Mucosal Melanoma: Epidemiology, Biology and Treatment

Primary Sinonasal Mucosal Melanoma: A Narrative Review

Mucosal melanomas (MMs) are under-researched tumors with a poor prognosis that arise from melanocytes found in the mucous membranes at different anatomical locations throughout the body. MMs are an uncommon yet highly aggressive tumor that typically develops on mucosal surfaces, predominantly in the head and neck region. MM of the head and neck occurs in 8-10% of all head and neck melanomas. It most commonly affects the mucosa of the nasal cavity and paranasal sinuses (75%), followed by the oral cavity mucosa (25%). A family history and the presence of mucosal nevi are associated with the occurrence of MM. Inhaled and dietary carcinogens are also linked to the development of sinonasal melanoma, much like other malignancies of the nasal cavity. Overexpression of the C-KIT gene is found in more than 80% of all primary mucosal melanomas, with somatic mutations in 10-30% of cases. The presence of these genetic alterations is also reflected in recent clinical studies of specific gene inhibitors that have proven efficiency in the systemic therapy of melanoma. There are various treatment modalities for MM. Surgical therapy involves en bloc surgical resection with a macroscopically visible and palpable mucosal margin of 1.5-2 cm. Partial resection of the maxilla may be considered if it ensures adequate tumor-free margine. Because of its rarity, outcome data for locally advanced head and neck MM is limited and primarily derived from retrospective studies with small case numbers. This review aims to update and summarize findings from clinical trials, prospective observational studies, and retrospective studies, while also exploring future directions for multimodal treatment approaches in this area.

Effectiveness of immune checkpoint inhibitors and other treatment modalities in patients with advanced mucosal melanomas: a systematic review and individual patient data meta-analysis

Background

Mucosal melanomas (MM) are an aggressive subtype of melanoma. Given the rarity of this disease, the conduct of clinical trials is challenging and has been limited. Current treatment options have been extrapolated from the more common cutaneous melanoma even though MM is distinct in pathogenesis, etiology and prognosis. This is the first meta-analysis to comprehensively assess the efficacy of immune checkpoint inhibitors (anti-PD1 and anti-CTLA4) and other treatment modalities (targeted therapy such as KIT inhibitors and VEGF inhibitors, as well as radiotherapy) on survival outcomes in MM to develop clinical guidelines for evidence-based management.

Methods

The protocol was prospectively registered on PROSPERO (PROSPERO ID: CRD42023411195). PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and Google Scholar were searched from inception until 25 July 2024, for all cohort and observational studies. Eligible studies included those with five or more participants with locally advanced or metastatic MM treated with anti-PD1, anti-CTLA4, VEGF inhibitors and/or KIT inhibitors. Titles and abstracts of potential articles were screened and full texts of all potentially eligible studies were retrieved and reviewed by two independent reviewers. Individual patient data (IPD) from published Kaplan-Meier curves were reconstructed using a graphical reconstruction method and pooled as a one-stage meta-analysis. A sensitivity analysis using a two-stage meta-analysis approach was conducted. Extracted outcomes included overall survival (OS) and progression-free survival (PFS). For each treatment arm, median survival time and 12-month survival proportion were estimated. Data from double-arm trials was pooled to estimate hazard ratios (HRs), ratios of restricted mean time lost (RMTL) and restricted mean survival time (RMST).

Findings

From a total of 7402 studies, 35 eligible studies comprising a total of 2833 participants were included. Combined anti-PD1 and anti-CTLA4 therapy had the highest 12-month OS and 12-month PFS at 71.8% (95% CI: 67.6%, 76.2%, n = 476) and 35.1% (95% CI: 30.5%, 40.4%, n = 401) respectively, followed by anti-PD1 therapy alone (OS: 64.0% (95% CI: 61.4%, 66.7%, n = 1399); PFS: was 28.3% (95% CI: 25.8%, 31.2%, n = 1142), anti-PD1 and VEGF inhibitor combination therapy (OS: 57.1% (95% CI: 51.0%, 63.9%)), KIT inhibitors (OS: 48.2% (95% CI: 37.6%, 61.8%); PFS: 8.3% (95% CI: 3.7%, 18.7%)) and anti-CTLA4 therapy alone (OS: 33.3% (95% CI: 28.4%, 39.1%); PFS: 9.8% (95% CI: 5.9%, 16.5%)). In the double-arm studies, combination therapy with anti-PD1 and anti-CTLA4 had similar OS and PFS with anti-PD1 alone (OS: HR 0.856 (95% CI: 0.704, 1.04); RMTL ratio 0.932 (95% CI: 0.832, 1.044, P = 0.225); RMST ratio 1.102 (95% CI: 0.948, 1.281, P = 0.204); PFS: HR 0.919 (95% CI: 0.788, 1.07); RMTL ratio 0.936 (95% CI: 0.866, 1.013, P = 0.100); RMST ratio 1.21 (95% CI: 0.979, 1.496, P = 0.078)), however, anti-PD1 therapy alone had significantly better PFS than anti-CTLA4 alone (HR 0.548 (95% CI: 0.376, 0.799); RMTL ratio 0.715 (95% CI: 0.606, 0.844, P < 0.001); RMST ratio 1.659 (95% CI: 1.316, 2.092, P < 0.001)). Anti-PD1 therapy with radiotherapy versus anti-PD1 alone showed no significant difference (OS: HR 0.854 (95% CI: 0.567, 1.29); RMTL ratio 0.855 (95% CI: 0.675, 1.083, P = 0.193); RMST ratio 1.194 (95% CI: 0.928, 1.536, P = 0.168; PFS: HR 0.994 (95% CI: 0.710, 1.39); RMTL ratio 1.006 (95% CI: 0.87, 1.162, P = 0.939); RMST ratio 0.984 (95% CI: 0.658, 1.472, P = 0.939)).

Interpretation

For the systemic treatment of MM, anti-PD1 is the best monotherapy. While combining anti-PD1 with other treatment options such as anti-CTLA4, VEGF inhibitors or radiotherapy might achieve better outcomes, these improvements did not reach statistical significance when evaluated by HR, RMTL and RMST ratios.

Funding

This work was supported by the National Medical Research Council Transition Award (TA20nov-0020), SingHealth Duke-NUS Oncology Academic Clinical Programme (08/FY2020/EX/67-A143 and 08/FY2021/EX/17-A47), the Khoo Pilot Collaborative Award (Duke-NUS-KP(Coll)/2022/0020A), the National Medical Research Council Clinician Scientist-Individual Research Grant-New Investigator Grant (CNIGnov-0025), the Terry Fox Grant (I1056) and the Khoo Bridge Funding Award (Duke-NUS-KBrFA/2024/0083I).

Rare Head and Neck Cancers and Pathological Diagnosis Challenges: A Comprehensive Literature Review

Head and neck cancers (HNCs) arise from anatomically adjacent sites and subsites, with varying etiological factors, diagnostic strategies, prognoses, and treatment approaches. While conventional squamous cell carcinoma (SCC) is the most common histology in the head and neck district, HNCs encompass a variety of rare histopathological entities, categorized into epithelial tumors such as salivary gland cancers, sinonasal tumors, neuroendocrine tumors, malignant odontogenic tumors, and SCC variants versus non-epithelial tumors including soft tissue sarcomas, mucosal melanomas, and hematological malignancies. Rare HNCs (R-HNCs) represent a diagnostic and clinical challenge, requiring histopathological expertise, the availability of peculiar molecular analysis, and the personalization of local and systemic treatments, all guided by a multidisciplinary tumor board. Here, we provide a comprehensive literature review on R-HNCs, emphasizing key histopathological and molecular characteristics that are crucial for guiding treatment decisions. An insight about the latest developments in systemic treatments is also reported.

