Peter M. Ferguson

Half of the participants in this randomized online experiment of 1655 Australian adults would prefer to not have a wide local excision (WLE) after a completely excised low-risk melanocytic lesion, if offered this option. Using the term ‘low-risk melanocytic neoplasm’ instead of ‘melanoma in situ’ reduced anxiety and the proportion choosing a WLE. Across all label groups, most participants preferred to attend routine 6-monthly clinic visits for follow-up, most likely reflecting the high prevalence of this in the Australian context.

Gene expression of major signalling pathways and multiplex immunohistochemical comparison of markers between timepoints and tumor sites. A) Gene expression of related oncogenic signalling pathways between treatment timepoints and site, B) Estimated mean difference of proteins and pathways between biopsy categories (95% confidence interval for the estimated mean difference is depicted as a segment), C) Multiplex immunohistochemical staining for key intracellular signalling proteins, D) Changes in immune intratumoral immune cell densities between treatment timepoints and site, E and F) Multiplex immunohistochemical staining depicted marked decrease in immune cell densities EDT in PT4 (steroid treated). PRE, collected prior to treatment; EDT, collected early during treatment (i.e., after 10-14 days of dabrafenib). MBM, melanoma brain metastasis; ECM, extracranial metastasis. PT, patient.

Supplementary Table S1. Representativeness of study participants Supplementary Table S2. Analysis of the intracranial response duration in the COMBI-MB trial. Supplementary Table S3. Analysis of overall survival in the COMBI-MB trial. Supplementary Table S4. Baseline clinical features of the COMBI-BRV trial. Supplementary Table S5. Gene expression score (SingScore) and multiplex immunohistochemical results. Supplementary Table S6. Summary statistics of the linear mixed models utilized to assess the association between protein/pathway expression/score and biopsy sites. Supplementary Table S7. Mutation annotated file of exome sequencing from melanoma biopsies.

Purpose:This study aimed to identify baseline clinical features associated with the outcomes of patients enrolled in the COMBI-MB phase II study of dabrafenib and trametinib treatment in patients with V600 BRAF-mutant metastatic melanoma with melanoma brain metastases (MBM). Exploratory biomarker analysis was also conducted as part of the synergistic COMBI-BRV trial (BRV116521), to identify molecular and immunologic changes associated with dabrafenib in MBMs and extracranial metastases (ECM).Patients and Methods:Post hoc analysis was performed for baseline features of patients (n = 125) enrolled in COMBI-MB. Analyses were performed to identify baseline clinical features associated with intracranial response rate (ICRR), progression-free survival (PFS), and overall survival (OS).Exploratory biomarker analysis was performed on biospecimen collected in the COMBI-BRV trial in which patients with BRAF-mutant, resectable MBM were treated with dabrafenib for 10 to 14 days prior to craniotomy. Accessible ECM were resected or biopsied at the time of craniotomy. Biospecimens underwent molecular and immunologic profiling for comparative analyses.Results:In COMBI-MB baseline treatment with corticosteroids was independently associated with lower ICRR [39% vs. 63%; OR, 0.323; 95 % confidence interval (CI), 0.105–0.996; P = 0.049] and shorter PFS (HR, 1.93; 95% CI, 1.06–3.51; P = 0.031). Additional significant associations identified in the multivariate analysis were improved PFS in patients with a BRAFV600E genotype (HR, 0.565; 95% CI, 0.321–0.996; P = 0.048) and improved OS in patients with Eastern Cooperative Oncology Group 0 (HR, 0.44; 95% CI, 0.25–0.78; P = 0.005).Conclusions:Corticosteroid treatment was associated with reduced ICRR and PFS in COMBI-MB, similar to results with immunotherapy for MBMs. Baseline corticosteroid treatment is a key factor to consider in MBM patient management and clinical trial design/interpretation.

Overdiagnosis in melanoma is a nuanced and evolutionary issue. It may appear to be an epidemic from an epidemiological point of view; however, it is important to appreciate all perspectives. We consider overdiagnosis a necessary challenge—which drives clinicians to improve diagnostic accuracy and reduce overtreatment—pathologists to recalibrate histopathological thresholds and reduce overcalling—and researchers to develop markers of biological activity for melanoma. In this article, we present our clinical perspective on the current burden of melanoma overdiagnosis and its future value for progress in the field of melanoma.

