Molecular pathology of malignant melanoma: changing the clinical practice paradigm toward a personalized approach

An Insight on Skin Cancer About Different Targets With Update on Clinical Trials and Investigational Drugs

Cancer is a diverse disease caused by transcriptional changes involving genetic and epigenetic features that influence a huge variety of genes and proteins. Skin cancer is a potentially fatal disease that affects equally men and women globally and is characterized by many molecular changes. Despite the availability of various improved approaches for detecting and treating skin cancer, it continues to be the leading cause of death throughout society. This review highlights a general overview of skin cancer, with an emphasis on epidemiology, types, risk factors, pathological and targeted facets, biomarkers and molecular markers, immunotherapy, and clinical updates of investigational drugs associated with skin cancer. The skin cancer challenges are acknowledged throughout this study, and the potential application of novel biomarkers of skin cancer formation, progression, metastasis, and prognosis is explored. Although the mechanism of skin carcinogenesis is currently poorly understood, multiple articles have shown that genetic and molecular changes are involved. Furthermore, several skin cancer risk factors are now recognized, allowing for efficient skin cancer prevention. There have been considerable improvements in the field of targeted treatment, and future research into additional targets will expand patients' therapeutic choices. In comparison to earlier articles on the same issue, this review focused on molecular and genetic factors and examined various skin cancer-related factors in depth.

Overview of current melanoma therapies

Melanoma is the most aggressive type of skin cancer and is responsible for the majority of deaths from skin cancer. Therapeutic advances in the last few decades, notably the development of novel targeted therapies and immunotherapies have significantly improved patient outcomes; nonetheless, these options remain limited due to the onset of resistance to treatment modalities and relapse. In this review, we focus on the available therapeutic options, their benefits, and limitations.

Prevalence of cannabidiol (CBD) consumption and cancer patients' expectations in one oncology day-hospital: A cross-sectional study and questionnaire validation

INTRODUCTION

The growing interest of cannabidiol (CBD) in medical care prompted French health authorities to explore the potential of CBD in cancer-related severe symptoms. This study aimed to assess the prevalence of CBD use among cancer patients with potential associated factors and to measure the cancer patient's health literacy (HL) on CBD consumption.

METHODS

In a prospective study in oncology day-care hospital including patients from 29 October to 20 December 2021, we collected demographic, biological, and oncological characteristics. Patient CBD HL was measured by the hetero-questionnaire 8-item-CBD HL scale (HLS-8-CBD) whose conception has been validated by a psychometric analysis.

RESULTS

Among 363 participants, 20 patients (5.5%) reported CBD use. Factors associated with CBD use were: age <60 years (odd ratio = 7.80[1.36-13.32], p < 10^-4 versus ≥60 years), smoking history (OR = 5.53[1.81-16.88], p < 0.01), and no smoking cessation (OR = 5.07[1.66-15.46], p < 0.01). CBD use was also associated with a better CBD total HL score than non-users (p-value = 0.02).

CONCLUSION

Identification of factors associated with CBD use and a relatively high patient CBD HL in CBD users showed that CBD use in cancer patients care represented a new concern and should enhance health professionals to consider CBD with its associated drug-related problems.

Determination of Common microRNA Biomarker Candidates in Stage IV Melanoma Patients and a Human Melanoma Cell Line: A Potential Anti-Melanoma Agent Screening Model

