omics and high-throughput analytical techniques have enabled the identification of numerous possible biomarkers, but their potentiality needs to be validated and standardized in prospective studies. Melanoma is considered an immunogenic tumor, being the first form of cancer to take advantage of the clinical use of the immune-checkpoint blockers. However, as immunotherapy is effective only in a limited number of patients, biomarkers associated with different responses are essential to select the more promising therapeutic approach and maximize clinical benefits. In this review, we summarize the most utilized biomarkers for Cutaneous Melanoma diagnosis, focusing on new prognostic and predictive biomarkers mainly associated with immunotherapy.

Defining the Criteria for Reflex Testing for BRAF Mutations in Cutaneous Melanoma Patients

Targeted therapy has been developed through an in-depth understanding of molecular pathways involved in the pathogenesis of melanoma. Approximately ~50% of patients with melanoma have tumors that harbor a mutation of the BRAF oncogene. Certain clinical features have been identified in BRAF-mutated melanomas (primary lesions located on the trunk, diagnosed in patients <50, visibly pigmented tumors and, at times, with ulceration or specific dermatoscopic features). While BRAF mutation testing is recommended for stage III-IV melanoma, guidelines differ in recommending mutation testing in stage II melanoma patients. To fully benefit from these treatment options and avoid delays in therapy initiation, advanced melanoma patients harboring a BRAF mutation must be identified accurately and quickly. To achieve this, clear definition and implementation of BRAF reflex testing criteria/methods in melanoma should be established so that patients with advanced melanoma can arrive to their first medical oncology appointment with a known biomarker status. Reflex testing has proven effective for a variety of cancers in selecting therapies and driving other medical decisions. We overview the pathophysiology, clinical presentation of BRAF-mutated melanoma, current guidelines, and present recommendations on BRAF mutation testing. We propose that reflex BRAF testing should be performed for every melanoma patient with stages ≥IIB.

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.

•

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

•

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

•

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

•

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

•

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

The Role of Senescent Cells in Acquired Drug Resistance and Secondary Cancer in BRAFi-Treated Melanoma

Simple Summary

Advances in melanoma treatment include v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors that target the predominant oncogenic mutation found in malignant melanoma. Despite initial success of the BRAF inhibitor (BRAFi) therapies, resistance and secondary cancer often occur. Mechanisms of resistance and secondary cancer rely on upregulation of pro-survival pathways that circumvent senescence. The repeated identification of a cellular senescent phenotype throughout melanoma progression demonstrates the contribution of senescent cells in resistance and secondary cancer development. Incorporating senotherapeutics in melanoma treatment may offer a novel approach for potentially improving clinical outcome.

Abstract

BRAF is the most common gene mutated in malignant melanoma, and predominately it is a missense mutation of codon 600 in the kinase domain. This oncogenic BRAF missense mutation results in constitutive activation of the mitogen-activate protein kinase (MAPK) pro-survival pathway. Several BRAF inhibitors (BRAFi) have been developed to specifically inhibit BRAF^V600 mutations that improve melanoma survival, but resistance and secondary cancer often occur. Causal mechanisms of BRAFi-induced secondary cancer and resistance have been identified through upregulation of MAPK and alternate pro-survival pathways. In addition, overriding of cellular senescence is observed throughout the progression of disease from benign nevi to malignant melanoma. In this review, we discuss melanoma BRAF mutations, the genetic mechanism of BRAFi resistance, and the evidence supporting the role of senescent cells in melanoma disease progression, drug resistance and secondary cancer. We further highlight the potential benefit of targeting senescent cells with senotherapeutics as adjuvant therapy in combating melanoma.

Not all melanomas are created equal: a review and call for more research into nodular melanoma

Among the histogenic subtypes of melanoma, nodular melanoma (NM) is the major contributor for thicker and fatal melanomas and it has been associated with melanoma-specific death in thin tumours, highlighting an important subgroup of 'aggressive thin' melanomas. This review provides a synthesis of the distinct characteristics of NM, with respect to epidemiology and risk factors, clinical presentation, histopathology, molecular and dermoscopic aspects, and screening practices. The real challenges are to find better biomarkers of aggressiveness and to know whether the control of such aggressive melanomas can be influenced by targeted interventions such as early detection, drug interventions and preventive strategies.

Emerging strategies to treat rare and intractable subtypes of melanoma

Melanoma is the deadliest form of skin cancer, possessing a diverse landscape of subtypes with distinct molecular signatures and levels of aggressiveness. Although immense progress has been achieved therapeutically for patients with the most common forms of this disease, little is known of how to effectively treat patients with rarer subtypes of melanoma. These subtypes include acral lentiginous (the rarest form of cutaneous melanoma; AL), uveal, and mucosal melanomas, which display variations in distribution across (a) the world, (b) patient age-groups, and (c) anatomic sites. Unfortunately, patients with these relatively rare subtypes of melanoma typically respond worse to therapies approved for the more common, non-AL cutaneous melanoma and do not have effective alternatives, and thus consequently have worse overall survival rates. Achieving durable therapeutic responses in these high-risk melanoma subtypes represents one of the greatest challenges of the field. This review aims to collate and highlight effective preclinical and/or clinical strategies against these rare forms of melanoma.

