Severe autoimmune hemolytic anemia following immunotherapy with checkpoint inhibitors in two patients with metastatic melanoma: a case report

Introduction

Over the past decade, immune checkpoint inhibitors such as antibodies against cytotoxicity T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) have become an important armamentarium against a broad spectrum of malignancies. However, these specific inhibitors can cause adverse autoimmune reactions by impairing self-tolerance. Hematologic side effects of immune checkpoint inhibitors, including autoimmune hemolytic anemia (AIHA), are rare but can be life-threatening.

Case report

Herein, we report two patients on immune checkpoint inhibitors for metastatic melanoma who developed AIHA with symptoms of dyspnea and fatigue. In the first patient, symptoms alleviated after discontinuation of combined anti CTLA-4 and anti-PD-1 therapy, initiation of corticosteroids and application of a single red blood cell transfusion. Due to subsequent progress of melanoma, combinational anti-PD-1 and tyrosine kinase inhibitor therapy was initiated based on multidisciplinary tumor board decision. After two months, she again developed the described hematological and clinical signs of AIHA leading to cessation of anti-PD-1 therapy and initiation of corticosteroids, which again resulted in an alleviation of her symptoms. Due to further progression, the patient received dacarbazine for several months before she decided to stop any therapy other than palliative supportive care. In the second patient, discontinuation of anti-PD-1 therapy and initiation of corticosteroids entailed a complete alleviation of his symptoms. After refusing chemotherapy due to subsequent melanoma progression, he received radiotherapy of bone metastases and is currently enrolled in a clinical trial. The patient did not develop AIHA ever since.

Conclusion

Hematologic immune-related adverse events due to treatment with immune checkpoint inhibitors are rare but can have life-threatening consequences. If dyspnea and other clinical symptoms are present, AIHA should be considered as a potential cause and treated promptly in a multidisciplinary setting. An expanded comprehension of risk factors and pathogenesis of AIHA is needed to identify high-risk patients beforehand, leading to more effective predictive and reactive treatment approaches.

Circulating Cell-Free SHOX2 DNA Methylation Is a Predictive, Prognostic, and Monitoring Biomarker in Adjuvant and Palliative Anti-PD-1-Treated Melanoma

BACKGROUND

The majority of metastatic melanoma patients initially do not respond or acquire resistance to anti-programmed cell death 1 (PD-1) immunotherapy. Liquid biopsy biomarkers might provide useful early response information and allow for personalized treatment decisions.

METHODS

We prospectively assessed circulating cell-free SHOX2 DNA methylation (SHOX2 ccfDNAm) levels and their dynamic changes in blood plasma of melanoma patients by quantitative methylation-specific polymerase chain reaction. Patients were treated with either palliative (n = 42) or adjuvant (n = 55) anti-PD-1 immunotherapy. Moreover, we included n = 126 control patients without evidence of malignant disease. We analyzed SHOX2 ccfDNAm status prior to and 4 weeks after palliative treatment initiation with regard to outcome [objective response, progression-free survival (PFS), and overall survival (OS)]. In the adjuvant setting, we associated longitudinal SHOX2 ccfDNAm status with disease recurrence.

RESULTS

Sensitivity was 60% with 25/42 melanoma patients showing increased SHOX2 ccfDNAm levels, whereas specificity was 98% with 123/126 (P < 0.001) control patients having SHOX2 ccfDNAm levels below cut-off. Pretreatment SHOX2 ccfDNAm status did not correlate with outcome; however, SHOX2 ccfDNAm negativity 4 weeks after palliative treatment initiation was strongly associated with improved survival [PFS: hazard ratio (HR) = 0.25, P = 0.002; OS: HR = 0.12, P = 0.007]. Pretreatment positive patients who reached SHOX2 ccfDNAm clearance after 4 weeks of immunotherapy showed an exceptionally beneficial outcome. SHOX2 ccfDNAm testing allowed for an early detection of distant metastases in adjuvant-treated melanoma patients.

CONCLUSIONS

Our study suggests SHOX2 ccfDNAm to be an early predictor of outcome in anti-PD-1 treated melanoma patients. SHOX2 ccfDNAm testing may aid individualized treatment decision-making.

CD52 mRNA expression predicts prognosis and response to immune checkpoint blockade in melanoma

The immune-modulating protein CD52 attenuates lymphocyte function and is associated with autoimmune disorders, for example, multiple sclerosis (MS). CD52 represents a therapeutic target in MS and chronic lymphocytic leukemia (CLL). Its expression has prognostic and predictive value in CLL and is prognostic in breast cancer. Its significance in melanoma is unclear. We analyzed CD52 mRNA expression data from tumor bulk tissues of N = 445 untreated melanoma patients from The Cancer Genome Atlas (TCGA) Research Network and of N = 121 melanoma patients undergoing anti-PD-1 immune checkpoint blockade (ICB) with regard to outcome (overall survival [OS], disease control [DC], and progression-free survival [PFS]), single-cell RNA-Seq data of N = 4645 cells from N = 19 melanoma tissues, and N = 15,457 cells from normal skin provided by N = 5 donors. Higher CD52 mRNA expression was associated with favorable OS (hazard ratio (HR) = 0.820, [95% CI 0.734-0.916], p < .001) in non-ICB-treated melanoma and with PFS (HR = 0.875, [95% CI 0.775-0.989], p = .033) and DC (p = .005) in ICB-treated melanoma. CD52 expression correlated significantly with distinct immune cell subsets and correlated negatively with immune checkpoint expression in T cells. Moreover, our results suggest CD52 expression by a certain type of tissue-resident macrophages. CD52 mRNA was expressed in a small subgroup (8%) of immune checkpoint coexpressing melanoma cells. CD52 expression is associated with features of ICB response in melanoma. Concomitant ICB and anti-CD52 treatment requires critical review.

Pharmaceutical management of acute radiation dermatitis in the German speaking radiation oncology community

BACKGROUND

Radiation dermatitis (RD) remains the most common side effect in radiation therapy (RT) with various pharmaceutical options available for prevention and treatment. We sought to determine pharmaceutical management patterns of radiation dermatitis among radiation oncology professionals.

METHODS

We conducted a survey on RD among the German-speaking community of radiation oncologists inquiring for their opinion on preventive and therapeutic pharmaceutical approaches for acute RD.

RESULTS

244 health professionals participated. Dexpanthenol lotion is the agent most widely used both for prevention (53.0%) and treatment (76.9%) of RD, followed by urea (29.8%) for prevention and corticosteroids (46.9%) for treatment. A wide range of substances is used by participants, though the overall experience with them is rather limited. 32.5% of participants do generally not recommend any preventative treatment. 53.4% of participants recommend alternative medicine for RD management. While seldomly used, corticosteroids were considered most effective in RD therapy, followed by dexpanthenol and low-level laser therapy. A majority of participants prefers moist over dry treatment of moist desquamation and 43.8% prescribe antiseptics.

CONCLUSIONS

Pharmaceutical management of RD in the German-speaking radiation oncology community remains controversial, inconsistent, and partially not supported by evidence-based medicine. Stronger evidence level and interdisciplinary consensus is required amongst practitioners to improve these care patterns.

Pharmazeutische Behandlung der akuten Radiodermatitis in der deutschsprachigen strahlentherapeutischen Gemeinschaft: Pharmaceutical management of acute radiation dermatitis in the German speaking radiation oncology community

Hintergrund

Die Radiodermatitis (RD) ist die häufigste Nebenwirkung der Strahlentherapie (RT), wobei verschiedene pharmazeutische Optionen zur Vorbeugung/Behandlung zur Verfügung stehen. Unser Ziel war, die pharmazeutischen Behandlungsmuster für die RD unter strahlentherapeutischen Fachleuten zu ermitteln.

Methodik

Wir haben eine Umfrage zum Thema RD in der deutschsprachigen radioonkologischen Gemeinschaft durchgeführt und ihre Meinung zu präventiven und therapeutischen pharmazeutischen Therapieansätzen betreffend die akute RD erfragt.

Ergebnisse

244 Angehörige zugehöriger Gesundheitsberufe nahmen teil. Dexpanthenol‐Lotion ist das am häufigsten verwendete Mittel sowohl zur Vorbeugung (53%) als auch zur Behandlung (76,9%) der RD, gefolgt von Harnstoff (29,8%) zur Vorbeugung und Kortikosteroiden (46,9%) zur Behandlung. Die Teilnehmer verwenden eine breite Palette an Substanzen, haben aber insgesamt wenig Erfahrung mit diesen. 32,5% der Teilnehmer empfehlen generell keine präventive Behandlung. 53,4% der Teilnehmer empfehlen Alternativmedizin. Obwohl selten eingesetzt, wurden Kortikosteroide als wirksamstes Behandlungsmittel angesehen, gefolgt von Dexpanthenol und Low‐Level‐Lasertherapie. Die Mehrheit der Teilnehmer bevorzugt die feuchte gegenüber der trockenen Behandlung der feuchten Desquamation und 43,8% verschreiben Antiseptika.

Schlussfolgerungen

Die pharmazeutische Behandlung der RD in der deutschsprachigen strahlentherapeutischen Fachwelt ist nach wie vor umstritten, sowie mitunter inkonsistent und nicht durch evidenzbasierte Medizin gestützt. Ein interdisziplinärer Konsens ist erforderlich, um die bestehenden Behandlungskonzepte zu verbessern.

Deep learning based histological classification of adnex tumors

BACKGROUND

Cutaneous adnexal tumors are a diverse group of tumors arising from structures of the hair appendages. Although often benign, malignant entities occur which can metastasize and lead to patients´ death. Correct diagnosis is critical to ensure optimal treatment and best possible patient outcome. Artificial intelligence (AI) in the form of deep neural networks has recently shown enormous potential in the field of medicine including pathology, where we and others have found common cutaneous tumors can be detected with high sensitivity and specificity. To become a widely applied tool, AI approaches will also need to reliably detect and distinguish less common tumor entities including the diverse group of cutaneous adnexal tumors.