MicroRNAs (miRNAs) are small, non-coding RNAs that play an important role in regulating gene expression. Dysregulation of miRNA expression is commonly observed in cancer, and it can contribute to malignant cell growth. Melanoma is the most fatal type of skin malignant neoplasia. Some microRNAs can be prospective biomarkers for melanoma in stage IV (advanced) at higher risk of relapses and require validation for diagnostic purposes. This work aimed to (1) determine the most significant microRNA biomarker candidates in melanoma using content analysis of the scientific literature, (2) to show microRNA biomarker candidates' diagnostic efficacy between melanoma patients and healthy control groups in a small-scale preliminary study by blood plasma PCR analysis, (3) to determine significant microRNA markers of the MelCher human melanoma cell line, which are also detected in patients with melanoma, that can be used as markers of drug anti-melanoma activity, and (4) test anti-melanoma activity of humic substances and chitosan by their ability to reduce level of marker microRNAs. The content analysis of the scientific literature showed that hsa-miR-149-3p, hsa-miR-150-5p, hsa-miR-193a-3p, hsa-miR-21-5p, and hsa-miR-155-5p are promising microRNA biomarker candidates for diagnosing melanoma. Estimating microRNA in plasma samples showed that hsa-miR-150-5p and hsa-miR-155-5p may have a diagnostic value for melanoma in stage IV (advanced). When comparing ΔCt hsa-miR-150-5p and ΔCt hsa-miR-155-5p levels in melanoma patients and healthy donors, statistically significant differences were found (p = 0.001 and p = 0.001 respectively). Rates ΔCt were significantly higher among melanoma patients (medians concerning the reference gene miR-320a were 1.63 (1.435; 2.975) and 6.345 (4.45; 6.98), respectively). Therefore, they persist only in plasma from the melanoma patients group but not in the healthy donors group. In human wild-type stage IV melanoma (MelCher) cell culture, the presence of hsa-miR-150-5p and hsa-miR-155-5p in supernatant was detected. The ability of humic substance fractions and chitosan to reduce levels of hsa-miR-150-5p and hsa-miR-155-5p was tested on MelCher cultures, which is associated with anti-melanoma activity. It was found that the hymatomelanic acid (HMA) fraction and its subfraction UPLC-HMA statistically significantly reduced the expression of miR-150-5p and miR-155-5p (p ≤ 0.05). For the humic acid (HA) fraction, this activity was determined only to reduce miR-155-5p (p ≤ 0.05). Ability to reduce miR-150-5p and miR-155-5p expression on MelCher cultures was not determined for chitosan fractions with a molecular weight of 10 kDa, 120 kDa, or 500 kDa. Anti-melanoma activity was also determined in the MTT test on MelCher cultures for explored substances. The median toxic concentration (TC50) was determined for HA, HMA and UPLC-HMA (39.3, 39.7 and 52.0 μg/mL, respectively). For 10 kDa, 120 kDa, or 500 kDa chitosan fractions TC50 was much higher compared to humic substances (508.9, 6615.9, 11352.3 μg/mL, respectively). Thus, our pilot study identified significant microRNAs for testing the in vitro anti-melanoma activity of promising drugs and melanoma diagnostics in patients. Using human melanoma cell cultures gives opportunities to test new drugs on a culture that has a microRNA profile similar to that of patients with melanoma, unlike, for example, murine melanoma cell cultures. It is necessary to conduct further studies with a large number of volunteers, which will make it possible to correlate the profile of individual microRNAs with specific patient data, including the correlation of the microRNA profile with the stage of melanoma.

BRAF V600E immunohistochemistry as a useful tool in the diagnosis of melanomas with ambiguous morphologies and immunophenotypes

We report three melanoma cases in which BRAF V600E immunohistochemistry (IHC) was valuable for diagnosis. Patient 1: In a patient with a history of primary melanoma on the chest and metastatic melanoma to right breast after undergoing multiple local and systemic therapies, a lung metastasis exhibited chondroid differentiation, aberrant myofibroblastic marker expression, and rare pancytokeratin positivity, without melanocytic marker expression. Patient 2: After targeted and immunotherapy for primary melanoma on the scalp as well as regional and distant metastatic melanoma, an omental metastasis showed CDX2-positive glandular structures that were negative for melanocytic markers. It was initially misdiagnosed as primary gastrointestinal adenocarcinoma. Patient 3: A patient with history of melanoma showing epithelioid morphology on the right thigh presented with multiple soft tissue nodules on skin, lymph nodes and internal organs after being lost to follow-up for 4 years. A biopsy specimen from the right thigh showed spindled cells with scattered pancytokeratin cocktail positivity and ambiguous staining for melanocytic markers. For melanomas with ambiguous morphologies and/or immunophenotypes in each of the three patients, BRAF V600E expression by IHC was maintained in both primary and metastatic melanoma specimens examined. These cases highlight the utility of BRAF V600E IHC in the diagnosis of melanoma.

Multiple predictive biomarker testing in melanoma: Another challenge in identifying the optimal approach on cytological samples

BACKGROUND

The management of cutaneous melanoma has changed dramatically in recent years thanks to the development of tyrosine kinase and immune-checkpoint inhibitors (ICIs). Thus, multiple biomarker testing is becoming ever more important for the identification of patients who are potentially eligible for these treatments. One reliable approach to the molecular evaluation of metastatic melanoma is fine needle cytology (FNC). To examine the utility of this approach for assessing PD-L1 expression levels, we evaluated the cellular adequacy of residual cell block (CB) material from metastatic melanomas that were previously tested for BRAF and NRAS mutations.

