Hypoxia controls the glycome signature and galectin-8 – ligand axis to promote pro-tumorigenic properties of metastatic melanoma.
Abstract The prognosis for patients with metastatic melanoma (MM) involving distant organs is grim, and treatment resistance is potentiated by tumor-initiating cells (TIC) that thrive under hypoxia. MM cells, including TICs, express a unique glycome featuring i-linear poly-N-acetyllactosamines (poly-LacNAc) via loss of I-branching enzyme, β1,6 N-acetylglucosaminyltransferase 2 (GCNT2). Whether hypoxia instructs MM TIC development by modulating the glycome signature remains unknown. Here, we explored hypoxia-dependent alterations in MM glycome-associated genes and found that GCNT2 was downregulated and a galectin (Gal)-8 – ligand axis, involving both extracellular and cell-intrinsic Gal-8, was induced. Low GCNT2 levels correlated with poor patient outcome [...]
Comparative genomics provides etiological and biological insights into melanoma subtypes
Abstract Background: Metastasectomy for selected patients with melanoma was associated with improved survival in the era before effective systemic therapy. Emerging evidence shows that these benefits persist even in this era of BRAF-targeted therapy and immune checkpoint inhibitor immunotherapy. This study aimed to evaluate the outcomes of salvage metastasectomy after failure of systemic therapy. Methods: Stage 3 or 4 melanoma patients with extracranial disease progression after at least 4 weeks of systemic treatment between 2009 and 2020 were identified and categorized as resected to no evidence of disease (NED), non-progressive residual disease (NPRD), or progressive residual disease (PRD). Systemic [...]
Unveiling the tumor immune microenvironment of organ-specific melanoma metastatic sites.
Abstract Background: The liver is a known site of resistance to immunotherapy and the presence of liver metastases is associated with shorter progression-free and overall survival (OS) in melanoma, while lung metastases have been associated with a more favorable outcome. There are limited data available regarding the immune microenvironment at different anatomical sites of melanoma metastases. This study sought to characterize and compare the tumor immune microenvironment of liver, brain, lung, subcutaneous (subcut) as well as lymph node (LN) melanoma metastases. Methods: We analyzed OS in 1924 systemic treatment-naïve patients with AJCC (American Joint Committee on Cancer) stage IV [...]
Higher polygenic risk for melanoma is associated with improved survival in a high ultraviolet radiation setting.
Abstract Background: The role of germline genetic factors in determining survival from cutaneous melanoma (CM) is not well understood. Objective: To perform a genome-wide association study (GWAS) meta-analysis of melanoma-specific survival (MSS), and test whether a CM-susceptibility polygenic risk score (PRS) is associated with MSS. Methods: We conducted two Cox proportional-hazard GWAS of MSS using data from the Melanoma Institute Australia, a high ultraviolet (UV) radiation setting (MIA; 5,762 patients with melanoma; 800 melanoma deaths) and UK Biobank (UKB: 5,220 patients with melanoma; 241 melanoma deaths), and combined them in a fixed-effects meta-analysis. Significant (P < 5 × 10-8) [...]
Diet-driven microbial ecology underpins associations between cancer immunotherapy outcomes and the gut microbiome.
Abstract The gut microbiota shapes the response to immune checkpoint inhibitors (ICIs) in cancer, however dietary and geographic influences have not been well-studied in prospective trials. To address this, we prospectively profiled baseline gut (fecal) microbiota signatures and dietary patterns of 103 trial patients from Australia and the Netherlands treated with neoadjuvant ICIs for high risk resectable metastatic melanoma and performed an integrated analysis with data from 115 patients with melanoma treated with ICIs in the United States. We observed geographically distinct microbial signatures of response and immune-related adverse events (irAEs). Overall, response rates were higher in Ruminococcaceae-dominated microbiomes [...]
Sentinel node biopsy: linchpin of melanoma management.
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Melanoma In Situ: A Critical Review and Re-Evaluation of Current Excision Margin Recommendations.
Abstract Most international clinical guidelines recommend 5-10 mm clinical margins for excision of melanoma in situ (MIS). While the evidence supporting this is weak, these guidelines are generally consistent. However, as a result of the high incidence of subclinical extension of MIS, especially of the lentigo maligna (LM) subtype, wider margins will often be needed to achieve complete histologic clearance. In this review, we assessed all available contemporary evidence on clearance margins for MIS. No randomized trials were identified and the 31 non-randomized studies were largely retrospective reviews of single-surgeon or single-institution experiences using Mohs micrographic surgery (MMS) for [...]
Impact of Next-generation Sequencing on Interobserver Agreement and Diagnosis of Spitzoid Neoplasms.
Abstract Atypical Spitzoid melanocytic tumors are diagnostically challenging. Many studies have suggested various genomic markers to improve classification and prognostication. We aimed to assess whether next-generation sequencing studies using the Tempus xO assay assessing mutations in 1711 cancer-related genes and performing whole transcriptome mRNA sequencing for structural alterations could improve diagnostic agreement and accuracy in assessing neoplasms with Spitzoid histologic features. Twenty expert pathologists were asked to review 70 consultation level cases with Spitzoid features, once with limited clinical information and again with additional genomic information. There was an improvement in overall agreement with additional genomic information. Most significantly, [...]
Assessing the Potential for Patient-led Surveillance After Treatment of Localized Melanoma (MEL-SELF): A Pilot Randomized Clinical Trial.
Abstract Importance: Patient-led surveillance is a promising new model of follow-up care following excision of localized melanoma. Objective: To determine whether patient-led surveillance in patients with prior localized primary cutaneous melanoma is as safe, feasible, and acceptable as clinician-led surveillance. Design, setting, and participants: This was a pilot for a randomized clinical trial at 2 specialist-led clinics in metropolitan Sydney, Australia, and a primary care skin cancer clinic managed by general practitioners in metropolitan Newcastle, Australia. The participants were 100 patients who had been treated for localized melanoma, owned a smartphone, had a partner to assist with skin self-examination (SSE), and had [...]
Multi-trait genetic analysis identifies auto-immune loci associated with cutaneous melanoma.
Abstract Genome-wide association studies (GWAS) have identified a number of risk loci for cutaneous melanoma. Cutaneous melanoma shares overlapping genetic risk (genetic correlation) with a number of other traits, including its risk factors such as sunburn propensity. This genetic correlation can be exploited to identify additional cutaneous melanoma risk loci by multitrait analysis of GWAS (MTAG). We used bivariate linkage disequilibrium-score regression score regression to identify traits that are genetically correlated with clinically confirmed cutaneous melanoma and then used publicly available GWAS for these traits in a multitrait analysis of GWAS. Multitrait analysis of GWAS allows GWAS to be [...]