| 1. |
- Crescitelli, Rossella, 1985, et al.
(författare)
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Subpopulations of extracellular vesicles from human metastatic melanoma tissue identified by quantitative proteomics after optimized isolation
- 2020
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- The majority of extracellular vesicle (EV) studies conducted to date have been performed on cell lines with little knowledge on how well these represent the characteristics of EVs in vivo. The aim of this study was to establish a method to isolate and categorize subpopulations of EVs isolated directly from tumour tissue. First we established an isolation protocol for subpopulations of EVs from metastatic melanoma tissue, which included enzymatic treatment (collagenase D and DNase). Small and large EVs were isolated with differential ultracentrifugation, and these were further separated into high and low-density (HD and LD) fractions. All EV subpopulations were then analysed in depth using electron microscopy, Bioanalyzer (R), nanoparticle tracking analysis, and quantitative mass spectrometry analysis. Subpopulations of EVs with distinct size, morphology, and RNA and protein cargo could be isolated from the metastatic melanoma tissue. LD EVs showed an RNA profile with the presence of 18S and 28S ribosomal subunits. In contrast, HD EVs had RNA profiles with small or no peaks for ribosomal RNA subunits. Quantitative proteomics showed that several proteins such as flotillin-1 were enriched in both large and small LD EVs, while ADAM10 were exclusively enriched in small LD EVs. In contrast, mitofilin was enriched only in the large EVs. We conclude that enzymatic treatments improve EV isolation from dense fibrotic tissue without any apparent effect on molecular or morphological characteristics. By providing a detailed categorization of several subpopulations of EVs isolated directly from tumour tissues, we might better understand the function of EVs in tumour biology and their possible use in biomarker discovery.
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| 2. |
- Benton, S., et al.
(författare)
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Impact of Next-generation Sequencing on Interobserver Agreement and Diagnosis of Spitzoid Neoplasms
- 2021
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Ingår i: American Journal of Surgical Pathology. - : Ovid Technologies (Wolters Kluwer Health). - 0147-5185 .- 1532-0979. ; 45:12, s. 1597-1605
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Tidskriftsartikel (refereegranskat)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, there was increase in agreement of the diagnosis of conventional melanoma from moderate (kappa=0.470, SE=0.0105) to substantial (kappa=0.645, SE=0.0143) as measured by an average Cohen kappa. Clinical follow-up was available in all 70 cases which substantiated that the improved agreement was clinically significant. Among 3 patients with distant metastatic disease, there was a highly significant increase in diagnostic recognition of the cases as conventional melanoma with genomics (P<0.005). In one case, none of 20 pathologists recognized a tumor with BRAF and TERT promoter mutations associated with fatal outcome as a conventional melanoma when only limited clinical information was provided, whereas 60% of pathologists correctly diagnosed this case when genomic information was also available. There was also a significant improvement in agreement of which lesions should be classified in the Spitz category/WHO Pathway from an average Cohen kappa of 0.360 (SE=0.00921) to 0.607 (SE=0.0232) with genomics.
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| 3. |
- Harbst, Katja, et al.
(författare)
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Molecular profiling reveals low- and high-grade forms of primary melanoma.
- 2012
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Ingår i: Clinical cancer research : an official journal of the American Association for Cancer Research. - 1557-3265. ; 18:15, s. 4026-4036
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Tidskriftsartikel (refereegranskat)abstract
- For primary melanomas, tumor thickness, mitotic rate, and ulceration are well-laid cornerstones of prognostication. However, a molecular exposition of melanoma aggressiveness is critically missing. We recently uncovered a four-class structure in metastatic melanoma, which predicts outcome and informs biology. This raises the possibility that a molecular structure exists even in the early stages of melanoma and that molecular determinants could underlie histophenotype and eventual patient outcome.We subjected 223 archival primary melanomas to a horizontally integrated analysis of RNA expression, oncogenic mutations at 238 lesions, histomorphometry, and survival data.Our previously described four-class structure that was elucidated in metastatic lesions was evident within the expression space of primary melanomas. Because these subclasses converged into two larger prognostic and phenotypic groups, we used the metastatic lesions to develop a binary subtype-based signature capable of distinguishing between "high" and "low" grade forms of the disease. The two-grade signature was subsequently applied to the primary melanomas. Compared with low-grade tumors, high-grade primary melanomas were significantly associated with increased tumor thickness, mitotic rate, ulceration (all P < 0.01), and poorer relapse-free (HR = 4.94; 95% CI, 2.84-8.59), and overall (HR = 3.66; 95% CI, 2.40-5.58) survival. High-grade melanomas exhibited elevated levels of proliferation and BRCA1/DNA damage signaling genes, whereas low-grade lesions harbored higher expression of immune genes. Importantly, the molecular-grade signature was validated in two external gene expression data sets.We provide evidence for a molecular organization within melanomas, which is preserved across all stages of disease.