BRAF: A Two-Faced Janus

Gain-of-function of V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF) is one of the most frequent oncogenic mutations in numerous cancers, including thyroid papillary carcinoma, melanoma, colon, and lung carcinomas, and to a lesser extent, ovarian and glioblastoma multiforme. This mutation aberrantly activates the mitogen-activated protein (MAP) kinase extracellular signal-regulated kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway, thereby eliciting metastatic processes. The relevance of BRAF mutations stems from its prognostic value and, equally important, from its relevant therapeutic utility as an actionable target for personalized treatment. Here, we discuss the double facets of BRAF. In particular, we argue the need to implement diagnostic molecular algorithms that are able to detect this biomarker in order to streamline and refine diagnostic and therapeutic decisions.

Discovery and Validation of a Metastasis-Related Prognostic and Diagnostic Biomarker for Melanoma Based on Single Cell and Gene Expression Datasets

Background

Single cell sequencing can provide comprehensive information about gene expression in individual tumor cells, which can allow exploration of heterogeneity of malignant melanoma cells and identification of new anticancer therapeutic targets.

Methods

Single cell sequencing of 31 melanoma patients in GSE115978 was downloaded from the Gene Expression Omniniub (GEO) database. First, the limma package in R software was used to identify the differentially expressed metastasis related genes (MRGs). Next, we developed a prognostic MRGs biomarker in the cancer genome atlas (TCGA) by combining univariate cox analysis and the least absolute shrinkage and selection operator (LASSO) method and was further validated in another two independent datasets. The efficiency of MRGs biomarker in diagnosis of melanoma was also evaluated in multiple datasets. The pattern of somatic tumor mutation, immune infiltration, and underlying pathways were further explored. Furthermore, nomograms were constructed and decision curve analyses were also performed to evaluate the clinical usefulness of the nomograms.

Results

In total, 41 MRGs were screened out from 1958 malignant melanoma cell samples in GSE115978. Next, a 5-MRGs prognostic marker was constructed and validated, which show more effective performance for the diagnosis and prognosis of melanoma patients. The nomogram showed good accuracies in predicting 3 and 5 years survival, and the decision curve of nomogram model manifested a higher net benefit than tumor stage and clark level. In addition, melanoma patients can be divided into high and low risk subgroups, which owned differential mutation, immune infiltration, and clinical features. The low risk subgroup suffered from a higher tumor mutation burden (TMB), and higher levels of T cells infiltrating have a significantly longer survival time than the high risk subgroup. Gene Set Enrichment Analysis (GSEA) revealed that the extracellular matrix (ECM) receptor interaction and epithelial mesenchymal transition (EMT) were the most significant upregulated pathways in the high risk group.

Conclusions

We identified a robust MRGs marker based on single cell sequencing and validated in multiple independent cohort studies. Our finding provides a new clinical application for prognostic and diagnostic prediction and finds some potential targets against metastasis of melanoma.

BRAF as a positive predictive biomarker: Focus on lung cancer and melanoma patients

In the era of personalized medicine, BRAF mutational assessment is mandatory in advanced-stage melanoma and non-small cell lung cancer (NSCLC) patients. The identification of actionable mutations is crucial for the adequate management of these patients. To date various drugs have been implemented in clinical practice. Similarly, various methods may be adopted for the identification of BRAF mutations. Here, we briefly review the current literature on BRAF in melanoma and NSCLC, focusing attention in particular on the different methods and drugs adopted in these patients. In addition, an overview of the real-world practice in different Italian laboratories with high expertise in molecular predictive pathology testing is provided.

Tumor Suppressor Role of hsa-miR-193a-3p and -5p in Cutaneous Melanoma

BACKGROUND

Remarkable deregulation of several microRNAs (miRNAs) is demonstrated in cutaneous melanoma. hsa-miR-193a-3p is reported to be under-expressed in tissues and in plasma of melanoma patients, but the role of both miR-193a arms in melanoma is not known yet.

METHODS

After observing the reduced levels of miR-193a arms in plasma exosomes of melanoma patients, the effects of hsa-miR-193a-3p and -5p transfection in cutaneous melanoma cell lines are investigated.

RESULTS

In melanoma cell lines A375, 501Mel, and MeWo, the ectopic over-expression of miR-193a arms significantly reduced cell viability as well as the expression of genes involved in proliferation (ERBB2, KRAS, PIK3R3, and MTOR) and apoptosis (MCL1 and NUSAP1). These functional features were accompanied by a significant downregulation of Akt and Erk pathways and a strong increase in the apoptotic process. Since in silico databases revealed TROY, an orphan member of the tumor necrosis receptor family, as a potential direct target of miR-193a-5p, this possibility was investigated using the luciferase assay and excluded by our results.

CONCLUSIONS

Our results underline a relevant role of miR-193a, both -3p and -5p, as tumor suppressors clarifying the intracellular mechanisms involved and suggesting that their ectopic over-expression could represent a novel treatment for cutaneous melanoma patients.

Synthesis of a 11C-Isotopologue of the B-Raf-Selective Inhibitor Encorafenib Using In-Loop [11C]CO2 Fixation

The serine/threonine kinase B-Raf is an essential regulator of cellular growth, differentiation, and survival. B-Raf protein expression is elevated throughout melanoma progression, making it an attractive target for noninvasive imaging using positron-emission tomography. Encorafenib is a potent and highly selective inhibitor of B-Raf used in the clinical management of melanoma. In this study, the radiosynthesis of a ¹¹C-isotopologue of encorafenib was developed using an in-loop [¹¹C]CO₂ fixation reaction. Optimization of reaction conditions reduced the formation of a radiolabeled side product and improved the isolated yields of [¹¹C]encorafenib (14.5 ± 2.4% radiochemical yield). The process was fully automated using a commercial radiosynthesizer for the production of 6845 ± 888 MBq of [¹¹C]encorafenib in high molar activity (177 ± 5 GBq μmol^-1), in high radiochemical purity (99%), and in a formulation suitable for animal injection. An in vitro cellular binding experiment demonstrated saturable binding of the radiotracer to A375 melanoma cells.

