KIT Pathway Alterations in Mucosal Melanomas of the Vulva and Other Sites

Clinicopathological and Molecular Features of Penile Melanoma With a Proposed Staging System

Penile melanomas (PM) are an exceedingly rare subtype of mucosal melanoma (MM), and we reviewed the clinicopathologic features and molecular profile in 8 PMs. The patient ages ranged from 46 to 78 (mean: 62.8) years with involvement on the glans (n=5; 62.5%), penile urethra (n=2; 25%), and foreskin (n=1, 12.5%). Tumor depth ranged from 1.6 to 10.0 (mean: 5.25) mm. Most of the patients underwent partial penectomy (n=6; 75%) and sentinel lymph node (LN) biopsy N=7; 87.5%). Seven patients had metastatic disease at diagnosis, 6 involving LNs and 1 the adrenal gland, and 4 died of disease with a mean follow-up period of 40.5 (2 to 95) months. Five of 7 (71%) cases identified 15 molecular alterations within KIT , CDKN2A , NF1 , PTEN , and APC (n=2 each), and NRAS , MAP3K1 , CDH1 , MSH6 , and TERT (n=1 each). Two cases were not found to harbor genetic aberrations, and 1 case failed testing. In addition, we reviewed the English literature and included 93 cases with a reported depth of invasion and follow-up. A total of 101 PMs were analyzed for prognostic parameters, and the overall survival was significantly worse in patients with LN metastasis (P=0.0008), distant metastasis (P=0.0016), and greater depth of invasion (P=0.0222) based upon T-stage. While T4 conferred substantially worse survival, the delineation of the survival curves between T2 and T3 was less clear, and combining T2+T3 disease had a strong prognostic impact ( P =0.0024). Prognostic parameters used in the staging of cutaneous melanomas may also be used in PMs. An alternative staging system expanding the inclusion criteria for T2 might provide a more accurate prognostic stratification.

Primary cervical malignant melanoma that was successfully treated with pembrolizumab: a case report and literature review

Primary malignant melanoma (MM) arising from the cervix is an exceedingly rare occurrence, and patients diagnosed with this condition often face a dismal clinical prognosis. Here, we present a case study of a postmenopausal woman presenting with vaginal bleeding and a conspicuous 5-centimeter black mass on the cervix. Based on the staging criteria established by the International Federation of Gynecology and Obstetrics, she was diagnosed with stage IIB primary cervical MM. The patient underwent neoadjuvant therapy prior to a radical hysterectomy and a bilateral salpingo-oophorectomy. Subsequently, she completed 18 cycles of pembrolizumab therapy, achieving clinical complete remission. Notably, at the 31-month follow-up, there were no signs of recurrence. This successful treatment outcome serves as a valuable clinical reference for the management of primary cervical MM.

Targeted next-generation sequencing of Japanese patients with sinonasal mucosal melanomas identifies frequent NRAS and CTNNB1 mutations

OBJECTIVE

Mucosal melanoma is a rare malignancy; however, the reported incidence rate of mucosal melanoma is higher in Asians than in Caucasians. Sinonasal mucosal melanoma (SNMM) is an aggressive malignancy with a poor prognosis due to distant metastasis. Systemic therapy with BRAF inhibitor and MEK inhibitor is one of the standards of care for cutaneous melanoma patients with BRAF V600 mutations. However, no molecular targeted therapy for patients with mucosal melanoma has been established. Relatively few studies have described the genetic mutations associated with mucosal melanoma because of its low frequency. Furthermore, to the best of our knowledge, the genetic mutations among Japanese patients have not been reported. Therefore, in the current study, we evaluated the genetic and clinicopathological characteristics of patients with SNMM.

METHODS

A total of 18 tissue samples obtained from patients with SNMM were analyzed for genetic mutations based on targeted next-generation sequencing to investigate the driver of tumorigenesis and/or candidate genes for predicting clinical outcomes in SNMM. We also performed immunohistochemistry for patients identified with CTNNB1 mutations.

RESULTS

Eight of the 18 (44 %) patients had genetic mutations. The most frequent mutation was NRAS (6/18, 33 %), followed by CTNNB1 (2/18, 11 %) and BRAF (1/18, 5.6 %). One patient had both NRAS and CTNNB1 mutations. Clinical outcomes did not differ significantly between those with and without genetic mutations. NRAS mutations were associated with relatively higher T classification and worse survival rates, although the differences were not significant. The nuclear translocation of β-catenin was detected in both tumors with CTNNB1 mutations. The amino acid change in the BRAF mutation was K601R in exon 15. In the current study, no BRAF V600 mutations were detected.

CONCLUSION

Genetic mutations were not significantly associated with clinical outcomes. However, NRAS mutations may be a prognostic predictor and CTNNB1 mutation may be a treatment effector for immune check inhibitors. A larger prospective study is required to clarify the clinical importance of genetic mutations in patients with SNMM.

Genetic landscape and prognosis of conjunctival melanoma in Chinese patients

AIMS

Conjunctival melanoma (CoM) is a rare but highly lethal ocular melanoma and there is limited understanding of its genetic background. To update the genetic landscape of CoM, whole-exome sequencing (WES) and targeted next-generation sequencing (NGS) were performed.

METHODS

Among 30 patients who were diagnosed and treated at Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, from January 2018 to January 2023, WES was performed on 16 patients, while targeted NGS was conducted on 14 patients. Samples were analysed to identify the mutated genes, and the potential predictive factors for progression-free survival were evaluated. Furthermore, the expression of the mutated gene was detected and validated in a 30-patient cohort by immunofluorescence.

RESULTS

Mutations were verified in classic genes, such as BRAF (n=9), NRAS (n=5) and NF1 (n=6). Mutated FAT4 and BRAF were associated with an increased risk for the progression of CoM. Moreover, decreased expression of FAT4 was detected in CoM patients with a worse prognosis.

CONCLUSIONS

The molecular landscape of CoM in Chinese patients was updated with new findings. A relatively high frequency of mutated FAT4 was determined in Chinese CoM patients, and decreased expression of FAT4 was found in patients with worse prognoses. In addition, both BRAF mutations and FAT4 mutations could serve as predictive factors for CoM patients.

[Anorectal melanoma : Update on clinical presentation, diagnosis and treatment]

Anorectal melanomas are a rare malignant type of cancer and pose a diagnostic challenge due to their hidden anatomical location. They are associated with nonspecific clinical symptoms and are therefore often misinterpreted as benign disease. The result is delayed diagnosis in the locally advanced or metastasized stage and an unfavorable prognosis. Given the overall low incidence of the tumor, no consensus guidelines for diagnosis or therapy are established either internationally or nationally at present. The present work intends to provide a comprehensive overview of the clinical aspects, diagnostics, and therapeutic approaches of anorectal melanoma based on the currently available literature.

Treatment of acral and mucosal melanoma: Current and emerging targeted therapies

Targeted therapies revolutionized the management of patients with advanced and metastatic cutaneous melanoma. However, despite recent advances in the understanding of the molecular drivers of melanoma and its treatment with targeted therapies, patients with rare and aggressive melanoma subtypes, including acral melanoma (AM) and mucosal melanomas (MM), show limited long-term clinical benefit from current targeted therapies. While patients with AM or MM and BRAF or KIT mutations may benefit from targeted therapies, the frequency of these mutations is relatively low, and there are no genotype-specific treatments for most patients with AM or MM who lack common driver mutations. The poor prognosis of AM and MM can also be attributed to the lack of understanding of their unique molecular landscapes and clinical characteristics, due to being under-represented in preclinical and clinical studies. We review current knowledge of the molecular landscapes of AM and MM, focusing on actionable therapeutic targets and pathways for molecular targeted therapies, to guide the development of more effective targeted therapies for these cancers. Current and emerging strategies for the treatment of these melanoma subtypes using targeted therapies are also summarized.

