Christian Posch

Christian Posch
Vienna Healthcare Group

MD PhD

About

174
Publications
23,532
Reads
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2,522
Citations
Additional affiliations
March 2018 - present
Technical University of Munich
Position
  • Principal Investigator
Vienna Healthcare Group
Position
  • Head of Department
July 2017 - February 2018
Wiener Krankenanstaltenverbund
Position
  • Attending Dermatologist

Publications

Publications (174)
Article
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Figure 1. Conceptual schema of NRAS cycling and mutation hotspots. (a) Wild-type NRAS cycles between an inactive GDP bound and an active GTP bound state. Upstream signals trigger the activation of NRAS which is regulated by GEFs (such as SOS1). NRAS deactivation is catalyzed by GAPs (such as NF1). (b) NRAS mutations are located at codon 12/13, affe...
Article
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In melanoma, mutant and thereby constantly active NRAS affects 15-20% of tumors, contributing to tumor initiation, growth, invasion and metastasis. Recent therapeutic approaches aim to mimic RAS extinction by interfering with critical signaling pathways downstream of the mutant protein. This study investigates the phospho-proteome of primary human...
Article
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Background: Effective medical treatment for patients with severe hidradenitis suppurativa (HS) is limited. Objectives: We sought to measure the impact of wide local excision on quality of life in HS Hurley grade III patients and to examine the rate of postoperative complications, disease recurrences, and satisfaction with the cosmetic results....
Article
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Background Conventional supervised deep‐learning approaches mostly focus on a small range of skin disease images. Recently, self‐supervised (SS) Vision Transformers have emerged, capturing complex visual patterns in hundreds of classes without any need for tedious image annotation. Objectives This study aimed to form the basis for an inexpensive a...
Preprint
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Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterized by painful nodules, abscesses, and scarring, predominantly affecting intertriginous regions. This study aimed to utilize single cell RNA and cell-surface protein sequencing (CITE-Seq) to delineate the immune composition of circulating cells in Hidradenitis suppurat...
Poster
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To investigate the efficacy and adverse events of modern adjuvant melanoma PD-1 and BRAF+MEK inhibitors in areal-life setting.
Conference Paper
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Background The majority cutaneous T cell lymphoma (CTCL) run an indolent clinical course. However, advanced stages (>=IIB) or certain CTCL subtypes such as folliculotropic Mycosis Fungoides (FMF) and Sézary Syndrome (SS) are associated with significantly worse prognosis and treatment options are limited. In previous studies, our group has described...
Article
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Simple Summary Immune-related adverse events (irAEs) as responses to immunotherapy are frequent and a burden to patients. While cutaneous irAEs (cutAEs) are a common side effect, some are linked to better overall survival and clinical responses to immunotherapy in patients. There are emerging reports on cutaneous side effects of immunotherapy; howe...
Article
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Background Hidradenitis suppurativa (HS) is a debilitating inflammatory skin disease. Tetracyclines are one of the few therapeutic options recommended for mild‐to‐moderate disease. This study aimed to investigate the efficacy of systemic fusidic acid's (FA) effectiveness in treating HS. Methods This retrospective study analyzed 55 FA therapy cycle...
Article
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Finding effective therapeutic targets to treat NRAS-mutated melanoma remains a challenge. Long non-coding RNAs (lncRNAs) recently emerged as essential regulators of tumorigenesis. Using a discovery approach combining experimental models and unbiased computational analysis complemented by validation in patient biospecimens, we identified a nuclear-e...
Article
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Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer. Inhibitors targeting the programmed cell death 1 (PD-1) immune checkpoint have improved MCC patient outcomes by boosting antitumor T cell immunity. Here, we identify PD-1 as a growth-promoting receptor intrinsic to MCC cells. In human MCC lines and clinical tumors, RT-PCR–based seque...
Article
Background The assessment of hidradenitis suppurativa (HS) severity requires detailed, and error‐prone lesion counts. This proof‐of‐concept study aimed to automatically classify HS disease severity using machine learning of clinical smartphone images. Methods 777 ambient‐light and size‐controlled images were used to build a class‐balanced syntheti...
Article
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Background Inter-individual differences in response to immune checkpoint inhibitors (ICI) remain a major challenge in cancer treatment. The composition of the gut microbiome has been associated with differential ICI outcome, but the underlying molecular mechanisms remain unclear, and therapeutic modulation challenging. Methods We established an in...
