[Periocular Merkel Cell Carcinoma - an overview of clinical aspects and current therapeutic options]

Merkel cell carcinoma (MCC) is a rare but highly aggressive and rapidly expanding malignant skin tumor. It affects the periocular region in approximately 10% of cases. The current treatment recommendation for resectable non-metastatic MCC comprises total surgical excision; however, lymph node or distant metastases are often already present by the time of the diagnosis. Since an immune checkpoint inhibitor therapy with avelumab was first approved for MCC in 2016, there has been considerable improvement in mean survival compared to cytostatic therapy; at the same time, there has been a reduction in serious treatment-associated adverse events. Other immune checkpoint inhibitors are currently still in clinical trials, with very promising initial results. Because of the complexity of the diagnosis, treatment, and prognosis, it is essential that MCC patients receive interdisciplinary care in a specialized center including consultation with a tumor review board.

Liver Injury after Selective Androgen Receptor Modulator Intake: A Case Report and Review of the Literature

Liver injury associated with selective androgen receptor modulators (SARMs) is an issue that has not been reported often. We report a case of a previously healthy 24-year-old male, who was referred to our hospital for severe jaundice with intense pruritus. He had previously taken the SARM Enobosarm (also known as Ostarine) for muscle-building purposes. Blood serum levels of total bilirubin exceeded 30 mg/dL with only a slight elevation of liver enzymes. Liver biopsy revealed isolated hepatocellular cholestasis (bland cholestasis) with limited inflammation or necrosis. Supportive treatment was begun in our hospital with molecular adsorbent recirculation system (MARS) albumin dialysis, as well as cholestyramine for pruritus relief. During therapy, bilirubin levels and symptoms regressed, and after five sessions of dialysis, the patient could be released from our clinic in a markedly improved clinical and laboratory condition. However, bilirubin parameters regressed slowly after this, reaching normal levels as late as six months after first intake of the compound. Exome-based genetic testing brought about no pathogenic variants for cholestatic liver disease in our patient. Nevertheless, three common heterozygous polymorphisms associated with an increased risk for intrahepatic cholestasis could be identified. Our case demonstrates that SARMs can cause severe liver injuries not prominently mentioned in safety data sheets. Therefore, these compounds constitute a potential danger to the user's health. This holds especially true when taking SARMs without supervision by a medical professional, which should consist of a thorough monitoring of liver enzyme and bilirubin levels.

Periocular Merkel Cell Carcinoma - An Overview of Clinical Aspects and Current Treatment Options

Merkel cell carcinoma (MCC) is a rare but highly aggressive and rapidly expanding malignant skin tumor. It affects the periocular region in approximately 10% of cases. The current treatment recommendation for resectable non-metastatic MCC comprises total surgical excision; however, lymph node or distant metastases are often already present by the time of the diagnosis. Since an immune checkpoint inhibitor therapy with avelumab was first approved for MCC in 2016, there has been considerable improvement in mean survival compared to cytostatic therapy; at the same time, there has been a reduction in serious treatment-associated adverse events. Other immune checkpoint inhibitors are currently still in clinical trials, with very promising initial results. Because of the complexity of the diagnosis, treatment, and prognosis, it is essential that MCC patients receive interdisciplinary care in a specialized center including consultation with a tumor review board.

Abstract PR004: Fusion protein-driven IGF-IR signals deregulate hippo pathway promoting oncogenic cooperation of YAP1 and FUS-DDIT3

Introduction: Myxoid liposarcoma (MLS) is molecularly characterized by a recurrent chromosomal translocation which generates a chimeric FUS-DDIT3 fusion gene. The FUS-DDIT3 oncoprotein, acting as a transcriptional dysregulator, has been shown to be essential in MLS pathogenesis, among others through deregulation of IGF-IR/PI3K/AKT signaling, but its exact mode of function remains incompletely understood. Recently, a particular reliance on the Hippo pathway effector and transcriptional co-regulator YAP1 was found in MLS; however, the molecular mechanism of FUS-DDIT3-dependent YAP1 activation and its contribution to MLS pathogenesis remain unclear. Experimental Procedures: The expression of IGF-IR and YAP1 was analyzed in a large cohort of MLS specimens by immunohistochemistry. In vitro analyses were performed employing a human mesenchymal stem cell system stably expressing FUS-DDIT3 and human MLS cell lines. RNA interference-based approaches, experiments with small-molecule kinase inhibitors, co-immunoprecipitation, proximity ligation assays, transcriptome sequencing and adipogenic differentiation assays were performed to determine the interplay of FUS-DDIT3, IGF-IR-dependent signals, and YAP1 in MLS cells. Results: Immunohistochemically, a significant subset of MLS samples showed concurrent expression of IGF-IR and nuclear YAP1. In vitro, FUS-DDIT3-driven IGF-IR signaling was found to promote stability and nuclear accumulation of YAP1 via deregulation of the Hippo pathway. Co-immunoprecipitation and proximity ligation assays revealed nuclear co-localization of FUS-DDIT3 and YAP1 in FUS-DDIT3-expressing mesenchymal stem cells and MLS cell lines. Transcriptome sequencing of MLS cells demonstrated that FUS-DDIT3 and YAP1 co-regulate specific oncogenic gene signatures related to proliferation, cell cycle progression, apoptosis, and adipogenesis. In differentiation assays, FUS-DDIT3 and YAP1 were found to cooperate in adipogenic differentiation arrest. Conclusions: Our study provides molecular insights into a complex FUS-DDIT3-driven network involving IGF-IR signals acting on Hippo/YAP1, and uncovers cooperative effects of YAP1 and FUS-DDIT3 in the pathogenesis of MLS.

Citation Format: Ruth Berthold, Ilka Isfort, Cihan Erkut, Lorena Heinst, Inga Grünewald, Eva Wardelmann, Thomas Kindler, Pierre Åman, Thomas G.P. Grünewald, Florencia Cidre-Aranaz, Marcel Trautmann, Stefan Fröhling, Claudia Scholl, Wolfgang Hartmann. Fusion protein-driven IGF-IR signals deregulate hippo pathway promoting oncogenic cooperation of YAP1 and FUS-DDIT3 [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr PR004.