Heterogeneous pathogenesis of melanoma: BRAF mutations and beyond

Melanoma pathogenesis, conventionally perceived as a linear accumulation of molecular changes, discloses substantial heterogeneity driven by non-linear biological processes, including the direct transformation of melanocyte stem cells. This heterogeneity manifests in diverse biological phenotypes and developmental states, influencing variable responses to treatments. Unveiling the aberrant mechanisms steering melanoma initiation, progression, and metastasis is imperative. Beyond mutations in oncogenic and tumor suppressor genes, the involvement of distinct molecular pathways assumes a pivotal role in melanoma pathogenesis. Ultraviolet (UV) radiations, a principal factor in melanoma etiology, categorizes melanomas based on cumulative sun damage (CSD). The genomic landscape of lesions correlates with UV exposure, impacting mutational load and spectrum of mutations. The World Health Organization's 2018 classification underscores the interplay between sun exposure and genomic characteristics, distinguishing melanomas associated with CSD from those unrelated to CSD. The classification elucidates molecular features such as tumor mutational burden and copy number alterations associated with different melanoma subtypes. The significance of the mutated BRAF gene and its pathway, notably BRAFV600 variants, in melanoma is paramount. BRAF mutations, prevalent across diverse cancer types, present therapeutic avenues, with clinical trials validating the efficacy of targeted therapies and immunotherapy. Additional driver mutations in oncogenes further characterize specific melanoma pathways, impacting tumor behavior. While histopathological examination remains pivotal, challenges persist in molecularly classifying melanocytic tumors. In this review, we went through all molecular characterization that aid in discriminating common and ambiguous lesions. Integration of highly sensitive molecular diagnostic tests into the diagnostic workflow becomes indispensable, particularly in instances where histology alone fails to achieve a conclusive diagnosis. A diagnostic algorithm based on different molecular features inferred by the various studies is here proposed.

A Retrospective Analysis of the Prognostic Factors and Adverse Events in the Treatment of Mucosal Melanoma in a Single Centre

Background: Despite the dramatic advances in the management of metastatic cutaneous melanoma, there remains no consensus-based, evidence-based strategy for the management of mucosal melanoma. The rare nature of the disease, its late clinical presentation, and distinct tumour biology all complicate efforts to optimise patient outcomes. Methods: To this end, we carried out a monocentric, retrospective analysis of all patients diagnosed with mucosal melanoma and treated between 2013 and 2021. Both tumour- and patient-specific characteristics were recorded, in addition to immune-related adverse events, in order to provide real-world data on disease progression, treatment efficacy, and the identification of prognostic markers. Results: A total of 20 patients were identified (14 females and 6 males), with a mean age at diagnosis of 65.9 years. The median follow-up was 3.9 years (95% CI 1.4-6.4 years) from the initiation of systemic therapy. The median OS in the entire cohort was 1.9 years (95% CI 0.5-3.3 years). Performance status, sex, body mass index, and the presence of brain metastases were not associated with poorer outcomes. However, serum lactate dehydrogenase levels (LDH) (p = 0.04) and an NRAS mutation were markers of a poor prognosis (p = 0.004). Conclusuion: There is a pressing need for real-world, prospective, and clinical trial data to inform the optimal management of mucosal melanoma, and data supporting the use of adjuvant and neo-adjuvant immunotherapy are currently lacking. However, an elevated LDH is a reliable, independent negative prognostic marker. Inter-disciplinary management remains essential in order to develop optimal treatment strategies.

Survival of patients with mucosal melanoma in Cali, Colombia: a retrospective cohort study

BACKGROUND

Mucosa melanoma is a rare condition with aggressive behavior and a less favorable prognosis compared to cutaneous melanoma. The objective of this study was to estimate the overall survival and clinical outcomes of patients diagnosed with mucosal melanoma in a Colombian hospital.

METHODS

A retrospective cohort study was conducted at Fundación Valle del Lili, a single center located in Cali, Colombia. Patients aged ≥ 18 years, both sexes, diagnosed with mucosal melanoma by histopathology study were included between 2010-2019. Patients who received extra-institutional treatment or whose vital status was unknown during follow-up were excluded. Demographic, clinical and laboratory data were obtained from medical records and laboratory and pathology databases. A descriptive analysis was performed. Survival analysis was conducted using the Kaplan-Meier method.

RESULTS

A total of 23 patients were included. Median age was 63 years old (IQR: 57-68) and 52.2% were woman. Clinical stage was 34.8% early, 26.1% locally advanced and 39.1% metastatic. The main primary locations were nasopharynx (30.4%), genitals (26.1%), rectum (21.7%), oral cavity (13%) and paranasal sinuses (8.7%). The majority received surgery (30.4%) and immunotherapy (26.1%) as first line treatment. Overall survival at one year was 80.8%, at three years 44.3%, and at five years 36.9%.

CONCLUSION

Mucosal melanoma is a rare, aggressive disease with adverse oncological outcomes due to late diagnosis and limited treatment options. This study provides real-world data in a single-center of Colombia.

Endoscopic ultrasound features of rectal melanoma: A case report and review of literature

BACKGROUND

Rectal mucosal melanoma is a rare and highly aggressive disease. Common symptoms include anal pain, an anal mass, or bleeding. As such, the disease is usually detected on rectal examination of patients with other suspected anorectal diseases. However, due to its rarity and nonspecific symptoms, melanoma of the rectal mucosa is easily misdiagnosed.

CASE SUMMARY

This report describes the case of a 58-year-old female patient who presented with a history of blood in her stool for the prior one or two months, without any identifiable cause. During colonoscopy, a bulge of approximately 2.2 cm × 2.0 cm was identified. Subsequently, the patient underwent endoscopic ultrasound (EUS) to characterize the depth of invasion of the lesions. EUS suggested a hypoechoic mucosal mass with involvement of the submucosal layer and heterogeneity of the internal echoes. Following surgical intervention, the excised tissue samples were examined and confirmed to be rectal malignant melanoma. The patient recovered well with no evidence of recurrence during follow-up.

CONCLUSION

This case shows that colonoscopy with EUS and pathological examination can accurately diagnose rare cases of rectal mucosal melanoma.

Primary lacrimal sac melanoma: a case report describing the novel use of fine needle aspiration cytology (FNAC) for diagnosis, together with literature review and immunotherapy treatment update

Primary lacrimal sac melanoma (PLSM) is exceedingly rare and associated with high morbidity and mortality. Unfortunately, PLSM often presents insidiously resulting in delayed detection and poor prognosis. A 69-year-old Black man was suspected of having a lacrimal sac tumour following presentation with a left sided watery eye, bloody tears, and a lacrimal mass. Due to the patient's implantable pacemaker, defibrillator, and high anticoagulation, an ultrasound-guided FNAC was performed instead of incisional biopsy, revealing a PLSM. Diagnosis was confirmed following complete tumour resection with free flap reconstruction and neck dissection. Unfortunately, disease progression ensued despite further neck dissection and three cycles of both pembrolizumab and iplimumab. This is the first description of FNAC to accurately diagnose PLSM and highlights its use as an accurate, rapid, and minimally invasive technique that may allow an earlier screening diagnosis of lacrimal sac tumours. We also discuss the outcome of immunotherapy in recent similar cases.

