Overall survival and central nervous system activity of crizotinib in ROS1-rearranged lung cancer-final results of the EUCROSS trial

BACKGROUND

In 2019, we reported the first efficacy and safety analysis of EUCROSS, a phase II trial investigating crizotinib in ROS1 fusion-positive lung cancer. At that time, overall survival (OS) was immature and the effect of crizotinib on intracranial disease control remained unclear. Here, we present the final analysis of OS, systemic and intracranial activity, and the impact of co-occurring aberrations.

MATERIALS AND METHODS

EUCROSS was a prospective, single-arm, phase II trial. The primary endpoint was best overall response rate (ORR) using RECIST 1.1. Secondary and exploratory endpoints were progression-free survival (PFS), OS, and efficacy in pre-defined subgroups.

RESULTS

Median OS of the intention-to-treat population (N = 34) was 54.8 months [95% confidence interval (CI) 20.3 months-not reached (NR); median follow-up 81.4 months] and median all-cause PFS of the response-evaluable population (N = 30) was 19.4 months (95% CI 10.1-32.2 months). Time on treatment was significantly correlated with OS (R = 0.82; P < 0.0001). Patients with co-occurring TP53 aberrations (28%) had a significantly shorter OS [hazard ratio (HR) 11; 95% CI 2.0-56.0; P = 0.006] and all-cause PFS (HR 4.2; 95% CI 1.2-15; P = 0.025). Patients with central nervous system (CNS) involvement at baseline (N = 6; 20%) had a numerically shorter median OS and all-cause PFS. Median intracranial PFS was 32.2 months (95% CI 23.7 months-NR) and the rate of isolated CNS progression was 24%.

CONCLUSIONS

Our final analysis proves the efficacy of crizotinib in ROS1-positive lung cancer, but also highlights the devastating impact of TP53 mutations on survival and treatment efficacy. Additionally, our data show that CNS disease control is durable and the risk of CNS progression while on crizotinib treatment is low.

Deregulation and epigenetic modification of BCL2-family genes cause resistance to venetoclax in hematologic malignancies

The BCL2 inhibitor venetoclax has been approved to treat different hematological malignancies. Because there is no common genetic alteration causing resistance to venetoclax in chronic lymphocytic leukemia (CLL) and B-cell lymphoma, we asked if epigenetic events might be involved in venetoclax resistance. Therefore, we employed whole-exome sequencing, methylated DNA immunoprecipitation sequencing, and genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 screening to investigate venetoclax resistance in aggressive lymphoma and high-risk CLL patients. We identified a regulatory CpG island within the PUMA promoter that is methylated upon venetoclax treatment, mediating PUMA downregulation on transcript and protein level. PUMA expression and sensitivity toward venetoclax can be restored by inhibition of methyltransferases. We can demonstrate that loss of PUMA results in metabolic reprogramming with higher oxidative phosphorylation and adenosine triphosphate production, resembling the metabolic phenotype that is seen upon venetoclax resistance. Although PUMA loss is specific for acquired venetoclax resistance but not for acquired MCL1 resistance and is not seen in CLL patients after chemotherapy-resistance, BAX is essential for sensitivity toward both venetoclax and MCL1 inhibition. As we found loss of BAX in Richter's syndrome patients after venetoclax failure, we defined BAX-mediated apoptosis to be critical for drug resistance but not for disease progression of CLL into aggressive diffuse large B-cell lymphoma in vivo. A compound screen revealed TRAIL-mediated apoptosis as a target to overcome BAX deficiency. Furthermore, antibody or CAR T cells eliminated venetoclax resistant lymphoma cells, paving a clinically applicable way to overcome venetoclax resistance.

KS02.7.A Impact of FET PET on multidisciplinary neurooncological tumor board decisions in patients with brain tumors

Background

Following neurooncological treatment of brain tumors, neurooncologists are often confronted with equivocal MRI findings (e.g., treatment-related changes such as pseudoprogression, non-measurable contrast-enhancing lesions, T2/FLAIR signal alterations, pseudoresponse). Especially in Europe, amino-acid PET is increasingly integrated into multidisciplinary neurooncological tumor boards (MNTB) to overcome these diagnostic uncertainties. We evaluated the correctness of MNTB decisions, in which amino acid PET findings were taken into account.