MicroRNAs as Potential Biomarkers in Gynecological Cancers

MicroRNAs are non-coding transcripts that, thanks to the ability to regulate the mRNA of target genes, can affect the expression of genes encoding tumor suppressors and oncogenes. They can control many important cellular processes, including apoptosis, differentiation, growth, division, and metabolism. Therefore, miRNAs play an important role in the development of many cancers, including gynecological cancers. Ovarian cancer, endometrial cancer, cervical cancer, and vulvar cancer are the most common cancers in women and are a frequent cause of death. The heterogeneity of the pathogenesis of these gynecological diseases makes the diagnostic process a significant obstacle for modern medicine. To date, many studies have been carried out, in which particular attention has been paid to the molecular pathomechanism of these diseases, with particular emphasis on miRNAs. To date, the changed profile of many miRNAs, which influenced the promotion of proliferation, migration, invasion processes and the simultaneous inhibition of programmed cell death, has been proven many times. Detailed understanding of the molecular effects of miRNAs in the above-mentioned gynecological cancers will enable the development of potential predictive and prognostic biomarkers, as well as the optimization of the diagnostic process.

Differential plasma protein expression after ingestion of essential amino acid-based dietary supplement verses whey protein in low physical functioning older adults

In a recent randomized, double-blind, placebo-controlled trial, we were able to demonstrate the superiority of a dietary supplement composed of essential amino acids (EAAs) over whey protein, in older adults with low physical function. In this paper, we describe the comparative plasma protein expression in the same subject groups of EAAs vs whey. The plasma proteomics data was generated using SOMA scan assay. A total of twenty proteins were found to be differentially expressed in both groups with a 1.5-fold change. Notably, five proteins showed a significantly higher fold change expression in the EAA group which included adenylate kinase isoenzyme 1, casein kinase II 2-alpha, Nascent polypeptide-associated complex subunit alpha, peroxiredoxin-1, and peroxiredoxin-6. These five proteins might have played a significant role in providing energy for the improved cardiac and muscle strength of older adults with LPF. On the other hand, fifteen proteins showed slightly lower fold change expression in the EAA group. Some of these 15 proteins regulate metabolism and were found to be associated with inflammation or other comorbidities. Gene Ontology (GO) enrichment analysis showed the association of these proteins with several biological processes. Furthermore, protein-protein interaction network analysis also showed distinct networks between upregulated and downregulated proteins. In conclusion, the important biological roles of the upregulated proteins plus better physical function of participants in the EAAs vs whey group demonstrated that EAAs have the potential to improve muscle strength and physical function in older adults. This study was registered with ClinicalTrials.gov: NCT03424265 "Nutritional interventions in heart failure."

The contemporary management of cancers of the sinonasal tract in adults

Sinonasal malignancies make up <5% of all head and neck neoplasms, with an incidence of 0.5-1.0 per 100,000. The outcome of these rare malignancies has been poor, whereas significant progress has been made in the management of other cancers. The objective of the current review was to describe the incidence, causes, presentation, diagnosis, treatment, and recent developments of malignancies of the sinonasal tract. The diagnoses covered in this review included sinonasal undifferentiated carcinoma, sinonasal adenocarcinoma, sinonasal squamous cell carcinoma, and esthesioneuroblastoma, which are exclusive to the sinonasal tract. In addition, the authors covered malignances that are likely to be encountered in the sinonasal tract-primary mucosal melanoma, NUT (nuclear protein of the testis) carcinoma, and extranodal natural killer cell/T-cell lymphoma. For the purpose of keeping this review as concise and focused as possible, sarcomas and malignancies that can be classified as salivary gland neoplasms were excluded.

Case Report: Durable complete pathologic response and organ preservation following ipilimumab and nivolumab for locally advanced primary vaginal mucosal melanoma

Optimal management of locally advanced vaginal mucosal melanoma is poorly understood because of its rarity and unique biology. Patients have a poor prognosis despite aggressive management approaches including pelvic exenteration and adjuvant radiation that carry major morbidities. We report a case of a patient in early 40’s who experienced complete pathologic response and organ preservation following immunotherapy consisting of 3 cycles of ipilimumab and nivolumab. Treatment was complicated by a high-grade immune mediated hepatitis that eventually resolved with immunosuppressive therapy. Immune monitoring studies utilizing vaginal tumor biopsies showed evidence of enhanced infiltration by CD3+/CD8+ cytotoxic T-cells and increased expression of MHC-I/PD-L1 within the tumor microenvironment following immunotherapy. The patient continues to be without evidence of disease recurrence by radiologic and gynecologic examinations with more than 2 years of follow up from the time of immunotherapy initiation. To our knowledge, this is the only case report in the literature of a patient with locally advanced vaginal mucosal melanoma experiencing a durable complete pathologic response and organ preservation following immune checkpoint blockade as the only treatment approach.

Alterations in key signaling pathways in sinonasal tract melanoma. A molecular genetics and immunohistochemical study of 90 cases and comprehensive review of the literature

Sinonasal mucosal melanoma is a rare tumor arising within the nasal cavity, paranasal sinuses, or nasopharynx (sinonasal tract). This study evaluated 90 cases diagnosed in 29 males and 61 females with median age 68 years. Most tumors involved the nasal cavity and had an epithelioid morphology. Spectrum of research techniques used in this analysis includes targeted-DNA and -RNA next-generation sequencing, Sanger sequencing, fluorescence in situ hybridization and immunohistochemistry. Sinonasal melanomas were commonly driven by RAS (38/90, 42%), especially NRAS (n = 36) mutations and rarely (4/90, 4%) displayed BRAF pathogenic variants. BRAF/RAS mutants were more frequent among paranasal sinuses (10/14, 71%) than nasal (26/64, 41%) tumors. BRAF/RAS-wild type tumors occasionally harbored alterations of the key components and regulators of Ras-MAPK signaling pathway: NF1 mutations (1/17, 6%) or NF1 locus deletions (1/25, 4%), SPRED1 (3/25, 12%), PIK3CA (3/50, 6%), PTEN (4/50, 8%) and mTOR (1/50, 2%) mutations. These mutations often occurred in a mutually exclusive manner. In several tumors some of which were NRAS mutants, TP53 was deleted (6/48, 13%) and/or mutated (5/90, 6%). Variable nuclear accumulation of TP53, mirrored by elevated nuclear MDM2 expression was seen in >50% of cases. Furthermore, sinonasal melanomas (n = 7) including RAS/BRAF-wild type tumors (n = 5) harbored alterations of the key components and regulators of canonical WNT-pathway: APC (4/90, 4%), CTNNB1 (3/90, 3%) and AMER1 (1/90, 1%). Both, TERT promoter mutations (5/53, 9%) and fusions (2/40, 5%) were identified. The latter occurred in BRAF/RAS-wild type tumors. No oncogenic fusion gene transcripts previously reported in cutaneous melanomas were detected. Eight tumors including 7 BRAF/RAS-wild type cases expressed ADCK4::NUMBL cis-fusion transcripts. In summary, this study documented mutational activation of NRAS and other key components and regulators of Ras-MAPK signaling pathway such as SPRED1 in a majority of sinonasal melanomas.

Advanced Acral Melanoma Therapies: Current Status and Future Directions

Melanoma is one of the deadliest malignancies. Its incidence has been significantly increasing in most countries in recent decades. Acral melanoma (AM), a peculiar subgroup of melanoma occurring on the palms, soles, and nails, is the main subtype of melanoma in people of color and is extremely rare in Caucasians. Although great progress has been made in melanoma treatment in recent years, patients with AM have shown limited benefit from current therapies and thus consequently have worse overall survival rates. Achieving durable therapeutic responses in this high-risk melanoma subtype represents one of the greatest challenges in the field. The frequency of BRAF mutations in AM is much lower than that in cutaneous melanoma, which prevents most AM patients from receiving treatment with BRAF inhibitors. However, AM has more frequent mutations such as KIT and CDK4/6, so targeted therapy may still improve the survival of some AM patients in the future. AM may be less susceptible to immune checkpoint inhibitors because of the poor immunogenicity. Therefore, how to enhance the immune response to the tumor cells may be the key to the application of immune checkpoint inhibitors in advanced AM. Anti-angiogenic drugs, albumin paclitaxel, or interferons are thought to enhance the effectiveness of immune checkpoint inhibitors. Combination therapies based on the backbone of PD-1 are more likely to provide greater clinical benefits. Understanding the molecular landscapes and immune microenvironment of AM will help optimize our combinatory strategies.