METHODS

We retrieved from our internal archives a series of FNC samples of metastatic melanoma that had been subjected to molecular testing on residual CB material or a dedicated needle rinse between January 2016 and July 2022. Real-time polymerase chain reaction was used to assess BRAF and NRAS status, and an SP263 assay was employed to ascertain PD-L1 expression levels.

RESULTS

Overall, n = 19 cases were selected. Of these, 11 (57.9%) cases revealed a BRAF exon 15 p.V600E mutation, one case (5.3%) revealed NRAS mutation, and seven cases (36.8%) showed no mutations. Regarding PD-L1 assessment, 16/19 (84.2%) cases were deemed adequate, meaning they contained at least 100 viable cells.

CONCLUSIONS

We highlighted the feasibility of assessing PD-L1 expression levels in residual CB material from metastatic melanomas previously tested for BRAF and NRAS mutations. Moreover, we pointed out that FNC needle rinses may be an alternative source of nucleic acids for molecular testing, preserving CB material for immunocytochemistry evaluation.

A cross-sectional study of clinical, dermoscopic, histopathological, and molecular patterns of scalp melanoma in patients with or without androgenetic alopecia

Scalp melanoma (SM) has a worse prognosis than melanoma in other locations likely because of late diagnosis due to hair coverage, difficulties in interpreting dermoscopy findings, and its unique molecular profile. We aimed to describe the clinical, histopathological, molecular, and dermoscopic patterns of SM and its relation to androgenetic alopecia/elastosis at the tumor site. Through a retrospective cross-sectional study, we identified all SM diagnosed at the A.C.Camargo Cancer Center between 2008 and 2018. In all, 48 SM were analyzed: 45.8% of which exhibited moderate/severe androgenetic alopecia and 54.1% exhibited elastosis. Androgenetic alopecia/elastosis at the site of the SM was associated with older age (p < 0.001), chronic sun damage (p < 0.001), lentigo maligna subtype (p = 0.029), and photodamaged dermoscopic pattern (p < 0.001). Additionally, 41 cases were evaluated with a 14-gene panel: 53.7% displayed mutations and 46.3% were wild-type. BRAF mutations were most common (77%), with BRAF V600K being more frequent (50%) than BRAF V600E (31.2%). The NF1 gene was evaluated in 40 samples, of which 20% exhibited mutations. SM presents differently in areas covered by hair compared to in areas with androgenetic alopecia. Patients without alopecia may have higher Breslow thickness due to late diagnosis because of hair concealment. The high frequency of detrimental mutations can also explain the poor prognosis of SM.

BRAF-Mutated Non-Small Cell Lung Cancer: Current Treatment Status and Future Perspective

V-Raf murine sarcoma viral oncogene homolog B (BRAF) kinase, which was encoded by BRAF gene, plays critical roles in cell signaling, growth, and survival. Mutations in BRAF gene will lead to cancer development and progression. In non-small cell lung cancer (NSCLC), BRAF mutations commonly occur in never-smokers, women, and aggressive histological types and accounts for 1%-2% of adenocarcinoma. Traditional chemotherapy presents limited efficacy in BRAF-mutated NSCLC patients. However, the advent of targeted therapy and immune checkpoint inhibitors (ICIs) have greatly altered the treatment pattern of NSCLC. However, ICI monotherapy presents limited activity in BRAF-mutated patients. Hence, the current standard treatment of choice for advanced NSCLC with BRAF mutations are BRAF-targeted therapy. However, intrinsic or extrinsic mechanisms of resistance to BRAF-directed tyrosine kinase inhibitors (TKIs) can emerge in patients. Hence, there are still some problems facing us regarding BRAF-mutated NSCLC. In this review, we summarized the BRAF mutation types, the diagnostic challenges that BRAF mutations present, the strategies to treatment for BRAF-mutated NSCLC, and resistance mechanisms of BRAF-targeted therapy.