Article
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Article
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Innate lymphoid cells (ILCs) are gatekeepers in barrier organs, where they maintain tissue integrity and contribute to host defense as well as tissue repair. Inappropriate activation of ILCs, however, can lead to immunopathology with detrimental results. In this study, we focused on type 1 ILCs (ILC1s), which under inflammatory conditions constitut...
Article
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The introduction of immune checkpoint inhibitors and targeted therapies has revolutionized melanoma treatment. The downside are immune‐mediated adverse events which are frequent and require close patient management. We report a case of severe immune‐mediated hepatitis and pneumonitis under combined immune‐checkpoint inhibitor therapy requiring immu...
Article
Merkel cell carcinoma (MCC, ICD-O M8247/3) is a rare, malignant, primary skin tumor with epithelial and neuroendocrine differentiation. The tumor cells share many morphologic, immunohistochemical, and ultrastructural features with cutaneous Merkel cells. Nevertheless, the cell of origin of MCC is unclear. MCC appears clinically as a reddish to purp...
Article
Zusammenfassung Das Merkelzellkarzinom (MCC, ICD‐O M8247/3) ist ein seltener, maligner, primärer Hauttumor mit epithelialer und neuroendokriner Differenzierung. Die Tumorzellen teilen viele morphologische, immunhistochemische und ultrastrukturelle Eigenschaften mit den Merkel‐Zellen der Haut. Die Ursprungszelle (cell of origin) des MCC ist dennoch...
Article
Immuncheckpoint‐Inhibitoren und weitere immuntherapeutische Behandlungsansätze haben die Therapieoptionen beim Melanom und anderen Hauttumoren im letzten Jahrzehnt erheblich erweitert. Die breite Anwendung von Immuntherapien erfordert geeignete Methoden zur Überwachung des Krankheitsverlaufs während der Therapie. Immuntherapien beruhen auf einer ge...
Article
Immune-checkpoint inhibitors and further immunotherapeutic treatment strategies have significantly extended therapy options for melanoma and other skin cancer entities over the last decade. In the context of a broader application of immunotherapeutic approaches, sufficient ways to monitor the course of the disease during therapy are required. Immun...
Article
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Merkel cell carcinoma is a rare, highly aggressive skin cancer with neuroendocrine differentiation. Immune checkpoint inhibition has significantly improved treatment outcomes in metastatic disease with response rates to programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) inhibition of up to 62%. However, primary and second...
Article
Background: PD-1 antibodies and BRAF+MEK inhibitors are widely used for adjuvant therapy of fully resected high-risk melanoma. Little is known about treatment efficacy outside of phase III trials. This real-world study reports on clinical outcomes of modern adjuvant melanoma treatment in specialized skin cancer centers in Germany, Austria and Switz...
Article
Background: Choosing the adequate systemic treatment for melanoma is driven by clinical parameters and personal preferences. Objective: Evaluation of the impact of disease and treatment on the daily life of patients receiving systemic therapy for melanoma. Methods: A German-wide, cross-sectional comparative study was conducted at 13 specialize...
Article
Hidradenitis suppurativa (HS) is a chronic debilitating disease, characterized by recurrent inflammatory nodules, abscesses and fistulas in the intertriginous areas. Pain and malodorous discharge lead to profound quality of life impairment. Follicular plugging seems to play a role in the pathomechanism of the disease. Genetic predispositions and se...
Article
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Background: Variants in genes of the nucleotide excision repair (NER) pathway have been associated with heterogeneous clinical presentations ranging from xeroderma pigmentosum to Cockayne syndrome and trichothiodystrophy. NER deficiencies manifest with photosensitivity and skin cancer, but also developmental delay and early-onset neurological dege...
Preprint
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MAPK-pathway up-regulation is responsible for over 40% of human cancer cases. Finding effective therapeutic targets for melanoma therapy continues to be a challenge due to drug resistance. Using a computational and experimental pipeline, we discovered the nuclear enriched long non-coding RNA (lncRNA) TRASH, which is induced upon MAPK-pathway-activa...
Preprint
Full-text available
Finding effective therapeutic targets to treat NRAS-mutated melanoma remains a challenge. Long non-coding RNAs (lncRNAs) recently emerged as essential regulators of tumorigenesis. Using a discovery approach combining experimental models and unbiased computational analysis complemented by validation in patient biospecimens, we identified a nuclear-e...
Preprint
Full-text available
Finding effective therapeutic targets to treat NRAS-mutated melanoma remains a challenge. Long non-coding RNAs (lncRNAs) recently emerged as essential regulators of tumorigenesis. Using a discovery approach combining experimental models and unbiased computational analysis complemented by validation in patient biospecimens, we identified a nuclear-e...