Mucosal Melanoma Clinical Management and Prognostic Implications: A Retrospective Cohort Study

Mucosal melanoma (MM) is an uncommon melanoma subtype affecting mucosal surfaces of the head and neck, anorectal region, and vulvovaginal area. We aimed to present our experience at a tertiary-level hospital regarding MM diagnosis, management, monitoring of progression, mutations, and outcome predictors. We performed a registry-based cohort study including MM cases diagnosed from 2012 to 2022 and retrospectively characterized somatic mutations on BRAF, NRAS and c-KIT. We employed Kaplan-Meier curves, log-rank tests, and Cox regression analysis to explore prognostic factors and survival outcomes in a cohort of 35 patients, mainly women (63%) with a median age of 70 years. Predominantly, MM occurred in the vulvovaginal region (48.6%). At diagnosis, 28.6% had lymph node involvement, and 31.4% also had distant metastasis. Mutations in BRAF and c-KIT were identified in 3/35 (9%) and 2/6 patients (33%), respectively. Surgery was performed in 71.4% of patients, and most received systemic treatment (65.7%). Lower disease stage, thinner Breslow depth, and surgical resection were associated with improved overall survival. Notably, age, sex, radiotherapy, and BRAF mutant status did not affect survival. Standard management typically involves immunotherapy. Cases with BRAF or c-KIT mutations may be considered for targeted therapies. Unfortunately, MM prognosis remains unfavorable, with a less than 50% survival rate at 2 years.

Mucosal melanoma: from molecular landscape to current treatment strategies

Mucosal melanoma (MM) is an aggressive tumor originating from melanocytes located in the respiratory, gastrointestinal, and urogenital tract with clinical and pathologic characteristics distinct from cutaneous melanoma. In addition, MMs have a unique biology that contributes to delayed diagnosis and, therefore an adverse prognosis. The factors all contribute to a treatment paradigm unique from its more studied cutaneous brethren. Due to the rarity of this disease, well-established protocols for the treatment of this pathology have yet to be established. The use of immune checkpoint inhibitors patterned after cutaneous melanoma has become the de facto primary therapeutic approach; however, cytotoxic strategies and pathway-targeted therapies have a defined role in treatment. Judicious use of these approaches can give rise to durable unmaintained disease responses.

Molecular investigation of some DNA viruses in mucosal melanoma: Case-control study

The association between viral infections and both cutaneous and mucosal melanoma (MM) has not been fully investigated. Here, we assessed the prevalence of the DNA of a broad range of viruses in 31 MMs and 15 biopsies of healthy mucosa (HM) using molecular methods. The parvoviruses CuV and B19V, herpesviruses HSV1, HSV2, EBV, HHV6, and HHV8, polyomavirus MCPyV, and α-HPVs were not detected, or rarely found, in MMs, and in HM, of the digestive, respiratory, and female genital tract. The overall prevalence of β-HPV in MMs was not significantly higher compared to that in HM (70.9% and 53.3% respectively; p = 0.514). However, the number of MMs positive for β-HPV types belonging to Species 3 and 5 and for some viral types belonging to Species 1, 2, 3, and 5 were significantly higher compared with HM (p < 0.05). Moreover, compared to HM, the MM samples contained a significantly higher number of β-HPV types, mainly belonging to Species 1, 3, and 5 (p < 0.05). Our data, although suggesting a role for certain β-HPV types in MM oncogenesis, require additional investigation in larger populations to support this hypothesis.

A human mucosal melanoma organoid platform for modeling tumor heterogeneity and exploring immunotherapy combination options

Mucosal melanoma (MM), an aggressive rare subtype of melanoma, is distinct from cutaneous melanoma and has poor prognoses. We addressed the lack of cell models for MM by establishing 30 organoids of human oral MM (OMM), which retained major histopathological and functional features of parental tumors. Organoid groups derived from chronologically or intratumorally distinct lesions within the same individual displayed heterogeneous genetics, expression profiles, and drug responses, indicating rapid tumor evolution and poor clinical response. Furthermore, transcriptome analysis revealed receptor tyrosine kinases (RTKs) signaling, particularly NGFR, a nerve growth factor receptor, was significantly up-regulated in OMMs and organoids from patients resistant to anti-programmed cell death protein 1 (anti-PD-1) therapy. Combining anti-PD-1 with anlotinib (a phase 2 multitarget RTK inhibitor for OMM) or NGFR knockdown enhanced the effective activity of immune cells in organoid-immune cell coculture systems. Together, our study suggested that OMM organoids serve as faithful models for exploring tumor evolution and immunotherapy combination strategies.

Prognostic models based on lymph node density for primary gastrointestinal melanoma: a SEER population-based analysis

OBJECTIVE

This study aimed to construct prognostic models to predict the overall survival (OS) and cancer-specific survival (CSS) of patients with primary gastrointestinal melanoma (PGIM).

DESIGN

An observational and retrospective study.

SETTING

Data were obtained from the Surveillance, Epidemiology and End Results (SEER) programme database, encompassing a broad geographical and demographic spectrum of patients across the USA.

PARTICIPANTS

A total of 991 patients diagnosed with PGIM were included in this study.

METHODS

A total of 991 patients with PGIM were selected from the SEER database. They were further divided into a training cohort and a validation cohort. Independent prognostic factors were identified by Cox regression analysis. Two prognostic models were constructed based on the results of multivariable Cox regression analysis. The concordance index (C-index) and area under the time-dependent receiver operating characteristic curve (time-dependent AUC) were used to evaluate the discriminative ability. Calibration curves were plotted to evaluate the agreement between the probability as predicted by the models and the actual probability. Risk stratification was developed given the model.

RESULTS

By the multivariable Cox regression analysis, we identified four independent risk factors (age, stage, lymph node density and surgery) for OS, and three independent risk factors (stage, lymph node density and surgery) for CSS, which were used to construct prognostic models. C-index, time-dependent AUC, calibration curves and Kaplan-Meier curves of risk stratification indicated that these two models had good discriminative ability, predictive ability as well as clinical value.

CONCLUSIONS

The prognostic models of OS and CSS had satisfactory accuracy and were of clinical value in evaluating the prognosis of patients with PGIM.

PAK1 and Therapy Resistance in Melanoma

Malignant melanoma claims more lives than any other skin malignancy. While primary melanomas are usually cured via surgical excision, the metastatic form of the disease portents a poor prognosis. Decades of intense research has yielded an extensive armamentarium of anti-melanoma therapies, ranging from genotoxic chemo- and radiotherapies to targeted interventions in specific signaling pathways and immune functions. Unfortunately, even the most up-to-date embodiments of these therapies are not curative for the majority of metastatic melanoma patients, and the need to improve their efficacy is widely recognized. Here, we review the reports that implicate p21-regulated kinase 1 (PAK1) and PAK1-related pathways in the response of melanoma to various therapeutic modalities. Ample data suggest that PAK1 may decrease cell sensitivity to programmed cell death, provide additional stimulation to growth-promoting molecular pathways, and contribute to the creation of an immunosuppressive tumor microenvironment. Accordingly, there is mounting evidence that the concomitant inhibition of PAK1 enhances the potency of various anti-melanoma regimens. Overall, the available information suggests that a safe and effective inhibition of PAK1-dependent molecular processes would enhance the potency of the currently available anti-melanoma treatments, although considerable challenges in implementing such strategies still exist.