Monoclonal Antibodies to CTLA-4 with Focus on Ipilimumab

The immune checkpoint cytotoxic T lymphocyte-associated antigen 4 (CTLA-4 or CD152) is a negative regulator of T-cell-mediated immune responses which plays a critical role in suppressing autoimmunity and maintaining immune homeostasis. Because of its inhibitory activity on T cells, CTLA-4 has been investigated as a drug target to induce immunostimulation, blocking the interaction with its ligands. The antitumor effects mediated by CTLA-4 blockade have been attributed to a sustained active immune response against cancer cells, due to the release of a brake on T cell activation. Ipilimumab (Yervoy, Bristol-Myers Squibb) is a fully human anti-CTLA-4 IgG1κ monoclonal antibody (mAb) that represents the first immune checkpoint inhibitor approved as monotherapy by FDA and EMA in 2011 for the treatment of unresectable/metastatic melanoma. In 2015, FDA also granted approval to ipilimumab monotherapy as adjuvant treatment of stage III melanoma to reduce the risk of tumour recurrence. The subsequent approved indications of ipilimumab for metastatic melanoma, regardless of BRAF mutational status, and other advanced/metastatic solid tumours always involve its use in association with the anti-programmed cell death protein 1 (PD-1) mAb nivolumab. Currently, ipilimumab is evaluated in ongoing clinical trials for refractory/advanced solid tumours mainly in combination with additional immunostimulating agents.

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.

BRAF Wild-type, PTEN Mutant Malignant Uveal Melanoma Arising Within a Mature Ovarian Teratoma: A Case Report and Review of the Literature

Mature cystic teratomas are common in women of all ages; however, malignant transformation within them is rare and difficult to diagnosis preoperatively. Primary melanoma of the ovary is exceptionally rare and only occurs in relation to a teratoma where it can originate from sporadic somatic mutagenesis within epidermal junctional melanocytes, through malignant transformation of a benign nevus formed within the mature cystic teratoma or from other well differentiated pigment-containing structures such as the uvea. We present a case of primary malignant melanoma arising within a mature cystic teratoma in a young patient, who ultimately developed widespread metastasis necessitating systemic therapy. Our case highlights the role of molecular medicine not only in forming an understanding the origin of the melanoma, but also guiding targeted systemic therapies. Alongside the case we present a review of the literature describing the incidence of molecular aberrations within melanoma as well as the established and emerging techniques and cytotoxic agents for malignant melanoma.

BRAF Heterogeneity in Melanoma

OPINION STATEMENT

In the era of molecular targeted therapy, the accurate detection of BRAF mutation in melanoma has become increasingly important. With the advances of molecular analyses and immunohistochemistry, the presence of BRAF mutational heterogeneity in melanoma has been widely recognized. Although most patients with melanoma have a homogeneous BRAF mutation status because the BRAF mutation occurs at an early stage of melanoma development and acts as a driver gene mutation, BRAF mutational heterogeneity does exist, among different tumor sites of a single patient (intertumor heterogeneity) and/or even within a single tumor (intratumor heterogeneity). To summarize the published reports, about 10% of melanoma patients may show intertumorally discordant BRAF status and about 15% of BRAF-mutated melanomas may have intratumor BRAF heterogeneity, although the reported results vary strikingly among the studies and methods used. Considering the BRAF heterogeneity of melanoma, a single biopsy from a single tumor may not be sufficient to uncover the entire BRAF status of a patient. Multiple samples from different sites may be preferable to assess the indication of BRAF/MEK inhibitors, as recommended by the current clinical guidelines. The impact of BRAF heterogeneity on patient survival or the response to treatment with BRAF/MEK inhibitors is an interesting issue, but requires further investigation.

NECTIN4: A Novel Therapeutic Target for Melanoma

Malignant melanoma is the most common lethal skin cancer and causes death in a short time when metastasized. Although BRAF inhibitors (BRAFi) have greatly improved the prognosis of BRAF-mutated melanoma, drug resistance is a major concern even when they are combined with MEK inhibitors. Alternative treatments for BRAFi-resistant melanoma are highly anticipated. Nectin cell adhesion molecule 4 (NECTIN4) is highly expressed and associated with progression in tumors. We aimed to investigate the role of NECTIN4 in melanoma and its potency as a therapeutic target using 126 melanoma samples and BRAFi-resistant cells. Immunohistochemically, most of the clinical samples expressed NECTIN4, at least in part. NECTIN4 was highly expressed in BRAF-mutated melanoma and its high expression was associated with disease-free survival. In BRAFi-resistant melanoma cells, NECTIN4 and the PI3K/Akt pathway were upregulated, along with the acquisition of BRAFi resistance. Monomethyl auristatin E, a cytotoxic part of NECTIN4-targeted antibody-drug conjugate, was effective for BRAF-mutated or BRAFi-resistant melanoma cells. NECTIN4 inhibition increased the sensitivity of BRAFi-resistant cells to BRAFi and induced apoptosis. In conclusion, we revealed the expression and roles of NECTIN4 in melanoma. Targeted therapies against NECTIN4 can be a novel treatment strategy for melanoma, even after the acquisition of BRAFi resistance.