Material and Methods

In a single-university center study, we retrospectively evaluated 182 MNTB decisions of 154 patients with histomolecularly defined WHO grade 3 or 4 gliomas (n=123), including glioblastoma (n=80), anaplastic glioma (n=42), and gliosarcoma (n=1), or brain metastases (n=31) secondary to lung cancer, melanoma, breast cancer, or colorectal cancer presenting equivocal MRI findings following anticancer treatment. All patients underwent O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET imaging as an adjunct for decision-making. Additionally, the patients’ clinical status, pretreatment, and conventional MRI findings were considered for decision-making. The presence of neoplastic tissue was considered if the mean FET uptake as assessed by tumor-to-brain ratios was &gt; 2.0. MNTB decisions were validated using the neuropathological result in 42% (n=77) or clinicoradiologically in 58% (n=105). The diagnostic performance of MTNB decisions was evaluated using 2x2 contingency tables.

Results

The validation of all 182 MNTB recommendations, which integrated FET PET in the decision-making process, were correct in 95% (sensitivity, 97%; specificity, 75%; positive predictive value, 96%). Due to tumor progression, MNTB recommendations prompted a treatment change in 88% (n=160 of 182 decisions). When FET PET findings suggested progressive disease (n=157), MNTB decisions were correct in 96% (positive predictive value, 97%). In 22 MNTB decisions with the recommendation to continue the current treatment regimen, 82% were correctly identified as treatment-related changes.

Conclusion

FET PET seems to have a significant impact on MNTB decisions. A prospective evaluation of MNTB decisions with and without the integration of FET PET is warranted to define the added value of FET PET.

European experts consensus: BRCA/homologous recombination deficiency testing in first-line ovarian cancer

BACKGROUND

Homologous recombination repair (HRR) enables fault-free repair of double-stranded DNA breaks. HRR deficiency is predicted to occur in around half of high-grade serous ovarian carcinomas. Ovarian cancers harbouring HRR deficiency typically exhibit sensitivity to poly-ADP ribose polymerase inhibitors (PARPi). Current guidelines recommend a range of approaches for genetic testing to identify predictors of sensitivity to PARPi in ovarian cancer and to identify genetic predisposition.

DESIGN

To establish a European-wide consensus for genetic testing (including the genetic care pathway), decision making and clinical management of patients with recently diagnosed advanced ovarian cancer, and the validity of biomarkers to predict the effectiveness of PARPi in the first-line setting. The collaborative European experts' consensus group consisted of a steering committee (n = 14) and contributors (n = 84). A (modified) Delphi process was used to establish consensus statements based on a systematic literature search, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

RESULTS

A consensus was reached on 34 statements amongst 98 caregivers (including oncologists, pathologists, clinical geneticists, genetic researchers, and patient advocates). The statements concentrated on (i) the value of testing for BRCA1/2 mutations and HRR deficiency testing, including when and whom to test; (ii) the importance of developing new and better HRR deficiency tests; (iii) the importance of germline non-BRCA HRR and mismatch repair gene mutations for predicting familial risk, but not for predicting sensitivity to PARPi, in the first-line setting; (iv) who should be able to inform patients about genetic testing, and what training and education should these caregivers receive.

CONCLUSION

These consensus recommendations, from a multidisciplinary panel of experts from across Europe, provide clear guidance on the use of BRCA and HRR deficiency testing for recently diagnosed patients with advanced ovarian cancer.

Impact of TP53 mutation status on systemic treatment outcome in ALK-rearranged non-small-cell lung cancer

Background

We analyzed whether co-occurring mutations influence the outcome of systemic therapy in ALK-rearranged non-small-cell lung cancer (NSCLC).

Patients and methods

ALK-rearranged stage IIIB/IV NSCLC patients were analyzed with next-generation sequencing and fluorescence in situ hybridization analyses on a centralized diagnostic platform. Median progression-free survival (PFS) and overall survival (OS) were determined in the total cohort and in treatment-related sub-cohorts. Cox regression analyses were carried out to exclude confounders.