Unmasking of Metamizole-Induced Liver Injury by Simultaneous Development of Characteristic Agranulocytosis

BACKGROUND

Metamizole is one of the most used analgesic, antipyretic, and spasmolytic agents in many countries worldwide. While metamizole-induced agranulocytosis is an, albeit seldom, well-known adverse event, metamizole-associated drug-induced liver injury has been reported rarely in the literature and hence often remains unconsidered. Here, we present a unique case where metamizole-induced hepatotoxicity got unmasked by the simultaneous development of characteristic agranulocytosis.

CASE REPORT

A 22-year-old woman without known conditions presented with a new onset of fever, jaundice, and maculopapular rash and explicitly denied intake of any new substances. Laboratory tests showed liver injury, granulopenia, and positive anti-nuclear and anti-mitochondrial (AMA-M2) antibodies. Liver biopsy revealed a histological pattern characteristic for drug-induced liver injury and bone marrow biopsy the classical picture of metamizole-induced agranulocytosis. Indeed, in-depth patient interview unveiled metamizole consumption over the last two months. Therefore, we could diagnose metamizole-induced hepato- and myelotoxicity. Accordingly, steroid therapy led to normalization of liver parameters and stimulation with granulocyte colony stimulating factor to leukocyte recovery.

CONCLUSION

This case report is intended to increase awareness of metamizole-associated drug-induced liver injury which should always be kept in mind due to its sometimes life-threatening course. Diagnosis can be difficult particularly if anamnesis and written records are without hints for prior metamizole intake.

SS18-SSX drives CREB activation in synovial sarcoma

Purpose

Synovial sarcoma (SySa) is a rare soft tissue tumor characterized by a reciprocal t(X;18) translocation. The chimeric SS18-SSX fusion protein represents the major driver of the disease, acting as aberrant transcriptional dysregulator. Oncogenic mechanisms whereby SS18-SSX mediates sarcomagenesis are incompletely understood, and strategies to selectively target SySa cells remain elusive. Based on results of Phospho-Kinase screening arrays, we here investigate the functional and therapeutic relevance of the transcription factor CREB in SySa tumorigenesis.

Methods

Immunohistochemistry of phosphorylated CREB and its downstream targets (Rb, Cyclin D1, PCNA, Bcl-xL and Bcl-2) was performed in a large cohort of SySa. Functional aspects of CREB activity, including SS18-SSX driven circuits involved in CREB activation, were analyzed in vitro employing five SySa cell lines and a mesenchymal stem cell model. CREB mediated transcriptional activity was modulated by RNAi-mediated knockdown and small molecule inhibitors (666-15, KG-501, NASTRp and Ro 31-8220). Anti-proliferative effects of the CREB inhibitor 666-15 were tested in SySa avian chorioallantoic membrane and murine xenograft models in vivo.

Results

We show that CREB is phosphorylated and activated in SySa, accompanied by downstream target expression. Human mesenchymal stem cells engineered to express SS18-SSX promote CREB expression and phosphorylation. Conversely, RNAi-mediated knockdown of SS18-SSX impairs CREB phosphorylation in SySa cells. Inhibition of CREB activity reduces downstream target expression, accompanied by suppression of SySa cell proliferation and induction of apoptosis invitro and in vivo.

Conclusion

In conclusion, our data underline an essential role of CREB in SySa tumorigenesis and provides evidence for molecular targeted therapies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13402-022-00673-w.

Progressive liver, kidney, and heart degeneration in children and adults affected by TULP3 mutations

Organ fibrosis is a shared endpoint of many diseases, yet underlying mechanisms are not well understood. Several pathways governed by the primary cilium, a sensory antenna present on most vertebrate cells, have been linked with fibrosis. Ciliopathies usually start early in life and represent a considerable disease burden. We performed massively parallel sequencing by using cohorts of genetically unsolved individuals with unexplained liver and kidney failure and correlated this with clinical, imaging, and histopathological analyses. Mechanistic studies were conducted with a vertebrate model and primary cells. We detected bi-allelic deleterious variants in TULP3, encoding a critical adaptor protein for ciliary trafficking, in a total of 15 mostly adult individuals, originating from eight unrelated families, with progressive degenerative liver fibrosis, fibrocystic kidney disease, and hypertrophic cardiomyopathy with atypical fibrotic patterns on histopathology. We recapitulated the human phenotype in adult zebrafish and confirmed disruption of critical ciliary cargo composition in several primary cell lines derived from affected individuals. Further, we show interaction between TULP3 and the nuclear deacetylase SIRT1, with roles in DNA damage repair and fibrosis, and report increased DNA damage ex vivo. Transcriptomic studies demonstrated upregulation of profibrotic pathways with gene clusters for hypertrophic cardiomyopathy and WNT and TGF-β signaling. These findings identify variants in TULP3 as a monogenic cause for progressive degenerative disease of major organs in which affected individuals benefit from early detection and improved clinical management. Elucidation of mechanisms crucial for DNA damage repair and tissue maintenance will guide novel therapeutic avenues for this and similar genetic and non-genomic diseases.

Hypertransaminasemia and liver fibrosis associated with haptoglobin retention and anhaptoglobinemia in a paediatric patient

Cryptogenic elevation of transaminases in childhood can in a few instances be linked to rare hereditary causes. In this paper, a 7-year old girl is reported who was diagnosed with elevated transaminases of unknown origin since infancy. A liver biopsy showed bridging fibrosis, pale eosinophilic intracytoplasmic hepatocellular inclusions and enlarged endoplasmic reticulum cisternae in the hepatocytes. Whole-exome sequencing revealed a homozygous in-frame deletion of 3 base pairs in the haptoglobin gene. The patient is anhaptoglobinemic measured by standard laboratory turbidometry, which was confirmed by Western Blotting and thereby shown to affect both protein chains of haptoglobin. A polyclonal antibody revealed haptoglobin retention in hepatocytes suggesting a defect in haptoglobin secretion. A novel, previously unknown haptoglobin storage disease is suspected to be the reason for the elevated liver enzymes and tissue abnormalities in this patient. The pathophysiology appears to be similar to endoplasmic reticulum storage diseases like alpha-1-antitrypsin-deficiency.

Abstract 2003: Oncogenic interplay of FUS-DDIT3 and YAP1 in myxoid liposarcoma

Introduction: Myxoid liposarcoma (MLS) represents the second most common subtype of liposarcoma. MLS is characterized by a chromosomal translocation t(12;16)(q13;p11) encoding a chimeric FUS-DDIT3 fusion gene. The resulting FUS-DDIT3 oncoprotein acts as a transcriptional dysregulator that was recently shown to mediate (i) IGF-IR/PI3K/AKT signaling and (ii) aberrant activation of the Hippo pathway effector YAP1 in MLS. This study was performed to analyze the functional interplay between IGF-IR/PI3K/AKT signals and aberrant YAP1 activity in MLS, aiming at a better functional understanding of MLS and the identification of specific molecular vulnerabilities.