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.

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.

Loss of prdm1a accelerates melanoma onset and progression

Melanoma is an aggressive, deadly skin cancer derived from melanocytes, a neural crest cell derivative. Melanoma cells mirror the developmental program of neural crest cells in that they exhibit the same gene expression patterns and utilize similar cellular mechanisms, including increased cell proliferation, epithelial-mesenchymal transition, and migration. Here we studied the role of neural crest regulator PRDM1 in melanoma onset and progression. In development, Prdm1a functions to promote neural crest progenitor fate, and in melanoma, we found that PRDM1 has reduced copy number and is recurrently deleted in both zebrafish and humans. When examining expression of neural crest and melanocyte development genes, we show that sox10 progenitor expression is high in prdm1a-/- mutants, while more differentiated melanocyte markers are reduced, suggesting that normally Prdm1a is required for differentiation. Data mining of human melanoma datasets indicates that high PRDM1 expression in human melanoma is correlated with better patient survival and decreased PRDM1 expression is common in metastatic tumors. When one copy of prdm1a is lost in the zebrafish melanoma model Tg(mitfa:BRAFV600E );p53-/- ;prdm1a+/- , melanoma onset occurs more quickly, and the tumors that form have a larger area with increased expression of sox10. These data demonstrate a novel role for PRDM1 as a tumor suppressor in melanoma.

Primary Melanoma of the Lung Treated with Surgery, Dabrafenib and Trametinib

This is a case report on a 69-year-old woman who was diagnosed with malignant melanoma presenting in the lung. A complete staging workup was performed by her oncologist, with no skin lesion identified as a primary. CT-guided needle biopsy of the lung nodule was completed, with pathology revealing atypical cells consistent with malignant melanoma. Following full body examination by the cutaneous oncologist, a robotic wedge resection and lymph node dissection accompanied by bronchoscopy were performed. Molecular testing (Caris Life Sciences) of the surgical tumor specimen revealed pathological BRAF DNA mutation in exon 15/p.V600K. The patient was initially treated with nivolumab, then treated with a combination of dabrafenib and trametinib at recurrence.

Optimal treatment strategy for metastatic melanoma patients harboring BRAF-V600 mutations

BRAF-V600 mutations occur in approximately 50% of patients with metastatic melanoma. Immune-checkpoint inhibitors and targeted therapies are both active as first-line treatments in these patients regardless of their mechanisms of action and toxicities. However, an upfront therapeutic strategy is still controversial. In fact, waiting for results of ongoing clinical trials and for new biomarkers, clinicians should base their decision on the clinical characteristics of the patient and on the biological aspects of the tumor. This review provides an overview on BRAF-V600 mutations in melanoma and will discuss their prognostic and clinical significance. Moreover, it will suggest a therapeutic algorithm that can drive therapeutic choice in a first-line setting for BRAF-V600 mutant melanoma patients.

The Role of Autophagy in the Resistance to BRAF Inhibition in BRAF-Mutated Melanoma

Malignant melanoma is the most aggressive and notorious skin cancer, and metastatic disease is associated with very poor long-term survival outcomes. Although metastatic melanoma patients with oncogenic mutations in the BRAF gene initially respond well to the treatment with specific BRAF inhibitors, most of them will eventually develop resistance to this targeted therapy. As a highly conserved catabolic process, autophagy is responsible for the maintenance of cellular homeostasis and cell survival, and is involved in multiple diseases, including cancer. Recent study results have indicated that autophagy might play a decisive role in the resistance to BRAF inhibitors in BRAF-mutated melanomas. In this review, we will discuss how autophagy is up-regulated by BRAF inhibitors, and how autophagy induces the resistance to these agents.

Molecular profiling of Spitz nevi identified by digital RNA counting

Supplemental Digital Content is available in the text.