Early-Stage Primary Rectal Melanoma: A Case Report

Malignant primary rectal melanomas (PRM) are rare tumors. Their diagnosis is frequently delayed as these lesions are often mistaken for benign diseases, resulting in extremely poor overall survival. Histological evaluation with special immunohistochemical (IHC) stains is often indispensable for a definitive diagnosis. The main treatment for this condition involves surgical resection. Adjuvant therapy has also been long recommended. We discuss the case of a 60-year-old woman who presented with changes in bowel habits, anal pain, and perineal burning with no bleeding. A digital rectal examination revealed a nodular mass extending 5 cm from the anal verge. Rectosigmoidoscopy demonstrated an ulcerated polypoid tumor extending 4 cm from the anal verge and over 5 cm into the lower rectum. Biopsy and IHC tests confirmed the diagnosis of rectal melanoma. The patient was successfully managed with surgery followed by external beam radiotherapy and a complete response was achieved after 10 months of follow-up.

Expression of microRNAs and their target genes in melanomas originating from gynecologic sites

Melanomas from gynecologic sites (MOGS) are rare and have poor survival. MicroRNAs (miRs) regulate gene expression and are dysregulated in cancer. We hypothesized that MOGS would display unique miR and mRNA expression profiles. The miR and mRNA expression profile in RNA from formalin fixed, paraffin embedded vaginal melanomas (relative to vaginal mucosa) and vulvar melanomas (relative to cutaneous melanoma) were measured with the Nanostring Human miRNA assay and Tumor Signaling mRNA assay. Differential patterns of expression were identified for 21 miRs in vaginal and 47 miRs in vulvar melanoma (fold change >2, p<0.01). In vaginal melanoma, miR-145-5p (tumor suppressor targeting TLR4, NRAS) was downregulated and miR-106a-5p, miR-17-5p, miR-20b-5p (members of miR-17-92 cluster) were upregulated. In vulvar melanoma, known tumor suppressors miR-200b-3p and miR-200a-3p were downregulated, and miR-20a-5p and miR-19b-3p, from the miR-17-92 cluster, were upregulated. Pathway analysis showed an enrichment of "proteoglycans in cancer". Among differentially expressed mRNAs, topoisomerase IIα (TOP2A) was upregulated in both MOGS. Gene targets of dysregulated miRs were identified using publicly available databases and Pearson correlations. In vaginal melanoma, suppressor of cytokine signaling 3 (SOCS3) was downregulated, was a validated target of miR-19b-3p and miR-20a-5p and trended toward a significant inverse Pearson correlation with miR-19b-3p (p = 0.093). In vulvar melanoma, cyclin dependent kinase inhibitor 1A (CDKN1A) was downregulated, was the validated target of 22 upregulated miRs, and had a significant inverse Pearson correlation with miR-503-5p, miR-130a-3p, and miR-20a-5p (0.005 < p < 0.026). These findings support microRNAs as mediators of gene expression in MOGS.

Cutaneous Malignant Melanoma Metastatic to the Larynx and Trachea: A Case Report and Review of the Literature

Malignant melanoma rarely develops in mucous membranes. Statistical data show that approximately 0.6-9.3% of patients with cutaneous malignant melanoma will develop metastases in the upper aerodigestive tract mucosa, and within these metastatic sites, the least common are the laryngeal and tracheobronchial ones. This exceedingly rare clinical entity has no clear treatment recommendations; radical surgery does not seem to benefit the patient in term of life expectancy. We present the case of a 56-year-old male patient diagnosed with laryngeal and tracheobronchial melanoma metastases. Prior to admission to our clinic the patient had a personal history of malignant melanoma of the nuchal region operated on 7 years ago, malignant melanoma of the gallbladder and metastatic left axillary polyadenopathy for which he underwent surgical treatment 3 months prior. Histopathological and immunohistochemical reports established the diagnosis of laryngeal metastasis of malignant melanoma. Genetic molecular analysis was positive for B-Raf (BRAF) gene and hence Vemurafenib was administered, with a favorable outcome at the one-year follow-up. Nevertheless, there are currently no clear universally accepted guidelines for the treatment of laryngeal melanoma, mainly due to the rarity of this clinical entity. We conducted a review of similar cases reported in the literature. Interestingly, reviewing the cases reported in the literature, it appears that laryngeal metastases of a primary cutaneous melanoma are more common in men, with an average time to metastasis of 4.3 years.

Plasma exosome-derived connexin43 as a promising biomarker for melanoma patients

BACKGROUND

To examine the levels of exosome-derived connexin 43 (Cx43) in plasma and estimate its forecast value in patients with melanoma.

METHODS

We measured the plasma exosome-derived Cx43 levels in the plasma of 112 melanoma patients and 50 healthy controls.

RESULTS

The plasma exosome-derived Cx43 levels in patients with melanoma were substantially downregulated as opposed to the levels in healthy controls (P < 0.001). Kaplan-Meier analysis indicated that overall survival (OS) and disease-free survival (DFS) were poorer in patients with melanoma who exhibited lower levels of plasma exosome-derived Cx43 (both P < 0.001). The levels of plasma exosome-derived Cx43 were considerably elevated in patients with melanoma whose tumor was situated in the skin, tumor size < 10 cm, with Clark level I-III, TNM stages IIb-IV, and had no lymph node metastasis as opposed to patients whose tumor was situated in the viscera or mucosa, tumor size ≥ 10 cm, Clark level IV-V, TNM stages IIb-IV and had lymph node metastasis (all P < 0.05). The receiver operating characteristic (ROC) of plasma exosome-derived Cx43 for forecasting 5-year DFS in patients with melanoma was 0.78 (95% confidence interval (CI): 0.70-0.86), with a specificity of 77.78% and a sensitivity of 81.55%. The ROC of plasma exosome-derived Cx43 for forecasting 5-year OS of patients with melanoma was 0.77 (95% CI: 0.68-0.84), with a specificity of 80.0% and sensitivity of 65.98%.

CONCLUSION

The overall findings indicated that the levels of plasma exosome-derived Cx43 in patients with melanoma were considerably downregulated. It can therefore be inferred that the levels of plasma exosome-derived Cx43 might be a prospective prognostic indicator for 5 5-year OS and 5-year DFS of patients with melanoma.

A Systematic Review of Primary Temporal Bone Mucosal Melanoma

OBJECTIVE

Temporal bone mucosal melanomas (MMs) are rare, and patients may experience delays in diagnosis and treatment. Our objective was to better characterize the presentation, diagnosis, treatment modalities, and outcomes of this process.

DATA SOURCES

PubMed/Medline, CINAHL (EBSCOhost), and Web of Science databases were searched in all languages without restriction of publication dates.

STUDY SELECTION

Inclusion criteria included that the article was either a case report or a case series with individual case data. All non-English articles were excluded if the corresponding abstract lacked data on demographics, initial presentation, and clinical management.

DATA EXTRACTION

After full-text analysis, data pertaining to demographics, diagnosis, medical and surgical management modalities, and outcomes were extracted.

DATA SYNTHESIS

Data were qualitatively synthesized, and means and averages were obtained for all continuous variables. Overall survival was measured by the Kaplan-Meier method, and significance was measured through log-rank testing.

CONCLUSIONS

Clinicians should suspect temporal bone MM in the differential diagnosis of patients with bloody otorrhea in the context of a chronic serous otitis media or an associated cranial nerve palsy. If suspected, physicians should not delay the acquisition of a biopsy or imaging studies. Management is highly variable and must be decided on a case-by-case basis. Outcomes remain poor because of the high propensity for MM to metastasize.