METHODS

To assess the potential of AI to recognize cutaneous adnexal tumors, we selected a diverse set of these entities from five German centers. The algorithm was trained with samples from four centers and then tested on slides from the fifth center.

RESULTS

The neural network was able to differentiate 14 different cutaneous adnexal tumors and distinguish them from more common cutaneous tumors (i.e. basal cell carcinoma and seborrheic keratosis). The total accuracy on the test set for classifying 248 samples into these 16 diagnoses was 89.92 %. Our findings support AI can distinguish rare tumors, for morphologically distinct entities even with very limited case numbers (< 50) for training.

CONCLUSION

This study further underlines the enormous potential of AI in pathology which could become a standard tool to aid pathologists in routine diagnostics in the foreseeable future. The final diagnostic responsibility will remain with the pathologist.

Manifestation of subacute cutaneous lupus erythematosus during treatment with anti-PD-1 antibody cemiplimab - a case report

Introduction

The anti-programmed cell death protein 1 (PD-1) antibody cemiplimab has shown promising results in the treatment of unresectable or metastatic squamous cell carcinoma, however, frequently leads to immune-related adverse events limiting therapy efficacy. Although cutaneous side effects are common, only very few cases of cutaneous lupus erythematosus have been reported under anti-PD-1 immunotherapy. So far, no case of cutaneous lupus has been described under treatment with cemiplimab.

Case report

For the first time, we report the case of a patient with advanced squamous cell carcinoma, who developed clinical and histological findings in sun-exposed skin that were consistent with anti-SS-A/Ro antibody-positive subacute cutaneous lupus erythematosus (SCLE) under treatment with cemiplimab. Additionally, laboratory chemical analyses revealed a severe immune-related hepatitis without clinical symptoms. Both, the SCLE and the hepatitis, resolved after the administration of topical and systemic steroids and the discontinuation of anti-PD-1 therapy.

Conclusion

Treatment with cemiplimab can be associated with the appearance of cutaneous lupus erythematosus in sun-exposed areas. Application of topical and systemic glucocorticoids can lead to a rapid resolution of the skin eruptions. Moreover, our case illustrates the possibility of simultaneously occurring severe immune-related adverse events. This highlights the importance of additional diagnostics to avoid overlooking additional immune-related adverse events.

PD-L1 (CD274) promoter hypomethylation predicts immunotherapy response in metastatic urothelial carcinoma

PD-L1 status assessed by immunohistochemistry (IHC) has failed to reliably predict outcomes for patients with metastatic urothelial carcinoma (mUC) on immune checkpoint blockade (ICB). PD-L1 promoter methylation is an epigenetic mechanism that has been shown to regulate PD-L1 mRNA expression in various malignancies. The aim of our present study was to evaluate the predictive potential of PD-L1 promoter methylation status (mPD-L1) in ICB-treated mUC compared to conventional IHC-based PD-L1 assessment. We quantified mPD-L1 in formalin-fixed and paraffin-embedded tissue sections using an established quantitative methylation-specific PCR assay (qMSP) in a well-characterized multicenter ICB-treated cohort comprising N = 107 patients with mUC. Additionally, PD-L1 protein expression in tumor tissues was assessed using regulatory approved IHC protocols. The effect of pharmacological hypomethylation by the DNA methyltransferase inhibitor decitabine in combination with interferon-γ stimulation in urothelial carcinoma cell lines was investigated by IHC and FACS. mPD-L1 hypomethylation predicted objective response rate at the first staging on ICB. Patients with tumors categorized as PD-L1 hypomethylated (lower quartile) showed significantly prolonged progression-free (PFS) and overall survival (OS) after ICB initiation. In contrast, PD-L1 protein expression status neither correlated with response nor survival. In multivariable Cox regression analyses, PD-L1 promoter hypermethylation remained an independent predictor of unfavorable PFS and OS. In urothelial carcinoma cell lines, pharmacological demethylation led to an upregulation of membranous PD-L1 expression and an enhanced inducibility of PD-L1 expression by interferon γ. Hypomethylation of the PD-L1 promoter is a promising predictive biomarker for response to ICB in patients with mUC.

The CD73 is induced by TGF-β1 triggered by nutrient deprivation and highly expressed in dedifferentiated human melanoma

CD73 is the key enzyme in the generation of extracellular adenosine, a mediator involved in tumor progression, tumor immune escape and resistance to anti-cancer therapeutics. Microenvironmental conditions influence the expression of CD73 in tumor cells. However how CD73 expression and activity is regulated in a stress condition of lower nutrient availability are largely unknown. Our results indicate that serum starvation leads to a marked up-regulation of CD73 expression on A375 melanoma cells in a time-dependent manner. The cell-surface expression of CD73 is associated with an increased release of TGF-β1 by starved cells. Blockade of TGF-β1 receptors or TGFβ/SMAD3 signaling pathway significantly reduce the expression of CD73 induced by starvation. Treatment of cells with rTGF-β1 up-regulates the expression of CD73 in a concentration-dependent manner, confirming the role of this pathway in regulating CD73 in melanoma A375 cells. The increased expression of CD73 is associated with enhanced AMPase activity, which is selectively reduced by inhibitors of CD73 activity, APCP and PSB-12489. Pharmacological blockade of CD73 significantly inhibits invasion of melanoma cells in a transwell system. Furthermore, using multiplex immunofluorescence imaging we found that, within human melanoma metastases, tumor cells at the dedifferentiated stage show the highest CD73 protein expression. In summary, our data provide new insights into the mechanism regulating the expression/activity of CD73 in melanoma cells in a condition of lower availability of nutrients, which is a common feature of the tumor microenvironment. Within human metastatic melanoma tissues elevated protein expression of CD73 is associated with an invasive-like phenotype.

CTLA4 DNA methylation is associated with CTLA-4 expression and predicts response to immunotherapy in head and neck squamous cell carcinoma

BACKGROUND

The majority of patients with recurrent or metastasized head and neck squamous cell carcinoma (HNSCC) do not benefit from immune checkpoint blockade (ICB) while several patients experience severe and persistent immune-mediated side effects. Therefore, predictive biomarkers are urgently needed to allow for a personalized treatment. In this study, we investigated DNA methylation of the immune checkpoint gene CTLA4 with regard to its predictive value.

METHODS

We analyzed CTLA4 promoter methylation in tumors of HNSCC patients (N = 29) treated with ICB at the University Medical Center Bonn with regard to response to ICB and progression-free survival. We further analyzed a second cohort (N = 138) of patients that did not receive ICB with regard to CTLA4 promoter methylation, CTLA-4 protein expression, and immune cell infiltrates. Finally, we tested inducibility of CTLA-4 protein expression in HNSCC cells using the DNA methyltransferase inhibitor decitabine.

RESULTS

Lower CTLA4 promoter methylation correlated with response to ICB and prolonged progression-free survival. We could show that not only tumor infiltrating immune cells, but also HNSCC cells harbor cytoplasmic and nuclear CTLA-4 expression. CTLA4 promoter methylation inversely correlated with infiltrates of CD3+, CD4+, CD8+, and CD45+ immune cells. CTLA4 methylation did not correlate with protein expression in tumors, however, decitabine treatment led to decreased CTLA4 methylation and an induction of CTLA4 mRNA and CTLA-4 protein expression in HNSCC cell lines.

CONCLUSIONS

Our results indicate that CTLA4 DNA hypomethylation is a predictive biomarker for response to ICB in HNSCC. Our study warrants further analyses of the predictive value of CTLA4 DNA methylation in clinical trials of anti-PD-1 and/or anti-CTLA-4 immunotherapy in HNSCC.

Deep learning detection of melanoma metastases in lymph nodes

BACKGROUND

In melanoma patients, surgical excision of the first draining lymph node, the sentinel lymph node (SLN), is a routine procedure to evaluate lymphogenic metastases. Metastasis detection by histopathological analysis assesses multiple tissue levels with hematoxylin and eosin and immunohistochemically stained glass slides. Considering the amount of tissue to analyze, the detection of metastasis can be highly time-consuming for pathologists. The application of artificial intelligence in the clinical routine has constantly increased over the past few years.

METHODS

In this multi-center study, a deep learning method was established on histological tissue sections of sentinel lymph nodes collected from the clinical routine. The algorithm was trained to highlight potential melanoma metastases for further review by pathologists, without relying on supplementary immunohistochemical stainings (e.g. anti-S100, anti-MelanA).

RESULTS

The established method was able to detect the existence of metastasis on individual tissue cuts with an area under the curve of 0.9630 and 0.9856 respectively on two test cohorts from different laboratories. The method was able to accurately identify tumour deposits>0.1 mm and, by automatic tumour diameter measurement, classify these into 0.1 mm to -1.0 mm and>1.0 mm groups, thus identifying and classifying metastasis currently relevant for assessing prognosis and stratifying treatment.

CONCLUSIONS

Our results demonstrate that AI-based SLN melanoma metastasis detection has great potential and could become a routinely applied aid for pathologists. Our current study focused on assessing established parameters; however, larger future AI-based studies could identify novel biomarkers potentially further improving SLN-based prognostic and therapeutic predictions for affected patients.

ICOS DNA methylation regulates melanoma cell-intrinsic ICOS expression, is associated with melanoma differentiation, prognosis, and predicts response to immune checkpoint blockade

BACKGROUND

Inducible T cell costimulator ICOS is an emerging target in immuno-oncology. The aim of this study was to investigate the epigenetic regulation of ICOS in melanoma by DNA methylation.

METHODS

We comprehensively investigate ICOS DNA methylation of specific CpG sites and expression pattern within the melanoma microenvironment with regard to immune correlates, differentiation, clinical outcomes, and immune checkpoint blockade (ICB) response.