Treatment Sequencing and Clinical Outcomes in BRAF-Positive and BRAF-Negative Unresectable and Metastatic Melanoma Patients Treated with New Systemic Therapies in Routine Practice

BACKGROUND

Although BRAF/MEK inhibitors are generally considered to be equally effective whether given before or after immunotherapy, no prospective trial has confirmed this hypothesis and contradictory data have been published in the melanoma field.

OBJECTIVE

We aimed to investigate the outcomes of patients with metastatic melanoma depending on the first-line treatment.

PATIENTS AND METHODS

In this ambidirectional cohort, single-center study, we included 253 consecutive melanoma patients treated in our institution with an anti-PD1 antibody or BRAF/MEK inhibitors, who started first-line treatment between December 2015 and March 2018. Kaplan-Meier estimator, log-rank test, and Cox proportional hazard model were used in this analysis.

RESULTS

First-line median progression-free survival (PFS) for all patients was 5.7 months (m), 6.9 m on anti-PD-1 therapy and 5.6 m for combination targeted therapy. Patients with BRAF mutated melanoma had 6.0 m median PFS on immunotherapy. At a median follow-up of 23.2 m with 149 events, in BRAF wild-type patients treated with anti-PD1, median overall survival (OS) was 18.1 m. BRAF mutated patients treated with first-line BRAF/MEK inhibitors had 11.7 m median OS. High neutrophil to lymphocyte ratio, high LDH level, ECOG > 0, and the presence of brain metastases negatively impacted PFS and OS.

CONCLUSIONS

In BRAF mutated patients with normal LDH, first-line immunotherapy seems a more effective approach. We have demonstrated that although BRAF mutation is a negative prognostic factor in stage IV melanoma, the use of two different systemic treatment modalities allows achievement of comparable survival in BRAF mutated and BRAF wild-type patients.

BRAF mutational status as a prognostic marker for survival in malignant melanoma: a systematic review and meta-analysis

Background: The analysis of the BRAF mutational status has been established as a standard procedure during diagnosis of advanced malignant melanoma due to the fact that BRAF inhibitors constitute a cornerstone in the treatment of metastatic disease. However, the general impact of BRAF mutational status on survival remains unclear. Our study aimed to assess the underlying prognostic significance of BRAF mutant versus wild type (WT) malignant melanoma on overall survival (OS), disease-free survival (DFS) and progression-free survival (PFS).Material and methods: A systematic literature search in EMBASE, Medline and Cochrane CENTRAL was performed. Studies were included if they reported survival outcomes for BRAF mutant versus WT patients as hazard ratios (HR) or in Kaplan-Meier (KM) curves. Random-effects meta-analysis models were used to pool HRs across the studies.Results: Data from 52 studies, representing 7519 patients, were pooled for analysis of OS. The presence of a BRAF mutation was statistically significantly associated with a reduced OS (HR [95% confidence interval (CI)]: 1.23 [1.09-1.38]), however, with substantial heterogeneity between the studies (I²: 58.0%). Meta-regression and sensitivity analyses showed that age, sex and BRAF mutation testing method did not have a significant effect on the OS HR. BRAF mutant melanoma showed comparable effect on DFS to non-BRAF mutant melanoma in stage I-III melanoma (combined HR: 1.16, 95% CI: 0.92-1.46), and on PFS in stage III-IV (HR: 0.98 (95% CI: 0.68-1.40)).Conclusion: Although there was substantial heterogeneity between the studies, the overall results demonstrated a poorer prognosis and OS in patients harbouring BRAF mutations. Future studies should take this into account when evaluating epidemiological data and treatment effects of new interventions in patients with malignant melanoma.

Cytotoxic Effect of Vanicosides A and B from Reynoutria sachalinensis Against Melanotic and Amelanotic Melanoma Cell Lines and in silico Evaluation for Inhibition of BRAFV600E and MEK1