Experimental procedures: Immunohistochemical stainings of IGF-IR, IGF-II and YAP1 were performed in a cohort of MLS specimens (n=45). To study FUS-DDIT3-dependency in vitro, SCP-1 mesenchymal stem cells stably expressing FUS-DDIT3, and MLS cell lines expressing a doxycycline-inducible shRNA against FUS-DDIT3 were employed. Interactions between the IGF-IR/PI3K/AKT and Hippo/YAP1 pathways were investigated using RNAi approaches as well as the small molecule compounds BMS-754807 and BKM120; effects were analyzed by immunoblotting and TEAD luciferase reporter assays. To determine the impact of YAP1 in FUS-DDIT3-mediated oncogenic effects, qPCR analysis and adipogenic differentiation assays were performed.

Results: Immunohistochemical analysis of human MLS tissue specimens demonstrated that expression of IGF-II and IGF-IR is associated with concomitant nuclear expression of YAP1 in a significant subset of MLS. Both, IGF-IR-dependent signals and YAP1 expression were shown to be functionally dependent on FUS-DDIT3. In MLS cell lines, inhibition of the IGF-IR/PI3K/AKT signaling cascade promoted downregulation of YAP1, accompanied by reduced TEAD transcriptional activity. Employing qPCR analyses, YAP1 was shown to co-regulate FUS-DDIT3 transcriptional targets and to be functionally involved in FUS-DDIT3-driven disruption of normal adipocytic differentiation.

Conclusions: Our study provides evidence of a complex regulatory interplay in MLS with FUS-DDIT3-driven IGF-IR/PI3K/AKT signals acting as activators of nuclear YAP1 expression. Conversely, YAP1 contributes to shape FUS-DDIT3 effects on the MLS transcriptional landscape and functionally adds to an immature non-lipogenic phenotype. Our data contribute to the understanding of MLS biology and reveal specific molecular liabilities to be considered in therapeutic approaches of MLS.

Citation Format: Ruth Berthold, Ilka Isfort, Jonas Breuer, Lorena Heinst, Thomas Kindler, Pierre Åman, Inga Grünewald, Eva Wardelmann, Thomas G. Grünewald, Florencia Cidre-Aranaz, Claudia Scholl, Stefan Fröhling, Marcel Trautmann, Wolfgang Hartmann. Oncogenic interplay of FUS-DDIT3 and YAP1 in myxoid liposarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2003.

Expression profiling on subclasses of primary parotid gland carcinomas

INTRODUCTION

The underlying molecular mechanisms of parotid gland carcinomas (PGC) are still unknown. Knowledge about the tumor-driving signaling pathways is necessary either for diagnostics or developing new therapeutic options in this heterogeneous and rare entity.

MATERIAL AND METHODS

94 matching RNA formalin-fixed and paraffin-embedded tissue samples from PGC and the corresponding non-tumor area, RNA quality and quantity were sufficient for gene expression profiling of 770 genes using the NanoString's nCounter technology. Oncogenic and tumor suppressor genes were examined in the three common PGC tumor entities: adenoid cystic carcinoma (ACC), adenocarcinoma NOS (AC-NOS), and mucoepidermoid carcinoma (MEC).

RESULTS

Expression profiling and subsequent hierarchical cluster analysis clearly differentiated between non-tumor gland tissue samples and PGC. In addition expression pattern of all three entities differed. The extensive pathway analysis proved a prominent dysregulation of the Wnt signaling pathway in the three PGC entities. Moreover, transcript upstream analysis demonstrated a pronounced activation of the PI3K pathway in ACC and MEC.

DISCUSSION

Our findings revealed divergent molecular expression profiles in MEC, ACC and AC-NOS that are presently studied for their potential application in PGC diagnostics. Importantly, identification of Wnt and PI3K signaling in PGC revealed novel options of PGC therapy.

ATP7B knockout disturbs copper and lipid metabolism in Caco-2 cells

Intestinal cells control delivery of lipids to the body by adsorption, storage and secretion. Copper (Cu) is an important trace element and has been shown to modulate lipid metabolism. Mutation of the liver Cu exporter ATP7B is the cause of Wilson disease and is associated with Cu accumulation in different tissues. To determine the relationship of Cu and lipid homeostasis in intestinal cells, a CRISPR/Cas9 knockout of ATP7B (KO) was introduced in Caco-2 cells. KO cells showed increased sensitivity to Cu, elevated intracellular Cu storage, and induction of genes regulating oxidative stress. Chylomicron structural protein ApoB48 was significantly downregulated in KO cells by Cu. Apolipoproteins ApoA1, ApoC3 and ApoE were constitutively induced by loss of ATP7B. Formation of small sized lipid droplets (LDs) was enhanced by Cu, whereas large sized LDs were reduced. Cu reduced triglyceride (TG) storage and secretion. Exposure of KO cells to oleic acid (OA) resulted in enhanced TG storage. The findings suggest that Cu represses intestinal TG lipogenesis, while loss of ATP7B results in OA-induced TG storage.

Novel pathogenic alterations in pediatric and adult desmoid-type fibromatosis - A systematic analysis of 204 cases

Desmoid-type fibromatosis (DTF, aggressive fibromatosis) is a non-metastasizing mesenchymal neoplasm of deep soft tissue with a tendency towards local recurrence. Genetic alterations affecting canonical Wnt/β-catenin signaling are reported in the majority of DTF. While most sporadic DTF harbor somatic mutations in CTNNB1, germline mutations in adenomatous polyposis coli (APC) are known to occur in hereditary DTF types (FAP, Gardner-Syndrome). Additional single nucleotide variants (SNVs) in AKT1 (E17K) and BRAF (V600E) were reported in pediatric DTF with potential clinical implications. We performed targeted next-generation sequencing (NGS) in a large cohort of 204 formalin-fixed DTF samples, comprising 22 pediatric cases (patients age ≤18 years). The mutational status was correlated with clinicopathological characteristics. Overall, deleterious CTNNB1 mutations were detected in 89% of DTF, most frequently affecting the serine/threonine phosphorylation sites T41 and S45 of β-catenin. While the T41A CTNNB1 mutation was significantly more often identified in the mesenterial localization, DTF originating from extra-intestinal sites more frequently harbored the S45P CTNNB1 alteration. Beyond common mutations in CTNNB1, additional SNVs were demonstrated in 7% of the DTF cohort and in 18% of the pediatric DTF subgroup. The mutational spectrum included deleterious mutations in AKT1 (G311S/D and T312I), ALK (R806H and G924S), AR (A159T), EGFR (P848L), ERBB2 (H174Y), IDH2 (H354Y), KIT (V559D), RET (T1038A), SDHA (R325M), and SDHD (R115W), as characterized by in silico prediction tools. In conclusion, our study indicates that DTF may harbor a broader mutational spectrum beyond CTNNB1 mutations, comprising targetable alterations including the herewith first reported imatinib-sensitive KIT V559D mutation in DTF.