Urethral Melanoma – Clinical, Pathological and Molecular Characteristics

BACKGROUND:

Mucosal melanoma involving the urethra is a rare disease with distinct clinical and molecular characteristics and poor outcomes. Our current knowledge is limited by the small number of reports regarding this disease.

OBJECTIVE:

To describe the clinical, pathological, and molecular characteristics of urethral melanoma.

METHODS:

We summarized the clinicopathologic data for 31 patients treated for urethral melanoma from 1986–2017 at our institution. Genomic data from our institutional sequencing platform MSK-IMPACT (n = 5) and gene-specific PCR data on BRAF, KIT, and/or NRAS (n = 8) were compared to genomic data of cutaneous melanomas (n = 143), vulvar/vaginal melanomas (n = 24), and primary non-melanoma urethral tumors (n = 5) from our institutional database.

RESULTS:

Twenty-three patients were diagnosed with localized disease, 7 had regional/nodal involvement and one had metastases. Initial treatment included surgery in 25 patients; seven had multimodal treatment. Median follow-up was 46 months (IQR 33–123). Estimated 5-year cancer-specific survival was 45%. No significant change in survival was observed based on a year of treatment.

Primary urethral melanomas showed a higher frequency of TP53 mutations compared to cutaneous (80.0% vs. 18.2%, p = 0.006) and vulvar/vaginal melanomas (80.0 vs. 25.0%, p = 0.04). BRAF mutations were absent in urethral primaries (0% vs. 46% in cutaneous melanoma, p = 0.02). Tumor mutation burden was higher in cutaneous than urethral melanomas (p = 0.04). Urethral melanomas had a higher number of somatic alterations compared to non-melanoma urethral tumors (median 11 vs. 5, p = 0.03).

CONCLUSIONS:

Our findings support a unique mutational landscape of urethral melanoma compared to cutaneous melanoma. Survival remains poor and is unchanged over the time studied.

Vulvar Melanoma in association with germline MITF p.E318K variant

Vulvar melanoma is a rare and aggressive cancer with a poor prognosis. The etiology of mucosal melanoma remains largely uncharacterized and no hereditary risk factors are established for this rare disease. While the germline variant MITF p.E318K confers an increased risk for cutaneous melanoma, this variant has not been associated with risk of non-cutaneous melanoma. Herein, we describe the presence of a germline MITF p.E318K pathogenic variant in a 47-year-old woman with vulvar melanoma and a family history of cutaneous melanoma in a first-degree relative. To our knowledge, this is the first reported case of MITF p.E318K in vulvar melanoma. This finding highlights the potential involvement of MITF p.E318K in risk assessment and clinical management of patients with vulvar melanoma. Further study of this observation is needed to inform appropriate identification of patients with non-cutaneous melanoma for MITF germline genomic evaluation and to potentially guide management for early detection of vulvar melanoma.

Clinicopathological profile and outcomes of anorectal melanoma from a tertiary care center in India

Background:

Anorectal melanoma (AM) is a rare subtype of melanoma.

Aim:

To study the clinic–pathologic features and outcomes in patients with AM.

Materials & methods:

Clinical, pathologic findings and outcomes of patients with AM were recorded.

Results:

Twenty-seven patients with AM were identified with median age of 57 years. Most patients presented in stage III (44.4%). Lymph node involvement was seen in 70.4%. The response to chemotherapy and immunotherapy was 16.6 and 25.0%, respectively. At a median follow up of 11 months, median overall survival was 30 months. Ballantine stage 3 and weight loss at presentation were predictors of poor survival.

Conclusion:

AM presents at an advanced stage with lymph node and distant metastasis.

Anorectal melanoma is a rare subset of melanoma presenting at an advanced stage with lymph node and distant metastasis. Early disease is managed surgically; however, optimal treatment of advanced disease is unclear. The stage at diagnosis is the most important prognostic factor. Prognosis is poor, but with the advent of targeted therapy and immunotherapy, the outcomes are improving.

New Therapeutic Approaches for Conjunctival Melanoma-What We Know So Far and Where Therapy Is Potentially Heading: Focus on Lymphatic Vessels and Dendritic Cells

Conjunctival melanoma (CM) accounts for 5% of all ocular melanomas and arises from malignantly transformed melanocytes in the conjunctival epithelium. Current therapies using surgical excision in combination with chemo- or cryotherapy still have high rates for recurrences and metastatic disease. Lately, novel signal transduction-targeted and immune checkpoint inhibitors like cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, programmed cell death protein-1 (PD-1) receptor inhibitors, BRAF- or MEK-inhibitors for systemic treatment of melanoma have improved the outcome even for unresectable cutaneous melanoma, improving patient survival dramatically. The use of these therapies is now also recommended for CM; however, the immunological background of CM is barely known, underlining the need for research to better understand the immunological basics when treating CM patients with immunomodulatory therapies. Immune checkpoint inhibitors activate tumor defense by interrupting inhibitory interactions between tumor cells and T lymphocytes at the so-called checkpoints. The tumor cells exploit these inhibitory targets on T-cells that are usually used by dendritic cells (DCs). DCs are antigen-presenting cells at the forefront of immune response induction. They contribute to immune tolerance and immune defense but in the case of tumor development, immune tolerance is often prevalent. Enhancing the immune response via DCs, interfering with the lymphatic pathways during immune cell migration and tumor development and specifically targeting tumor cells is a major therapeutic opportunity for many tumor entities including CM. This review summarizes the current knowledge on the function of lymphatic vessels in tumor growth and immune cell transport and continues to compare DC subsets in CM with related melanomas, such as cutaneous melanoma and mucosal melanoma.

Anorectal and Genital Mucosal Melanoma: Diagnostic Challenges, Current Knowledge and Therapeutic Opportunities of Rare Melanomas

Mucosal melanomas (MM) are rare tumors, being less than 2% of all diagnosed melanomas, comprising a variegated group of malignancies arising from melanocytes in virtually all mucosal epithelia, even if more frequently found in oral and sino-nasal cavities, ano-rectum and female genitalia (vulva and vagina). To date, there is no consensus about the optimal management strategy of MM. Furthermore, the clinical rationale of molecular tumor characterization regarding BRAF, KIT or NRAS, as well as the therapeutic value of immunotherapy, chemotherapy and targeted therapy, has not yet been deeply explored and clearly established in MM. In this overview, focused on anorectal and genital MM as models of rare melanomas deserving of a multidisciplinary approach, we highlight the need of referring these patients to centers with experts in melanoma, anorectal and uro-genital cancers treatments. Taking into account the rarity, the poor outcomes and the lack of effective treatment options for MM, tailored research needs to be promptly promoted.

Exosome application in tumorigenesis: diagnosis and treatment of melanoma

Melanoma is the most aggressive of skin cancer derived from genetic mutations in the melanocytes. Current therapeutic approaches include surgical resection, chemotherapy, photodynamic therapy, immunotherapy, biochemotherapy, and targeted therapy. However, the efficiency of these strategies may be decreased due to the development of diverse resistance mechanisms. Here, it has been proven that therapeutic monoclonal antibodies (mAbs) can improve the efficiency of melanoma therapies and also, cancer vaccines are another approach for the treatment of melanoma that has already improved clinical outcomes in these patients. The use of antibodies and gene vaccines provides a new perspective in melanoma treatment. Since the tumor microenvironment is another important factor for cancer progression and metastasis, in recent times, a mechanism has been identified to provide an opportunity for melanoma cells to communicate with remote cells. This mechanism is involved by a novel molecular structure, named extracellular vesicles (EVs). Depending on the functional status of origin cells, exosomes contain various cargos and different compositions. In this review, we presented recent progress of exosome applications in the treatment of melanoma. Different aspects of exosome therapy and ongoing efforts in this field will be discussed too.