Vanicosides A and B are the esters of hydroxycinnamic acids with sucrose, occurring in a few plant species from the Polygonaceae family. So far, vanicosides A and B have not been evaluated for anticancer activity against human malignant melanoma. In this study, we tested these two natural products, isolated from Reynoutria sachalinensis rhizomes, against two human melanoma cell lines (amelanotic C32 cell line and melanotic A375 cell line, both bearing endogenous BRAFV600E mutation) and two normal human cell lines-keratinocytes (HaCaT) and the primary fibroblast line. Additionally, a molecular docking of vanicoside A and vanicoside B with selected targets involved in melanoma progression was performed.&nbsp;Cell viability was studied using an MTT assay. A RealTime-Glo™ Annexin V Apoptosis and Necrosis assay was used for monitoring programmed cell death (PCD). Vanicoside A demonstrated strong cytotoxicity against the amelanotic C32 cell line (viability of the C32 cell line was decreased to 55% after 72 h incubation with 5.0 µM of vanicoside A), significantly stronger than vanicoside B. This stronger cytotoxic activity can be attributed to an additional acetyl group in vanicoside A. No significant differences in the cytotoxicity of vanicosides were observed against the less sensitive A375 cell line. Moreover, vanicosides caused the death of melanoma cells at concentrations from 2.5 to 50 µM, without harming the primary fibroblast line. The keratinocyte cell line (HaCaT) was more sensitive to vanicosides than fibroblasts, showing a clear decrease in viability after incubation with 25 µM of vanicoside A as well as a significant phosphatidylserine (PS) exposure, but without a measurable cell death-associated fluorescence. Vanicosides induced an apoptotic death pathway in melanoma cell lines, but because of the initial loss of cell membrane integrity, an additional cell death mechanism might be involved like permeability transition pore (PTP)-mediated necrosis that needs to be explored in the future. Molecular docking indicated that both compounds bind to the active site of the BRAFV600E kinase and MEK-1 kinase; further experiments on their specific inhibitory activity of these targets should be considered.

Differential responsiveness to BRAF inhibitors of melanoma cell lines BRAF V600E-mutated

Background

Most mutations in melanoma affect one critical amino acid on BRAF gene, resulting in the V600E substitution. Patient management is often based on the use of specific inhibitors targeting this mutation.

Methods

DNA and RNA mutation status was assessed in 15 melanoma cell lines by Sanger sequencing and RNA-seq. We tested the cell lines responsiveness to BRAF inhibitors (vemurafenib and PLX4720, BRAF-specific and sorafenib, BRAF non-specific). Cell proliferation was assessed by MTT colorimetric assay. BRAF V600E RNA expression was assessed by qPCR. Expression level of phosphorylated-ERK protein was assessed by Western Blotting as marker of BRAF activation.

Results

Three cell lines were discordant in the mutation detection (BRAF V600E at DNA level/Sanger sequencing and BRAF WT on RNA-seq). We initially postulated that those cell lines may express only the WT allele at the RNA level although mutated at the DNA level. A more careful analysis showed that they express low level of BRAF RNA and the expression may be in favor of the WT allele. We tested whether the discordant cell lines responded differently to BRAF-specific inhibitors. Their proliferation rate decreased after treatment with vemurafenib and PLX4720 but was not affected by sorafenib, suggesting a BRAF V600E biological behavior. Yet, responsiveness to the BRAF specific inhibitors was lower as compared to the control. Western Blot analysis revealed a decreased expression of p-ERK protein in the BRAF V600E control cell line and in the discordant cell lines upon treatment with BRAF-specific inhibitors. The discordant cell lines showed a lower responsiveness to BRAF inhibitors when compared to the BRAF V600E control cell line. The results obtained from the inhibition experiment and molecular analyses were also confirmed in three additional cell lines.

Conclusion

Cell lines carrying V600E mutation at the DNA level may respond differently to BRAF targeted treatment potentially due to a lower V600E RNA expression.

BRAF V600E mutation as a prognostic factor in cutaneous melanoma patients

The prognostic significance of BRAF mutations in the natural course of melanoma is controversial. The aim of study was to assess the prognostic significance of BRAF V600E mutation in cutaneous melanoma patients. A total of 151 melanomas were included in the study. BRAF V600E mutation was detected using the real-time PCR. BRAF V600E mutation rate was 51%. BRAF mutation rate was higher for young patients (61.4%) and upper limbs (63.2%), trunk (59.3%) and head and neck (59.2%) were the most frequently afflicted sites in BRAF-mutant patients, whereas lower limbs were mostly affected in BRAF-wild patients (77.8%). Likewise, acral melanomas rarely harbored BRAF mutation (17.1%). The disease-free survivals regarding the entire and Stage III cohorts were longer in the BRAF-mutant group than in the BRAF-wild group (p = .006 and p = .004, respectively), whereas Stage I-II patients had no survival differences between BRAF statuses (p = .2). Likewise, BRAF-mutant patients had better overall survival (OS) time compared to BRAF-wild patients in all stages (p = .01), in Stage III (p = .01), and in Stage IV patients (p = .001). However, no differences between BRAF statuses were observed in Stage I-II melanomas (p = .3). In conclusion, BRAF V600E-mutant melanomas show favorable prognostic impact on both disease-free and OSs in all staged melanomas except local disease.

KRAS and BRAF Mutations as Prognostic and Predictive Biomarkers for Standard Chemotherapy Response in Metastatic Colorectal Cancer: A Single Institutional Study

KRAS mutation is a confirmed predictive biomarker for anti-EGFR monoclonal antibody therapy response for metastatic colorectal cancer. However, its prognosis impact and the predictive potential for first-line standard chemotherapy remains unclear. On the other hand, V600E mutation is the most frequent and studied mutation in the BRAF gene, and it has been associated with a poor outcome of patients and a low response to anti-EGFR treatment. Thus, the aim of this study is to evaluate the role of KRAS and BRAF mutations as prognosis factors and predictive biomarkers for 1st line standard chemotherapy in metastatic colorectal cancer. KRAS mutations and BRAF V600E mutations exhibited a poor outcome (p = 0.021 and p < 0.0001, respectively). Cox multivariate analysis showed that the presence of liver metastasis (HR = 1.595; 95% CI: 1.086–2.343; p = 0.017), KRAS mutation (HR = 1.643; 95% CI: 1.110–2.431; p = 0.013) and BRAF V600E mutation (HR = 5.861; 95% CI: 2.531–13.570; p < 0.0001) were statistically significant co-variables for progression-free survival. Interestingly, patients with KRAS mutations were associated with a poor response to first line standard chemotherapy (p = 0.008). In contrast, the BRAF V600E mutation did not have any impact on the first line standard chemotherapy response (p = 0.540). Therefore, in the present study, we provide new insight on the role of KRAS and BRAF, not only as prognosis biomarkers, but also as first line standard chemotherapy response biomarkers in metastatic colorectal cancer.