RESULTS

Our study revealed a sequence-contextual CpG methylation pattern consistent with an epigenetically regulated gene. We found a cell type-specific methylation pattern and locus-specific correlations and associations of CpG methylation with ICOS mRNA expression, immune infiltration, melanoma differentiation, prognosis, and response to ICB. High ICOS mRNA expression was identified as a surrogate for enriched immune cell infiltration and was associated with favorable overall survival (OS) in non-ICB-treated patients and predicted response and a prolonged progression-free survival (PFS) following ICB therapy initiation. ICOS hypomethylation, however, significantly correlated with poor OS in non-ICB patients but predicted higher response and prolonged PFS and OS in ICB-treated patients. Moreover, we observed cytoplasmic and sporadically nuclear tumor cell-intrinsic ICOS protein expression. Tumor cell-intrinsic ICOS protein and mRNA expression was inducible by pharmacological demethylation with decitabine.

CONCLUSION

Our study identified ICOS DNA methylation and mRNA expression as promising prognostic and predictive biomarkers for immunotherapy in melanoma and points towards a hitherto undescribed role of ICOS in tumor cells.

DNA methylation of GITR, OX40, 4-1BB, CD27 , and CD40 correlates with BAP1 aberrancy and prognosis in uveal melanoma

Uveal melanoma represents an aggressive tumor that responds mostly poorly to established melanoma treatments. Comprehensive methylation profiling of the next-generation immunotherapeutic target genes, for example, members of the tumor necrosis factor receptor superfamily, might allow for the development of companion predictive biomarkers. We have analyzed CpG sites within the immune checkpoint genes GITR, OX40, 4-1BB, CD 27, and CD40 probed by the Illumina Infinium HumanMethylation450 BeadChip in N  = 80 uveal melanomas included in The Cancer Genome Atlas with regard to BAP1 aberrancy, mRNA expression, and overall survival. In all analyzed immune checkpoint genes, BAP1 aberrancy was associated with decreased CpG methylation levels. We identified specific CpG sites that significantly correlated with BAP1 aberrancy, mRNA expression levels, and overall survival. Our results suggest epigenetic regulation of the analyzed immune checkpoint genes via DNA methylation in uveal melanoma and provide rationale for methylation testing in biomarker programs in clinical trials.

Five-Fraction Stereotactic Radiotherapy for Brain Metastases-A Retrospective Analysis

PURPOSE

To determine the safety and outcome profile of five-fraction stereotactic radiotherapy (FSRT) for brain metastases (BM), either as a definitive or adjuvant treatment.

METHODS

We assessed clinical data of patients receiving five fractions of 7 Gy each (cumulative physical dose of 35 Gy) to BM or surgical cavities. The primary endpoints were toxicity and radiation necrosis (RN) rates. Secondary endpoints were 1-year cumulative local control rate (LCR) and estimated overall survival (OS).

RESULTS

A total of 36 eligible patients receiving FSRT to a total of 49 targets were identified and included. The median follow up was 9 (1.1-56.2) months. The median age was 64.5 (34-92) years, the median ECOG score was 1, and the median Diagnostic-Specific Graded Prognostic Assessment (DS-GPA) score was 2. Treatment was well tolerated and there were no grade 3 adverse events or higher. The overall RN rate was 14.3% and the median time to RN was 12.9 (1.8-23.8) months. RN occurrence was associated with immunotherapy, young age (≤45 years), and large PTV. The cumulative 1-year local control rate was 83.1% and the estimated median local progression free-survival was 18.8 months. The estimated median overall survival was 11 (1.1-56.2) months and significantly superior in those patients presenting with RN.

CONCLUSIONS

FSRT with 5 × 7 Gy represents a feasible, safe, and efficient fast track approach of intensified FSRT with acceptable LC and comparable RN rates for both the adjuvant and definitive RT settings.

CTLA4 , PD-1 , PD-L1 , PD-L2 , TIM-3 , TIGIT , and LAG3 DNA Methylation Is Associated With BAP1 -Aberrancy, Transcriptional Activity, and Overall Survival in Uveal Melanoma

Uveal melanoma (UM) is an aggressive disease with poor response to oncological treatment, including immunotherapy. Loss of the epigenetic modifier BRCA1-associated protein 1 (BAP1) function drives UM oncogenesis and is associated with an immune-suppressive tumor microenvironment, poor prognosis, and a distinct DNA methylation and gene expression profile. Our study aimed to analyze comprehensively the DNA methylation status of the immune checkpoint genes PD-1 , PD-L1 , PD-L2 , CTLA4, TIM-3 ( HAVCR2 ), TIGIT , and LAG3 and its association with mRNA expression, BAP1 -aberrancy, and patients' survival. We analyzed the DNA methylation landscape of immune checkpoint genes at single CpG resolution in N=80 UM samples provided by The Cancer Genome Atlas. We analyzed CpG methylation levels of the immune checkpoints with regard to their transcriptional signatures and patient outcomes.Methylation of specific CpG sites within the immune checkpoint genes PD-1 , PD-L1 , PD-L2 , CTLA4 , TIM-3 , TIGIT , and LAG3 correlated strongly with mRNA expression levels, indicating a strong regulation of gene expression through DNA methylation. Moreover, immune checkpoint gene methylation was strongly associated with BAP1 -mutation status and associated with overall survival in UM. Our data indicate an epigenetic regulation of immune checkpoints through DNA methylation in UM. Further, our data highlight the prognostic significance of DNA methylation of immune checkpoint genes in UM thereby providing a rationale for methylation testing as predictive biomarkers for immunotherapy response.

Inhibition of melanoma cell-intrinsic Tim-3 stimulates MAPK-dependent tumorigenesis

T-cell immunoglobulin and mucin domain 3 (Tim-3) is an immune checkpoint receptor that dampens effector functions and causes terminal exhaustion of cytotoxic T-cells. Tim-3 inhibitors are under investigation in immuno-oncology (IO) trials, because blockade of T-cell-Tim-3 enhances antitumor immunity. Here, we identify an additional role for Tim-3 as a growth-suppressive receptor intrinsic to melanoma cells. Inhibition of melanoma cell-Tim-3 promoted tumor growth in both immunocompetent and immunocompromised mice, while melanoma-specific Tim-3 overexpression attenuated tumorigenesis. Antibody (Ab)-mediated Tim-3 blockade inhibited growth of immunogenic murine melanomas in T-cell-competent hosts, consistent with established antitumor effects of T-cell Tim-3 inhibition. In contrast, Tim-3 Ab administration stimulated tumorigenesis of both highly and lesser immunogenic murine and human melanomas in T-cell-deficient mice, confirming growth-promoting effects of melanoma-Tim-3 antagonism. Melanoma-Tim-3 activation suppressed, while its blockade enhanced, phosphorylation of pro-proliferative downstream mitogen-activated protein kinase (MAPK) signaling mediators. Finally, pharmacologic MAPK inhibition reversed unwanted Tim-3 Ab-mediated tumorigenesis in T-cell-deficient mice and promoted desired antitumor activity of Tim-3 interference in T-cell-competent hosts. These results identify melanoma-Tim-3 blockade as a mechanism that antagonizes T-cell-Tim-3-directed IO therapeutic efficacy. They further reveal MAPK targeting as a combination strategy for circumventing adverse consequences of unintended melanoma-Tim-3 inhibition.

DNA Methylation and mRNA Expression of OX40 (TNFRSF4) and GITR (TNFRSF18, AITR) in Head and Neck Squamous Cell Carcinoma Correlates With HPV Status, Mutational Load, an Interferon-γ Signature, Signatures of Immune Infiltrates, and Survival

The tumor necrosis factor receptor superfamily members 4 (TNFRSF4, OX40) and 18 (TNFRSF18, GITR, AITR) are under investigation as targets for immunotherapy of various cancers, including head and neck squamous cell carcinomas. Understanding the regulation of OX40 and GITR, particularly on an epigenetic level, might help to develop companion predictive biomarkers. We conducted broad correlation analyses of DNA methylation of 46 CpG sites within the GITR/OX40 gene locus in head and neck squamous cell carcinomas and normal adjacent tissues provided by The Cancer Genome Atlas (TCGA) Research Network. We analyzed methylation levels with regard to transcriptional gene activity (mRNA expression), human papillomavirus (HPV) infection, differential methylation between tumors and normal adjacent tissues, signatures of immune cell infiltrates, an interferon-γ signature, mutational load, and overall survival. Moreover, we investigated methylation levels in HPV-positive and HPV-negative cell lines and in isolated monocytes, granulocytes, CD8+ and CD4+ T cells, and B cells from peripheral blood from healthy donors. Our results revealed a complex and sequence-contextual methylation pattern in accordance with features of epigenetic regulated genes. We detected significant methylation differences between normal adjacent and tumor tissues, between HPV-positive and HPV-negative tumors, between tumor and immune cells, and significant correlations between methylation and mRNA expression. We further found significant correlations of CpG methylation with overall survival, signatures of immune cell infiltrates, an interferon-γ signature, and mutational load. Our study provides a framework to prospectively test specific CpG sites as biomarkers, in particular in the context of immunotherapies.

DNA methylation regulates TIGIT expression within the melanoma microenvironment, is prognostic for overall survival, and predicts progression-free survival in patients treated with anti-PD-1 immunotherapy

BACKGROUND

TIGIT is an immune checkpoint under investigation as therapeutic target. Understanding the regulation of TIGIT on an epigenetic level might support the development of companion biomarkers.

