Prospective tumour mutation burden and neoantigen profiling predicts immunotherapy response in metastatic melanoma
Abstract Tumour mutation burden (TMB) is a promising biomarker in predicting immunotherapy response, yet its reproducibility across target panels needs to be established. This study assessed the reproducibility of TMB estimates in melanoma using TruSight Oncology 500 across two laboratories and compared these results with the FoundationOne CDx and QIAseq TMB IO panels. High concordances in TMB estimation, mutation calls, and BRAF and N/K/HRAS hotspot variants were observed between platforms. In a cohort of 198 pre-treatment biopsies from patients treated with immune checkpoint inhibitors, high TMB (≥10 mut/Mb) was associated with significantly improved response and progression-free survival (PFS), while [...]
Real-world evaluation of the use of melanoma risk prediction tools by clinicians in Australia: a mixed methods study
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A cost comparison of radiotherapy and topical imiquimod for lentigo maligna treatment: Considerations for clinical decision-making
Abstract Background: Lentigo maligna (LM) is an in situ melanoma occurring on sun-damaged skin. Radiotherapy or topical imiquimod are potential alternatives to surgery; a recent randomized trial showed no difference in treatment failure between those approaches (underpowered because of pandemic disruption). Objective: To conduct an economic evaluation comparing radiotherapy versus topical imiquimod for treating LM. Methods: Based on no difference in clinical outcomes, a cost analysis was performed alongside the RADICAL trial, a multi-institutional randomized (1:1) phase 3 study (118/126 patients randomized completed treatment; 60 imiquimod and 58 radiotherapy) conducted in Australia, New Zealand, and Brazil. Direct medical costs and indirect costs [...]
The impact of next generation sequencing studies on the diagnosis of BAP1 inactivated melanocytic tumors.
Abstract BAP1 inactivated melanocytic tumors (BIMTs) are recognized for their potential for significant morphologic atypia including nuclear atypia, expansile growth, and mitotic activity, making it difficult to form firm morphologic criteria for malignancy. Next generation sequencing (NGS) is becoming increasingly utilized in melanocytic pathology. We conducted a two-phase survey with 26 dermatopathologists from the International Melanoma Pathology Study Group to assess the impact of NGS on diagnostic accuracy and interobserver agreement in 31 BIMTs. After NGS results, interobserver agreement improved from fair on Survey 1 (κ = 0.348) to moderate on Survey 2 (κ = 0.441). Respondents were 1.7 [...]
The Impact of Next-Generation Sequencing on Interobserver Agreement and Diagnostic Accuracy of Deep Penetrating Melanocytic Neoplasms
Abstract Background: Next-generation sequencing (NGS) is becoming more commonly used for diagnosis in dermatopathology. It's critical to appraise its efficacy and limitations. Distinguishing benign deep penetrating nevi (DPN) from deep penetrating like-melanoma (DPN-M) is a challenging diagnostic scenario even for experienced dermatopathologists. Methods: We sent a two-phase survey (pre-and postgenomics) to 32 experienced dermatopathologists to evaluate 39 diagnostically challenging cases from the DPN/WNT-activated family of melanocytic neoplasms. Results: With NGS data, interobserver agreement improved from 0.41 to 0.51 (p < 0.0001) in distinguishing DPN-M from nonmelanoma cases. Overall diagnostic accuracy improved, mostly driven by a 16% increase in accurate diagnosis of DPN-M. [...]
Updated pan-tumor guidelines for neoadjuvant scoring of pathologic response: a joint SITC and INMC effort
Abstract Background: Practice-changing clinical trials for novel therapeutic regimens administered in the neoadjuvant setting have been reported for multiple cancer types, bringing this treatment strategy to the forefront for patients with high-risk surgically resectable disease. Previously, tumor-type- or therapy-type-specific scoring systems were used for pathologic response assessment. The goal of this effort is to update, harmonize, and standardize the emerging system(s) for pathologic response assessment and data capture. Materials and methods: Leaders in pathology, oncology, and surgery, including those from the Society for Immunotherapy of Cancer's Pan-tumor Harmonization of Pathologic Response Assessment (PATHdata) efforts and the International Neoadjuvant Melanoma Consortium (INMC), [...]
Pathological response calculation assessment remains accurate with reduced tumor bed examination after neoadjuvant immunotherapy in clinically detectable stage III melanoma.
Abstract Background: Neoadjuvant immunotherapy produces event-free survival advantage over adjuvant therapy for patients with surgically resectable macroscopic stage IIIB/C/D melanoma. Pathological response, determined as percentage residual viable tumor (% RVT), provides critical prognostic information and informs management decisions. Here, we assessed accuracy of %RVT calculation when reduced tumor bed (TB) was examined and leverage these results proposing streamlined protocols for pathological examination. Patients and methods: Comprehensive histopathological examination was carried out on 134 patient specimens after neoadjuvant immunotherapy with ipilimumab and nivolumab. Impact on %RVT when evaluating less TB than recommended by the initial International Neoadjuvant Melanoma Consortium (INMC) protocol was [...]
GLUT1 expression, lymphocyte distribution and CD3+ T-cell metabolic subsets as predictive markers of response to immunotherapy in advanced melanoma
Abstract Background: Glycolysis, commonly used by malignant tumors for energy production, results in acidification of the tumor microenvironment (TME) through the secretion and accumulation of lactic acid. Acidosis is a potent inhibitor of immune cell function and may therefore affect T-cell infiltration and the efficacy of immunotherapy. This study aimed to characterize the metabolic tumor microenvironment and its association with lymphocyte distribution in patients with advanced melanoma treated with immune checkpoint blockade (ICB) therapies. Methods: Pre-treatment formalin-fixed, paraffin-embedded metastatic melanoma specimens from 45 patients treated with anti-PD-1 ± anti-CTLA-4 ICB were included in this study. Patients with progression-free survival (PFS) ≥ [...]
Evaluation of Multiple Tissue Levels Frequently Upstages Patients With Clinically Localized Thin Primary Cutaneous Melanoma
Abstract Background: Breslow thickness (BT), ulceration, and microsatellitosis are critical prognostic parameters for cutaneous melanoma staging. These parameters can vary depending on the number of tissue levels examined from individual paraffin blocks. We sought to evaluate all prognostic histopathologic parameters in melanoma for their variations between levels, taken at regular intervals, in a single study. Methods: We analyzed 40 consecutive cases of primary cutaneous (nonacral) melanoma through five hematoxylin and eosin sections, taken at 100 μm intervals, for staging and prognostic parameters. Results: Examination of additional levels resulted in (a) an increase in BT in 47.5% (19 out of 40) of cases [...]
The Prognostic Significance of Tumoral Melanosis
Abstract 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 [...]