Article
Full-text available
Malignant melanoma is an aggressive tumor with a tendency to metastasize early and with an increasing incidence worldwide. Although in early stage, melanoma is well treatable by excision, the chances of cure and thus the survival rate decrease dramatically after metastatic spread. Conventional treatment options for advanced disease include surgical...
Article
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Zusammenfassung In den letzten Jahren hat die Wissenschaft um biologische Prozesse der (Haut‑)Alterung enorm an Fahrt aufgenommen. Alterung und die damit assoziierten Erkrankungen werden nicht mehr als unausweichliches Schicksal angesehen, sondern als ein hochkomplexes System, in das dank moderner Technologien Einblick genommen werden kann und das...
Article
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Anti-CTLA-4-antibodies can induce long-lasting tumor remissions. However, only a few patients respond, necessitating the development of predictive companion biomarkers. Increasing evidence suggests a major role of epigenetics, including DNA methylation, in immunology and resistance to immune checkpoint blockade. Here, we tested CTLA4 promoter methy...
Article
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Purpose Uveal melanoma (UM) is an orphan cancer of high unmet medical need. Current patterns of care and surveillance remain unclear as they are situated in an interdisciplinary setting. Methods A questionnaire addressing the patterns of care and surveillance in the management of patients with uveal melanoma was distributed to 70 skin cancer cente...
Article
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Introduction Malignant melanoma is the third most common primary in the diagnosis of brain metastases. Stereotactic radiosurgery (SRS) is a well-established treatment option in limited brain disease. We analyzed outcomes of SRS with a particular focus on the graded prognostic assessment (GPA, melanoma molGPA), prognostic factors, and toxicity. Met...
Article
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The incidence of melanoma and nonmelanoma skin cancer has increased tremendously in recent years. Although novel treatment options have significantly improved patient outcomes, the prognosis for most patients with an advanced disease remains dismal. It is, thus, imperative to understand the molecular mechanisms involved in skin carcinogenesis in or...
Article
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This article prepared by the EADV Task Force on Melanoma aims at providing consensus‐based recommendations on how to address the main challenges in management of patients with cutaneous melanoma during the COVID‐19 pandemic (1). In‐person physical examinations remain irreplaceable for patients who have noticed new suspicious lesions or are referred...
Article
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Background Talimogene laherparepvec (T-VEC) is a licensed therapy for use in melanoma patients of stage IIIB-IVM1a with injectable, unresectable metastatic lesions in Europe. Approval was based on the Oncovex Pivotal Trial in Melanoma study, which also included patients with distant metastases and demonstrated an overall response rate (ORR) of 40.5...
Article
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Background Patients with cancer who are infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more likely to develop severe illness and die compared with those without cancer. The impact of immune checkpoint inhibition (ICI) on the severity of COVID-19 illness is unknown. The aim of this study was to investigate whether ICI...
Article
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Zusammenfassung Vemurafenib, ein BRAF‐Inhibitor, weist als häufige kutane Nebenwirkung eine erhöhte Photosensitivität auf, die sich klinisch im Auftreten eines sofortigen Hitzegefühls und eines ödematösen Erythems bei Sonnenexposition sowie einer Sonnenbrandreaktion im Sinne einer Spätreaktion äußert. Phototestungen konnten sowohl für die Sofortrea...
Conference Paper
Background: ICI are widely used in the treatment of various cancer types. It has been hypothesized that ICI could confer an increased risk of severe acute lung injury or other complications associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: We analyzed data from 113 patients with laboratory-confirmed COVID-19 whi...
Article
Ever since the FDA‐approval of the combined immune checkpoint (ICP) inhibition with the programmed death 1 (PD‐1) antibody Nivolumab and the cytotoxic T‐lymphocyte antigen 4 (CTLA4) antibody Ipilimumab for the treatment of malignant melanoma, the range and our understanding of immune‐related adverse events (irAE) keeps broadening. Algorithms for th...
Article
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Linked article : S.S. Ertekin et al. J Eur Acad Dermatol Venereol 2020; 34:1482‐1488. https://doi.org/10.1111/jdv.16212.
Article
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Background: PD-L1 (programmed cell death 1 ligand 1) expression in melanoma has been associated with a better response to anti-PD-1 (programmed cell death 1) therapy. However, patients with PD-L1-negative melanomas can respond to anti-PD-1 blockade, suggesting that the other PD-1 ligand, PD-L2 (programmed cell death 1 ligand 2), might also be rele...