Radiotherapy of extranodal low-grade follicular and marginal zone lymphomas: long-term follow-up of 159 patients

OBJECTIVE

To evaluate clinical, histopathologic, and radiation (RT) dose parameters in patients with extranodal low-grade (ENLG) non-Hodgkin lymphoma (NHL) and their possible impact on local control (LC) and survival.

MATERIALS AND METHODS

The medical records of 159 patients with 181 histologically confirmed ENLG-NHL lesions treated at our institution were reviewed retrospectively.

RESULTS

The predominant histological subtype (73%) was marginal zone lymphoma (MZL). Common lesion sites were the gastrointestinal tract (GIT; 33%), skin (26%), and orbit (21%). The majority of patients (88%) presented with stage I/II disease. Thirty-three (20%) lesions were treated with reduced-dose RT (≤30.6 Gy) and 148 lesions (80%) with conventional-dose RT (>30.6 Gy), with an overall median dose of 39.6 Gy (range 4-63). The median follow-up period was 72 months. The 10-year local control (LC), Progression-free survival (PFS), and overall survival (OS) rates were 96, 65, and 82%, respectively. Higher overall response rate (ORR; 98% vs. 94%, p = 0.001) and complete response rate (CRR; 95% vs. 73%, p = 0.001) were observed in patients treated with conventional-dose regimens than in those treated with reduced-dose regimens. Ten-year PFS (p = 0.90) and OS (p = 0.40) was similar between the two dose groups. RT was well tolerated in both dose groups, with no grade 4/5 toxicities. In the multivariate analysis, RT dose and timing (upfront or salvage) were related to LC, whereas age, histology, and complete response (CR) to RT were associated with PFS. Patient age and radiation field size impacted OS.

CONCLUSION

RT is an effective and curative local treatment for early-stage FL and MZL at conventional and reduced radiation doses. Conventional-doses seems to be associated with local response improvement, without significant differences in PFS rates. Age, histology, and response to RT may influence the PFS.

Phosphatidylinositol-3-kinase (PI3K)/Akt Signaling is Functionally Essential in Myxoid Liposarcoma

Myxoid liposarcoma (MLS) is an aggressive soft-tissue tumor characterized by a specific reciprocal t(12;16) translocation resulting in expression of the chimeric FUS-DDIT3 fusion protein, an oncogenic transcription factor. Similar to other translocation-associated sarcomas, MLS is characterized by a low frequency of somatic mutations, albeit a subset of MLS has previously been shown to be associated with activating PIK3CA mutations. This study was performed to assess the prevalence of PI3K/Akt signaling alterations in MLS and the potential of PI3K-directed therapeutic concepts. In a large cohort of MLS, key components of the PI3K/Akt signaling cascade were evaluated by next generation seqeuncing (NGS), fluorescence in situ hybridization (FISH), and immunohistochemistry (IHC). In three MLS cell lines, PI3K activity was inhibited by RNAi and the small-molecule PI3K inhibitor BKM120 (buparlisib) in vitro An MLS cell line-based avian chorioallantoic membrane model was applied for in vivo confirmation. In total, 26.8% of MLS cases displayed activating alterations in PI3K/Akt signaling components, with PIK3CA gain-of-function mutations representing the most prevalent finding (14.2%). IHC suggested PI3K/Akt activation in a far larger subgroup of MLS, implying alternative mechanisms of pathway activation. PI3K-directed therapeutic interference showed that MLS cell proliferation and viability significantly depended on PI3K-mediated signals in vitro and in vivo Our preclinical study underlines the elementary role of PI3K/Akt signals in MLS tumorigenesis and provides a molecularly based rationale for a PI3K-targeted therapeutic approach which may be particularly effective in the subgroup of tumors carrying activating genetic alterations in PI3K/Akt signaling components.

Stromal collagen type VI associates with features of malignancy and predicts poor prognosis in salivary gland cancer

PURPOSE

Collagen Type VI (COLVI) is an extracellular matrix protein that is upregulated in various solid tumours during tumour progression and has been shown to stimulate proliferation, suppress apoptosis and promote invasion and metastasis. It has also been described as a mediator of chemotherapy resistance and as a therapeutic target in preclinical cancer models. Here, we aimed to analyse the prognostic role of COLVI in salivary gland cancer (SGC).

METHODS

Stromal COLVI protein expression was assessed in primary SGC specimens of 91 patients using immunohistochemistry (IHC). The IHC expression patterns obtained were subsequently correlated with various survival and clinicopathological features, including Ki-67 and p53 expression.

RESULTS

We found that COLVI was expressed in all SGC specimens. High expression was found to be associated with features of malignancy such as high histologic grades, advanced and invasive T stages and metastatic lymph node involvement (p < 0.05 for all variables). COLVI expression was also found to correlate with both Ki-67 and p53 expression (p < 0.01). We found that high COLVI expression predicted a significantly inferior 5-year overall survival (38.3%, 55.1% and 93.8%; p = 0.002) and remained a significant predictor of prognosis in a multivariate Cox regression analysis (hazard ratio, 2.62; 95% confidence interval, 1.22-5.61; p = 0.013). In all low-risk subgroups COLVI expression identified patients with an adverse outcome. Patients receiving adjuvant radiotherapy had a poor survival when expressing high levels of COLVI.

CONCLUSIONS

Our data indicate that stromal COLVI expression associates with key features of malignancy, represents a novel independent prognostic factor and may affect response to radiotherapy in SGC. Although our results warrant validation in an independent cohort, assessing stromal COLVI expression may be suitable for future diagnostic and therapeutic decision making in patients with SGC.