Acral lentiginous melanoma-Population, treatment, and survival using the NCDB from 2004 to 2015

Acral lentiginous melanoma (ALM) is a rare histological subtype of cutaneous malignant melanoma that typically presents on the palms and soles. To characterize the demographic and treatment characteristics of ALM, we used the National Cancer Database (NCDB) to describe a large multi-institutional cohort of ALM patients, consisting of 4,796 ALM patients from 2004 to 2015. ALM was more likely to be diagnosed at a later stage overall compared with non-ALM cutaneous melanomas, and more likely to be thicker, ulcerated, lymph node positive, and have lymphovascular invasion and positive margins. When stratified by stage, ALM had worse survival compared with non-ALM patients, most notably in stage III patients with 5-year survival of 47.5% versus 56.7%, respectively (p < .001). In ALM patients, older age, male sex, higher comorbidity burden, increased tumor thickness and ulceration, positive lymph nodes, and positive metastasis were independently associated with lower 5-year survival. Multimodality therapy, defined as surgery in addition to systemic therapy and/or radiation therapy, was associated with higher survival in stage III patients but not in other stages. These results call for further investigation into possible treatment intensification in the ALM population in the future.

Genetic characteristics and response to systemic therapies of acral lentiginous melanoma at a tertiary care center-a retrospective review

BACKGROUND

Acral lentiginous melanoma (ALM) is an aggressive subtype of cutaneous malignant melanomas that accounts for 50-80% of melanomas in ethnic minorities. Studies on the genetic profile of these tumors largely result from cohorts in Europe, Asia, and Latin America, few inclusive of Black patients.

OBJECTIVE

We aim to describe the clinicopathological and genetic characteristics in a diverse cohort of ALM patients.

METHODS

A retrospective analysis of 93 patients with a pathology confirmed diagnosis of ALM between March 1984 and October 2020 was conducted at a large tertiary care center. Melanoma mutation panel testing for frequently mutated regions of the BRAF, NRAS, KIT and PIK3CA genes were reviewed in patient records when available.

RESULTS

Of the 93 patients identified, 62.4% were Caucasian, 25.8% Black, 4.30% Hispanic, 4.30% Asian, and 3.22% identified as other. Fourteen of 17 patients receiving targeted or immunologic agents experienced disease progression during treatment, including all patients with a BRAF V600E mutation.

LIMITATIONS

This was a single-center retrospective analysis.

CONCLUSION

Response to targeted and immunologic therapies in ALM patients was overwhelming poor, particularly in BRAF V600E-mutated tumors in contrast to the positive prognosis associated with BRAF V600E mutations in other advanced cutaneous melanoma subtypes.

Vulvar Melanoma: Molecular Characteristics, Diagnosis, Surgical Management, and Medical Treatment

Ten percent of all women have pigmented vulvar lesions. Fortunately, most of these are benign but 1% of all melanomas in women affect the vulva. While the mortality rate of cutaneous melanoma has dropped by 7% annually during the last 5 years, the prognosis of vulvar melanoma remains dismal: the 5-year overall survival rate is 47% compared with 92% for cutaneous melanoma. The current evidence suggests that this likely results from a combination of delayed diagnosis and different tumor biology, treatment strategies, and treatment response. Although many landmark trials on checkpoint inhibitors included mucosal and vulvar melanomas, the results were often not reported separately. Post-hoc analyses indicate overall response rates between 19 and 37% for checkpoint inhibitors. A recently published retrospective study on vulvar melanomas suggests an objective response in 33.3% with a similar safety profile to cutaneous melanoma. Tyrosine kinase inhibitors may be considered in recurrent disease if a c-KIT mutation is present.

Mucosal Melanoma: Pathological Evolution, Pathway Dependency and Targeted Therapy

Mucosal melanoma (MM) is a rare melanoma subtype that originates from melanocytes within sun-protected mucous membranes. Compared with cutaneous melanoma (CM), MM has worse prognosis and lacks effective treatment options. Moreover, the endogenous or exogenous risk factors that influence mucosal melanocyte transformation, as well as the identity of MM precursor lesions, are ambiguous. Consequently, there remains a lack of molecular markers that can be used for early diagnosis, and therefore better management, of MM. In this review, we first summarize the main functions of mucosal melanocytes. Then, using oral mucosal melanoma (OMM) as a model, we discuss the distinct pathologic stages from benign mucosal melanocytes to metastatic MM, mapping the possible evolutionary trajectories that correspond to MM initiation and progression. We highlight key areas of ambiguity during the genetic evolution of MM from its benign lesions, and the resolution of which could aid in the discovery of new biomarkers for MM detection and diagnosis. We outline the key pathways that are altered in MM, including the MAPK pathway, the PI3K/AKT pathway, cell cycle regulation, telomere maintenance, and the RNA maturation process, and discuss targeted therapy strategies for MM currently in use or under investigation.

Vulvar and Vaginal Melanomas-The Darker Shades of Gynecological Cancers

Melanomas of the skin are poorly circumscribed lesions, very frequently asymptomatic but unfortunately with a continuous growing incidence. In this landscape, one can distinguish melanomas originating in the mucous membranes and located in areas not exposed to the sun, namely the vulvo-vaginal melanomas. By contrast with cutaneous melanomas, the incidence of these types of melanomas is constant, being diagnosed in females in their late sixties. While hairy skin and glabrous skin melanomas of the vulva account for 5% of all cancers located in the vulva, melanomas of the vagina and urethra are particularly rare conditions. The location in areas less accessible to periodic inspection determines their diagnosis in advanced stages, often metastatic. Moreover, despite the large number of drugs newly approved in recent decades for the treatment of cutaneous melanoma, especially in the category of biological drugs, the mortality of vulvo-vaginal melanomas has remained almost constant. This, together with the absence of specific treatment guidelines due to the lack of a sufficient number of cases to conduct randomized clinical trials, makes melanomas with this localization a discouraging diagnosis, associated with a very poor prognosis. Our aim is therefore to draw attention to this oftentimes overlooked entity in order to encourage the community to employ various strategies meant to increase research in this area. By highlighting the main risk factors of vulvar and vaginal melanomas, as well as the clinical manifestations and molecular changes underlying these neoplasms, ideally novel therapeutic schemes will, in time, be brought into effect.

Recurrent KRAS, KIT and SF3B1 mutations in melanoma of the female genital tract

BACKGROUND

Malignant melanoma of the female genital tract is relatively uncommon and accounts for 3-7% of all melanoma localizations. This study aimed to identify driver genes in melanoma of the female genital tract with the purpose of enhancing understanding of disease pathogenesis and identifying potential new therapeutic targets to develop effective therapies.

METHODS

KIT (CD117) and BRAF expression were detected immunohistochemically. Polymerase Chain Reaction (PCR) and Sanger sequencing techniques were performed to identify the mutational status of BRAF, NRAS, KRAS, NF1, KIT, PDGFRA and SF3B1 on 19 melanomas of the female genital tract, paired with 25 cutaneous melanomas, 18 acral melanomas and 11 melanomas of nasal cavity.

RESULTS

Somatic variant analysis identified KRAS (6/19; 32%) as the most commonly mutated gene, followed by KIT (4/19; 21%), SF3B1 (3/19; 16%) and NRAS (1/19; 5%). None of the cases were found to harbor BRAF, NF1 and PDGFRA mutations in melanomas of the female genital tract. However, none of the cases were found to harbor SF3B1 and KIT mutations in cutaneous melanomas, acral melanomas and melanomas of nasal cavity. Recurrent KIT mutations, as well as mutations in the less frequently mutated genes NRAS and SF3B1, were exclusively detected in vulvovaginal melanomas, but not in tumors arising in the cervix. However, recurrent KRAS mutations were detected in similar frequencies in tumors of the vulva, vagina, and cervix. Additionally, recurrent KRAS and KIT mutations occurred predominantly in polygonal and epithelioid cell types of melanoma in the female genital tract. Immunohistochemistry revealed moderate or strong cytoplasmic CD117 expression in 6 of the 19 cases (31.6%).