METHODS

We correlated TIGIT DNA methylation of single CpG sites with gene expression, signatures of immune infiltrates and interferon-γ, and survival in melanoma. We further analyzed methylation levels in immune cell subsets, melanocyte and melanoma cell lines. TIGIT expression patterns within components of the melanoma microenvironment were analyzed by single cell sequencing. We used quantitative methylation-specific PCR, flow cytometry, and immunohistochemistry for correlations between expression and methylation and to assess the effect of pharmacological demethylation of melanoma cells treated with 5-aza-2-deoxycytidine (decitabine). Finally, we investigated the association of patients' survival with TIGIT mRNA and methylation.

RESULTS

Depending on the sequence context of the analyzed CpG site, we found a cell type-specific TIGIT gene locus methylation pattern and significant correlations of TIGIT methylation with mRNA expression, an interferon γ signature, and distinct immune cell infiltrates, including TIGIT⁺ lymphocytes. We detected a melanoma cell-intrinsic TIGIT protein expression. Pharmacological demethylation of the A375 melanoma cell line led to a constitutive TIGIT expression. Low promoter flank methylation and high mRNA expression was associated with patients' prognosis and predicted progression-free survival in patients treated with anti-PD-1 immunotherapy. A high TIGIT⁺ lymphocyte score was associated with better progression-free survival under anti-PD-1 immunotherapy.

CONCLUSIONS

Our data demonstrate an epigenetic regulation of TIGIT expression via DNA methylation within the melanoma microenvironment. TIGIT DNA methylation and expression may serve as predictive biomarkers in the context of immunotherapies in melanoma.

It’s not always SIAD – Immunotherapy-triggered Endocrinopathies enter the Field of Cancer-related Hyponatremia

While the syndrome of inadequate antidiuresis (SIAD) is still the most common cause of hyponatremia in cancer patients, the rise in endocrine immune-related adverse events (irAEs) owing to immune checkpoint inhibitors (ICI) considerably shaped the differential diagnosis of electrolyte disorders in cancer patients. We here report three cases of different endocrine irAEs, first manifesting with new-onset hyponatremia under ICI therapy for malignant melanoma: one with primary adrenal insufficiency, one with hypophysitis and one with autoimmune type 1 diabetes. Early diagnosis of endocrine toxicities can save lives, but may be challenged and essentially delayed by subtle or nonspecific clinical presentation and lacking availability of readily available endocrinological laboratory evaluation in primary care setting.

This exemplary case series demonstrates the broad spectrum of endocrinopathies that physicians should be aware of under ICI therapy and emphasizes new-onset hyponatremia as a possibly early, simple and low-cost biomarker of irAEs, which may be considered as a red flag in patients receiving checkpoint blockade. As ICI-induced endocrinopathies are still under-represented in clinical practice guidelines, we here propose an updated algorithm for diagnosis of cancer-related hyponatremia, highlighting the important diagnostic steps to be considered before making the diagnosis of SIAD.

Deep Learning-Based Body Composition Analysis Predicts Outcome in Melanoma Patients Treated with Immune Checkpoint Inhibitors

Previous studies suggest an impact of body composition on outcome in melanoma patients. We aimed to determine the prognostic value of CT-based body composition assessment in patients receiving immune checkpoint inhibitor therapy for treatment of metastatic disease using a deep learning approach. One hundred seven patients with staging CT examinations prior to initiation of checkpoint inhibition between January 2013 and August 2019 were retrospectively evaluated. Using an automated deep learning-based body composition analysis pipeline, parameters for estimation of skeletal muscle mass (skeletal muscle index, SMI) and adipose tissue compartments (visceral adipose tissue index, VAI; subcutaneous adipose tissue index, SAI) were derived from staging CT. The cohort was binarized according to gender-specific median cut-off values. Patients below the median were defined as having low SMI, VAI, or SAI, respectively. The impact on outcome was assessed using the Kaplan-Meier method with log-rank tests. A multivariable logistic regression model was built to test the impact of body composition parameters on 3-year mortality. Patients with low SMI displayed significantly increased 1-year (25% versus 9%, p = 0.035), 2-year (32% versus 13%, p = 0.017), and 3-year mortality (38% versus 19%, p = 0.016). No significant differences with regard to adipose tissue compartments were observed (3-year mortality: VAI, p = 0.448; SAI, p = 0.731). On multivariable analysis, low SMI (hazard ratio (HR), 2.245; 95% confidence interval (CI), 1.005-5.017; p = 0.049), neutrophil-to-lymphocyte ratio (HR, 1.170; 95% CI, 1.076-1.273; p < 0.001), and Karnofsky index (HR, 0.965; 95% CI, 0.945-0.985; p = 0.001) remained as significant predictors of 3-year mortality. Lowered skeletal muscle index as an indicator of sarcopenia was associated with worse outcome in patients with metastatic melanoma receiving immune checkpoint inhibitor therapy.

Preoperative Metastatic Brain Tumor-Associated Intracerebral Hemorrhage Is Associated With Dismal Prognosis

Object

Intra-tumoral hemorrhage is considered an imaging characteristic of advanced cancer disease. However, data on the influence of intra-tumoral hemorrhage in patients with brain metastases (BM) remains scarce. We aimed at investigating patients with BM who underwent neurosurgical resection of the metastatic lesion for a potential impact of preoperative hemorrhagic transformation on overall survival (OS).

Methods

Between 2013 and 2018, 357 patients with BM were surgically treated at the authors’ neuro-oncological center. Preoperative magnetic resonance imaging (MRI) examinations were assessed for the occurrence of malignant hemorrhagic transformation.

Results

122 of 375 patients (34%) with BM revealed preoperative intra-tumoral hemorrhage. Patients with hemorrhagic transformed BM exhibited a median OS of 5 months compared to 12 months for patients without intra-tumoral hemorrhage. Multivariate analysis revealed preoperative hemorrhagic transformation as an independent and significant predictor for worsened OS.

Conclusions

The present study identifies preoperative intra-tumoral hemorrhage as an indicator variable for poor prognosis in patients with BM undergoing neurosurgical treatment.

Molecular and Immune Correlates of PDCD1 (PD-1), PD-L1 (CD274), and PD-L2 (PDCD1LG2) DNA Methylation in Triple Negative Breast Cancer

Immune checkpoints are important targets in oncological therapy. Recent studies have proven efficacy of immune checkpoint inhibition (ICI) in treatment of triple negative breast cancer (TNBC). However, only a proportion of TNBC-patients benefit from ICI. Thus, current scientific efforts in this context are focused on the identification of a robust biomarker that enables patient stratification. In the present study, we investigated the epigenetic regulation of PD-1 (PDCD1), PD-L1 (CD274), and PD-L2 (PDCD1LG2). Methylation data of PD-1, PD-L1, and PD-L2, and complex immunogenomic data were obtained from The Cancer Genome Atlas (TCGA). Methylation were systematically analyzed with regard to the transcriptional activity of the studied immune checkpoint genes and the tumor microenvironment. We found differential methylation of PD-1, PD-L1, and PD-L2 in normal adjacent tissue and TNBC tumor tissue. In the TNBC-TCGA cohort, methylation status of PD-1, PD-L1, and PD-L2 were significantly correlated with mRNA levels indicating a strong epigenetic regulation of the transcriptional activity. Moreover, PD-1, PD-L1, and PD-L2 methylation status was strongly associated with a distinct immune cell infiltration pattern. Our results indicate an epigenetic regulation of immune checkpoint genes through DNA methylation in TNBC. In addition, the methylation status was associated with a distinct composition of the tumor microenvironment. Overall, this provides a strong rationale for assessing the value of PD-1, PD-L1, and PD-L2 DNA methylation to predict response to ICI and immunogenicity in TNBC.

Epigallocatechin-3-gallate exhibits anti-inflammatory effects in a human interface dermatitis model-implications for therapy

BACKGROUND

Epigallocatechin-3-gallate (EGCG) has been proven effective in treating viral warts. Since anticarcinogenic as well as anti-inflammatory properties are ascribed to the substance, its use has been evaluated in the context of different dermatoses. The effect of EGCG on interface dermatitis (ID), however, has not yet been explored.

OBJECTIVES

In this study, we investigated the effect of EGCG on an epidermal human in vitro model of ID.

METHODS

Via immunohistochemistry, lesional skin of lichen planus patients and healthy skin were analysed concerning the intensity of interferon-associated mediators, CXCL10 and MxA. Epidermal equivalents were stained analogously upon ID-like stimulation and EGCG treatment. Monolayer keratinocytes were treated likewise and supernatants were analysed via ELISA while cells were processed for vitality assay or transcriptomic analysis.

RESULTS

CXCL10 and MxA are strongly expressed in lichen planus lesions and induced in keratinocytes upon ID-like stimulation. EGCG reduces CXCL10 and MxA staining intensity in epidermis equivalents and CXCL10 secretion by keratinocytes upon stimulation. It furthermore minimizes the cytotoxic effect of the stimulus and downregulates a magnitude of typical pro-inflammatory cytokines that are crucial for the perpetuation of ID.

CONCLUSIONS

We provide evidence concerning anti-inflammatory effects of EGCG within a human in vitro model of ID. The capacity to suppress mediators that are centrally involved in disease perpetuation suggests EGCG as a potential topical therapeutic in lichen planus and other autoimmune skin diseases associated with ID.