Immunohistochemical Investigation of Mutant BRAF V600E in Common Pigmented Skin Neoplasms, Study on a Sample of Iranian Patients

Background & Objective:

This study was designed for the first time for the detec- tion of mutant BRAF V600E and its correlation with clinicophathologic features in a sample of Iranian patients with pathologically proved pigmented skin neoplasms.

Methods:

82 paraffin-embedded blocks, including melanocytic nevi, malignant melanoma, Basel cell carcinoma, and squamous cell carcinoma were evaluated for BRAF V600E expression by immunohistochemistry in the patients admitted to Ibn Sina Hospital, in the city of Sari, Mazandaran province, North of Iran. The evaluation of immunohistochemical staining was performed by two of the authoring pathologists, and staining intensity was graded from negative (0), weak (1+), moderate (2+) to strong (3+). If twenty percent (or greater) of the tumor cells showed modest to strong cytoplasmic immunoreactivity (score 3+), the neoplasm was considered positive for this tumor marker.

Results:

Among 82 studied patients, 12 cases (60%) of the malignant melanoma group revealed a high intensity of immunostaining for BRAF V600E, while a signifi- cant expression of this marker did not occur in the other investigated skin neoplasm. A great relation between BRAF (V600E) expression and the histologic type of skin cancer was noted. No significant relationship with other parameters such as gender, age, and the grade differentiation of the non-melanoma skin cancer was found. BRAF V600E was weakly correlated with the Clark level of cutaneous malignant melanoma.

Conclusion:

This data provided further evidence for the strong role of the BRAF V600E mutation in the development of cutaneous malignant melanoma, compared to non-melanoma skin cancers in the North of Iran. We advised future studies to evaluate the beneficial effects of anti-BRAF V600E target therapy on the Iranian melanoma patient who harbors this marker by way of immunostaining tumor tissue.

Low BRAF V600 mutation prevalence in primary skin nodular melanoma in Indonesia: a real-time PCR detection among Javanese patients

BACKGROUND

Cutaneous melanoma is a rare, aggressive skin malignancy with a high mortality rate. Although only contributing 7.6% of the cases worldwide, Asia is responsible for 18.6% of deaths from cutaneous melanoma. BRAF V600 mutation presents a potential prognostic predictor in melanoma. Unfortunately, studies on that mutation in melanoma, particularly nodular subtype, in Indonesia are still scarce. This research aimed to investigate the prevalence of BRAF V600 mutation in primary skin nodular melanoma in Yogyakarta and Central Java, Indonesia. Its association with clinicopathological parameters was also analyzed.

METHODS

Forty paraffin-embedded tissue samples from primary skin nodular melanoma cases in 2011-2018 were collected from the two biggest referral hospitals in Yogyakarta and Central Java, Indonesia. The BRAF V600 mutation status was assessed using qualitative real-time PCR and its associations with age, sex, anatomic location, lymph node metastasis, tumor thickness, ulceration, mitotic index, necrosis, lymphovascular invasion, and tumor-infiltrating lymphocytes were analyzed.

RESULTS

BRAF V600 mutations were found in 4 (10%) samples. These mutations were significantly associated with the central (non-extremity) region (p = 0.013) and presence of lymphovascular invasion (p = 0.005). However, it was not associated with any other variables analyzed in this study.

CONCLUSION

The prevalence of BRAF V600 mutation in Indonesian primary skin nodular melanoma cases is low and significantly associated with anatomic location and lymphovascular invasion. It is lower than prevalences in other Asian populations as well as in Caucasian populations and suggests that melanoma cases in Javanese people may have distinct clinicopathological characteristics from other Asian ethnicities.

The Hidden Story of Heterogeneous B-raf V600E Mutation Quantitative Protein Expression in Metastatic Melanoma-Association with Clinical Outcome and Tumor Phenotypes

In comparison to other human cancer types, malignant melanoma exhibits the greatest amount of heterogeneity. After DNA-based detection of the BRAF V600E mutation in melanoma patients, targeted inhibitor treatment is the current recommendation. This approach, however, does not take the abundance of the therapeutic target, i.e., the B-raf V600E protein, into consideration. As shown by immunohistochemistry, the protein expression profiles of metastatic melanomas clearly reveal the existence of inter- and intra-tumor variability. Nevertheless, the technique is only semi-quantitative. To quantitate the mutant protein there is a fundamental need for more precise techniques that are aimed at defining the currently non-existent link between the levels of the target protein and subsequent drug efficacy. Using cutting-edge mass spectrometry combined with DNA and mRNA sequencing, the mutated B-raf protein within metastatic tumors was quantitated for the first time. B-raf V600E protein analysis revealed a subjacent layer of heterogeneity for mutation-positive metastatic melanomas. These were characterized into two distinct groups with different tumor morphologies, protein profiles and patient clinical outcomes. This study provides evidence that a higher level of expression in the mutated protein is associated with a more aggressive tumor progression. Our study design, comprised of surgical isolation of tumors, histopathological characterization, tissue biobanking, and protein analysis, may enable the eventual delineation of patient responders/non-responders and subsequent therapy for malignant melanoma.