Shaping the Future of Immunotherapy Targets and Biomarkers in Melanoma and Non-Melanoma Cutaneous Cancers

Recent advances in treating cutaneous melanoma have resulted in impressive patient survival gains. Refinement of disease staging and accurate patient risk classification have significantly improved our prognostic knowledge and ability to accurately stratify treatment. Undoubtedly, the most important step towards optimizing patient outcomes has been the advent of cancer immunotherapy, in the form of immune checkpoint inhibition (ICI). Immunotherapy has established its cardinal role in the management of both early and late-stage melanoma. Through leveraging outcomes in melanoma, immunotherapy has also extended its benefit to other types of skin cancers. In this review, we endeavor to summarize the current role of immunotherapy in melanoma and non-melanoma skin cancers, highlight the most pertinent immunotherapy-related molecular biomarkers, and lastly, shed light on future research directions.

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.

Clinical Review of Mucosal Melanoma: The 11-Year Experience of a Referral Center

INTRODUCTION

Mucosal melanoma is a rare neoplasm. Late diagnosis is caused by occult anatomic sites and scarcity of symptoms. Novel biological therapies have now become available. Demographic, therapeutical and survival records on mucosal melanoma are scarce.

OBJECTIVES

To provide an 11-year retrospective clinical review of real-world data on mucosal melanomas managed in a tertiary referral center in Italy.

METHODS

We included patients with histopathological mucosal melanoma diagnoses from January 2011 to December 2021. Data were collected until the last known follow-up or death. Survival analysis was performed.

RESULTS

Among 33 patients, we found 9 sinonasal, 13 anorectal and 11 urogenital mucosal melanomas (median age 82, females 66.7%). Eighteen cases (54.5%) presented with metastasis (p<0.05). In the urogenital subgroup, only 4 patients (36.4%) had metastasis at diagnosis, all in regional lymph nodes. Sinonasal melanomas were surgically managed with a debulking procedure (44.4%); every case of anorectal and urogenital melanomas underwent radical surgery (30.8% and 45.5%). Fifteen patients were treated with biological therapy (p<0.05). Radiation therapy was used in all melanomas of the sinonasal region (p<0.05). Overall survival was longer for urogenital melanomas (26 months). Univariate analysis showed an increased hazard ratio for death in patients with metastasis. A negative prognostic value of metastatic status was reported by the multivariate model, while administration of first-line immunotherapy demonstrated a protective role.

CONCLUSIONS

At diagnosis, the absence of metastatic disease is the most relevant factor that influences the survival of mucosal melanomas. Moreover, the use of immunotherapy might prolong the survival of metastatic mucosal melanoma patients.

Comprehensive genomic analysis of primary malignant melanoma of the esophagus reveals similar genetic patterns compared with epithelium-associated melanomas

Primary malignant melanoma of the esophagus (PMME) is an exceedingly rare disease with a poor prognosis. The etiology of PMME remains largely unknown and genetic characteristics are yet to be clarified, essential for identifying potential therapeutic targets and defining treatment guidelines. Here, we performed whole-exome sequencing on 47 formalin-fixed paraffin-embedded specimens from 18 patients with PMME, including 23 tumor samples, 6 metastatic lymph nodes, and 18 tumor-adjacent normal tissues. The genomic features of PMME were comprehensively characterized, and comparative genomic analysis was further performed between these specimens and 398 skin cutaneous melanomas (SKCM), 67 non-esophagus mucosal melanomas (NEMM), and 79 uveal melanomas (UVM). In the PMME cohort, recurrently mutated driver genes, such as MUC16, RANBP2, NRAS, TP53, PTPRT, NF1, MUC4, KMT2C, and BRAF, were identified. All RANBP2 mutations were putatively deleterious, and most affected samples had multipoint mutations. Furthermore, RANBP2 showed parallel evolution by multiregional analysis. Whole-genome doubling was an early truncal event that occurred before most driver mutations, except for in TP53. An ultraviolet radiation-related mutational signature, SBS38, was identified as specific to epithelial melanomas and could predict inferior survival outcomes in both PMME and SKCM patients. Comparing the mutational and copy number landscapes between PMME and other subtypes of melanoma revealed that PMME has a similar genomic pattern and biological characteristics to SKCM. In summary, we comprehensively defined the key genomic aberrations and mutational processes driving PMME and suggested for the first time that PMME may share similar genomic patterns with SKCM; therefore, patients with rare melanomas, such as PMME, may benefit from the current treatment used for common cutaneous melanoma.

Metabolic heterogeneity protects metastatic mucosal melanomas cells from ferroptosis

Cancer heterogeneity has been proposed to be one of the main causes of metastatic dissemination and therapy failure. However, the underlying mechanisms of this phenomenon remain poorly understood. Melanoma is an aggressive malignancy with a high heterogeneity and metastatic potential. Therefore, the present study investigated the possible association between cancer heterogeneity and metastasis in melanoma. In total, two novel Chinese oral mucosal melanoma (COMM) cell lines, namely COMM-1 and COMM-2, were established for exploring methods into preventing the loss of cellular heterogeneity caused by long-term cell culture. Each cell line was grown under two different models of culture, which yielded two subtypes, one exhibited an adhesive morphology (COMM-AD), whereas the other was grown in suspension (COMM-SUS). Compared with the COMM-AD cells, the COMM-SUS cells exhibited higher metastatic capacities and autofluorescence. Further investigations indicated that the COMM-SUS cells exhibited metabolic reprogramming by taking up lactate produced by COMM-AD cells at increased levels to accumulate NADH through monocarboxylate transporter 1, whilst also increasing NADPH levels through the pentose phosphate pathway (PPP). Additionally, increased NADH and NADPH levels in the COMM-SUS cells, coupled with the upregulation of the anti-ferroptotic proteins, glutathione peroxidase 4 and ferroptosis suppressor protein 1, enabled them to resist ferroptotic cell death induced by oxidative stress during hematogenous dissemination. The inhibition of ferroptosis was found to substantially increase the metastatic capacity of COMM-AD cells. Furthermore, suppressing lactate uptake and impairing PPP activation significantly decreased the metastatic potential of the COMM-SUS cells. Thus, the present study on metabolic heterogeneity in COMM cells potentially provides a novel perspective for exploring this mechanism underlying cancer metastasis.

Management of Acral and Mucosal Melanoma: Medical Oncology Perspective

Acral and mucosal melanomas (MM) are rare subtypes of melanoma that are biologically and clinically distinct from cutaneous melanoma. Despite the progress in the treatment of cutaneous melanomas with the development of targeted and immune therapies, the therapeutic options for these less common subtypes remain limited. Difficulties in early diagnosis, the aggressive nature of the disease, and the frequently occult sites of origin have also contributed to the poor prognosis associated with acral and MM, with substantially worse long-term prognosis. The rarity of these subtypes has posed significant barriers to better understanding their biological features and investigating novel therapies. Consequently, establishing standardized treatment guidelines has been a challenge. In this review, we provide a brief overview of the current knowledge regarding acral and MM, focusing on their epidemiology, genetic backgrounds, and unique clinical characteristics. Further discussion centers around the management of primary and advanced disease and the role of emerging targeted and immune therapies for these subtypes, specifically focusing on issues relevant to medical oncologists.

Wandering Mucosal Melanoma Presenting as Occult Gastrointestinal Blood Loss Anemia

Malignant melanoma is a highly aggressive cancer arising from the skin, retina, and mucosal lining of the respiratory, gastrointestinal (GI), or genitourinary tracts, all of which contain melanocytes. Mucosal or extracutaneous melanomas (ECMs) are rare accounting for 1% of all melanomas. We herein report a case of a metastatic mucosal melanoma presenting as occult blood loss anemia.