Cardiac MRI Depicts Immune Checkpoint Inhibitor-induced Myocarditis: A Prospective Study

Background Immune checkpoint inhibitors (ICIs) for cancer treatment are associated with a spectrum of immune-related adverse events, including ICI-induced myocarditis; however, the extent of subclinical acute cardiac effects related to ICI treatment is unclear. Purpose To explore the extent of cardiac injury and inflammation related to ICI therapy that can be detected with use of cardiac MRI. Materials and Methods In this prospective study from November 2019 to April 2021, oncologic participants, without known underlying structural heart disease or cardiac symptoms, underwent multiparametric cardiac MRI before planned ICI therapy (baseline) and 3 months after starting ICI therapy (follow-up). The cardiac MRI protocol incorporated assessment of cardiac function, including systolic myocardial strain, myocardial edema, late gadolinium enhancement (LGE), T1 and T2 relaxation times, and extracellular volume fraction. The paired t test, Wilcoxon signed-rank test, and McNemar test were used for intraindividual comparisons. Results Twenty-two participants (mean age ± standard deviation, 65 years ± 14; 13 men) were evaluated, receiving a median of four infusions of ICI therapy (interquartile range, four to six infusions). Compared with baseline MRI, participants displayed increased markers of diffuse myocardial edema at follow-up (T1 relaxation time, 972 msec ± 26 vs 1006 msec ± 36 [P < .001]; T2 relaxation time, 54 msec ± 3 vs 58 msec ± 4 [P < .001]; T2 signal intensity ratio, 1.5 ± 0.3 vs 1.7 ± 0.3 [P = .03]). Left ventricular average systolic longitudinal strain had decreased at follow-up MRI (-23.4% ± 4.8 vs -19.6% ± 5.1, respectively; P = .005). New nonischemic LGE lesions were prevalent in two of 22 participants (9%). Compared with baseline, small pericardial effusions were more evident at follow-up (one of 22 participants [5%] vs 10 of 22 [45%]; P = .004). Conclusion In participants who received immune checkpoint inhibitor therapy for cancer treatment, follow-up cardiac MRI scans showed signs of systolic dysfunction and increased parameters of myocardial edema and inflammation. © RSNA, 2021 Online supplemental material is available for this article.

Fertility preservation and management of pregnancy in melanoma patients requiring systemic therapy

Melanoma is one of the most common cancers in adolescents and adults at fertile age, especially in women. With novel and more effective systemic therapies that began to profoundly change the dismal outcome of melanoma by prolonging overall survival, the wish for fertility preservation or even parenthood has to be considered for a growing portion of melanoma patients-from the patients' as well as from the physicians' perspective. The dual blockade of the mitogen-activated protein kinase pathway by B-Raf proto-oncogene serine/threonine kinase and mitogen-activated protein kinase inhibitors and the immune checkpoint inhibition by anti-programmed cell death protein 1 and anti-cytotoxic T-lymphocyte-associated protein-4 monoclonal antibodies constitute the current standard systemic approaches to combat locally advanced or metastatic melanoma. Here, the preclinical data and clinical evidence of these systemic therapies are reviewed in terms of their potential gonadotoxicity, teratogenicity, embryotoxicity and fetotoxicity. Recommendations for routine fertility and contraception counseling of melanoma patients at fertile age are provided in line with interdisciplinary recommendations for the diagnostic work-up of these patients and for fertility-protective measures. Differentiated recommendations for the systemic therapy in both the adjuvant and the advanced, metastatic treatment situation are given. In addition, the challenges of pregnancy during systemic melanoma therapy are discussed.

Outcome of Elderly Patients With Surgically Treated Brain Metastases

Object

In the light of an aging population and ongoing advances in cancer control, the optimal management in geriatric patients with brain metastases (BM) poses an increasing challenge, especially due to the scarce data available. We therefore analyzed our institutional data with regard to factors influencing overall survival (OS) in geriatric patients with BM.

Methods

Between 2013 and 2018, patients aged ≥ 65 years with surgically treated BM were included in this retrospective analysis. In search of preoperatively identifiable risk factors for poor OS, in addition to the underlying cancer, the preoperative frailty of patients was analyzed using the modified Frailty Index (mFI).

Results

A total of 180 geriatric patients with surgically treated BM were identified. Geriatric patients categorized as least-frail achieved a median OS of 18 months, whereas frailest patients achieved an OS of only 3 months (p<0.0001). Multivariable cox regression analysis detected “multiple intracranial metastases” (p=0.001), “infratentorial localization” (p=0.011), “preoperative CRP >5 mg/l” (p=0.01) and “frailest patients (mFI ≥ 0.27)” (p=0.002) as predictors for reduced OS in older patients undergoing surgical treatment for BM.

Conclusions

In this retrospective series, pre-operative frailty was associated with poor survival in elderly patients with BM requiring surgery. Our analyses warrant thorough counselling and support of affected elderly patients and their families.

Intercellular cGAMP transmission induces innate immune activation and tissue inflammation in Trex1 deficiency

Intercellular transmission of the second messenger 2′,3′-cGAMP, synthesized by the viral DNA sensor cGAMP synthase (cGAS), is a potent mode of bystander activation during host defense. However, whether this mechanism also contributes to cGAS-dependent autoimmunity remains unknown. Here, using a murine bone marrow transplantation strategy, we demonstrate that, in Trex1^−/−-associated autoimmunity, cGAMP shuttling from radioresistant to immune cells induces NF-κB activation, interferon regulatory factor 3 (IRF3) phosphorylation, and subsequent interferon signaling. cGAMP travel prevented myeloid cell and lymphocyte death, promoting their accumulation in secondary lymphoid tissue. Nonetheless, it did not stimulate B cell differentiation into autoantibody-producing plasmablasts or aberrant T cell priming. Although cGAMP-mediated bystander activation did not induce spontaneous organ disease, it did trigger interface dermatitis after UV light exposure, similar to cutaneous lupus erythematosus. These findings reveal that, in Trex1-deficiency, intercellular cGAMP transfer propagates cGAS signaling and, under conducive conditions, causes tissue inflammation.

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In Trex1^−/−-associated autoimmunity radioresistant cells transfer cGAMP to immune cells

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cGAMP shuttling induces NF-κB activation, IRF3 and IFN signaling in vivo

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Intercellular cGAMP transmission is sufficient to cause UV skin inflammation

Combined Assessment of Preoperative Frailty and Sarcopenia Allows the Prediction of Overall Survival in Patients with Lung Cancer (NSCLC) and Surgically Treated Brain Metastasis

Simple Summary

Patients with brain metastasis are at a severe stage of cancer, and brain surgery can prevent neurological morbidity. However, the success of brain surgery might require a patient’s physical integrity prior to the operation. In the present study, we asked whether a preoperative physical decline affects survival in patients with brain metastasis from lung cancer. In order to measure the physical condition, we used a commonly-known index—the so-called frailty index—and additionally measured the thickness of a particular masticatory muscle as muscle loss correlates to physical decline. We found that a decreased muscle thickness was accompanied by worsened survival for patients < 65 years and an increased frailty index correlated to worsened survival for patients ≥ 65 years. These results encourage to use of the frailty index and muscle thickness as easily available parameters in order to more sufficiently estimate individual treatment success in patients with metastatic lung cancer.

Abstract

Neurosurgical resection represents an important therapeutic pillar in patients with brain metastasis (BM). Such extended treatment modalities require preoperative assessment of patients’ physical status to estimate individual treatment success. The aim of the present study was to analyze the predictive value of frailty and sarcopenia as assessment tools for physiological integrity in patients with non-small cell lung cancer (NSCLC) who had undergone surgery for BM. Between 2013 and 2018, 141 patients were surgically treated for BM from NSCLC at the authors’ institution. The preoperative physical condition was assessed by the temporal muscle thickness (TMT) as a surrogate parameter for sarcopenia and the modified frailty index (mFI). For the ≥65 aged group, median overall survival (mOS) significantly differed between patients classified as ‘frail’ (mFI ≥ 0.27) and ‘least and moderately frail’ (mFI < 0.27) (15 months versus 11 months (p = 0.02)). Sarcopenia revealed significant differences in mOS for the <65 aged group (10 versus 18 months for patients with and without sarcopenia (p = 0.036)). The present study confirms a predictive value of preoperative frailty and sarcopenia with respect to OS in patients with NSCLC and surgically treated BM. A combined assessment of mFI and TMT allows the prediction of OS across all age groups.

No evidence to support the impact of migration background on treatment response rates and cancer survival: a retrospective matched-pair analysis in Germany

Background

Immigration has taken the central stage in world politics, especially in the developed countries like Germany, where the continuous flow of immigrants has been well documented since 1960s. Strikingly, emerging data suggest that migrant patients have a poorer response to the treatment and lower survival rates in their new host country, raising concerns about health disparities. Herein, we present our investigation on the treatment response rate and cancer survival in German patients with and without an immigrant background that were treated at our comprehensive cancer center in Germany.

Methods

Initially, we considered 8162 cancer patients treated at the Center for Integrated Oncology (CIO), University Hospital Bonn, Germany (April 2002–December 2015) for matched-pair analysis. Subsequently, the German patients with a migration background and those from the native German population were manually identified and catalogued using a highly specific name-based algorithm. The clinical parameters such as demographic characteristics, tumor characteristics, defined staging criteria, and primary therapy were further adjusted. Using these stringent criteria, a total of 422 patients (n = 211, Germans with migration background; n = 211, native German population) were screened to compare for the treatment response and survival rates (i.e., 5-year overall survival, progression-free survival, and time to progression).

Results

Compared to the cohort with migration background, the cohort without migration background was slightly older (54.9 vs. 57.9 years) while having the same sex distribution (54.5% vs. 55.0% female) and longer follow-up time (36.9 vs. 42.6 months). We did not find significant differences in cancer survival (5-year overall survival, P = 0.771) and the response rates (Overall Remission Rate; McNemar’s test, P = 0.346) between both collectives.

Conclusion

Contrary to prior reports, we found no significant differences in cancer survival between German patients with immigrant background and native German patients. Nevertheless, the advanced treatment protocols implemented at our comprehensive cancer center may possibly account for the low variance in outcome. To conduct similar studies with a broader perspective, we propose that certain risk factors (country-of-origin-specific infections, dietary habits, epigenetics for chronic diseases etc.) should be considered, specially in the future studies that will recruit new arrivals from the 2015 German refugee crisis.