CONCLUSIONS

We observed that gynecologic melanoma harbored distinct mutation rates in the KIT, BRAF, SF3B1, KRAS, and NRAS genes. Our findings support the notion that gynecologic melanoma is a distinct entity from non-gynecologic melanoma, and these findings offer insights into future therapeutic options for these patients.

Mutational Profile in Vulvar, Vaginal, and Urethral Melanomas: Review of 37 Cases With Focus on Primary Tumor Site

Melanomas of female genital tract are rare tumors with poor prognosis. While BRAF-V600E is the most common pathogenic mutation seen in cutaneous sun-exposed melanomas, mucosal and anogenital melanomas usually lack BRAF mutations and instead they harbor KIT alterations. The American Joint Committee on Cancer staging guideline (AJCC eighth edition) recommends using cutaneous melanoma guidelines for vulvar melanoma staging and does not provide any recommendations for vaginal melanoma staging. The aim of this study is to investigate the mutational status of invasive melanomas arising from different anatomic sites in lower female genital tract (vulvar hair-bearing skin, glabrous skin, vagina and urethra) in a group of 37 patients. Tumors were analyzed using a DNA targeted next-generation sequencing panel covering the 21 most common genes and mutation hotspots in melanomas. The most common genetic alterations in invasive melanomas of lower female genital tract are KIT (32%), TP53 (22%), and NF1 (19%). Overall 66% (21/32) of cases showed a pathogenic alteration in at least one of the MAPK pathway genes. No statistical significance seen between different primary tumor sites and the frequency of the oncogenic mutations, nor were any significant differences found by mutation status. Only one case of urethral melanoma showed a BRAF non-V600E mutation (D594G). Our results suggest a similar molecular pathogenesis and overall survival in melanomas arising from lower female genital tract, irrespective of their exact location in the urogenital area. Future classifications of melanoma should consider grouping vulvar melanomas with mucosal rather than cutaneous melanomas.

Survival following surgical treatment for anorectal melanoma seems similar for local excision and extensive resection regardless of nodal involvement

BACKGROUND

Anorectal melanoma is a rare malignancy with a dismal prognosis. The purpose of this study was to investigate whether the survival per stage is influenced by the surgical approaches (local excision or extensive resection), to assess prognostic factors of survival, and to answer the question whether the practiced surgical approaches changed over time.

METHODS

Dutch cancer registry organizations (IKNL and PALGA) were queried for all patients with a diagnosis of anorectal melanoma (1989-2019). Patients with disseminated disease at diagnosis were excluded. Survival outcomes were compared for the two surgical approaches stratified by stage (clinical node negative (cN0) and clinical node positive (cN+)) and date of diagnosis.

RESULTS

A total of 103 patients were included in this study. In both cN0 and cN+ patients the surgical strategy did not significantly influence survival (cN0: 21.7% 5-year survival, median 25 months for local excision versus 13.7% 5-year survival, median 17 months for extensive resection (p = 0.228), cN+: 11.1% 5-year survival for local excision, median 17 months versus 8.7% 5-year survival, median 14 months for extensive resection (p = 0.741)). Stage and date of diagnosis showed to be prognostic factors of survival. The ratio between the two surgical approaches was unchanged over three decades.

CONCLUSIONS

Extensive resection does not seem to improve survival in both cN0 and cN+ anorectal melanoma patients compared to local excision. However in the past three decades no shift towards local excision has been found. cN+ stage and an older date of diagnosis are predictors for worse survival.

Meta-Analysis and Systematic Review of the Genomics of Mucosal Melanoma

Mucosal melanoma is a rare subtype of melanoma. To date, there has been no comprehensive systematic collation and statistical analysis of the aberrations and aggregated frequency of driver events across multiple studies. Published studies using whole genome, whole exome, targeted gene panel, or individual gene sequencing were identified. Datasets from these studies were collated to summarize mutations, structural variants, and regions of copy-number alteration. Studies using next-generation sequencing were divided into the "main" cohort (n = 173; fresh-frozen samples), "validation" cohort (n = 48; formalin-fixed, paraffin-embedded samples) and a second "validation" cohort comprised 104 tumors sequenced using a targeted panel. Studies assessing mutations in BRAF, KIT, and NRAS were summarized to assess hotspot mutations. Statistical analysis of the main cohort variant data revealed KIT, NF1, BRAF, NRAS, SF3B1, and SPRED1 as significantly mutated genes. ATRX and SF3B1 mutations occurred more commonly in lower anatomy melanomas and CTNNB1 in the upper anatomy. NF1, PTEN, CDKN2A, SPRED1, ATM, CHEK2, and ARID1B were commonly affected by chromosomal copy loss, while TERT, KIT, BRAF, YAP1, CDK4, CCND1, GAB2, MDM2, SKP2, and MITF were commonly amplified. Further notable genomic alterations occurring at lower frequencies indicated commonality of signaling networks in tumorigenesis, including MAPK, PI3K, Notch, Wnt/β-catenin, cell cycle, DNA repair, and telomere maintenance pathways. This analysis identified genomic aberrations that provide some insight to the way in which specific pathways may be disrupted. IMPLICATIONS: Our analysis has shown that mucosal melanomas have a diverse range of genomic alterations in several biological pathways. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/6/991/F1.large.jpg.

Cancer of the Vulva: A Review

BACKGROUND

Vulvar cancers, although rare, are becoming an increasingly serious threat to women's health. Cancer of the vulva accounted for 0.3% of all new cancers in the United States in 2019, with 6,070 newly diagnosed cases. This review details the epidemiology, pathogenesis, diagnosis, staging, and treatment of vulvar malignancies.

OBJECTIVE

To review cancer entities of the vulva, including vulvar intraepithelial neoplasms, squamous cell carcinoma (SCC), malignant melanoma, basal cell carcinoma, neuroendocrine tumors, and adenocarcinomas.

MATERIALS AND METHODS

Literature review using PubMed search for articles related to cancer of the vulva.

RESULTS

Vulvar intraepithelial neoplasms represent premalignant precursors to SCC of the vulva. There are several different histopathologic subtypes of SCC, and treatment is dependent on characteristics of primary tumor and lymph node involvement. Melanoma is the second most common cancer to affect the vulva, and staging is based on tumor, node, and metastatic spread.

CONCLUSION

Vulvar malignancies are rare, and diagnosis is dependent on biopsy and pathologic evaluation. Treatment for vulvar malignancies depends on histopathologic diagnosis but ranges from wide local excision with or without lymph node biopsy or dissection to radiation therapy with chemo- or immunotherapy. Overall survival varies by diagnosis.

Cutaneous and Mucosal Melanomas of Uncommon Sites: Where Do We Stand Now?

Melanomas arising at uncommon sites include a group of lesions related to unusual localizations in specific ethnic groups. The rarity of the disease often represents a limit to the participation of patients in specific trials. However, this peculiar genetic scenario has important therapeutic implications regarding new oncologic therapies. The aim of this article is to review the clinical features, somatic alterations and therapeutic options for melanomas of uncommon sites. They can be classified as cutaneous and mucosal lesions affecting the nail apparatus, palms/soles, oral mucosa, genital area and scalp. The prognosis may be worse compared to melanomas of other districts, and a prompt diagnosis may dramatically influence the outcome. Dermatologists and oncologists should therefore distinguish this melanoma subgroup in terms of surgical intervention and medical treatment. Due to the lack of mutations in genes usually found in cutaneous melanomas, the discovery of novel targets is required to develop new strategies and to change the prognosis of non-responders or wild-type patients.