AAA+ ATPases Reptin and Pontin as potential diagnostic and prognostic biomarkers in salivary gland cancer - a short report

PURPOSE

Salivary gland cancer (SGC) is a rare and heterogeneous disease with significant differences in recurrence and metastasis characteristics. As yet, little is known about the mechanisms underlying the initiation and/or progression of these diverse tumors. In recent years, the AAA+ ATPase family members Pontin (RuvBL1, Tip49a) and Reptin (RuvBL2, Tip49b) have been implicated in various processes, including transcription regulation, chromatin remodeling and DNA damage repair, that are frequently deregulated in cancer. The aim of this study was to assess the clinical and functional significance of Reptin and Pontin expression in SGC.

METHODS

Immunohistochemical staining of Pontin, Reptin, β-catenin, Cyclin D1, TP53 and MIB-1 was performed on a collection of 94 SGC tumor samples comprising 13 different histological subtypes using tissue microarrays.

RESULTS

We found that Reptin and Pontin were expressed in the majority of SGC samples across all histological subtypes. Patients with a high Reptin expression showed a significantly inferior 5-year overall survival rate compared to patients with a low Reptin expression (47.7% versus 78.3%; p = 0.033), whereas no such difference was observed for Pontin. A high Reptin expression strongly correlated with a high expression of the proliferation marker MIB-1 (p = 0.003), the cell cycle regulator Cyclin D1 (p = 0.006), accumulation of TP53 as a surrogate p53 mutation marker (p = 0.042) and cytoplasmic β-catenin expression (p = 0.002). Increased Pontin expression was found to significantly correlate with both cytoplasmic and nuclear β-catenin expression (p = 0.037 and p = 0.018, respectively), which is indicative for its oncogenic function.

CONCLUSIONS

Our results suggest a role of Reptin and Pontin in SGC tumor progression and/or patient survival. Therefore, SGC patients exhibiting a high Reptin expression may benefit from more aggressive therapeutic regimens. Future studies should clarify whether such patients may be considered for more radical surgery, extended adjuvant therapy and/or targeted therapy.

MDM2 and CDK4 amplifications are rare events in salivary duct carcinomas

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands associated with poor clinical outcome. SDCs are known to carry TP53 mutations in about 50%, however, only little is known about alternative pathogenic mechanisms within the p53 regulatory network. Particularly, data on alterations of the oncogenes MDM2 and CDK4 located in the chromosomal region 12q13-15 are limited in SDC, while genomic rearrangements of the adjacent HMGA2 gene locus are well documented in subsets of SDCs. We here analyzed the mutational status of the TP53 gene, genomic amplification of MDM2, CDK4 and HMGA2 rearrangement/amplification as well as protein expression of TP53 (p53), MDM2 and CDK4 in 51 de novo and ex pleomorphic adenoma SDCs.

25 of 51 cases were found to carry TP53 mutations, associated with extreme positive immunohistochemical p53 staining levels in 13 cases. Three out of 51 tumors had an MDM2 amplification, one of them coinciding with a CDK4 amplification and two with a HMGA2 rearrangement/amplification. Two of the MDM2 amplifications occurred in the setting of a TP53 mutation. Two out of 51 cases showed a CDK4 amplification, one synchronously being MDM2 amplified and the other one displaying concurrent low copy number increases of both, MDM2 and HMGA2.

In summary, we here show that subgroups of SDCs display genomic amplifications of MDM2 and/or CDK4, partly in association with TP53 mutations and rearrangement/amplification of HMGA2. Further research is necessary to clarify the role of chromosomal region 12q13-15 alterations in SDC tumorigenesis and their potential prognostic and therapeutic relevance.

Expression of PSMA in tumor neovasculature of high grade sarcomas including synovial sarcoma, rhabdomyosarcoma, undifferentiated sarcoma and MPNST

AIMS

PSMA (prostate specific membrane antigen) is physiologically expressed in normal prostate tissue. It is overexpressed in prostate cancer cells and has been suggested as a target for antibody-based radioligand therapy. As PSMA expression so far has not been systematically analyzed in soft tissue tumors, the current study aims at investigating a large cohort of different subtypes.

METHODS AND RESULTS

Immunohistochemistry was used to detect PSMA expression in 779 samples of soft tissue tumors and Ewing sarcoma as a primary bone malignancy. CD34 coexpression was employed to study PSMA expression in the neovasculature. PSMA expression was found in the tumor-associated neovasculature of 151/779 soft tissue/bone tumors (19.38%) and was more frequent in malignant tumors compared to tumors with intermediate or benign biological potential (p=0.078). Strong neovascular PSMA expression was predominantly observed in subsets of different sarcomas including 3/20 rhabdomyosarcomas (15%), 4/21 malignant peripheral nerve sheath tumors (19.05%), 6/16 synovial sarcomas (35.29%) and 6/33 undifferentiated pleomorphic sarcomas (18.18%).

CONCLUSION

We conclude that PSMA is expressed in the neovasculature of a subset of soft tissue tumors to a variable extent. Our observation of strong PSMA expression predominantly occurring in sarcomas might provide a rationale to evaluate PSMA-targeted radioligand therapy in these entities.

Abstract B04: Functional characterization of IGF-IR/PI3K/Akt signaling in myxoid liposarcoma

Introduction: Myxoid liposarcoma (MLS) is the second most common type of liposarcoma and an aggressive disease with particular propensity to develop hematogenic metastases. Ninety percent of MLS are characterized by a reciprocal translocation t(12;16) (q13;p11), leading to the pathogenic gene fusion of FUS and DDIT3. The resulting chimeric FUS-DDIT3 fusion protein is suggested to play a crucial role in MLS pathogenesis, although the specific mechanism of action remains to be substantiated. Aiming at the preclinical identification of novel therapeutic options, we here investigate the functional relevance of FUS-DDIT3 in IGF-IR/PI3K/Akt signal transduction.

Experimental Procedures: Immunohistochemical analyses of IGF-IR/PI3K/Akt signaling effectors and modulators were performed in a comprehensive cohort of clinical MLS specimens. FUS-DDIT3-dependent activation of the IGF-IR/PI3K/Akt signaling cascade was analyzed by siRNA and immunoblotting in vitro. Cell proliferation and FACS assays were performed in multiple tumor-derived MLS cell lines. An established MLS chorioallantoic membrane model (CAM) was employed for in vivo confirmation of the preclinical in vitro data.