A 58-year-old male presented with generalized weakness, anorexia, weight loss, and intermittent melena for one year. On exam, he was tachycardic, borderline hypotensive, and pale without epigastric tenderness. Labs showed severe anemia [hemoglobin, Hgb 3.8 mg/dL, mean corpuscular volume (MCV) 72 fl] for which he received two units of red cells. Endoscopy revealed an 8 mm non-bleeding, gastric ulcer with a raised border and a clean base on the wall of the gastric body. Histologic analysis was consistent with malignant melanoma displaying strong positivity for S-100, Melan A, and HMB 45 stains. The CT of the abdomen revealed multifocal metastatic disease with subcutaneous, intramuscular, and perinephric implants with suspicion of small bowel carcinomatosis. The patient underwent an excisional biopsy for the abdominal wall mass and surgical pathology confirmed melanoma. The patient is planned to be started on immunotherapy for advanced disease.

Most melanomas found in the GI tract are metastatic. Mucosal melanoma presenting as a gastric ulcer is extremely rare. As a result, metastasis from other sites must be ruled out before making a diagnosis of primary gastric melanoma (PGM). In our case, a widespread disease with unknown primary elucidated the diagnosis but post-operative inspection failed to find any potential lesion on the skin, genitals, or other organs, suggesting the possible diagnosis of metastatic gastric melanoma. However, follow-up is still required to confirm the diagnosis according to the established criteria. Pathologic diagnosis of melanoma requires the identification of melanin in the cytoplasm and immunohistochemistry with specific markers such as S-100, Melan A, and HMB-45. Although the pathologic diagnosis of PGM is similar to cutaneous melanoma, preoperative diagnosis is difficult due to the extremely low incidence, lack of obvious melanin pigmentation, similar microscopic patterns as more common gastric cancers, and lack of awareness among physicians and pathologists.

The prognosis of mucosal melanoma is poor, with a five-year survival rate of 25% versus 80% for cutaneous melanoma. Advanced age, surgically unresectable disease, and lymph node involvement are all poor prognostic markers. There is no standard protocol for treatment. Surgery is the only curative treatment for the resectable disease. Adjuvant chemotherapy, radiation, and immunotherapy have an established role in cutaneous melanoma but there is only limited data on adjuvant systemic therapy with mucosal melanoma. Further research is imperative to establish proper management guidelines for this rare disease entity.

Sinonasal Mucosal Melanoma: An Update and Review of the Literature

ABSTRACT

Primary sinonasal mucosal melanoma (SNMM) is an aggressive tumor with high metastatic potential and poor outcomes. Presenting symptoms are nonspecific, and the nasal cavity is the most common site of origin followed by the maxillary and ethmoid sinuses. Histopathologically, SNMMs are pleomorphic and predominantly composed of epithelioid cell type. Identifying these tumors requires a high index of suspicion for melanoma and the use of a panel of immunohistochemical markers when typical histopathological features are missing. Not infrequently, these tumors are undifferentiated and/or amelanotic. Currently, SNMM falls into 2 different staging systems proposed by the American Joint Committee on Cancer, one for carcinoma of the nasal cavity and sinuses and the other for head and neck melanoma. Although therapeutic standards do not exist, surgical resection with adjuvant radiotherapy and/or systemic therapy may offer the best outcome. Lymphadenectomy including possible parotidectomy and neck dissection should be considered in patients with regional lymph node metastasis. However, the role of elective lymph node dissection is controversial. Genetic profiling has identified a number of recurrent gene mutations that may prove useful in providing targets for novel, emerging biological treatments. In this article, we provide an update on clinicopathological features, staging, molecular discoveries, and treatment options for SNMM.

Risk factors for cardiovascular mortality and melanoma-specific mortality among patients with melanoma: a SEER based study

OBJECTIVE

This study aims to identify the risk factors for cardiovascular mortality in melanoma patients.

METHODS

Data of melanoma patients were obtained from the Surveillance, Epidemiology, and End Results database. We used Person's chi-square test to assess the relationships between categorical variables. We used Kaplan-Meier test in the univariate analysis and Cox regression test for the multivariate analysis. Analyses were conducted using the SPSS software.

RESULTS

We analyzed data of 194 503 melanoma patients. Among them, 28 818 (14.8 %) died due to cardiovascular diseases. Cardiovascular-specific survival was higher in younger patients, women, married, localized disease, superficial spreading melanoma and in patients who had surgery. It was lower in patients who received chemotherapy or radiotherapy. The multivariate analysis revealed a higher risk of cardiovascular mortality in patients aged 50-64 years [hazard ratio (HR), 7.297; 95% confidence interval (CI), 6.68-7.97], patients aged ≥65 years (HR, 43.309; 95% CI, 39.706-47.240), men (HR, 1.535; 95% CI, 1.475-1.597), Blacks (HR, 1.29; 95% CI, 1.044-1.594), separated (HR, 1.286; 95% CI, 1.058-1.562), widowed (HR, 1.829; 95% CI, 1.706-1.961), patients with no or unknown history of chemotherapy (HR, 1.302; 95% CI, 1.071-1.583) or radiotherapy (HR, 1.477; 95% CI, 1.217-1.793) and patients with no surgery (HR, 1.468; 95% CI, 1.264-1.706).

CONCLUSIONS

In patients with melanoma, the risk of cardiovascular death is higher in older patients, men, Blacks, separated, widowed and patients with nodular or lentigo maligna melanoma. The risk is lower in married, patients with superficial spreading or acral lentiginous melanoma, and patients who had chemotherapy, radiotherapy or surgery.

Histone Deacetylase (HDAC) Inhibitors: A Promising Weapon to Tackle Therapy Resistance in Melanoma

Melanoma is an aggressive malignant tumor, arising more commonly on the skin, while it can also occur on mucosal surfaces and the uveal tract of the eye. In the context of the unresectable and metastatic cases that account for the vast majority of melanoma-related deaths, the currently available therapeutic options are of limited value. The exponentially increasing knowledge in the field of molecular biology has identified epigenetic reprogramming and more specifically histone deacetylation (HDAC), as a crucial regulator of melanoma progression and as a key driver in the emergence of drug resistance. A variety of HDAC inhibitors (HDACi) have been developed and evaluated in multiple solid and hematologic malignancies, showing promising results. In melanoma, various experimental models have elucidated a critical role of histone deacetylases in disease pathogenesis. They could, therefore, represent a promising novel therapeutic approach for advanced disease. A number of clinical trials assessing the efficacy of HDACi have already been completed, while a few more are in progress. Despite some early promising signs, a lot of work is required in the field of clinical studies, and larger patient cohorts are needed in order for more valid conclusions to be extracted, regarding the potential of HDACi as mainstream treatment options for melanoma.

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.

c-Kit inhibitors for unresectable or metastatic mucosal, acral or chronically sun-damaged melanoma: a systematic review and one-arm meta-analysis

BACKGROUND

Activating genomic alterations of the receptor tyrosine kinase KIT are found preferentially in certain melanoma subtypes such as acral and mucosal melanoma or melanoma arising in chronically sun-damaged skin. However, the therapeutic value of c-Kit inhibitors for these subtypes currently remains unclear.

OBJECTIVES

The objective of this study was to summarise the efficacy and safety of c-Kit inhibitors for unresectable or metastatic mucosal, acral or chronically sun-damaged melanoma.

