Background: Immune checkpoint inhibition and in particular anti-PD-1 immunotherapy have revolutionized the treatment of advanced melanoma. In this regard, higher tumoral PD-L1 protein (gene name: CD274) expression is associated with better clinical response and increased survival to anti-PD-1 therapy. Moreover, there is increasing evidence that tumor suppressor proteins are involved in immune regulation and are capable of modulating the expression of immune checkpoint proteins. Here, we determined the role of p53 protein (gene name: TP53) in the regulation of PD-L1 expression in melanoma. Methods: We analyzed publicly available mRNA and protein expression data from the cancer genome/proteome atlas and performed immunohistochemistry on tumors with known TP53 status. Constitutive and IFN-ɣ-induced PD-L1 expression upon p53 knockdown in wildtype, TP53-mutated or JAK2-overexpressing melanoma cells or in cells, in which p53 was rendered transcriptionally inactive by CRISPR/Cas9, was determined by immunoblot or flow cytometry. Similarly, PD-L1 expression was investigated after overexpression of a transcriptionally-impaired p53 (L22Q, W23S) in TP53-wt or a TP53-knockout melanoma cell line. Immunoblot was applied to analyze the IFN-ɣ signaling pathway. Results: For TP53-mutated tumors, an increased CD274 mRNA expression and a higher frequency of PD-L1 positivity was observed. Interestingly, positive correlations of IFNG mRNA and PD-L1 protein in both TP53-wt and -mutated samples and of p53 and PD-L1 protein suggest a non-transcriptional mode of action of p53. Indeed, cell line experiments revealed a diminished IFN-ɣ-induced PD-L1 expression upon p53 knockdown in both wildtype and TP53-mutated melanoma cells, which was not the case when p53 wildtype protein was rendered transcriptionally inactive or by ectopic expression of p53^L22Q,W23S, a transcriptionally-impaired variant, in TP53-wt cells. Accordingly, expression of p53^L22Q,W23S in a TP53-knockout melanoma cell line boosted IFN-ɣ-induced PD-L1 expression. The impaired PD-L1-inducibility after p53 knockdown was associated with a reduced JAK2 expression in the cells and was almost abrogated by JAK2 overexpression. Conclusions: While having only a small impact on basal PD-L1 expression, both wildtype and mutated p53 play an important positive role for IFN-ɣ-induced PD-L1 expression in melanoma cells by supporting JAK2 expression. Future studies should address, whether p53 expression levels might influence response to anti-PD-1 immunotherapy.

Immune checkpoint blockade therapy is beneficial and even curative for some cancer patients. However, the majority don’t respond to immune therapy. Across different tumor types, pre-existing T cell infiltrates predict response to checkpoint-based immunotherapy. Based on in vitro pharmacological studies, mouse models and analyses of human melanoma patients, we show that the cytokine GDF-15 impairs LFA-1/β2-integrin-mediated adhesion of T cells to activated endothelial cells, which is a pre-requisite of T cell extravasation. In melanoma patients, GDF-15 serum levels strongly correlate with failure of PD-1-based immune checkpoint blockade therapy. Neutralization of GDF-15 improves both T cell trafficking and therapy efficiency in murine tumor models. Thus GDF-15, beside its known role in cancer-related anorexia and cachexia, emerges as a regulator of T cell extravasation into the tumor microenvironment, which provides an even stronger rationale for therapeutic anti-GDF-15 antibody development.

Introduction: Cold atmospheric plasma (CAP) has positive effects on wound healing and antimicrobial properties. However, an ongoing challenge is the development of specific modes of application for different clinical indications. Objectives: We investigated in a prospective pilot study the response and tolerability of a newly developed CAP wound dressing for the acute healing of split skin graft donor sites compared to conventional therapy. Methods: We applied both treatments to each patient (n = 10) for 7 days and measured 4 parameters of wound healing every other day (i.e., 1,440 measurements) using a hyperspectral imaging camera. Additionally, we evaluated the clinical appearance and pain levels reported by the patients. Results: The CAP wound dressing was superior to the control (p < 0.001) in the improvement of 3 wound parameters, that is, deep tissue oxygen saturation, hemoglobin distribution, and tissue water distribution. CAP was well tolerated, and pain levels were lower in CAP-treated wound areas. Conclusion: CAP wound dressing is a promising new tool for acute wound healing.