Introduction A diagnosis of melanoma in situ presents negligible risk to a person’s lifespan or physical well-being, but existing terminology makes it difficult for patients to distinguish these from higher risk invasive melanomas. This study aims to explore whether using an alternative label for melanoma in situ may influence patients’ management choices and anxiety levels. Methods and analysis This study is a between-subjects randomised online experiment, using hypothetical scenarios. Following consent, eligible participants will be randomised 1:1:1 to three labels: ‘melanoma in situ’ (control), ‘low-risk melanocytic neoplasm’ (intervention 1) and ‘low-risk melanocytic neoplasm, in situ’ (intervention 2). The required sample size is 1668 people. The co-primary outcomes are (1) choice between no further surgery or further surgery to ensure clear histological margins greater than 5 mm and (2) choice between patient-initiated clinical follow-up when needed (patient-led surveillance) and regular routinely scheduled clinical follow-up (clinician-led surveillance). Secondary outcomes include diagnosis anxiety, perceived risk of invasive melanoma and of dying from melanoma and management choice anxiety (after surgery choice and follow-up choice). We will make pairwise comparisons across the three diagnostic label groups using regression models (univariable and multivariable). Ethics and dissemination The study has been registered with the Australian New Zealand Clinical Trials Registry (ACTRN12624000740594). Ethics approval has been received from The University of Sydney Human Research Ethics Committee (2024/HE000019). The results of the study will be published in a peer-reviewed medical journal, and a plain language summary of the findings will be shared on the Wiser Healthcare publication page (https://www.wiserhealthcare.org.au/category/publications/). Trial registration number Australian New Zealand Clinical Trials Registry (ID 386943).

Background: Tumoral melanosis (TM) is a histological term to describe a nodular aggregation of macrophages containing melanin pigment (melanophages) that is devoid of viable melanocytes. It is most often identified in skin, where it may be appreciated clinically as a pigmented lesion; however, it can also be found in other organs such as lymph nodes. The presence of TM is usually thought to signify the presence of a regressed melanoma or other pigmented tumor. Until recently, it was a relatively uncommon finding; however, with the use of effective systemic therapies against melanoma, its occurrence in histological specimens is more frequent. Methods: We identified and reviewed all histopathological diagnoses of TM at any organ site reported at a single institution from 2006 to 2018. TM cases were paired with non‐TM cases of cutaneous melanoma through propensity score matching at a 1:2 ratio, and their survival outcomes were compared. The clinical outcomes examined included recurrence‐free survival (RFS), distant disease‐free survival (DDFS), melanoma‐specific survival (MSS), and overall survival (OS). Results: TM was reported in 79 patients. Their median age was 65 years (range 22–88), with a 2:1 male predominance (51 out of 79, 65%). The most common organ involved was the skin (67%), with a third of all cases localized to a lower limb (36%). TM had a strong association with the presence of melanoma (91%) and regression at other sites of melanoma (54%), suggesting that it is part of a systemic immune response against melanoma. Most patients with TM either previously or subsequently developed histologically confirmed melanoma in the same anatomical region as the TM (89%). Thirty‐five TM patients were matched with 70 non‐TM cases. Patients with melanoma who developed TM without prior regional or systemic therapy showed improved MSS ( p = 0.03), whereas no statistically significant differences were observed in terms of RFS, DDFS, and OS. Conclusions: TM usually occurs in the context of a previous or subsequent cutaneous melanoma and is associated with improved MSS. It is important that TM is recognized by pathologists and documented in pathology reports.

The biological underpinnings of therapeutic resistance to immune checkpoint inhibitors (ICI) in adolescent and young adult (AYA) melanoma patients are incompletely understood. Here, we characterize the immunogenomic profile and spatial architecture of the tumor microenvironment (TME) in AYA (aged ≤ 30 years) and older adult (aged 31–84 years) patients with melanoma, to determine the AYA-specific features associated with ICI treatment outcomes. We identify two ICI-resistant spatiotypes in AYA patients with melanoma showing stroma-infiltrating lymphocytes (SILs) that are distinct from the adult TME. The SIL^high subtype was enriched in regulatory T cells in the peritumoral space and showed upregulated expression of immune checkpoint molecules, while the SIL^low subtype showed a lack of immune activation. We establish a young immunosuppressive melanoma score that can predict ICI responsiveness in AYA patients and propose personalized therapeutic strategies for the ICI-resistant subgroups. These findings highlight the distinct immunogenomic profile of AYA patients, and individualized TME features in ICI-resistant AYA melanoma that require patient-specific treatment strategies.

Whereas CD4 ⁺ T cells conventionally mediate antitumor immunity by providing help to CD8 ⁺ T cells, recent clinical studies have implied an important role for cytotoxic CD4 ⁺ T cells in cancer immunity. Using an orthotopic melanoma model, we provide a detailed account of antitumoral CD4 ⁺ T cell responses and their regulation by major histocompatibility complex class II (MHC II) in the skin. Intravital imaging revealed prominent interactions of CD4 ⁺ T cells with tumor debris-laden MHC II ⁺ host antigen-presenting cells that accumulated around tumor cell nests, although direct recognition of MHC II ⁺ melanoma cells alone could also promote CD4 ⁺ T cell control. CD4 ⁺ T cells stably suppressed or eradicated tumors even in the absence of other lymphocytes by using tumor necrosis factor–α and Fas ligand (FasL) but not perforin-mediated cytotoxicity. Interferon-γ was critical for protection, acting both directly on melanoma cells and via induction of nitric oxide synthase in myeloid cells. Our results illustrate multifaceted and context-specific aspects of MHC II–dependent CD4 ⁺ T cell immunity against cutaneous melanoma, emphasizing modulation of this axis as a potential avenue for immunotherapies.