Results: In a significant subset of MLS specimens, immunohistochemical staining revealed elevated phosphorylation levels of various signaling components, representing a strong indication of activated IGF-IR/PI3K/Akt signaling to be a frequent feature in MLS. IGF-IR inhibition significantly suppressed the IGF-IR/PI3K/Akt signaling cascade, associated with impairment of MLS cell viability and induction of apoptosis in vitro and in vivo. Furthermore, siRNA-mediated knockdown of FUS-DDIT3 led to dephosphorylation of IGF-IR/PI3K/Akt signaling components, implying that the FUS-DDIT3 fusion protein is involved in the IGF-IR regulated signaling cascade.

Conclusions: Our preclinical study emphasizes the pivotal role of the IGF-IR/PI3K/Akt signaling pathway in MLS pathogenesis and indicates its functional dependence on the MLS-specific FUS-DDIT3 fusion protein. Furthermore, our in vitro and in vivo results demonstrate that targeting the IGF-IR/PI3K/Akt signaling pathway provides a rational, molecularly founded therapeutic strategy in the treatment of MLS.

Citation Format: Marcel Trautmann, Magdalene Alice Cyra, Christian Bertling, Ilka Isfort, Jasmin Menzel, Konrad Steinestel, Inga Grünewald, Bianca Altvater, Claudia Rossig, Pierre Åman, Eva Wardelmann, Sebastian Huss, Wolfgang Hartmann. Functional characterization of IGF-IR/PI3K/Akt signaling in myxoid liposarcoma [abstract]. In: Proceedings of the AACR Conference on Advances in Sarcomas: From Basic Science to Clinical Translation; May 16-19, 2017; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(2_Suppl):Abstract nr B04.

Spatial investigation of the elemental distribution in Wilson's disease liver after d-penicillamine treatment by LA-ICP-MS

At present, the copper chelator d-penicillamine (DPA) is the first-line therapy of Wilson's disease (WD), which is characterized by an excessive copper overload. Lifelong DPA treatments aim to reduce the amount of detrimental excess copper retention in the liver and other organs. Although DPA shows beneficial effect in many patients, it may cause severe adverse effects. Despite several years of copper chelation therapy, discontinuation of DPA therapy can be linked to a rapidly progressing liver failure, indicating a high residual liver copper load. In order to investigate the spatial distribution of remaining copper and additional elements, such as zinc and iron, in rat and human liver samples after DPA treatment, a high resolution (spotsize of 10μm) laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging method was applied. Untreated LPP^-/- rats, an established animal model for WD, appeared with a high overall copper concentration and a copper distribution of hotspots distributed over the liver tissue. In contrast, a low (>2-fold decreased) overall copper concentration was detected in liver of DPA treated animals. Importantly, however, copper distribution was highly inhomogeneous with lowest concentrations in direct proximity to blood vessels, as observed using novel zonal analysis. A human liver needle biopsy of a DPA treated WD patient substantiated the finding of an inhomogeneous copper deposition upon chelation therapy. In contrast, comparatively homogenous distributions of zinc and iron were observed. Our study indicates that a high resolution LA-ICP-MS analysis of liver samples is excellently suited to follow efficacy of chelator therapy in WD patients.

Abstract B04: Oncogenic relevance of IGF-IR and PI3K/AKT/GSK3-beta signaling in myxoid liposarcoma

Introduction: Myxoid liposarcoma (MLS) accounts for 30-35% of all LS cases and is the second most common type of liposarcoma. One third of MLS lesions will become metastatic with tumors spreading to unusual bone and soft tissue locations. Ninety percent of MLS are characterized by a specific reciprocal translocation t (12; 16) (q13; p11), leading to the pathogenic gene fusion of FUS and DDIT3. The resulting chimeric FUS-DDIT3 fusion protein is suggested to play a crucial role in MLS pathogenesis, although the specific biological function and the mechanism of action remain to be defined. Aiming at the preclinical identification of novel therapeutic options in vitro and in vivo, we investigate the functional relevance of IGF-IR and PI3K/AKT/GSK3-beta signaling in primary MLS and tumor-derived cell lines.

Methods: Immunohistochemical analyses of IGF-IR and PI3K/AKT/GSK3-beta signaling effectors and modulators were performed in a comprehensive cohort of primary MLS specimens. FUS-DDIT3-dependent activation of the PI3K/AKT/GSK3-beta signaling cascade was analyzed by siRNA knockdown experiments and protein immunoblotting in vitro. Cell proliferation and FACS assays were performed in two different MLS cell lines. An in vivo tumor model was successfully established performing the chicken chorioallantoic membrane (CAM) assay.

Results: In a significant subset of MLS specimens, immunohistochemical staining revealed elevated phosphorylation levels of the respective signaling components, indicating that activated IGF-IR and PI3K/AKT/GSK3-beta signaling is a frequent feature in MLS. IGF-IR inhibition significantly suppressed the PI3K/AKT/GSK3-beta downstream cascade, associated with reduced phosphorylation levels of several signaling components, impairment of MLS cell viability and induction of apoptosis in vitro and in vivo. Furthermore, siRNA-mediated knockdown of FUS-DDIT3 lead to dephosphorylation of PI3K/AKT/GSK3-beta signaling components, implying that the FUS-DDIT3 fusion protein is involved in the IGF-IR regulated signaling cascade.

Conclusion: Our study emphasizes the pivotal role of IGF-IR and PI3K/AKT/GSK3-beta signaling in MLS pathogenesis and indicates its functional dependence on the characteristic FUS-DDIT3 fusion protein. Furthermore, our in vitro and in vivo results demonstrate that targeting the IGF-IR and PI3K/AKT/GSK3-beta signaling pathway might provide a specific, molecular founded therapeutic strategy in the treatment of MLS.

Citation Format: Marcel Trautmann, Christian Bertling, Jasmin Menzel, Magdalene Cyra, Konrad Steinestel, Inga Grünewald, Pierre Åman, Eva Wardelmann, Sebastian Huss, Wolfgang Hartmann. Oncogenic relevance of IGF-IR and PI3K/AKT/GSK3-beta signaling in myxoid liposarcoma [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr B04.