Genetic drivers of non-cutaneous melanomas: Challenges and opportunities in a heterogeneous landscape

Non-cutaneous melanomas most frequently involve the uveal tract and mucosal membranes, including the conjunctiva. In contrast to cutaneous melanoma, they often present at an advanced clinical stage, are associated with worse clinical outcomes and show poorer responses to immunotherapy. The mutational load within most non-cutaneous melanomas reflects their lower ultraviolet light (UV) exposure. The genetic drivers within non-cutaneous melanomas are heterogeneous. Within ocular melanomas, posterior uveal tract melanomas typically harbour one of two distinct, sets of driver mutations and alterations of clinical and biological significance. In contrast to posterior uveal tract melanomas, anterior uveal tract melanomas of the iris and conjunctival melanomas frequently carry both a higher mutational burden and specific mutations linked with UV exposure. The genetic drivers in iris melanomas more closely resemble those of the posterior uveal tract, whereas conjunctival melanomas harbour similar genetic driver mutations to cutaneous melanomas. Mucosal melanomas occur in sun-shielded sites including sinonasal and oral cavities, nasopharynx, oesophagus, genitalia, anus and rectum, and their mutational landscape is frequently associated with a dominant process of spontaneous deamination and infrequent presence of UV mutation signatures. Genetic drivers of mucosal melanomas are diverse and vary with anatomic location. Further understanding of the causes of already identified recurrent molecular events in non-cutaneous melanomas, identification of additional drivers in specific subtypes, integrative multi-omics analyses and analysis of the tumor immune microenvironment will expand knowledge in this field. Furthermore, such data will likely uncover new therapeutic strategies which will lead to improved clinical outcomes in non-cutaneous melanoma patients.

KIT Somatic Mutations and Immunohistochemical Expression in Canine Oral Melanoma

Simple Summary

Malignant melanomas arising from mucosal sites are very aggressive neoplastic entities which affect both humans and dogs. The family of tyrosine kinase receptors has been increasingly studied in humans for this type of neoplasm, especially the gene coding for the proto-oncogene KIT, and tyrosine kinase inhibitors are actually available as treatment. However, KIT alteration status in canine oral melanoma still lacks characterization. In this study, we investigated the mutational status and the tissue expression of KIT through DNA sequencing and immunohistochemical analysis, respectively. A homogeneous cohort of 14 canine oral melanomas has been collected, and while tissue expression of the protein was detected, no mutations were identifiable, most likely attributing the dysregulation of this oncogene to a more complex pattern of genomic aberration.

Abstract

Canine oral melanoma (COM) is an aggressive neoplasm with a low response to therapies, sharing similarities with human mucosal melanomas. In the latter, significant alterations of the proto-oncogene KIT have been shown, while in COMs only its exon 11 has been adequately investigated. In this study, 14 formalin-fixed, paraffin-embedded COMs were selected considering the following inclusion criteria: unequivocal diagnosis, presence of healthy tissue, and a known amplification status of the gene KIT (seven samples affected and seven non-affected by amplification). The DNA was extracted and KIT target exons 13, 17, and 18 were amplified by PCR and sequenced. Immunohistochemistry (IHC) for KIT and Ki67 was performed, and a quantitative index was calculated for each protein. PCR amplification and sequencing was successful in 97.62% of cases, and no single nucleotide polymorphism (SNP) was detected in any of the exons examined, similarly to exon 11 in other studies. The immunolabeling of KIT was positive in 84.6% of the samples with a mean value of 3.1 cells in positive cases, yet there was no correlation with aberration status. Our findings confirm the hypothesis that SNPs are not a frequent event in KIT activation in COMs, with the pathway activation relying mainly on amplification.

The challenge of primary gastric melanoma: a systematic review

Aim:

Primary gastric melanoma is a rare clinical presentation. The purpose of this review was to compare the 1-year survival in patients who underwent surgery with patients who did not receive treatment.

Patients & methods:

A systematic search of databases for case reports and case series of primary gastric melanoma was conducted.

Results:

The mean survival of patients was 22 months. One-year survival was 56.5% with surgery, rising to 66% with adjuvant therapy. Mean survival of the surgical group was 21.05 months (±20.2) versus 4.5 months (±3.61) in the nonsurgical group.

Conclusion:

Primary gastric melanoma has a poor prognosis but early surgical intervention can have a significant impact on patient outcome. We reviewed the biology and clinical diagnosis of gastrointestinal melanoma and the current management options available.

Uncommon Subtypes of Malignant Melanomas: A Review Based on Clinical and Molecular Perspectives

Malignant melanoma represents the most aggressive type of skin cancer. Modern therapies, including targeted agents and immune checkpoint inhibitors, have changed the dismal prognosis that characterized this disease. However, most evidence was obtained by studying patients with frequent subtypes of cutaneous melanoma (CM). Consequently, there is an emerging need to understand the molecular basis and treatment approaches for unusual melanoma subtypes. Even a standardized definition of infrequent or rare melanoma is not clearly established. For that reason, we reviewed this challenging topic considering clinical and molecular perspectives, including uncommon CMs-not associated with classical V600E/K BRAF mutations-malignant mucosal and uveal melanomas, and some unusual independent entities, such as amelanotic, desmoplastic, or spitzoid melanomas. Finally, we collected information regarding melanomas from non-traditional primary sites, which emerge from locations as unique as meninges, dermis, lymph nodes, the esophagus, and breasts. The aim of this review is to summarize and highlight the main scientific evidence regarding rare melanomas, with a particular focus on treatment perspectives.

The role of sentinel lymph node mapping in lower genital tract melanoma

INTRODUCTION

Vulvar and vaginal melanomas are rare cancers of the female genital tract and account for 1% to 3% of all melanomas diagnosed in women. Due to the rarity of the disease, few data are available on the clinical and pathologic features of these cancers. Furthermore, treatment options are generally based on extrapolations of the information available for the more common cutaneous counterparts. Surgery represents the mainstay of treatment for lower genital tract melanoma. Moreover, the role of sentinel lymph node (SLN) assessment is controversial because no prospective data are available.

EVIDENCE ACQUISITION

Data were collected from Medline, Embase, Web of Sciences and Scopus databases. On July 10, 2020, we used the search comprising the terms "vulvar melanoma," "genital melanoma" and "vulvovaginal melanoma" including only studies in which SLN biopsy was performed.

EVIDENCE SYNTHESIS

Ten retrospective studies have been found. No randomized trials have been reported. The studies included 132 patients while only 63 (47%) undergone SLN. 99mTC with or without blue dye followed by ultrastaging was highly accurate and is currently the gold standard. Mean detection rate was 98.3%. No clear evidence supported the execution of back lymphadenectomy (after SLN mapping), in fact, extrapolating data from cutaneous melanomas of other sites, completion of lymphadenectomy does not confer a melanoma-specific survival advantage.

CONCLUSIONS

Although the small amount of available data, sentinel lymph node procedure is feasible and capable of identifying patients who have occult lymph node metastases. However, the potential role of the sentinel lymph node procedure as an alternative method of lymph node staging in patients with vulvar or vaginal melanoma needs further investigation.

Molecular Alterations in Vaginal Melanomas: Report of 4 Cases and Literature Review

ABSTRACT

Melanomas of the female gynecological tract comprise approximately 18% of mucosal melanomas, a rare subtype of melanoma. Within the female genital tract, 70% of primary melanomas of the gynecological tract are from the vulva with the remainder occurring in the vagina and rarely, in the cervix. We investigate molecular alterations by next-generation sequencing-based molecular tests targeting 99 cancer genes and translocation/fusion assays in 4 and 3 vaginal melanomas, respectively. The ages of the 4 patients range from 65 to 90 years. Postmenopausal bleeding was the most common presenting symptom. Tumor size ranged from 0.5 to 6.6 cm. KIT L576P mutation was documented in case 1, whereas TP53 mutation was seen in cases 2 and 3 (L130F and Y163C). Case 2 also harbored NF2 E204Q and ATRX D1719H mutations. A number of gene copy alterations were noted in case 4, which included GNA11 loss, MYC gain, RET loss, SMO loss, SUFU loss, and TSC2 loss. No gene fusion was detected in any of the 3 tested cases. In conclusion, in addition to KIT, TP53, and ATRX mutations, which have been previously reported, our cases harbor NF2 mutation and multiple gene copy alterations that have not previously been documented in vaginal melanomas. These findings highlight the potential role of targeted therapy in this rare melanoma subtype.