The molecular properties of benign melanocytic lesions are poorly understood. Only a few studies have been carried out on specific nevi subtypes, including common nevocellular nevi (NCN) or Spitz nevi (SN). Genomic alterations in melanoma-associated oncogenes are typically absent in SN. In the present study, mRNA expressions of 25 SN and 15 NCN were analyzed. Molecular profiling was performed using the RNA NanoString nCounter Gene Expression Platform (number of genes=770). Marker discovery was performed with a training set consisting of seven SN and seven NCN samples from the same patients, and validation was performed using a second set consisting of 18 SN and eight NCN samples. Using the training set, 197 differentially expressed genes were identified in SN versus NCN. Of these, 74 genes were validated in the validation set (false discovery rate q≤0.13). In addition, using random forest and least absolute shrinkage and selection operator feature selection, a molecular signature of SN versus NCN was identified including 15 top-ranked genes. The present study identified a distinct molecular expression profile in SN compared with NCN, even when lesions were obtained from the same patients. Gene set analysis showed upregulation of gene pathways with increased expression of transcripts related to immunomodulatory, inflammatory, and extracellular matrix interactions as well as angiogenesis-associated processes in SN. These findings strongly indicate that SN represent a distinct group of melanocytic neoplasms and evolve differentially and not sequentially from NCN.

Quantitative Interrogation of the Human Kinome Perturbed by Two BRAF Inhibitors

Oncogenic BRAF mutations contribute to the development of a number of cancers, and small-molecule BRAF inhibitors have been approved by the Food and Drug Administration (FDA) for anticancer therapy. In this study, we employed two targeted quantitative proteomics approaches for monitoring separately the alterations in protein expression and ATP binding affinities of kinases in cultured human melanoma cells elicited by two FDA-approved small-molecule BRAF inhibitors, dabrafenib and vemurafenib. Our results showed that treatment with the two inhibitors led to markedly different reprograming of the human kinome. Furthermore, we confirmed that vemurafenib could compromise the ATP binding capacity of MAP2K5 in vitro and inhibit its kinase activity in cells. Together, our targeted quantitative proteomic methods revealed profound changes in expression levels of kinase proteins in cultured melanoma cells upon treatment with clinically used BRAF inhibitors and led to the discovery of novel putative target kinases for these inhibitors.

An Update Regarding the Molecular Genetics of Melanocytic Neoplasms and the Current Applications of Molecular Genetic Technologies in Their Diagnosis and Treatment

Molecular genetic technologies are used to aid in diagnosis and treatment of borderline melanocytic tumors as an adjuvant to the gold standard histopathologic evaluation. A specific set of fluorescence in situ hybridization probes is widely used to aid in diagnosing challenging melanocytic lesions. New melanoma probe cocktails have revealed increased sensitivity and specificity in ambiguous melanocytic cases. Array comparative genomic hybridization is a more complex technology used for the work-up of diagnostically problematic Spitzoid melanocytic proliferations. Cutting-edge technologies, including next-generation sequencing and cell-free nucleic acid analysis, are promising biomarker applications for mutation detection towards personalized patient management.

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.

Molecular Biology and Genetic Mechanisms in the Progression of the Malignant Skin Melanoma

Malignant skin melanoma is a tumor deriving from transformed skin melanocytes as a result of complex interactions between genetic and environmental factors. This melanoma has a potential to metastasize early and very often it is resistant to the existing modalities of the systemic therapy. As in any other neoplasms, certain types of melanoma may skip certain stages of progression. The progression from one stage to another is accompanied by specific biological changes. Several key changes in the melanoma tumorogenesis influence the regulation of the cell proliferation and vitality, including the RAS-RAF-ERK, PI3K-AKT, and p16INK4/CDK4/RB pathways. A key role in the dissreguarity of the RAS-RAF-ERK (MAPK) pathway in the malignant melanoma development have been demonstrated by many studies. To date, the molecular genetic alterations during melanoma development have been partially known. In the pathogenesis of the malignant melanoma, there are mutations of various genes such as NRAS, BRAF, and PTEN and mutations and deletions of CDKN2A. In the past years, great advance has been made in the insights of the molecular aspects of the melanoma pathogenesis. However, this field yet poses a challenge to discover new details about the melanoma molecular characteristics. The research results are focused towards the improvement of the melanoma patients prognosis by introducing personalized targeted therapy.

The clinical features, treatment, and prognosis of primary mediastinal malignant melanoma: A case report

RATIONALE

Primary malignant melanoma (MM) of the mediastinum is exceedingly rare; a review of the English-language literature reveals only a small number of case reports. In this paper, we discuss a case of primary mediastinal MM and present a review of the relevant literature on its clinical features and treatment.