Abstract B05: Myxoid liposarcoma: A molecular and clinicopathological analysis by targeted next-generation sequencing and fluorescence in situ hybridization

Introduction: Myxoid liposarcoma (MLS) is the second most common type of liposarcoma, accounting for 30-35% of all LS cases. Over 90% of tumors are characterized by a reciprocal translocation t (12; 16) (q13; p11), resulting in a pathogenic gene fusion. The chimeric FUS-DDIT3 fusion protein is suggested to play a crucial role in MLS tumorigenesis and progression, although the specific biological function and the mechanism of action remain to be defined. We compiled a comprehensive cohort of 105 well-characterized MLS tissue specimens to identify actionable genetic aberrations.

Methods: Targeted next-generation sequencing (NGS) using the Illumina MiSeq platform was performed to examine the mutational status of 23 cancer-related genes (covering all exons) known to be frequently mutated across various neoplasms. Furthermore, we examined the amplification/deletion status and characterized the specific chromosomal FUS-DDIT3 rearrangements by FISH and RT-PCR. A multivariate analysis was conducted to investigate the prognostic significance of mutation/amplification/deletion status.

Results: Targeted next-generation sequencing drives the potential to generate comprehensive genetic information including less frequent mutated genes relevant for actionable treatments and prognostic assessment. Besides PIK3CA, six additional genes showed at least five mutations, including AKT1, CTNNB1, EGFR, ERBB2, MET and PTEN. Several oncogenic mutations were detected which have not been reported in MLS previously. We demonstrated several gene amplification/deletion events in MLS.

Conclusion: Our results indicate the occurrence of mutational aberrations besides the chromosomal FUS-DDIT3 hallmark. These appear not to be related to specific subtypes of FUS-DDIT3 fusion transcripts in terms of a molecular pattern. Molecular screening for actionable mutations might represent a rational tool for the implementation of innovative targeted therapeutic approaches in MLS. To our best knowledge, this study is the most extensive one to yield a detailed map of actionable genetic aberrations across a comprehensive cohort of &gt;100 well-characterized MLS tissue specimens. Moreover, it reveals several molecular alteration-specific targets for innovative therapy strategies.

Citation Format: Marcel Trautmann, Arne Krüger, Birte Jeiler, Christian Bertling, Jasmin Menzel, Magdalene Cyra, Konrad Steinestel, Inga Grünewald, Pierre Åman, Eva Wardelmann, Sebastian Huss, Wolfgang Hartmann. Myxoid liposarcoma: A molecular and clinicopathological analysis by targeted next-generation sequencing and fluorescence in situ hybridization [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr B05.

Abstract 2703: Extraskeletal myxoid chondrosarcoma: a clinicopathologic and molecular study reveals novel genetic aberrations by targeted next-generation sequencing

Background: Extraskeletal myxoid chondrosarcomas (EMCs) are rare mesenchymal neoplasms comprising approx. 3% of all soft tissue tumors. EMCs arise mainly from the deep soft tissues of the extremities, accompanied with high rates of recurrence and metastases. The molecular hallmarks of EMCs are various cytogenetic NR4A3 rearrangements, generating chimeric -NR4A3 proteins. The most common reciprocal translocation t(9;22)(q22;q12), results in a fusion of the EWS RNA-binding protein 1 gene (EWSR1) to the nuclear receptor subfamily 4, group A, member 3 gene (NR4A3 or TEC; approximately 75% of cases). Further cytogenetic t(9;17)(q22;q11) rearrangements involve TAF15 RNA polymerase II, TATA box binding protein (TBP)-associated factor (TAF15; approximately 15% of cases). The less frequent reciprocal translocations t(9;15)(q22;q21) and t(9;3)(q22;q12), result in transcription factor 12 (TCF12)-NR4A3 and TRK-fused gene (TFG)-NR4A3 fusion proteins. Although the oncogenic -NR4A3 fusion transcripts seem to have a crucial role in EMC tumorigenesis and progression, the specific biological function and the mechanism of action remain to be defined.

Methods: We characterized the cytogenetic rearrangements of 25 comprehensive EMC tumors by RT-PCR and/or fluorescence in situ hybridization (FISH). Next generation sequencing (NGS) was performed (Illumina MiSeq platform) to reveal additional genetic alterations besides the known chromosomal translocation. Therefore, a comprehensive cancer panel was designed, comprising 27 cancer-related genes known to be frequently mutated across various malignancies.

Results: Overall, fusion transcripts were detected in 22 of 25 samples (88%). Sixteen were positive for the EWSR1-NR4A3 and six for the TAF15-NR4A3 fusion gene. The t(9;15) and t(9;3) translocations, resulting in TCF12-NR4A3 and TFG-NR4A3 fusion proteins were not identified in any EMC case. In Addition, several known oncogenic mutations were detected which have not been previously reported in EMC.

Conclusions: The combination of RT-PCR and FISH on paraffin-embedded tissue is a sensitive and specific method for the molecular detection of the pathogenic translocations to be applied in the differential diagnosis of extraskeletal myxoid chondrosarcomas. Our results emphasize that cytogenetic NR4A3 rearrangements are the initiating events in the pathogenesis of EMC. Furthermore, our results indicate the occurrence of additional genetic aberrations providing a rational base for novel targeted therapeutic approaches.

Citation Format: Marcel Trautmann, Magdalene Cyra, Ilka Isfort, Inga Grünewald, Konrad Steinestel, Sebastian Huss, Reinhard Büttner, Eva Wardelmann, Wolfgang Hartmann. Extraskeletal myxoid chondrosarcoma: a clinicopathologic and molecular study reveals novel genetic aberrations by targeted next-generation sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2703. doi:10.1158/1538-7445.AM2017-2703

Expression and clinical significance of MAGE and NY-ESO-1 cancer-testis antigens in adenoid cystic carcinoma of the head and neck

BACKGROUND

Adenoid cystic carcinoma (ACC) of the head and neck is a rare but highly malignant tumor. Cancer-testis antigens (CTAs) represent an immunogenic family of cancer-specific proteins and thus represent an attractive target for immunotherapy.

METHODS

Eighty-four cases of ACC were identified, the CTAs pan-Melanoma antigen (pan-MAGE; M3H67) and New York esophageal squamous cell carcinoma (NY-ESO-1; E978) were detected immunohistochemically (IHC) and correlated with clinical data.