The New Genetic Landscape of Cushing's Disease: Deubiquitinases in the Spotlight

Cushing’s disease (CD) is a rare condition caused by adrenocorticotropic hormone (ACTH)-producing adenomas of the pituitary, which lead to hypercortisolism that is associated with high morbidity and mortality. Treatment options in case of persistent or recurrent disease are limited, but new insights into the pathogenesis of CD are raising hope for new therapeutic avenues. Here, we have performed a meta-analysis of the available sequencing data in CD to create a comprehensive picture of CD’s genetics. Our analyses clearly indicate that somatic mutations in the deubiquitinases are the key drivers in CD, namely USP8 (36.5%) and USP48 (13.3%). While in USP48 only Met415 is affected by mutations, in USP8 there are 26 different mutations described. However, these different mutations are clustering in the same hotspot region (affecting in 94.5% of cases Ser718 and Pro720). In contrast, pathogenic variants classically associated with tumorigenesis in genes like TP53 and BRAF are also present in CD but with low incidence (12.5% and 7%). Importantly, several of these mutations might have therapeutic potential as there are drugs already investigated in preclinical and clinical setting for other diseases. Furthermore, network and pathway analyses of all somatic mutations in CD suggest a rather unified picture hinting towards converging oncogenic pathways.

Molecular evaluation of BRAF V600 mutation and its association with clinicopathological characteristics: First findings from Indian malignant melanoma patients

Mutations in the BRAF gene have been described to occur in two-third of melanomas. The objective of the study was to establish the frequency of BRAF V600E/K/R mutation in a series of melanomas from Indian origin and to correlate mutation status with clinicopathological features. Seventy melanoma cases were evaluated for BRAF V600 mutation by pyrosequencing. Overall, BRAF mutations were detected in 30% of the patients. All mutations observed were missense type (GTG > GAG) resulting in p.V600E, while none showed V600K/R mutation. The frequency of BRAF V600E mutations were more in patients with onset age of 50 years. BRAF mutations were significantly associated with tumor site wherein more mutations were seen in tumors from head and neck and extremities region. Acral and mucosal tumor subtype showed a mutation frequency of 31% and 20%, respectively. Epithelial cell morphology tends to harbor frequent BRAF V600E mutation (36%) than other morphological subtypes. Tumors with ulceration and necrosis showed increased BRAF mutation rate (32.5% and 33%) respectively. In conclusion, this is the first study to report a mutation frequency of 30% in this cohort. Our results demonstrated that the BRAF V600E mutation is a frequent event in Indian melanomas, and represents an important molecular target for novel therapeutic approaches.

BRAF Mutation Status in Primary, Recurrent, and Metastatic Malignant Melanoma and Its Relation to Histopathological Parameters

Background

BRAF mutations are a common finding in malignant melanoma (MM). Nevertheless, apart from their significance as a therapeutic target in advanced melanoma, their prognostic value is still debated.

Objective

To assess BRAF mutation status in primary, recurrent, or metastatic MM and its correlations with histopathological findings.

Methods

We analyzed 203 samples from 178 consecutive patients: 129 primary cutaneous MM, 49 metastatic and recurrent MM of unknown primary site, and 25 cases of recurrences or metastases of primary MM. BRAF mutations in exon 15 were identified with real-time polymerase chain reaction and/or direct sequencing or pyrosequencing. Histopathological examination was performed according to standard procedures.

Results

We observed a 42.1% prevalence of BRAF mutations at codon 600 among our patients, 84% of whom harbored the V600E mutation. Mutations showed a statistically significant increase in younger patients (P = 0.011), in ulcerated tumors (P = 0.020), and in tumors lacking solar elastosis in adjacent dermis (P = 0.008). Mutations were also more common in male patients, as well as in primary MMs of the torso, and in nonvisceral metastases, however without reaching statistical significance. Logistic regression analysis identified type and ulceration as the only significant predictors of BRAF mutation. The highest frequencies of mutated BRAF were identified in superficial spreading and nodular types, and the lowest in acral lentiginous and lentigo maligna types. In situ MM and primary dermal melanoma displayed intermediate frequencies.

Conclusion

Frequency of mutated BRAF is type-related and correlated with ulceration, a known adverse prognostic factor.

Prognostic value of uPAR expression and angiogenesis in primary and metastatic melanoma

Angiogenesis is important for the progression of cutaneous melanoma. Here, we analyzed the prognostic impact of the angiogenic factor urokinase plasminogen activator resecptor (uPAR), vascular proliferation index (VPI) and tumor necrosis as a measure of hypoxia in a patient series of nodular melanomas (n = 255) and matched loco-regional metastases (n = 78). Expression of uPAR was determined by immunohistochemistry and VPI was assessed by dual immunohistochemistry using Factor-VIII/Ki67 staining. Necrosis was recorded based on HE-slides. As novel findings, high uPAR expression and high VPI were associated with each other, and with increased tumor thickness, presence of tumor necrosis, tumor ulceration, increased mitotic count and reduced cancer specific survival in primary melanoma. In matched cases, VPI was decreased in metastases, whereas the frequency of necrosis was increased. Our findings demonstrate for the first time the impact on melanoma specific survival of uPAR expression and VPI in primary tumors, and of increased necrosis as an indicator of tumor hypoxia in loco-regional metastases. These findings support the importance of tumor angiogenesis in melanoma aggressiveness, and suggest uPAR as an indicator of vascular proliferation and a potential biomarker in melanoma.