Background: Programmed death‐1 (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 Switzerland.Methods: Multicenter, retrospective study investigating stage III–IV melanoma patients receiving adjuvant nivolumab (NIV), pembrolizumab (PEM) or dabrafenib + trametinib (D + T) between 1/2017 and 10/2021. The primary endpoint was 12‐month recurrence‐free survival (RFS). Further analyses included descriptive and correlative statistics, and a multivariate linear‐regression machine learning model to assess the risk of early melanoma recurrence.Results: In total, 1198 patients from 39 skin cancer centers from Germany, Austria and Switzerland were analysed. The vast majority received anti PD‐1 therapies (n = 1003). Twelve‐month RFS for anti PD‐1 and BRAF + MEK inhibitor‐treated patients were 78.1% and 86.5%, respectively (hazard ratio [HR] 1.998 [95% CI 1.335–2.991]; p = 0.001). There was no statistically significant difference in overall survival (OS) in anti PD‐1 (95.8%) and BRAF + MEK inhibitor (96.9%) treated patients (p > 0.05) during the median follow‐up of 17 months. Data indicates that anti PD‐1 treated patients who develop immune‐related adverse events (irAEs) have lower recurrence rates compared to patients with no irAEs (HR 0.578 [95% CI 0.443–0.754], p = 0.001). BRAF mutation status did not affect overall efficacy of anti PD‐1 treatment (p > 0.05). In both, anti PD‐1 and BRAF + MEK inhibitor treated cohorts, data did not show any difference in 12‐month RFS and 12‐month OS comparing patients receiving total lymph node dissection (TLND) versus sentinel lymph node biopsy only (p > 0.05). The recurrence prediction model reached high specificity but only low sensitivity with an AUC = 0.65. No new safety signals were detected. Overall, recorded numbers and severity of adverse events were lower than reported in pivotal phase III trials.Conclusions: Despite recent advances in adjuvant melanoma treatment, early recurrence remains a significant clinical challenge. This study shows that TLND does not reduce the risk of early melanoma recurrence and should only be considered in selected patients. Data further highlight that variables collected during clinical routine are unlikely to allow for a clinically relevant prediction of individual recurrence risk.

Patient-centered motives and expectations of the treatment of actinic keratoses (AK) have received little attention until now. Hence, we aimed to profile and cluster treatment motivations and expectations among patients with AK in a nationwide multicenter, cross-sectional study including patients from 14 German skin cancer centers. Patients were asked to complete a self-administered questionnaire. Treatment motives and expectations towards AK management were measured on a visual analogue scale from 1–10. Specific patient profiles were investigated with subgroup and correlation analysis. Overall, 403 patients were included. The highest motivation values were obtained for the items “avoid transition to invasive squamous cell carcinoma” (mean ± standard deviation; 8.98 ± 1.46), “AK are considered precancerous lesions” (8.72 ± 1.34) and “treating physician recommends treatment” (8.10 ± 2.37; p < 0.0001). The highest expectation values were observed for the items “effective lesion clearance” (8.36 ± 1.99), “safety” (8.20 ± 2.03) and “treatment-related costs are covered by health insurance” (8.00 ± 2.41; p < 0.0001). Patients aged ≥77 years and those with ≥7 lesions were identified at high risk of not undergoing any treatment due to intrinsic and extrinsic motivation deficits. Heat mapping of correlation analysis revealed four clusters with distinct motivation and expectation profiles. This study provides a patient-based heuristic tool for a personalized treatment decision in patients with AK.

Introduction: Rosacea is a common, facial, chronic inflammatory skin disease. Due to its complex pathogenesis, adequate therapy of rosacea can be challenging. An innovative recent therapeutic tool is cold atmospheric plasma (CAP), which is already established in the treatment of chronic wounds and promising in different other skin diseases. Methods: In a split-face pilot study we investigated dielectric-barrier-discharged CAP in erythemato-telangiectatic (ETR) and/or papulopustular rosacea (PPR). CAP treatment was applied on lesional skin of a randomized side once daily (90 s/area) for 6 weeks. The other untreated side served as control. Co-primary endpoints were ≥1 improvement of the Investigator Global Assessment (IGA) score on the treated side compared to control and a decline of the Dermatology Life Quality Index (DLQI) after 6 weeks. Secondary endpoints included inflammatory lesion count (papules and pustules), skin redness intensity and erythema size. Adverse events (AEs) were recorded constantly. Additionally, participants were weekly assessed for symptoms, skin condition, trigger factors, skin care, treatment success, and local tolerance parameters. All p values were calculated using the Wilcoxon signed-rank test. Results: Twelve subjects (ETR, n = 3; ETR and PPR, n = 9) completed the study. DLQI was significantly improved after 6 weeks (p = 0.007). On the CAP-treated side, lesions (p = 0.007) and erythema size (p = 0.041) were significantly reduced compared to the control. IGA (p = 0.2) and skin redness intensity (p = 0.5) did not differ significantly between control and CAP-treated side. No serious AEs occurred and treatment was well tolerated. Conclusion: CAP is a promising new treatment of rosacea, especially for PPR.