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| 4. |
- Johansson, Iva, 1973
(författare)
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Studies of molecular features and novel prognostic biomarkers of cutaneous melanoma
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cutaneous malignant melanoma is a highly heterogeneous disease. Immunotherapy has revolutionized the treatment of stage IV disease and is now successfully administered as adjuvant treatment in stage III and soon in stage II. Correct identification of the patients at high risk for progressive disease who will benefit from the treatment is crucial. Important prognostic features in the early phase of the disease are to be found within the primary tumor and sentinel lymph node, but plenty is still to be investigated. Sentinel lymph node biopsy (SLNB) status is one of the independent prognostic factors guiding treatment decisions, but not without controversy. Approximately 80% of the SLNB are negative, contrasting to a wide range of prognosis in node-negative patients. In paper I, we explored the molecular features of melanoma arising in chronic sun-damage skin, proving that this type of melanoma is a distinct molecular entity with a different progression compared to the more common melanoma in intermittently sun-exposed skin. In papers II and III, we evaluated a novel non-invasive prognostic test to be utilized in primary cutaneous melanoma. In our investigation, the CP-GEP test was able to safely identify the patients where the sentinel lymph node biopsy is unnecessary. The same CP-GEP test was able to stratify the patients with high and low risk of disease progression, but the test algorithm still needs to be optimized for this purpose in a clinical setting. In paper IV, we showed that digital quantification of crucial inflammatory cells in the primary tumor microenvironment using immunohistochemistry has a potential to further stratify primary melanoma at risk of brain metastasis.
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| 5. |
- Moncrieff, Marc D, et al.
(författare)
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Clinical Outcomes and Risk Stratification of Early-Stage Melanoma Micrometastases From an International Multicenter Study: Implications for the Management of American Joint Committee on Cancer IIIA Disease.
- 2022
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Ingår i: Journal of clinical oncology : official journal of the American Society of Clinical Oncology. - 1527-7755. ; 40:34, s. 3940-3951
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Tidskriftsartikel (refereegranskat)abstract
- Indications for offering adjuvant systemic therapy for patients with early-stage melanomas with low disease burden sentinel node (SN) micrometastases, namely, American Joint Committee on Cancer (AJCC; eighth edition) stage IIIA disease, are presently controversial. The current study sought to identify high-risk SN-positive AJCC stage IIIA patients who are more likely to derive benefit from adjuvant systemic therapy.Patients were recruited from an intercontinental (Australia/Europe/North America) consortium of nine high-volume cancer centers. All were adult patients with pathologic stage pT1b/pT2a primary cutaneous melanomas who underwent SN biopsy between 2005 and 2020. Patient data, primary tumor and SN characteristics, and survival outcomes were analyzed.Three thousand six hundred seven patients were included. The median follow-up was 34 months. Pairwise disease comparison demonstrated no significant survival difference between N1a and N2a subgroups. Survival analysis identified a SN tumor deposit maximum dimension of 0.3 mm as the optimal cut point for stratifying survival. Five-year disease-specific survival rates were 80.3% and 94.1% for patients with SN metastatic tumor deposits ≥ 0.3 mm and < 0.3 mm, respectively (hazard ratio, 1.26 [1.11 to 1.44]; P < .0001). Similar findings were seen for overall disease-free and distant metastasis-free survival. There were no survival differences between the AJCC IB patients and low-risk (< 0.3 mm) AJCC IIIA patients. The newly identified high-risk (≥ 0.3 mm) subgroup comprised 271 (66.4%) of the AJCC IIIA cohort, whereas only 142 (34.8%) patients had SN tumor deposits > 1 mm in maximum dimension.Patients with AJCC IIIA melanoma with SN tumor deposits ≥ 0.3 mm in maximum dimension are at higher risk of disease progression and may benefit from adjuvant systemic therapy or enrollment into a clinical trial. Patients with SN deposits < 0.3 mm in maximum dimension can be managed similar to their SN-negative, AJCC IB counterparts, thereby avoiding regular radiological surveillance and more intensive follow-up.
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| 6. |
- Mulder, Evalyn E A P, et al.
(författare)
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Using a Clinicopathologic and Gene Expression (CP-GEP) Model to Identify Stage I-II Melanoma Patients at Risk of Disease Relapse.
- 2022
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 14:12
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Tidskriftsartikel (refereegranskat)abstract
- The current standard of care for patients without sentinel node (SN) metastasis (i.e., stage I-II melanoma) is watchful waiting, while >40% of patients with stage IB-IIC will eventually present with disease recurrence or die as a result of melanoma. With the prospect of adjuvant therapeutic options for patients with a negative SN, we assessed the performance of a clinicopathologic and gene expression (CP-GEP) model, a model originally developed to predict SN metastasis, to identify patients with stage I-II melanoma at risk of disease relapse.This study included patients with cutaneous melanoma ≥18 years of age with a negative SN between October 2006 and December 2017 at the Sahlgrenska University Hospital (Sweden) and Erasmus MC Cancer Institute (the Netherlands). According to the CP-GEP model, which can be applied to the primary melanoma tissue, the patients were stratified into high or low risk of recurrence. The primary aim was to assess the 5-year recurrence-free survival (RFS) of low- and high-risk CP-GEP. A secondary aim was to compare the CP-GEP model with the EORTC nomogram, a model based on clinicopathological variables only.In total, 535 patients (stage I-II) were included. CP-GEP stratification among these patients resulted in a 5-year RFS of 92.9% (95% confidence interval (CI): 86.4-96.4) in CP-GEP low-risk patients (n = 122) versus 80.7% (95%CI: 76.3-84.3) in CP-GEP high-risk patients (n = 413; hazard ratio 2.93 (95%CI: 1.41-6.09), p < 0.004). According to the EORTC nomogram, 25% of the patients were classified as having a 'low risk' of recurrence (96.8% 5-year RFS (95%CI 91.6-98.8), n = 130), 49% as 'intermediate risk' (88.4% 5-year RFS (95%CI 83.6-91.8), n = 261), and 26% as 'high risk' (61.1% 5-year RFS (95%CI 51.9-69.1), n = 137).In these two independent European cohorts, the CP-GEP model was able to stratify patients with stage I-II melanoma into two groups differentiated by RFS.
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