METHODS

We performed a systematic literature research in MEDLINE, Embase and CENTRAL and hand searched pertinent trial registers and conference abstracts for eligible trials until 23rd June 2020. Results were pooled using a random-effects model to calculate pooled proportions of objective response rates (ORRs) and severe adverse events (sAEs) from unselected KIT mutant or amplified cohorts.

RESULTS

Nineteen single-arm studies with an overall sample size of 601 patients were included. The studies investigated imatinib (n = 8), nilotinib (n = 7), dasatinib (n = 3) and sunitinib (n = 1). The pooled ORR for all inhibitors was 15% (95% confidence interval [CI]: 12-18%). Subgroup analysis revealed the highest ORR (20%; 95% CI: 14-26%) for nilotinib. The ORR for mucosal melanoma was 14% (95% CI: 6-24%) and 22% for acral lentiginous melanoma (95% CI: 14-30%). At least one sAE was reported in 42% of patients (95% CI: 34-50%).

CONCLUSIONS

c-Kit inhibitors represent a valuable treatment option for patients with KIT-mutant melanoma, in particular for mutations of exons 11 and 13. Furthermore, high-quality trials are urgently needed to investigate putative combinations of specific targeted therapies with immunotherapy.

Magnetite Fe3O4 Nanoparticles Enhance Mild Microwave Ablation of Tumor by Activating the IRE1-ASK1-JNK Pathway and Inducing Endoplasmic Reticulum Stress

Purpose

With the development of nanomedicine, microwave ablation enhanced by multifunctional nanoplatforms has been widely studied for synergistic cancer therapy. Though scientists have got a lot of significant achievements in this field, the detailed molecular mechanisms and potential targets of microwave ablation enhanced by multifunctional nanoplatforms still need further exploration. In this study, we found that a kind of magnetite Fe₃O₄ nanoparticles (Fe₃O₄ NPs) could induce severe endoplasmic reticulum stress and activate cancer apoptosis under the irradiation of mild microwave.

Methods

In this study, plenty of studies including cell immunofluorescence, mitochondrial membrane potential, electron microscopy, atomic force microscopy and microwave ablation in vivo were conducted to explore the molecular mechanisms and potential targets of microwave ablation enhanced by the Fe₃O₄ NPs.

Results

The IRE1-ASK1-JNK pathway was strongly activated in A375 cells treated with both Fe₃O₄ NPs and mild microwave. The endoplasmic reticulum of the A375 cells was significantly dilated and exhibited ballooning degeneration. By investigating the mitochondrial membrane potential (ΔΨm), we found that the mitochondria of cancer cells had been significantly damaged under microwave treatment coupled with Fe₃O₄ NPs. In addition, melanoma of B16F10-bearing mice had also been effectively inhibited after being treated with Fe₃O₄ NPs and microwave.

Conclusion

In this study, we found that a kind of magnetite Fe₃O₄ nanoparticles could induce severe ER stress and activate cancer apoptosis under mild microwave irradiation. Apparent apoptosis had been observed in the A375 cells under a scanning electron microscope and transmission electron microscope. Moreover, melanoma had also been inhibited effectively in vivo. As a result, the endoplasmic reticulum stress is a promising target with clinical potential in nanomedicine and cancer therapy.

Clonal dynamics of circulating tumor DNA during immune checkpoint blockade therapy for melanoma

Assessment of treatment efficacy of immune checkpoint inhibitors in melanoma patients is difficult as the response to these therapies varies among patients or lesions. The clonal evolution of cancer during immune checkpoint blockade therapy could cause treatment resistance. We investigated the potential of liquid biopsy in monitoring the mutational profiles of metastatic melanoma during immunotherapy. Plasma samples collected from 21 Japanese metastatic melanoma patients before immune checkpoint blockade therapy were subjected to whole‐exome sequencing (WES). Furthermore, 14 Japanese patients with melanoma were enrolled for longitudinal analysis of circulating tumor DNA (ctDNA). Plasma samples were collected prospectively before and during therapy and sequenced. WES of the pretreatment plasma from Japanese melanoma patients showed detectable ctDNA levels with wide ranges of variant allele frequencies within a sample, suggesting clonal and subclonal mutations in ctDNA. In targeted sequencing using longitudinal samples, ctDNA levels correlated with increased tumor size, while ctDNA content immediately decreased after a surge in a patient exhibiting pseudo‐progression, suggesting the potential of ctDNA analysis in discriminating between pseudo‐ and true progression. Mutant ctDNA levels showed different patterns within the clinical course of specific patients, suggesting that these mutations were derived from different tumor clones with distinct therapeutic responses. During further investigation, WES of plasma samples from 1 patient showed marked differences in the mutational profiles of ctDNA, including expansive tumor evolution during an acute exacerbation. Immunotherapy may induce characteristic clonal evolutions of tumors; longitudinal analysis of ctDNA has the potential of determining these tumor evolution patterns and therapeutic responses.

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.

Observed progression from melanosis with melanocyte hyperplasia to sinonasal melanoma with distant metastasis and a unique genetic rearrangement

Melanosis, clinically presenting as a benign macular hyperpigmentation, consists of increased pigmentation (melanotic or melanocytic) either in the mucosal epithelial cells or as subepithelial pigment-laden macrophages. On the other hand, primary sinonasal mucosal melanoma (SNMM) is a rare disease with poor prognosis and high rates of local recurrence and metastasis. We report follow-up on a previously presented case of a 53-year-old man with recurrent clinical melanosis that progressed from histopathological melanocytic hyperplasia to melanoma in situ over a period of 4.8 years (Yao et al. Allergy Rhinol (Providence), 2016;7(3):164-167). The patient experienced multiple recurrences and local spread despite multiple extensive surgeries. We now report that this patient ultimately developed bilateral invasive SNMM and died with metastatic melanoma. Molecular analysis of the invasive melanoma revealed ALK rearrangement, specifically an EML4-ALK fusion, which represents the first report of this particular genetic variant in mucosal melanoma.

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.

Histopathologic classification and prognostic factors of melanoma: a 2021 update

Despite the rapid recent advances in molecular analysis of tumors, which allow large-scale and high-resolution genomics, the "gold standard" for melanoma diagnosis continues to be histopathology, in conjunction with clinical characteristics and sometimes with important support of immunohistochemistry. Observations, where postulated that cutaneous melanomas may arise through two distinct pathways, discoveries such as that BRAF^V600E mutations were mostly common in melanomas on sun-exposed skin with little solar elastosis and seminal works for melanoma progression and evolution set the groundwork for the new WHO Classification of Melanoma: a classification of melanoma that not only encompasses histologic but also clinical, epidemiologic, and genetic characteristics. The melanomas were divided into those etiologically related to sun exposure and those that are not, based on their mutational signatures, anatomic site, and epidemiology. On the basis of degree of associated solar elastosis melanomas on the sun exposed skin were further divided by the histopathologic degree of cumulative solar damage (CSD) of the surrounding skin, into low and high CSD. On the low-CSD group of melanomas are included superficial spreading melanomas, while the high-CSD melanomas encompasses lentigo maligna and desmoplastic melanomas. The "non-CSD" classification includes acral melanomas, some melanomas in congenital nevi, melanomas in blue nevi, Spitz melanomas, mucosal melanomas, and uveal melanomas. Nodular and nevoid melanoma may occur in any pathway. A group of intermediate tumors termed melanocytoma is proposed for tumors that in addition to mutations that activate the MAPK pathway, harbor multiple driver mutations, and they are either low-grade or high-grade, to indicate that they may carry a higher risk of malignant transformation. In this review a summary of the most recent WHO classification of melanoma is provided. A short analysis of essential histopathologic prognostic parameters is also provided. The new classification of melanoma discriminates distinct types of melanoma based on their clinicopathologic, and genomic characteristics. Undoubtedly, melanoma research will continue to evolve as new clinical, pathological, molecular data accumulates. The challenge of the forthcoming years is to better characterize the intermediate category of melanocytic lesions.