CD155 on Tumor Cells Drives Resistance to Immunotherapy by Inducing the Degradation of the Activating Receptor CD226 in CD8+ T Cells

The activating receptor CD226 is expressed on lymphocytes, monocytes, and platelets and promotes anti-tumor immunity in pre-clinical models. Here, we examined the role of CD226 in the function of tumor-infiltrating lymphocytes (TILs) and resistance to immunotherapy. In murine tumors, a large proportion of CD8⁺ TILs had decreased surface expression of CD226 and exhibited features of dysfunction, whereas CD226^hi TILs were highly functional. This correlation was seen also in TILs isolated from HNSCC patients. Mutation of CD226 at tyrosine 319 (Y319) led to increased CD226 surface expression, enhanced anti-tumor immunity and improved efficacy of immune checkpoint blockade (ICB). Mechanistically, tumor-derived CD155, the ligand for CD226, initiated phosphorylation of Y319 by Src kinases, thereby enabling ubiquitination of CD226 by CBL-B, internalization, and proteasomal degradation. In pre-treatment samples from melanoma patients, CD226⁺CD8⁺ T cells correlated with improved progression-free survival following ICB. Our findings argue for the development of therapies aimed at maintaining the expression of CD226.

The Impact of Prolonged Mechanical Ventilation on Overall Survival in Patients With Surgically Treated Brain Metastases

Objective

Surgical resection represents a common treatment modality in patients with brain metastasis (BM). Postoperative prolonged mechanical ventilation (PMV) might have an enormous impact on the overall survival (OS) of these patients suffering from advanced cancer disease. We therefore have analyzed our institutional database with regard to a potential impact of PMV on OS of patients who had undergone surgery for brain metastases.

Methods

360 patients with surgically treated brain metastases were included. The definition of PMV consisted of postoperative mechanical ventilation lasting for more than 48 hours. Analysis of survival incorporating established prognostic factors such as age, location of BM, and preoperative physical status was performed.

Results

14 of 360 patients with BM (4%) suffered from postoperative PMV after surgical treatment of BM. Patients with PMV presented in a significantly more impaired neurological condition preoperatively than patients without (p<0.0001). Multivariate analysis determined PMV to be a significant prognostic factor for OS after surgical treatment in patients with BM, independent of other predictive factors (p<0.0001).

Conclusions

The present study demonstrates postoperative PMV as significantly related to poor OS in patients with surgically treated BM. Postoperative PMV is a so far underestimated prognostic predictor, but might be utilized for optimized patient management early in the postoperative phase. For this purpose, the results of the present study should encourage the initiation of further scientific efforts.

Grzybowski's Generalized Eruptive Keratoacanthomas in a Patient with Terminal Kidney Disease-An Unmet Medical Need Equally Ameliorated by Topical Imiquimod Cream and Lapacho Tea Wraps: A Case Report

Introduction

Development of singular keratoacanthoma (KA) is generally considered a benign condition as it has a tendency to regress spontaneously in spite of histological similarity to squamous cell carcinoma. Most KAs undergo excision to rule out differential diagnoses. Several alternative treatment modalities (keratinolytic, ablative, immunomodulating, antiproliferative, or targeted therapy) have been described in the past with varying success, underlining the therapeutic challenges associated with large or multiple lesions. Isomorphic response (Koebner phenomenon) may limit the efficacy of ablative options, and comorbidity may limit the use of systemic treatments. Less aggressive topical immunomodulatory treatment options represent an alternative with varying therapeutic success.

Case Report

Here, we describe the clinical course of a 51-year-old male patient with terminal kidney disease who suffered from the rare benign pruritic condition of Grzybowski’s generalized eruptive keratoacanthomas (GEKA) and experienced a significant reduction of lesions and symptoms upon topical therapy with imiquimod 5% cream and lapacho tea dressings alike.

Conclusions

Very little is known about the potential antiinflammatory or antiproliferative effects on the epidermis of the popular phytotherapeutic agent lapacho tea. More studies are warranted considering both the etiology and treatment of GEKA and topical use of phytotherapeutics in dermatology in general. Management of large or multiple KAs remains challenging.

Human dendritic cells adenovirally-engineered to express three defined tumor antigens promote broad adaptive and innate immunity

Dendritic cell (DC) immunotherapy has shown a promising ability to promote anti-tumor immunity in vitro and in vivo. Many trials have tested single epitopes and single antigens to activate single T cell specificities, and often CD8(+) T cells only. We previously found that determinant spreading and breadth of antitumor immunity correlates with improved clinical response. Therefore, to promote activation and expansion of polyclonal, multiple antigen-specific CD8(+) T cells, as well as provide cognate help from antigen-specific CD4(+) T cells, we have created an adenovirus encoding three full length melanoma tumor antigens (tyrosinase, MART-1 and MAGE-A6, "AdVTMM"). We previously showed that adenovirus (AdV)-mediated antigen engineering of human DC is superior to peptide pulsing for T cell activation, and has positive biological effects on the DC, allowing for efficient activation of not only antigen-specific CD8(+) and CD4(+) T cells, but also NK cells. Here we describe the cloning and testing of "AdVTMM2," an E1/E3-deleted AdV encoding the three melanoma antigens. This novel three-antigen virus expresses mRNA and protein for all antigens, and AdVTMM-transduced DC activate both CD8(+) and CD4(+) T cells which recognize melanoma tumor cells more efficiently than single antigen AdV. Addition of physiological levels of interferon-α (IFNα) further amplifies melanoma antigen-specific T cell activation. NK cells are also activated, and show cytotoxic activity. Vaccination with multi-antigen engineered DC may provide for superior adaptive and innate immunity and ultimately, improved antitumor responses.

Lower Genital Tract Melanomas: Staging, Predictors of Outcome, and New Therapeutic Options

BACKGROUND/AIM

Identification of predictors of survival of patients with lower genital tract melanoma (LGTM) and evaluation of the effectiveness of immunotherapy.

PATIENTS AND METHODS

Data of twenty women with LGTM were retrospectively collected. Survival outcomes were evaluated using the Kaplan-Meier method. Survival distributions were analyzed using the Log rank test.

RESULTS

Twenty patients with LGTM (6 vaginal/14 vulvar) were evaluated. Factors significantly affecting Five-year OS was the stage of the American Joint Committee on Cancer (AJCC 2017) (I+II: 55.6% vs. III+IV: 25.9%; p=0.030) and the T-Stage (I+II: 100% vs. III+IV: 7.5%; p=0.280). Factors negatively affecting Five-year PFS was T-Stage >II (p=0.005), AJCC stage >II (p<0.001), depth of tumor infiltration >3 mm (p=0.008), nodal involvement (p=0.013), distant disease (p=0.002), and resection margins <10 mm (p=0.024). Nine patients received immunotherapy [median duration of response (DOR)=4 months]. Three patients received immuno- and radiation therapy (median DOR of 5 months). Two patients received T-VEC, only one responded.

CONCLUSION

Surgery has a therapeutic effect in early stage LGTM. Advanced stages may be treated with immunotherapy, radiation therapy, a combination of both, and oncolytic viral immunotherapy.

CTLA4 promoter methylation predicts response and progression-free survival in stage IV melanoma treated with anti-CTLA-4 immunotherapy (ipilimumab)

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 methylation and CTLA-4 protein expression as predictive biomarkers for response to anti-CTLA-4 immunotherapy. We identified retrospectively N = 30 stage IV melanoma patients treated with single-agent anti-CTLA-4 immunotherapy (ipilimumab). We used quantitative methylation-specific PCR and immunohistochemistry to quantify CTLA4 methylation and protein expression in pre-treatment samples. CTLA4 methylation was significantly higher in progressive as compared to responding tumors and significantly associated with progression-free survival. A subset of infiltrating lymphocytes and tumor cells highly expressed CTLA-4. However, CTLA-4 protein expression did not predict response to treatment. We conclude that CTLA4 methylation is a predictive biomarker for response to anti-CTLA-4 immunotherapy.

Comorbidity Burden and Presence of Multiple Intracranial Lesions Are Associated with Adverse Events after Surgical Treatment of Patients with Brain Metastases

Simple Summary

Patients with brain metastasis must face advanced cancer diseases, and neurosurgical resection is often considered an inevitable part of treatment. However, peri- and postoperative complications might further worsen the prognosis for these vulnerable patients. It is therefore important to investigate risk factors for such unfavorable events in order to recognize high-risk patients at the earliest possible stage of disease. For this purpose, we aimed to identify risk factors for early postoperative complications following surgical resection of brain metastases. Our results showed that the presence of multiple brain metastases in a single patient and a high rate of additional comorbidities were associated with elevated levels of postoperative complications. Furthermore, patients who suffered from such unfavorable postoperative events were significantly more likely to die during the initial hospital stay. The present study therefore might help to preoperatively select for critically ill patients who are in mandatory need of advanced treatment and care.

Abstract

Surgical resection is a key treatment modality for brain metastasis (BM). However, peri- and postoperative adverse events (PAEs) might be associated with a detrimental impact on postoperative outcome. We retrospectively analyzed our institutional database with regard to patient safety indicators (PSIs), hospital-acquired conditions (HACs) and specific cranial surgery-related complications (CSCs) as high-quality metric profiles for PAEs in patients who had undergone surgery for BM in our department between 2013 and 2018. The comorbidity burden was assessed by means of the Charlson comorbidity index (CCI). A multivariate analysis was performed to identify independent predictors for the development of PAEs after surgical resection of BM. In total, 33 patients (8.5%) suffered from PAEs after surgery for BM. Of those, 17 PSI, 5 HAC and 11 CSC events were identified. Multiple brain metastases (p = 0.02) and a higher comorbidity burden (CCI > 10; p = 0.003) were associated with PAEs. In-hospital mortality of patients suffering from a PAE was significantly higher than that of patients without a PAE (24% vs. 0.6%; p < 0.0001). Awareness of risk factors for postoperative complications enables future prevention and optimal response, particularly in vulnerable oncological patients. The present study identified the presence of multiple brain metastases and increased comorbidity burden associated with PAEs in patients suffering from BM.