Conjunctival Melanoma: Current Treatments and Future Options

Conjunctival melanoma is a rare tumor of the conjunctival epithelium with a heterogenous clinical presentation and a propensity for regional and distant metastatic spread. Guidelines for the treatment of local conjunctival melanoma are well-established, but there are no standard efficacious therapies for metastatic disease. Given that conjunctival melanoma is genetically similar to cutaneous melanoma and mucosal melanomas, targeted therapies effective in the treatment of these diseases, such as BRAF inhibitors and KIT inhibitors, may be effective in the treatment of patients with metastatic conjunctival melanoma. Other targeted small-molecule drugs in the drug development pipeline for the treatment of more prevalent melanomas could also be applicable to conjunctival melanoma. Furthermore, systemic immunotherapy treatments that are now a mainstay in the treatment of cutaneous melanoma, such as programmed cell death-1 and cytotoxic T lymphocyte-associated antigen-4 inhibitors, could also stand to benefit patients with metastatic conjunctival melanoma. Limited case reports provide clues about the effectiveness of both targeted small-molecule inhibitors and immunotherapy in patients with advanced local and metastatic conjunctival melanoma and give credence to the argument that conjunctival melanoma patients should be included in major trials studying new therapies in both cutaneous and mucosal melanomas where applicable.

The mutational landscape of mucosal melanoma

Mucosal melanoma is a rare and aggressive subtype of melanoma that has a less favorable prognosis due to the lack of understanding and identification of oncogenic drivers. Recently, whole genome and whole exome sequencing have unveiled the molecular landscape and potential oncogenic drivers of mucosal melanoma, which remains distinct from cutaneous melanoma. In this review, we provide an overview of the genomic landscape of mucosal melanoma, with a focus on molecular studies identifying potential oncogenic drivers allowing for a better mechanistic understanding of the biology of mucosal melanoma. We summarized the published genomics and clinical data supporting the observations that mucosal melanoma harbors distinct genetic alterations and oncogenic drivers from cutaneous melanoma, and thus should be treated accordingly. The common drivers (BRAF and NRAS) found in cutaneous melanoma have lower mutation rate in mucosal melanoma. In contrast, SF3B1 and KIT have higher mutation rate in mucosal melanoma as compared to cutaneous melanoma. From the meta-analysis, we also observed that the mutational profiles are slightly different between the "upper" and "lower" regions of mucosal melanoma, providing new insights and therapeutic options for the mucosal melanoma patients. Mutations identified in mucosal melanoma should be incorporated into routine clinical testing, as there are targeted therapies already developed for treating patients with these mutations in the precision medicine era.

Oxymatrine Inhibits Proliferation and Migration of Vulvar Squamous Cell Carcinoma Cells via Attenuation of the RAS/RAF/MEK/ERK Pathway

Purpose

To evaluate the anti-tumor effects of oxymatrine in vulvar squamous cell carcinoma (VSCC) cells and to explore the underlying mechanisms.

Methods

We selected SW962 and A431 VSCC cell lines. Cell proliferation was examined using MTT assay. Cell cycle and apoptosis were detected using flow cytometry. Migration and invasion were evaluated using transwell and wound-healing assays. The relevant protein expression and signaling pathways were analyzed using Western blotting.

Results

Oxymatrine inhibited the proliferation of SW962 and A431 VSCC cells in a time- and dose-dependent manner. Oxymatrine induced cell cycle arrest in the G2/M phase by increasing the protein expression of P21 and decreasing levels of cyclin B1 and CDC2. Oxymatrine upregulated the expression of cleaved-caspase 3 and BAX and downregulated the expression of BCL2, which led to an increase in apoptosis. Oxymatrine also suppressed the migration and invasion of SW962 and A431 cells by reducing levels of MMP2 and MMP9. After treatment with oxymatrine or a RAS inhibitor (salirasib), expression levels of RAS, p-RAF, p-MEK, p-ERK, C-MYC, and MMP2 were reduced. When TGF-β1 was used to stimulate SW962 and A431 cells, the expression of the above proteins increased; this increase was reversed by using oxymatrine or salirasib again.

Conclusion

Oxymatrine inhibits proliferation and migration of VSCC cells by blocking the RAS/RAF/MEK/ERK pathway.

Prevalence of NRAS Mutation, PD-L1 Expression and Amplification, and Overall Survival Analysis in 36 Primary Vaginal Melanomas

Background

Primary vaginal melanomas are uncommon and aggressive tumors with poor prognosis, and the development of new targeted therapies is essential. This study aimed to identify the molecular markers occurring in these patients and potentially improve treatment strategies.

Materials and Methods

The clinicopathological characteristics of 36 patients with primary vaginal melanomas were reviewed. Oncogenic mutations in BRAF, KIT, NRAS, GNAQ and GNA11 and the promoter region of telomerase reverse transcriptase (TERT) were investigated using the Sanger sequencing. The expression and copy number of programmed death‐ligand 1 (PD‐L1) were also assessed.

Results

Mutations in NRAS, KIT, and TERT promoter were identified in 13.9% (5/36), 2.9% (1/34), and 5.6% (2/36) of the primary vaginal melanomas, respectively. PD‐L1 expression and amplification were observed in 27.8% (10/36) and 5.6% (2/36) of cases, respectively. PD‐L1 positive expression and/or amplification was associated with older patients (p = .008). Patients who had NRAS mutations had a poorer overall survival compared with those with a wild‐type NRAS (33.5 vs. 14.0 months; hazard ratio [HR], 3.09; 95% CI, 1.08–8.83). Strikingly, two patients with/without PD‐L1 expression receiving immune checkpoint inhibitors had a satisfying outcome. Multivariate analysis demonstrated that >10 mitoses per mm² (HR, 2.96; 95% CI, 1.03–8.51) was an independent prognostic factor.

Conclusions

NRAS mutations and PD‐L1 expression were most prevalent in our cohort of primary vaginal melanomas and can be potentially considered as therapeutic targets.

Implications for Practice

This study used the Sanger sequencing, immunohistochemistry, and fluorescence in situ hybridization methods to detect common genetic mutations and PD‐L1 expression and copy number in 36 primary vaginal melanomas. NRAS mutations and PD‐L1 expression were the most prevalent, but KIT and TERT mutations occurred at a lower occurrence in this rare malignancy. Two patients receiving immune checkpoint inhibitors had a satisfying outcome, signifying that the PD‐L1 expression and amplification can be a possible predictive marker of clinical response. This study highlights the possible prospects of biomarkers that can be used for patient selection in clinical trials involving treatments with novel targeted therapies based on these molecular aberrations.

Little is known about the molecular characteristics of primary vaginal melanoma. This article reports on the molecular markers of this rare and aggressive disease, focusing on improvements in treatment strategies.

BRAF Mutations and Dysregulation of the MAP Kinase Pathway Associated to Sinonasal Mucosal Melanomas

Sinonasal mucosal melanoma (SNM) is a rare and aggressive type of melanoma, and because of this, we currently have a limited understanding of its genetic and molecular constitution. The incidence among SNMs of somatic mutations in the genes involved in the main molecular pathways, which have been largely associated with cutaneous melanoma, is not yet fully understood. Through a next-generation sequencing (NGS) approach using a panel of 25 genes involved in melanoma pathogenesis customized by our group, we performed a mutation analysis in a cohort of 25 SNM patients. Results showed that pathogenic mutations were found in more than 60% of SNM cases at a somatic level, with strikingly 32% of them carrying deleterious mutations in the BRAF gene. The identified mutations mostly lack the typical UV signature associated with cutaneous melanomas and showed no significant association with any histopathological parameter. Oncogenic activation of the BRAF-depending pathway, which may induce immune tolerance into the tumour microenvironment (i.e., by increasing the VEGF production) was poorly associated with mutations in genes that have been related to diminished clinical benefit of the treatment with BRAF inhibitors. Screening for mutations in BRAF and other MAPK genes should be included in the routine diagnostic test for a better classification of SNM patients.