Hypoxia-dependent drivers of melanoma progression

Hypoxia, a condition of low oxygen availability, is a hallmark of tumour microenvironment and promotes cancer progression and resistance to therapy. Many studies reported the essential role of hypoxia in regulating invasiveness, angiogenesis, vasculogenic mimicry and response to therapy in melanoma. Melanoma is an aggressive cancer originating from melanocytes located in the skin (cutaneous melanoma), in the uveal tract of the eye (uveal melanoma) or in mucosal membranes (mucosal melanoma). These three subtypes of melanoma represent distinct neoplasms in terms of biology, epidemiology, aetiology, molecular profile and clinical features.In this review, the latest progress in hypoxia-regulated pathways involved in the development and progression of all melanoma subtypes were discussed. We also summarized current knowledge on preclinical studies with drugs targeting Hypoxia-Inducible Factor-1, angiogenesis or vasculogenic mimicry. Finally, we described available evidence on clinical studies investigating the use of Hypoxia-Inducible Factor-1 inhibitors or antiangiogenic drugs, alone or in combination with other strategies, in metastatic and adjuvant settings of cutaneous, uveal and mucosal melanoma.Hypoxia-Inducible Factor-independent pathways have been also reported to regulate melanoma progression, but this issue is beyond the scope of this review.As evident from the numerous studies discussed in this review, the increasing knowledge of hypoxia-regulated pathways in melanoma progression and the promising results obtained from novel antiangiogenic therapies, could offer new perspectives in clinical practice in order to improve survival outcomes of melanoma patients.

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.

Primary malignant melanoma of uterine cervix treated with pembrolizumab as adjuvant immunotherapy

This is the case report of primary malignant melanoma (MM) of uterine cervix treated by immune checkpoint inhibitor: the Pembrolizumab. Despite the merge of the novel drugs that has been strikingly improving prognosis of MM, we still struggle treatment of MM of uterine cervix that has aggressive characteristics with unknown etiology. We present our case to contribute its rarity of the disease case report, the primary MM of the uterine cervix that had poor response to pembrolizumab and had OS of 6 months. The treatment ineffectiveness is mainly considered for mucosal MM of low tumor mutation burden and its unusual type of pathology. Accumulation of retrospective studies exclusively on cervical melanoma needs to be proceeded to investigate on characteristics between poor and long survival to establish standardized treatment.

Mucosal Melanoma of the Head and Neck: A Retrospective Review and Current Opinion

Introduction: Head and Neck Mucosal Melanoma (HNMM) is an uncommon malignancy that arises in decreasing order in the nasal cavity, the paranasal sinuses, and the oral cavity. Although radical surgery followed by eventual radiotherapy is acknowledged as the mainstay treatment, patients with advanced stages or multi-focal tumors benefit from new systemic therapies. We wish to share our experience with these treatments and review the current literature. Materials and Methods: We present a case review of every patient treated in our center for an HNMM over the past 10 years, including every patient treated in our center for an HNMM over the past 10 years. We analyzed clinical characteristics, treatment modalities, and outcomes. Results: We included eight patients aged from 62 to 85 years old. We found six MM in the nasal cavity, one in the sphenoidal sinus, and one in the piriform sinus. Six patients underwent endoscopic surgery with negative margins, six underwent radiotherapy with variable modalities. Immunotherapy or targeted therapy was given in cases extensive tumors without the possibility of a surgical treatment or in two patient as an adjuvant treatment after R0 surgery. The three-year overall survival was 50%, and three patients (37.5%) are in remission. Conclusions: HNMM is associated with poor oncologic outcomes regarding the concerned patients of our review, as reported in the literature. New treatments such as immunotherapies or targeted therapies have not significantly changed the prognosis, but they may offer new interesting perspectives. Our small series of cases seems to confirm that surgical resection with negative margins improves overall survival.

RAGE Signaling in Melanoma Tumors

Despite recent progresses in its treatment, malignant cutaneous melanoma remains a cancer with very poor prognosis. Emerging evidences suggest that the receptor for advance glycation end products (RAGE) plays a key role in melanoma progression through its activation in both cancer and stromal cells. In tumors, RAGE activation is fueled by numerous ligands, S100B and HMGB1 being the most notable, but the role of many other ligands is not well understood and should not be underappreciated. Here, we provide a review of the current role of RAGE in melanoma and conclude that targeting RAGE in melanoma could be an approach to improve the outcomes of melanoma patients.

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.

Surgically treated gastric melanoma of unknown primary: A case report from a 10-year survivor

We describe an extremely rare case of simultaneous double melanoma of the stomach with no other obvious primary source. The patient has survived for more than 12 years post-complete gastrectomy. The patient was a woman in her seventies who was referred for anemia by another clinic. Esophagogastroscopy revealed an ulcerated gastric tumor that was diagnosed as a gastrointestinal stromal tumor (GIST) by endoscopic biopsy. She was admitted to our hospital for further examination and treatment. Gastroscopy at our institution revealed two submucosal tumors in the gastric wall. Since no metastatic lesions were detected after systemic exploration, multiple GIST of the stomach was diagnosed, and a total gastrectomy was performed. Malignant melanoma was diagnosed in both lesions by a histopathological study of the resected stomach. The patient's postoperative progress was good, and thorough examination of the skin did not result in the discovery of any systemic neoplastic lesions which could be regarded as the source for the primary tumor. No anticancer treatments were used. The patient has survived, with no recurrence for over ten years postsurgery. Strong evidence is presented in this case for the diagnosis and treatment of gastric malignant melanoma.

Loss-of-function variants in FSIP1 identified by targeted sequencing are associated with one particular subtype of mucosal melanoma

BACKGROUND

Mucosal melanoma is a tumor caused by the malignant transformation of pigment-producing cells and can arise from any mucosal tissue where melanocytes are present. Due to its rarity, the mucosal melanoma subtype is poorly described, and its genetic characteristics are infrequently studied. The discovery or confirmation of new mucosal melanoma susceptibility genes will provide important insights for the study of its pathogenesis.

MATERIALS AND METHODS

We performed deep targeted sequencing of 100 previously reported melanoma-related genes in 39 mucosal melanoma samples and a gene-level loss-of-function (LOF) variant enrichment analysis for mucosal melanoma from different incidence sites.

RESULTS

We detected 7,589 variants in these samples, and 484 were LOF variants (gain or loss of a stop codon, missense, and splice site). Four different gene-level enrichment analyses revealed that FSIP1 (fibrous sheath interacting protein 1) is a susceptibility gene for oral mucosal melanoma (OR = 0.33, P_Chi = 4.05 × 10^-2, P_burden = 3.06 × 10^-2, P_skat = 3.01 × 10^-2, P_skato = 3.01 × 10^-2), whereas the different methods did not detect a significant susceptibility gene for the other subtypes.

CONCLUSIONS

In our study, a susceptibility gene for oral mucosal melanoma was confirmed in a Chinese Han population, and these findings contribute to a better genetic understanding of mucosal melanoma of different subtypes.