PATIENT CONCERNS

A 52-year-old male presenting with back pain was admitted to our hospital for treatment. Imaging examination revealed an anterior mediastinal mass and no evidence of other metastatic or primary lesions.

DIAGNOSES

After complete resection by video-assisted thoracoscopic surgery (VATS), histopathologic examination showed evidence of brown melanin pigment in the tumor cells, which were immunohistochemically positive for antimelanoma antibodies (HMB-45, Melan-A, S-100, and Ki67).

INTERVENTIONS

Given the diagnosis of MM after surgery, the tumor was tested for the mutation in the BRAF gene (which encodes the serine/threonine-protein kinase B-raf) that leads to a V600E amino acid substitution, and the tumor was found to be wild type. Then the patient has been given immunotherapy.

OUTCOMES

The patient completed 4 cycles of immunotherapy, and no recurrence or metastasis has been detected to date.

LESSONS

In such cases, it is difficult to prove the primary nature of the intrathoracic melanoma. Moreover, preoperative identification of this disease is challenging, making misdiagnosis likely. Due to fast progression and poor prognosis, timely and effective systemic treatment is necessary to improve the outcomes for patients with primary mediastinal MM.

Fluorescence in situ hybridization in surgical pathology: principles and applications

Identification of recurrent tumour‐specific chromosomal translocations and novel fusion oncogenes has important diagnostic, therapeutic and prognostic implications. Over the past decade, fluorescence in situ hybridization (FISH) analysis of tumour samples has been one of the most rapidly growing areas in genomic medicine and surgical pathology practice. Unlike traditional cytogenetics, FISH affords a rapid analysis of formalin‐fixed, paraffin‐embedded cells within a routine pathology practice workflow. As more diagnostic and treatment decisions are based on results of FISH, demand for the technology will become more widespread. Common FISH‐detected alterations are chromosome deletions, gains, translocations, amplifications and polysomy. These chromosome alterations may have diagnostic and therapeutic implications for many tumour types. Integrating genomic testing into cancer treatment decisions poses many technical challenges, but rapid progress is being made to overcome these challenges in precision medicine. FISH assessment of chromosomal changes relevant to differential diagnosis and cancer treatment decisions has become an important tool for the surgical pathologist. The aim of this review is to provide a theoretical and practical survey of FISH detected translocations with a focus on strategies for clinical application in surgical pathology practice.

Investigation of BRAF mutation analysis with different technical platforms in metastatic melanoma

In metastatic melanoma, the detection of somatic mutations in the BRAF gene is crucial regarding patient selection for targeted therapy. Several screening methods have been developed to identify BRAF gene mutations. In this study, our objective was to evaluate the detection of the BRAF V600 mutations using two molecular methods, real-time polymerase chain (real-time PCR) assay and pyrosequencing, and immunohistochemistry (IHC), and to compare the results of these different technical platforms. This study included 98 patients diagnosed with metastatic melanoma at the Hacettepe University, Department of Pathology between 2002 and 2014. BRAF mutation analysis was tested with real-time PCR, pyrosequencing and IHC methods. The results of all three tests were compared with a reference test, and the sensitivity, specificity rates and kappa coefficient values were analysed for each test. We successfully analysed BRAF mutations using all three methods in 92 patients. According to our findings, the pyrosequencing method had the highest kappa value regarding the determination of BRAF V600 mutations. The kappa values were at almost perfect agreement levels in pyrosequencing and real-time PCR assay (kappa coefficient for pyrosequencing=0.895 (95% CI: 0.795-0.995); kappa coefficient for real-time PCR=0.871 (95% CI: 0.761-0.981). The kappa value was at a substantial agreement level in the IHC analysis (kappa coefficient=0.776 (95% CI: 0.629-0.923). According to our results, we found that real-time PCR and pyrosequencing methods were equally excellent in determination of BRAF V600 mutations. The IHC method, which is commonly used in routine pathology practice, can also be safely used as a screening test for determination of BRAF V600 mutations.