Results

Among 216 patients with ALK-rearranged NSCLC, the frequency of pathogenic TP53 mutations was 23.8%, while other co-occurring mutations were rare events. In ALK/TP53 co-mutated patients, median PFS and OS were significantly lower compared with TP53 wildtype patients [PFS 3.9 months (95% CI: 2.4–5.6) versus 10.3 months (95% CI: 8.6–12.0), P < 0.001; OS 15.0 months (95% CI: 5.0–24.9) versus 50.0 months (95% CI: 22.9–77.1), P = 0.002]. This difference was confirmed in all treatment-related subgroups including chemotherapy only [PFS first-line chemotherapy 2.6 months (95% CI: 1.3–4.1) versus 6.2 months (95% CI: 1.8–10.5), P = 0.021; OS 2.0 months (95% CI: 0.0–4.6) versus 9.0 months (95% CI: 6.1–11.9), P = 0.035], crizotinib plus chemotherapy [PFS crizotinib 5.0 months (95% CI: 2.9–7.2) versus 14.0 months (95% CI: 8.0–20.1), P < 0.001; OS 17.0 months (95% CI: 6.7–27.3) versus not reached, P = 0.049] and crizotinib followed by next-generation ALK-inhibitor [PFS next-generation inhibitor 5.4 months (95% CI: 0.1–10.7) versus 9.9 months (95% CI: 6.4–13.5), P = 0.039; OS 7.0 months versus 50.0 months (95% CI: not reached), P = 0.001).

Conclusions

In ALK-rearranged NSCLC co-occurring TP53 mutations predict an unfavorable outcome of systemic therapy. Our observations encourage future research to understand the underlying molecular mechanisms and to improve treatment outcome of the ALK/TP53 co-mutated subgroup.

[Hereditary colon cancer in Lynch syndrome/HNPCC syndrome in Germany]

BACKGROUND

Hereditary nonpolyposis colorectal cancer (Lynch/HNPCC syndrome) is based on a germline mutation inducing increased occurrence of colorectal cancer and extracolonic carcinomas in young age. The German HNPCC consortium aims to increase awareness for detection of hereditary colon cancer among patients and physicians.

OBJECTIVES

Reliable detection of HNPCC patients is based on a thorough documentation of patients' medical history and on further diagnostics delivered by human genetics and surgical pathology. This manuscript presents a standardized diagnostic concept.

METHODS

Relevant literature is reviewed and discussed and diagnostic parameters are outlined. In addition, operating figures of the German HNPCC consortium are presented.

RESULTS

The German HNPCC consortium is based on an efficient cooperation between clinical physicians, human geneticists, and surgical pathologists. After a funding period from the Deutsche Krebshilfe, HNPCC diagnostics and preventive medical examinations were transferred into standard care in Germany. In total, 5770 families (8873 patients) were included in HNPCC diagnostics. To date, in 1296 families, mutations of the MLH1-, MSH2-, MSH6-, PMS2-, or EPCAM-gene have been detected. Furthermore, 612 pathogenic variants and 325 variants of unknown significance were found.

CONCLUSIONS

Reliable detection of HNPCC patients is based on a standardized diagnostic concept, which has been established within the German HNPCC consortium.

[The national Network Genomic Medicine (nNGM) : Model for innovative diagnostics and therapy of lung cancer within a public healthcare system]

BACKGROUND

Since 2012, the Network Genomic Medicine (NGM) has been providing a large number of lung cancer patients from referring partner sites with comprehensive molecular-pathological diagnostics on the single diagnostic platform at the University Hospital Cologne. In addition, the network headquarters in Cologne interprets the findings in close interdisciplinary coordination between pathologists and oncologists, provides information on innovative treatment options, and evaluates the personalized therapies using the central database. As part of one of its largest single grants in 2018, the German Cancer Aid (DKH) rolled out this interdisciplinary and intersectoral care model to all existing DKH-funded German comprehensive cancer centers at the time of the initial application.

GOAL

Presentation of the treatment reality within the national Network Genomic Medicine (nNGM) with its core elements and actors (network centers and intersectoral clinical partners sites).

METHODS

This article is based on our own experience in NGM and nNGM and includes a summary of the currently applicable guidelines for reimbursement and an overview of the treatment landscape in the field of molecular-pathological diagnostics in Germany.

RESULTS

The focus of nNGM is on the implementation of innovative molecular diagnostics and personalized therapy in broad clinical routine in Germany. This is enabled by developing molecular-pathological diagnostics within the network centers on an ongoing basic, interdisciplinary counseling of referring partner sites, offering innovative clinical trials, and performing central evaluation. In particular, a focus of nNGM is the development of regional networks to treat the affected lung cancer patients close to home at the partner sites whenever possible.

DISCUSSION

Interdisciplinary teams are essential for the success of a broad implementation of molecular-pathological diagnostics. nNGM addresses a severe deficit in German lung cancer care and in the future will be expanded to further network centers while meeting the defined quality criteria.