RESULTS

Expression of NY-ESO-1 was found in 48 of 84 patients (57.1%) and of pan-MAGE in 28 of 84 patients (31.2%). Median overall survival (OS) in NY-ESO-1 positive versus negative patients was 130.8 and 282.0 months (p = .223), respectively. OS in pan-MAGE positive versus negative patients was 105.3 and 190.5 months, respectively (p = .096). Patients expressing both NY-ESO-1 and pan-MAGE simultaneously had significantly reduced OS with a median of 90.5 months compared with 282.0 months in negative patients (p = .047).

CONCLUSION

A significant fraction of patients with ACC show expression of the CTAs NY-ESO-1 and/or pan-MAGE with promising immunotherapeutic implications. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1008-1016, 2016.

PD-1 and PD-L1 Expression in NSCLC Indicate a Favorable Prognosis in Defined Subgroups

BACKGROUND

Immunotherapy can become a crucial therapeutic option to improve prognosis for lung cancer patients. First clinical trials with therapies targeting the programmed cell death receptor PD-1 and its ligand PD-L1 have shown promising results in several solid tumors. However, in lung cancer the diagnostic, prognostic and predictive value of these immunologic factors remains unclear.

METHOD

The impact of both factors was evaluated in a study collective of 321 clinically well-annotated patients with non-small lung cancer (NSCLC) using immunohistochemistry.

RESULTS

PD-1 expression by tumor infiltrating lymphocytes (TILs) was found in 22%, whereas tumor cell associated PD-L1 expression was observed in 24% of the NSCLC tumors. In Fisher's exact test a positive correlation was found for PD-L1 and Bcl-xl protein expression (p = 0.013). Interestingly, PD-L1 expression on tumor cells was associated with improved overall survival in pulmonary squamous cell carcinomas (SCC, p = 0.042, log rank test), with adjuvant therapy (p = 0.017), with increased tumor size (pT2-4, p = 0.039) and with positive lymph node status (pN1-3, p = 0.010). These observations were confirmed by multivariate cox regression models.

CONCLUSION

One major finding of our study is the identification of a prognostic implication of PD-L1 in subsets of NSCLC patients with pulmonary SCC, with increased tumor size, with a positive lymph node status and NSCLC patients who received adjuvant therapies. This study provides first data for immune-context related risk stratification of NSCLC patients. Further studies are necessary both to confirm this observation and to evaluate the predictive value of PD-1 and PD-L1 in NSCLC in the context of PD-1 inhibition.

Targeting interleukin-2 to the bone marrow stroma for therapy of acute myeloid leukemia relapsing after allogeneic hematopoietic stem cell transplantation

The antibody-based delivery of IL2 to extracellular targets expressed in the easily accessible tumor-associated vasculature has shown potent antileukemic activity in xenograft and immunocompetent murine models of acute myelogenous leukemia (AML), especially in combination with cytarabine. Here, we report our experience with 4 patients with relapsed AML after allogeneic hematopoietic stem cell transplantation (allo-HSCT), who were treated with the immunocytokine F16-IL2, in combination with low-dose cytarabine. One patient with disseminated extramedullary AML lesions achieved a complete metabolic response identified by PET/CT, which lasted 3 months. Two of 3 patients with bone marrow relapse achieved a blast reduction with transient molecular negativity. One of the 2 patients enjoyed a short complete remission before AML relapse occurred 2 months after the first infusion of F16-IL2. In line with a site-directed delivery of the cytokine, F16-IL2 led to an extensive infiltration of immune effector cells in the bone marrow. Grade 2 fevers were the only nonhematologic side effects in 2 patients. Grade 3 cytokine-release syndrome developed in the other 2 patients but was manageable in both cases with glucocorticoids. The concept of specifically targeting IL2 to the leukemia-associated stroma deserves further evaluation in clinical trials, especially in patients who relapse after allo-HSCT.

Comparison of high resolution melting analysis, pyrosequencing, next generation sequencing and immunohistochemistry to conventional Sanger sequencing for the detection of p.V600E and non-p.V600E BRAF mutations

Background

The approval of vemurafenib in the US 2011 and in Europe 2012 improved the therapy of not resectable or metastatic melanoma. Patients carrying a substitution of valine to glutamic acid at codon 600 (p.V600E) or a substitution of valine to leucine (p.V600K) in BRAF show complete or partial response. Therefore, the precise identification of the underlying somatic mutations is essential. Herein, we evaluate the sensitivity, specificity and feasibility of six different methods for the detection of BRAF mutations.

Methods

Samples harboring p.V600E mutations as well as rare mutations in BRAF exon 15 were compared to wildtype samples. DNA was extracted from formalin-fixed paraffin-embedded tissues by manual micro-dissection and automated extraction. BRAF mutational analysis was carried out by high resolution melting (HRM) analysis, pyrosequencing, allele specific PCR, next generation sequencing (NGS) and immunohistochemistry (IHC). All mutations were independently reassessed by Sanger sequencing. Due to the limited tumor tissue available different numbers of samples were analyzed with each method (82, 72, 60, 72, 49 and 82 respectively).

Results

There was no difference in sensitivity between the HRM analysis and Sanger sequencing (98%). All mutations down to 6.6% allele frequency could be detected with 100% specificity. In contrast, pyrosequencing detected 100% of the mutations down to 5% allele frequency but exhibited only 90% specificity. The allele specific PCR failed to detect 16.3% of the mutations eligible for therapy with vemurafenib. NGS could analyze 100% of the cases with 100% specificity but exhibited 97.5% sensitivity. IHC showed once cross-reactivity with p.V600R but was a good amendment to HRM.

Conclusion

Therefore, at present, a combination of HRM and IHC is recommended to increase sensitivity and specificity for routine diagnostic to fulfill the European requirements concerning vemurafenib therapy of melanoma patients.

Paroxetine as antidepressant in combined antidepressant-neuroleptic therapy in delusional depression: observation of clinical use

The combination of antidepressive and antipsychotic (neuroleptic) medication is often used in the psychopharmacological treatment of delusional depression. In most studies of the treatment of delusional depression, tricyclic antidepressants have been used, and very little has been written about experience with SSRIs such as fluvoxamine, fluoxetine, or paroxetine. This paper therefore presents the preliminary findings of an open clinical study in which 14 delusional depressed inpatients, consecutively admitted to our Depression Unit, were given paroxetine combined with either zotepine or haloperidol. It was possible to observe a significantly impressive decline in the HAMD (24-item version) total score, of so-called delusional items (HAMD subscore of items 2, 17, 18, 20, 23, 24) and of the subscore of remaining HAMD items over 21 treatment days. There were no unusual side-effects.