Droplet digital PCR for detection of BRAF V600E mutation in formalin-fixed, paraffin-embedded melanoma tissues: a comparison with Cobas® 4800, Sanger sequencing, and allele-specific PCR

Cutaneous melanoma has the worst prognosis of all skin cancers. Although emerging targeted therapies, such as B-Raf kinase inhibitor vemurafenib, improve prognosis they require an accurate and sensitive means of detecting the pathogenic BRAF V600E mutation. We compared the sensitivity of four BRAF V600E detection methods in formalin-fixed, paraffin-embedded melanoma biopsies from 87 consecutive melanoma patients with Breslow stage I-V disease (staging based on the depth of tumor of invasion). The methods assessed were the widely used Cobas^® 4800 system based on real-time PCR amplification, Sanger sequencing, allele-specific PCR (AS-PCR), and droplet digital PCR (ddPCR). The BRAF V600E mutation was found in 8 (9.2%), 23 (26.4%), 23 (26.4%) and 31 (35.6%) biopsies, respectively. The limit of detection (LoD) was determined by three different methods: Poisson confidence limits, calibration regression and Tzonev's method. Pair-wise agreement between the methods was as follows: Cobas vs. Sanger, P = 0.33; Cobas^® 4800 vs. AS-PCR, P = 0.33; Cobas^® 4800 vs. ddPCR, P = 0.65; Sanger vs. AS-PCR, P = 1; Sanger vs. ddPCR, P = 0.08; AS-PCR vs. ddPCR, P = 0.06. Multinomial logistic regression was used for predictive modeling of the Breslow-Clark score; ddPCR emerged as the best predictor, the other predictors were mitotic activity, type of malignant melanoma and patient's age. Our results demonstrate that ddPCR is the most sensitive method of detecting the BRAF V600E mutation.

Metastases risk in thin cutaneous melanoma: prognostic value of clinical-pathologic characteristics and mutation profile

Background

A high percentage of patients with thin melanoma (TM), defined as lesions with Breslow thickness ≤1 mm, presents excellent long-term survival, however, some patients develop metastases. Existing prognostic factors cannot reliably differentiate TM patients at risk for metastases.

Objective

We aimed at characterizing the clinical-pathologic and mutation profile of metastatic and not-metastatic TM in order to distinguish lesions at risk of metastases.

Methods

Clinical-pathologic characteristics were recorded for the TM cases analyzed. We used a Next Generation Sequencing (NGS) multi-gene panel to characterize TM for multiple somatic mutations.

Results

A statistically significant association emerged between the presence of metastases and Breslow thickness ≥0.6 mm (p=0.003). None of TM with lymph-node involvement had Breslow thickness <0.6 mm. Somatic mutations were identified in 19 of 21 TM analyzed (90.5%). No mutations were observed in two not-metastatic cases with the lowest Breslow thickness (≤0.4 mm), whereas mutations in more than one gene were detected in one metastatic case with the highest Breslow thickness (1.00 mm).

Conclusion

Our study indicates Breslow thickness ≥0.6 mm as a valid prognostic factor to distinguish TM at risk for metastases.

Prognostic Role of BRAFV600E Cellular Localization in Melanoma

BACKGROUND

Approximately half of cutaneous melanoma tissues harbor BRAF^V600E mutations, resulting in a constitutive activation of the mitogen-activated protein kinase (MAPK) pathway. Nuclear-cytoplasmic transport machinery is dysregulated in neoplastic cells and alters the key regulatory proteins that can lead to tumor progression and drug resistance. The significance of nuclear localization of BRAF^V600E has not been fully understood. We examined the clinical significance of intracellular localization of BRAF^V600E in cutaneous melanoma.

STUDY DESIGN

Immunohistochemical analysis of BRAF^V600E was performed on formalin-fixed, paraffin-embedded specimens of cutaneous melanoma (n = 91). Staining intensity was graded in a blinded manner. Correlations to clinical factors were analyzed by Fisher's exact test and 2-tailed t-test. Localization of BRAF^V600E was determined in melanoma cells, and we investigated their resistance to BRAF^V600E-specific inhibitor according to nuclear localization in both in vitro and in vivo models.

RESULTS

We included 91 patients, of whom 32% (29 of 91) had cytoplasmic BRAF^V600E. Nuclear BRAF^V600E was observed in 30% (27 of 91). Overall, BRAF^V600E expression correlated with TNM stage (p = 0.011), mitotic activity (p = 0.010), and ulceration (p = 0.045). Nuclear BRAF^V600E expression correlated with overall clinical stage (p < 0.001), tumor size (p < 0.001), regional lymph node (p < 0.017), depth of invasion (p = 0.005), Clark level (p < 0.001), mitotic activity (p < 0.001), ulceration (p < 0.001), and margin status (p = 0.017). On a cellular level, BRAF^V600E was identified in the nucleus, and its translocation was serum dependent. Our in vitro and in vivo data revealed sequestration of BRAF^V600E in the cytosol-sensitized resistant cells to vemurafenib; nuclear retention of BRAF^V600E was associated with aggressiveness and drug resistance.