An evaluation of masitinib for treating systemic mastocytosis

Introduction: Systemic Mastocytosis (SM) is a complex family of rare diseases, against which pharmacological therapies are still very few. It is a c-kit driven disease, whose disregulation leads to uncontrolled activation and proliferation of mast cells (MCs) with consequent release of effector molecules which are responsible for its clinical manifestations. Areas covered: Masitinib is a relatively new potential drug against SM and its chemical structure strictly derives from imatinib, the first tyrosine kinase inhibitor which entered the pharmaceutical market about 15 years ago. In this review, the authors present masitinib in all its properties, from chemistry to pharmacology and toxicity to its potential clinical application in SM, focusing the discussion on the few clinical trials in which it has been involved, with a particular attention on the still open challenge to determine how to measure the response to therapy. Expert opinion: In spite of their similarity in chemistry and biological activity against submolecular targets, masitinib is much more selective towards c-kit receptors than other tyrosine kinases, such as Bcl-Abl. Furthermore, its ability to inhibit degranulation, cytokine production and MCs migration from bone marrow gives it a great chance to become an important therapeutic option for selected SM patients.

Diagnosis and management of vulvar cancer: A review

Vulvar malignancies represent a serious gynecologic health concern, especially given the increasing incidence over the past several decades. Squamous cell carcinoma and melanoma are common subtypes, although other neoplasms, such as basal cell carcinoma and Paget disease of the vulva, might be seen. Many vulvar cancers are initially misdiagnosed as inflammatory conditions, delaying diagnosis and worsening prognosis. It is essential that dermatologists are familiar with characteristic findings for each malignancy to ensure appropriate diagnosis and management. Herein, we review the unique epidemiologic and clinical characteristics of each major vulvar malignancy, as well as discuss their respective prognoses and current management recommendations.

Genome-wide analysis of canine oral malignant melanoma metastasis-associated gene expression

Oral malignant melanoma (OMM) is the most common canine melanocytic neoplasm. Overlap between the somatic mutation profiles of canine OMM and human mucosal melanomas suggest a shared UV-independent molecular aetiology. In common with human mucosal melanomas, most canine OMM metastasise. There is no reliable means of predicting canine OMM metastasis, and systemic therapies for metastatic disease are largely palliative. Herein, we employed exon microarrays for comparative expression profiling of FFPE biopsies of 18 primary canine OMM that metastasised and 10 primary OMM that did not metastasise. Genes displaying metastasis-associated expression may be targets for anti-metastasis treatments, and biomarkers of OMM metastasis. Reduced expression of CXCL12 in the metastasising OMMs implies that the CXCR4/CXCL12 axis may be involved in OMM metastasis. Increased expression of APOBEC3A in the metastasising OMMs may indicate APOBEC3A-induced double-strand DNA breaks and pro-metastatic hypermutation. DNA double strand breakage triggers the DNA damage response network and two Fanconi anaemia DNA repair pathway members showed elevated expression in the metastasising OMMs. Cross-validation was employed to test a Linear Discriminant Analysis classifier based upon the RT-qPCR-measured expression levels of CXCL12, APOBEC3A and RPL29. Classification accuracies of 94% (metastasising OMMs) and 86% (non-metastasising OMMs) were estimated.

Vulvar malignant melanoma: Pathogenesis, clinical behaviour and management: Review of the literature

Vulvar malignant melanoma (VMM) is a rare disease, accounting for 5% of all vulvar malignancies and is characterized by low survival and high recurrence rates. It is considered as a distinct entity of mucosal melanoma. Prognostic factors are higher age, advanced Breslow thickness, and lymph node involvement whilst central localization and ulceration status are still under debate. Surgery is the cornerstone for the treatment of primary VMM, however, it can be mutilating due to the anatomical location of the disease. Elective lymph node dissection is not part of standard care. The value of sentinel lymph node biopsy in VMM is still being studied. Radiation therapy and chemotherapy as adjuvant treatment do not benefit survival. Immunotherapy in cutaneous melanoma has shown promising results but clinical studies in VMM are scarce. In metastatic VMM, checkpoint inhibitors and in case of BRAF or KIT mutated metastatic VMM targeted therapy have shown clinical efficacy. In this review, we present an overview of clinical aspects, clinicopathological characteristics and its prognostic value and the latest view on (adjuvant) therapy and follow-up.

KIT exon 11 and PDGFRA exon 18 gene mutations in gastric GIST: proposal of a short panel for predicting therapeutic response

Background

GIST is the most common mesenchymal tumor of gastrointestinal tract and is more frequent in stomach. Its main mutations affect KIT and PDGFRA genes. Full genetic analysis panels are currently used to study mutations in GIST and other tumors. Considering that in gastric GIST KIT gene mutations in exon 11 are sensitive to IM whereas PDGFRΑ gene mutations in exon 18 (D842V) are resistant to the same drug, the aim of this study is to focus on these two molecular targets as a short alternative panel for predicting therapeutic response in gastric GIST which might optimize resources.

Methods

The genotypes of 38 cases of primary GIST were determined by performing bidirectional DNA sequencing.

Results

Exon 11 of KIT gene showed mutations in 65.3% and the exon 18 of PDGFRA gene showed 9% of cases. So it was possible to determine a subgroup of tumors which presented mutations in KIT exon 11 and PDGFRA exon 18.

Conclusion

Considering all of the foregoing analyzed globally, the application of short panel has impact on the cost and time of release of results to the physician, allowing a rapid approach to patients eligible for treatment with the target therapy.

Carving out another slice of the pie: Exceptional response to single agent imatinib in an asian female never-smoker with advanced NSCLC with a de-novo PDGFR-α N848 K mutation

Non-small cell lung cancer (NSCLC) has emerged as a paradigm for clinical application of precision medicine as optimal therapy is commonly chosen based on genomic biomarkers identified in a patient's tumor sample. Recurrent driver alterations are well described, however, a need to continually identify rare variants remains clinically relevant. We identified an incident case of advanced NSCLC with a PDGFR-α N848 K activation loop mutation with no other concurrent oncogenic drivers. Amino acid sequence alignment confirmed homology to the imatinib-sensitive KIT N822 K activation loop mutation observed in GIST. The patient achieved a 2-year response to single agent imatinib that is ongoing. While PDGFR-α N848 K is rare among public sequencing databases our cases strongly suggests functional relevance and highlights the importance of studying rare variants in NSCLC.

Diagnosis and Management of Acral Lentiginous Melanoma

OPINION STATEMENT

Melanoma is one of the most aggressive malignant skin tumors and its incidence has been increasing worldwide in recent decades. Among the four subtypes, acral lentiginous melanoma (ALM) shows the highest incidence in Asian countries, whereas ALM comprises only 1% of all melanomas in white populations. Early clinical diagnosis of ALM is essential, but early ALM lesions are often difficult to diagnose because the pigmentation of the lesions sometimes follows the skin marking of the palms and soles, resulting in an asymmetrical appearance and an irregular border in both ALM and benign melanocytic nevus. To overcome this difficulty, dermoscopy was introduced, and determination of the patterns by this method is essential for accurate clinical diagnosis of ALM. Although recent clinical trials have demonstrated that immune checkpoint inhibitors and BRAF/MEK inhibitors showed significantly improved overall survival of patients with advanced melanoma, ALM may be less susceptible to immune checkpoint inhibitors because of the poor immune response to the tumor. Therefore, strategies for enhancing the immune response to the tumor cells may be required when we apply immune checkpoint inhibitors in advanced ALM. In this context, imiquimod, dacarbazine, or interferon are possible therapies that may enhance the effectiveness of the immune checkpoint inhibitors. In addition to being known to have poor immunogenicity, ALM is also known to have infrequent BRAF mutation. Therefore, the majority of ALM patients may not benefit from therapy with BRAF/MEK inhibitors. However, some ALMs have mutations such as KIT and NRAS mutations, and therefore, targeted therapies may improve the survival of ALM patients in the future.