Distinct clinicopathological features in metanephric adenoma harboring BRAF mutation

BRAF mutation recently has been reported in metanephric adenoma. We sought to determine the clinical and morphologic features of BRAF-mutated metanephric adenoma and to correlate BRAF mutation with BRAF V600E immunohistochemical staining results. A series of 48 metanephric adenomas and 15 epithelial-predominant nephroblastomas were analyzed for the occurrence of BRAF mutation (BRAF V600E/V600E complex, BRAF V600D, BRAF V600K and BRAF V600R) using the BRAF RGQ PCR kit (Qiagen). Immunohistochemistry was performed using monoclonal mouse antibodies against p16^INK4 and VE1 (Spring Bioscience), recognizing the BRAF V600E mutant protein. Forty-one of 48 cases (85%) showed BRAF V600E mutation; none of the other BRAF variants was detected. Of 41 BRAF-mutated metanephric adenomas, 33 showed positive VE1 immunostaining (sensitivity 80%, specificity 100%); in all cases we detected p16^INK4 expression regardless of BRAF mutation status. All epithelial-predominant nephroblastomas were BRAF-wild-type and none expressed VE1. The following features were associated with BRAF V600E mutation: older patients (p=0.01), female predominance (p=0.005) and the presence of a predominantly acinar architecture (p=0.003). In summary, BRAF-mutated metanephric adenomas were associated with older age, female predominance, and the presence of a predominant acinar component. A subset (20%) of BRAF-mutated metanephric adenomas was not detected by VE1 immunostaining.

Malignant Melanoma: Beyond the Basics

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Discuss the initial management of cutaneous malignant melanoma with regard to diagnostic biopsy and currently accepted resection margins. 2. Be familiar with the management options for melanoma in specific situations such as subungual melanoma, auricular melanoma, and melanoma in the pregnant patient. 3. Discuss the differentiating characteristics of desmoplastic melanoma and its treatment options. 4. List the indications for sentinel lymph node biopsy and be aware of the ongoing trials and current literature. 5. Discuss the medical therapies available to patients with metastatic melanoma.

SUMMARY

Management of the melanoma patient is a complex and evolving subject. Plastic surgeons should be aware of the recent changes in the field. Excisional biopsy remains the gold standard for diagnosis, although there is no evidence that use of other biopsy types alters survival or recurrence. Wide local excisions should be carried out with margins as recommended by National Comprehensive Cancer Network guidelines according to lesion Breslow depth, with sentinel lymph node biopsy being offered to all medically suitable candidates with intermediate thickness melanomas (1.0 to 4.0 mm), and with sentinel lymph node biopsy being considered for high-risk lesions (ulceration and/or high mitotic figures) with melanomas of 0.75 to 1.0 mm. Melanomas diagnosed during pregnancy can be treated with preoperative lymphoscintigraphy and wide local excision under local anesthesia, with sentinel lymph node biopsy under general anesthesia delayed until after delivery. Management of desmoplastic melanoma is currently controversial with regard to the indications for sentinel lymph node biopsy and the efficacy of postoperative radiation therapy. Subungual and auricular melanoma have evolved from being treated by amputation of the involved appendage to less radical procedures-ear reconstruction is now attempted in the absence of gross invasion into the perichondrium, and subungual melanomas may be treated with wide local excision down to and including the periosteum, with immediate full-thickness skin grafting over bone. Although surgical treatment remains the current gold standard, recent advances in immunotherapy and targeted molecular therapy for metastatic melanoma show great promise for the development of medical therapies for melanoma.

Discordancy in BRAF mutations among primary and metastatic melanoma lesions: clinical implications for targeted therapy

Systemic targeted molecular therapy, in the form of a selective BRAF inhibitor with or without a MEK inhibitor, is a standard treatment for patients with BRAF V600 mutation-positive melanoma with unresectable stage III and IV disease. Patients with BRAF mutation-negative primary tumors may manifest BRAF mutation-positive metastatic disease. It is unclear whether all metastatic lesions carry the same BRAF mutation status found in the primary tumor and if discordancy exists, in what frequency it occurs. Primary and matched metastatic lesions in 25 melanoma patients were tested for the BRAF V600E/Ec, V600K, V600D, and V600R mutations using a BRAF RGQ PCR kit (Qiagen). Four patients (16%) had discrepancies between their primary and metastatic melanoma BRAF status. Of these patients, 2 (8%) had BRAF mutation-positive primary melanomas with BRAF mutation-negative metastatic lesions and 2 (8%) patient had BRAF mutation-negative melanoma with a BRAF mutation-positive metastatic lesion. In summary, discordancy of BRAF mutation status is not an infrequent finding between primary and metastatic melanoma. It may be prudent in previously negative patients to determine BRAF mutation status of new metastatic tumors for proper allocation of BRAF inhibitor therapy. Discordant BRAF status may have a role in the varying patterns of response and inevitable resistance seen with BRAF inhibitor therapies.