CONCLUSIONS

Nuclear localization of BRAF^V600E is associated with melanoma aggressiveness. Further multi-institutional studies are warranted to confirm the clinical relevance of nuclear localization of BRAF^V600E.

Molecular testing for BRAF mutations to inform melanoma treatment decisions: a move toward precision medicine

Approximately one-half of advanced (unresectable or metastatic) melanomas harbor a mutation in the BRAF gene, with V600E being the most common mutation. Targeted therapy with BRAF and MEK inhibitors is associated with significant long-term treatment benefit in patients with BRAF V600-mutated melanoma. Therefore, molecular testing for BRAF mutations is a priority in determining the course of therapy. A literature search was performed using MEDLINE/PubMed and scientific congress databases using the terms 'BRAF,' 'mutation,' and 'cancer/tumor.' These results were filtered to include manuscripts that focused on diagnostic tests for determining BRAF mutation status. Numerous BRAF testing methods were identified, including DNA-based companion diagnostic tests and DNA- and protein-based laboratory-developed tests. Herein we review the characteristics of each method and highlight the strengths and weaknesses that should be considered before use and when interpreting results for each patient. Molecular profiling has shown that mutation load increases with melanoma tumor progression and that unique patterns of genetic changes and evolutionary trajectories for different melanoma subtypes can occur. Discordance in the BRAF mutational status between primary and metastatic lesions, as well as intratumoral heterogeneity, is known to occur. Additionally, the development of acquired resistance to combination BRAF and MEK inhibitor therapy is still a formidable obstacle. Therefore, tumor heterogeneity and the development of acquired resistance have important implications for molecular testing and ultimately the treatment of patients with advanced-stage melanoma. Overall, this information may help community oncologists more accurately and effectively interpret results of diagnostic tests within the context of recent data characterizing melanoma tumor progression.

Prognostic impact and concordance of TERT promoter mutation and protein expression in matched primary and metastatic cutaneous melanoma

Background:

TERT promoter mutations are frequent in melanoma. Here we analysed the concordance and prognostic impact of TERT mutation and telomerase reverse transcriptase (TERT) protein expression in a large melanoma series.

Methods:

In 194 primary nodular melanomas with 72 matched loco-regional metastases, TERT promoter mutation status was assessed by Sanger sequencing and TERT protein expression by immunohistochemistry.

Results:

TERT mutations were found in 68% of primary melanomas and 64% of metastases, and the mutation status was discordant between primary tumour and metastasis in 24% of the cases. 6 of the 10 cases with discordant and wild-type metastases were also TERT wild type when re-tested in other intra-tumour regions, whereas 4 cases were mutation positive. TERT-mutated tumours tended to be thicker, have a higher mitotic count and higher patient age than TERT wild-type cases, but there was no significant association with reduced survival. TERT protein expression did not correlate with mutation status, but showed a similar discordancy between the primary and first metastatic lesion, and was significantly associated with reduced survival.

Conclusions:

TERT promoter mutations showed inter- and intra-tumoural discordancy, whereas only expression of TERT protein was associated with reduced patient survival.

Network Meta-analysis of Progression-Free Survival and Overall Survival in First-Line Treatment of BRAF Mutation-Positive Metastatic Melanoma

INTRODUCTION

The present study aimed to inform an economic evaluation of dabrafenib and trametinib combination as first-line treatment of metastatic melanoma in a Canadian setting. A network meta-analysis was conducted to estimate hazard ratios (HRs) for progression-free survival (PFS)and overall survival (OS) of dabrafenib plus trametinib versus other first-line treatments of BRAF mutation-positive metastatic melanoma including dabrafenib, trametinib, vemurafenib, ipilimumab, and dacarbazine (DTIC).

METHODS

HRs for PFS and OS were from randomized controlled trials identified from systematic literature reviews. HRs for PFS and OS (adjusted for crossover as appropriate) were analyzed using multivariate and univariate Bayesian network meta-analysis.

RESULTS

In multivariate network-meta analyses (HRs for PFS and OS estimated simultaneously to account for the correlation of treatment effects on PFS and OS), HRs (95% credible interval) for PFS and OS favored dabrafenib plus trametinib [PFS: 0.23 (0.18-0.29) versus DTIC, 0.32 (0.24-0.42) versus ipilimumab plus DTIC, 0.52 (0.32-0.83) versus trametinib, 0.57 (0.48-0.69) versus vemurafenib, and 0.59 (0.50-0.71) versus dabrafenib]; OS [0.41 (0.29-0.56) versus DTIC, 0.52 (0.38-0.71) versus ipilimumab plus DTIC, 0.68 (0.47-0.95) versus trametinib, 0.69 (0.57-0.84) versus vemurafenib, and 0.72 (0.60-0.85) versus dabrafenib]. The beneficial effects on OS of dabrafenib plus trametinib versus ipilimumab plus DTIC and versus trametinib were attenuated when HRs were estimated using univariate network meta-analysis (HRs for PFS and OS estimated separately).

CONCLUSION

This analysis demonstrates improved PFS and OS with dabrafenib + trametinib versus dabrafenib, trametinib, vemurafenib, ipilimumab plus DTIC, and DTIC as first-line treatment for patients with BRAF mutation-positive metastatic melanoma.

FUNDING

Novartis Pharmaceuticals.