Treatment Monitoring of Immunotherapy and Targeted Therapy Using 18F-FET PET in Patients with Melanoma and Lung Cancer Brain Metastases: Initial Experiences

We investigated the value of O-(2-¹⁸F-fluoroethyl)-l-tyrosine (¹⁸F-FET) PET for treatment monitoring of immune checkpoint inhibition (ICI) or targeted therapy (TT) alone or in combination with radiotherapy in patients with brain metastasis (BM) since contrast-enhanced MRI often remains inconclusive. Methods: We retrospectively identified 40 patients with 107 BMs secondary to melanoma (n = 29 with 75 BMs) or non-small cell lung cancer (n = 11 with 32 BMs) treated with ICI or TT who had ¹⁸F-FET PET (n = 60 scans) for treatment monitoring from 2015 to 2019. Most patients (n = 37; 92.5%) had radiotherapy during the course of the disease. In 27 patients, ¹⁸F-FET PET was used to differentiate treatment-related changes from BM relapse after ICI or TT. In 13 patients, ¹⁸F-FET PET was performed for response assessment to ICI or TT using baseline and follow-up scans (median time between scans, 4.2 mo). In all lesions, static and dynamic ¹⁸F-FET PET parameters were obtained (i.e., mean tumor-to-brain ratios [TBR], time-to-peak values). Diagnostic accuracies of PET parameters were evaluated by receiver-operating-characteristic analyses using the clinical follow-up or neuropathologic findings as a reference. Results: A TBR threshold of 1.95 differentiated BM relapse from treatment-related changes with an accuracy of 85% (P = 0.003). Metabolic responders to ICI or TT on ¹⁸F-FET PET had a significantly longer stable follow-up (threshold of TBR reduction relative to baseline, ≥10%; accuracy, 82%; P = 0.004). Furthermore, at follow-up, time to peak in metabolic responders increased significantly (P = 0.019). Conclusion: ¹⁸F-FET PET may add valuable information for treatment monitoring in BM patients treated with ICI or TT.

Molecular, clinicopathological, and immune correlates of LAG3 promoter DNA methylation in melanoma

Background

The co-receptor lymphocyte-activation gene-3 (LAG3, LAG-3, CD223) is a potential target for immune checkpoint inhibition immunotherapies. However, little is known about the biological and clinical significance of LAG3 DNA methylation in melanoma and its microenvironment.

Methods

We evaluated LAG3 promoter and gene body methylation in a cohort of N = 470 melanoma patients obtained from The Cancer Genome Atlas (TCGA cohort), an independent cohort of N = 120 patients from the University Hospital Bonn, and in subsets of peripheral blood leukocytes, melanocytes, and melanoma cell lines. We validated the association of LAG3 methylation with mRNA expression in vitro in the melanoma cell line A375 treated with the hypomethylating agent 5-azacytidine and stimulated with interferon-γ. Finally, we investigated correlations between LAG3 methylation and progression-free survival in patients treated with immune checkpoint blockade (ICB cohort, N = 118).

Findings

Depending on the analysed locus (promoter, gene body) we found region-dependent significant LAG3 methylation differences between monocytes, B cells, CD8⁺ and CD4⁺ T cells, regulatory T cells, melanocytes, and melanoma cell lines. In tumor tissues, methylation correlated significantly with LAG3 mRNA expression, immune cell infiltrates (histopathologic lymphocyte score and RNA-Seq signatures of distinct immune infiltrates), and an interferon-γ signature. Finally, LAG3 methylation was associated with overall survival in the TCGA cohort and progression-free survival in the ICB cohort. We detected basal LAG3 mRNA expression in the melanoma cell A375 and an interferon-γ inducible expression after demethylation with 5-azacytidine.

Interpretation

Our study points towards an epigenetic regulation of LAG3 via promoter methylation and suggests a prognostic and predictive significance of LAG3 methylation in melanoma. Our results give insight in the tumor cell-intrinsic transcriptional regulation of LAG3 in melanoma. In perspective, our results might pave the way for investigating LAG3 methylation as a predictive biomarker for response to anti-LAG3 immune checkpoint blockage.

Funding

A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

32. TREATMENT MONITORING OF IMMUNOTHERAPY AND TARGETED THERAPY USING AMINO ACID PET IN PATIENTS WITH BRAIN METASTASES

PURPOSE

Recently, the RANO group has analyzed the additional diagnostic value of amino acid PET in patients with primary and secondary brain tumors and recommended the use of this imaging technique in addition to conventional MRI. Here, we investigated the value of PET using the radiolabled amino acid O-(2-[¹⁸F]fluoroethyl)-L-tyrosine (FET) for treatment monitoring of immune checkpoint inhibition (ICI) or targeted therapy (TT) alone or in combination with radiotherapy in patients with brain metastases (BM) since contrast-enhanced MRI often remains inconclusive.

METHODS

We retrospectively identified 40 patients with 107 BM secondary to melanoma (n=29 with 75 BM) or non-small cell lung cancer (n=11 with 32 BM) treated with ICI or TT who had FET PET (n=60 scans) for treatment monitoring from 2015–2019. The majority of patients (n=37; 92.5%) had radiotherapy during the course of disease. In 27 patients, FET PET was used for the differentiation of treatment-related changes from BM relapse following ICI or TT. In 13 patients, FET PET was performed for response assessment to ICI or TT using baseline and follow-up scans (median time between scans, 4.2 months). In all lesions, static and dynamic FET PET parameters were obtained (i.e., mean tumour-to-brain ratios (TBR), time-to-peak values). Diagnostic accuracies of PET parameters were evaluated by receiver-operating-characteristic analyses using the clinical follow-up or neuropathological findings as reference.

RESULTS

A TBR threshold of 1.95 differentiated BM relapse from treatment-related changes with an accuracy of 85% (P=0.003). Metabolic Responders to ICI or TT on FET PET had a significantly longer stable follow-up (threshold of TBR reduction relative to baseline, ≥10%; accuracy, 82%; P=0.004). Furthermore, at follow-up, time-to-peak values in metabolic responders increased significantly (P=0.019).

CONCLUSIONS

FET PET may add valuable information for treatment monitoring in BM patients treated with ICI or TT.

Prognostic and predictive value of PD-L2 DNA methylation and mRNA expression in melanoma

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 relevant for efficacy of PD-1 inhibition. We investigated PD-L2 expression and methylation as a prognostic and predictive biomarker in melanoma.

METHODS

DNA methylation at five CpG loci and gene expression of PD-L2 were evaluated with regard to survival in 470 melanomas from The Cancer Genome Atlas. PD-L2 promoter methylation in correlation with PD-L2 mRNA and protein expression was analyzed in human melanoma cell lines. Prognostic and predictive value of PD-L2 methylation was validated using quantitative methylation-specific PCR in a multicenter cohort of 129 melanoma patients receiving anti-PD-1 therapy. mRNA sequencing data of 121 melanoma patients receiving anti-PD-1 therapy provided by Liu et al. were analyzed for PD-L2 mRNA expression.

RESULTS

We found significant correlations between PD-L2 methylation and mRNA expression levels in melanoma tissues and cell lines. Interferon-γ inducible PD-L2 protein expression correlated with PD-L2 promoter methylation in melanoma cells. PD-L2 DNA promoter hypomethylation and high mRNA expression were found to be strong predictors of prolonged overall survival. In pre-treatment melanoma samples from patients receiving anti-PD-1 therapy, low PD-L2 DNA methylation and high PD-L2 mRNA expression predicted longer progression-free survival.

CONCLUSION

PD-L2 expression seems to be regulated via DNA promoter methylation. PD-L2 DNA methylation and mRNA expression may predict progression-free survival in melanoma patients receiving anti-PD-1 immunotherapy. Assessment of PD-L2 should be included in further clinical trials with anti-PD-1 antibodies.

Talimogene Laherparepvec in Advanced Mucosal Melanoma of the Urethra Upon Primary Resistance on Immune Checkpoint Inhibition: A Case Report

Background: Mucosal melanomas including melanomas of the urogenital tract represent a rare type of melanoma characterized by low mutational burden and poor prognosis. Immune checkpoint inhibition has so far only been assessed in a limited number of mucosal melanoma patients and, in contrast to response in cutaneous melanoma, was associated with disappointing response rates. The oncolytic viral immunotherapy Talimogene laherparepvec (T-VEC) has recently been approved for treatment of locally advanced or unresectable melanoma. T-VEC combines direct oncolytic effects with local and systemic immune-mediated anti-tumor response. Our rationale to use T-VEC in this case was an expected augmentation of immunogenicity by tumor lysis to overcome primary resistance of a mucosal melanoma to immune checkpoint blockade.

Objective: To report the first case of an advanced mucosal melanoma of the urethra treated with intralesional application of Talimogene laherparepvec.

Case Report: A 78-years old female patient was diagnosed with an advanced mucosal melanoma of the urethra with inguinal lymph node metastases and intravaginal mucosal metastases. Shortly after surgical resection of the tumor mass, intravaginal mucosal metastases, and new nodal metastases in proximity of the left iliac vessels were diagnosed. The patient was treated with the anti-PD1 antibody pembrolizumab and obtained a stable disease lasting for 30 weeks. However, upon checkpoint inhibition the patient developed a loco-regional progressive disease featuring bleeding intravaginal metastases, while nodal metastases remained stable. We stopped treatment with pembrolizumab and administered T-VEC directly into the intravaginal mucosal metastases. After five injections T-VEC yielded a partial response with clinical regression of the injected mucosal metastases. Disease remained stable for 16 weeks under biweekly T-VEC treatment. Thereafter the patient showed disease progression in nodal metastases. T-VEC was discontinued. Immunotherapy with pembrolizumab was restarted but failed to achieve a response. Finally, targeted therapy with imatinib was induced in presence of a druggable c-KIT mutation, leading to a considerable response of all tumor sites that is still ongoing.

Conclusion: T-VEC represents an effective and well-tolerated treatment option for patients with loco-regionally advanced mucosal melanoma. In combination with immunotherapy, T-VEC bears the potential of synergistic effects to overcome the specific primary resistance of mucosal melanoma to immune checkpoint blockade.

Clinical Management of Locally Advanced Basal-Cell Carcinomas and Future Therapeutic Directions

Treatment of choice for nodular basal-cell carcinomas (BCCs) is complete excision, implying that small lesions are of minor concern. Metastasis is very rare (< 1%). However, locally advanced basal-cell carcinomas (laBCCs), which are ineligible for surgery or radiation, are a therapeutic challenge. First-generation Smoothened (SMO) inhibitors (vismodegib, sonidegib) have been approved for treatment, but common side effects limit their use. Numerous new compounds are being investigated in clinical trials as potential therapeutic alternatives, among them second-generation SMO inhibitors, other Hedgehog signaling pathway inhibitors, immune-checkpoint inhibitors and intralesional modalities such as oncolytic viruses. Neoadjuvant treatment regimens open another field. This article deals with the clinical management of laBCCs, based on the description of an illustrative case from our department featuring multiple extensive lesions of the scalp. In this short review we will discuss therapeutic options and implications for the future. Some of the new strategies might potentially evolve as alternatives in the management of genodermatoses such as basal-cell carcinoma syndrome, if proven effective and safe.

Talimogene laherparepvec treatment to overcome loco-regional acquired resistance to immune checkpoint blockade in tumor stage IIIB-IV M1c melanoma patients

BACKGROUND

Resistance to immune checkpoint blockade and targeted therapy in melanoma patients is currently one of the major clinical challenges. With the approval of talimogene laherparepvec (T-VEC), oncolytic viruses are now in clinical practice for locally advanced or non-resectable melanoma. Here, we describe the usage of T-VEC in stage IVM1b-M1c melanoma patients, who achieved complete remission or stable disease upon systemic treatment but suffered from a loco-regional recurrence. To our knowledge, there are no case reports so far describing T-VEC as a means to overcome acquired resistance to immune checkpoint blockade or targeted therapy.

METHODS

All melanoma patients in our department treated with T-VEC in the period of 2016-2018 were evaluated retrospectively. Data on clinicopathological characteristics, treatment response, and toxicity were analyzed.

RESULTS

Fourteen melanoma patients were treated with T-VEC in our center. Six patients (43%) received T-VEC first-line. In eight patients (57%), T-VEC followed a prior systemic therapy. Three patients with M1b stage and one patient with M1c stage melanoma were treated with T-VEC. These patients suffered from loco-regional progress, whilst distant metastases had regressed during prior systemic treatment. 64% of patients showed a benefit from therapy with T-VEC. The durable response rate was 36%.

CONCLUSION

T-VEC represents an effective and tolerable treatment option. This is true not only for loco-regionally advanced melanoma patients, but also for patients with stable or regressive systemic metastases who develop loco-regionally acquired resistance upon treatment with immune checkpoint blockade or targeted therapy. A sensible selection of suitable patients seems to be crucial.

Higher number of multidisciplinary tumor board meetings per case leads to improved clinical outcome

BACKGROUND

This analysis aims at evaluating the impact of multidisciplinary tumor boards on clinical outcome of multiple tumor entities, the effect of the specific number of multidisciplinary tumor boards and potential differences between the tumor entities.

METHODS

By a matched-pair analysis we compared the response to treatment, overall survival, relapse or disease free survival and progression free survival of patients whose cases were discussed in a tumor board meeting with patients whose cases were not. It was performed with patients registered in the cancer registry of the University of Bonn and diagnosed between 2010 and 2016. After the matching process with a pool of 7262 patients a total of 454 patients with 66 different tumor types were included in this study.

RESULTS

First, patients with three or more multidisciplinary tumor board meetings in their history show a significantly better overall survival than patients with no tumor board meeting. Second, response to treatment, relapse free survival and time to progression were not found to be significantly different. Third, there was no significant difference for a specific tumor entity.

CONCLUSION

This study revealed a positive impact of a higher number of multidisciplinary tumor boards on the clinical outcome. Also, our analysis hints towards a positive effect of multidisciplinary tumor boards on overall survival.

The landscape of CD28, CD80, CD86, CTLA4, and ICOS DNA methylation in head and neck squamous cell carcinomas

CTLA-4 blocking therapeutic antibodies are currently under investigation in head and neck squamous cell carcinoma (HNSCC). A better understanding of the epigenetic regulation of the CD28 superfamily members CD28, CTLA-4, and ICOS and their B7 ligands, CD80 and CD86, could support the development of biomarkers for response prediction to anti-CTLA-4 immunotherapy. We investigated methylation of the encoding genes CD28, CTLA4, ICOS, CD80, and CD86 at single CpG resolution (51 CpG sites) in a cohort of HNSCC (N = 528) and normal adjacent tissue samples (N = 50) provided by The Cancer Genome Research Atlas, in isolated blood leukocytes from healthy individuals (N = 28), and HNSCC cell lines (N = 39). We analysed methylation levels with regard to mRNA expression, overall survival, mutational load, interferon-γ signature, and signatures of immune cell infiltrates. Depending on the location of the CpG sites (promoter, promoter flank, gene body, and intergenic sites), we found significant differences in methylation levels among isolated leukocytes, between leukocytes and HNSCC cell lines, and among HNSCCs. Methylation of all analysed genes correlated inversely or positively with mRNA expression, depending on the CpG site. CD28, CTLA4, and ICOS revealed almost identical correlation patterns. Furthermore, we found significant correlations with survival and features of response to immunotherapy, i.e. interferon-γ signature, signatures of tumour infiltrating immune cells, and mutational load. Our results suggest CD28, CTLA4, ICOS, CD80, and CD86 expression levels are epigenetically co-regulated by DNA methylation. This study provides rationale to test their DNA methylation as potential biomarker for prediction of response to CTLA-4 immune checkpoint inhibitors.

H3K27me3 and EZH2 expression in melanoma: relevance for melanoma progression and response to immune checkpoint blockade

Background

Upregulation of the histone methyltransferase enzyme EZH2 and its histone modification H3K27me3 has been linked to melanoma progression, metastasis, and resistance to immune checkpoint blockade (ICB). In clinical trials, EZH2 inhibitors are currently tested to overcome resistance to ICB. The aim of this study is to evaluate expression patterns and the predictive value of H3K27me3 and EZH2 in metastatic melanoma samples prior to ICB. As H3K27me3 expression has been associated with a dedifferentiated, invasive melanoma phenotype, we also investigated the prognostic value of H3K27me3 expression in primary melanomas.

Results

H3K27me3 and EZH2 expression were evaluated in a cohort of 44 metastatic melanoma samples before ICB using immunohistochemistry (IHC). 29/44 (66%) of melanomas showed H3K27me3 expression, and 6/44 (14%) showed EZH2 expression. No predictive value for therapeutic response to anti-PD-1 therapy could be found for H3K27me3 or EZH2 expression on melanoma cells. To investigate the prognostic significance of H3K27me3, we analyzed H3K27me3 expression in a representative cohort of 136 primary melanomas with known sentinel lymph node status. H3K27me3 expression is associated with increased tumor thickness and nodal involvement. Melanoma metastases showed a higher expression of H3K27me3 in comparison to primary melanomas. In human melanoma cell lines, TNFα and INFγ could not induce H3K27me3 expression.

Conclusion

Our study shows that H3K27me3 expression is more frequent than EZH2 and is associated with a more invasive and metastatic melanoma cell phenotype. We suggest that H3K27me3 expression by IHC might be a suitable method to evaluate the activity of EZH2 inhibitors in clinical trials.

Molecular and immune correlates of TIM-3 (HAVCR2) and galectin 9 (LGALS9) mRNA expression and DNA methylation in melanoma

BACKGROUND

The T cell immunoglobulin and mucin-domain containing-3 receptor TIM-3 (also known as hepatitis A virus cellular receptor 2, encoded by HAVCR2) and its ligand galectin 9 (LGALS9) are promising targets for immune checkpoint inhibition immunotherapies. However, little is known about epigenetic regulation of the encoding genes. This study aimed to investigate the association of TIM-3 and LGALS9 DNA methylation with gene expression, patients' survival, as well as molecular and immune correlates in malignant melanoma.

RESULTS

Methylation of all six TIM-3 CpGs correlated significantly with TIM-3 mRNA levels (P ≤ 0.05). A strong inverse correlation (Spearman's ρ = - 0.49) was found in promoter regions, while a strong positive correlation (ρ = 0.63) was present in the gene body of TIM-3. High TIM-3 mRNA expression (hazard ratio (HR) = 0.88, 95% confidence interval (CI) [0.81-0.97], P = 0.007) was significantly associated with better overall survival. Seven of the eight LGALS9 CpG sites correlated significantly with LGALS9 mRNA levels (P ≤ 0.003). Methylation at five CpG sites showed a strong inverse correlation (Spearman's ρ = - 0.67) and at two sites a weak positive correlation (Spearman's ρ = 0.15). High LGALS9 mRNA expression was significantly associated with increased overall survival (HR = 0.83, 95%CI [0.75-0.93], P = 0.001). In addition, we found significant correlations between TIM-3 and LGALS9 methylation and mRNA expression with immune cell infiltrates and significant differences among distinct immune cell subsets.

CONCLUSIONS

Our study points toward an epigenetic regulation of TIM-3 and LGALS9 via DNA methylation and might provide an avenue for the development of a predictive biomarker for response to immune checkpoint blockade.