Gene expression profiling in aggressive digital papillary adenocarcinoma sheds light on the architecture of a rare sweat gland carcinoma

BACKGROUND

Sweat gland carcinomas are rare cutaneous adnexal malignancies. Aggressive digital papillary adenocarcinoma (ADPA) represents a very rare subentity, thought to arise almost exclusively from the sweat glands of the fingers and toes. The aetiology of sweat gland carcinomas and ADPA is largely unknown. ADPAs are most likely driven by somatic mutations. However, somatic mutation patterns are largely unexplored, creating barriers to the development of effective therapeutic approaches to the treatment of ADPA.

OBJECTIVES

To investigate the transcriptome profile of ADPA using a sample of eight formalin-fixed, paraffin-embedded tissue samples of ADPA and healthy control tissue.

METHODS

Transcriptome profiling was performed using the Affymetrix PrimeView Human Gene Expression Microarray and findings were validated via reverse transcription of RNA and real-time quantitative polymerase chain reaction.

RESULTS

Transcriptome analyses showed increased tumour expression of 2266 genes, with significant involvement of cell cycle, ribosomal and crucial cancer pathways. Our results point to tumour overexpression of FGFR2 (P = 0·001).

CONCLUSIONS

The results indicate the involvement of crucial oncogenic driver pathways, highlighting cell cycle and ribosomal pathways in the aetiology of ADPA. Suggested tumour overexpression of FGFR2 raises the hope that targeting the fibroblast growth factor (FGF)/FGF receptor axis might be a promising treatment for ADPA and probably for the overall group of sweat gland carcinomas.

[Consequences of autopsies for the living : Causes of death in the clinical diagnosis "septic and toxic shock"]

BACKGROUND

There is reason to believe that the diagnosis of septic and toxic shock, as indicated on the death certificate, cannot be confirmed as the cause of death without autopsy and subsequent histological analysis. The external examination of the corpse can therefore not represent the sole basis for a reliable statement about the infection status of a corpse, e. g. as a prerequisite for embalming.

MATERIAL AND METHODS

The validity of autopsy in determining septic and toxic shock as the cause of death is demonstrated in 7 exemplary cases.

RESULTS

Decades of experience in a university pathology institute have shown that an external examination of the corpse alone is not suitable for certifying the cause of death if an infectious disease is suspected. Consequently, only autopsy with subsequent histological analysis provides reliable statements on the etiopathogenesis of the underlying process. Possible problems and discrepancies between clinical and pathological diagnoses are discussed on the basis of several cases with or without autoptic confirmation of the septic shock. The case of a missionary from Africa infected with Lassa virus serves to point out the seriousness of the threat an undiagnosed infection may represent to the attending staff.

CONCLUSION

During the treatment of patients suspected to have an infectious cause of fever of unknown origin, compliance with the usual safety regulations, including adequate disinfecting measures, is essential. In cases with fatal outcome, not infrequently under the clinical picture of a septic and toxic shock, autopsy should be regularly performed to confirm the type of infection and the infectious cause of death. Rapid and open communication between the professional groups involved plays a crucial role in this process.

First case report of a curative wedge resection in epithelial-myoepithelial carcinoma of the lung

Epithelial-myoepithelial carcinoma is a well differentiated malignant neoplasm, which originates from the salivary glands. The primary pulmonary manifestation is rare-about 30 cases have been reported worldwide. In the literature, anatomical resection has been described as the standard surgical approach. In the presented case, a wedge resection was performed, with no evidence for tumor relapse in the follow-up reevaluation after 24 months. This is the first case report of a primary pulmonary epithelial-myoepithelial carcinoma that has been treated with a non-anatomical wedge resection and lymph node dissection as a curative approach.

The branched-chain amino acid transaminase 1 sustains growth of antiestrogen-resistant and ERα-negative breast cancer

Antiestrogen-resistant and triple-negative breast tumors pose a serious clinical challenge because of limited treatment options. We assessed global gene expression changes in antiestrogen-sensitive compared with antiestrogen-resistant (two tamoxifen resistant and two fulvestrant resistant) MCF-7 breast cancer cell lines. The branched-chain amino acid transaminase 1 (BCAT1), which catalyzes the first step in the breakdown of branched-chain amino acids, was among the most upregulated transcripts in antiestrogen-resistant cells. Elevated BCAT1 expression was confirmed in relapsed tamoxifen-resistant breast tumor specimens. High intratumoral BCAT1 levels were associated with a reduced relapse-free survival in adjuvant tamoxifen-treated patients and overall survival in unselected patients. On a tissue microarray (n=1421), BCAT1 expression was detectable in 58% of unselected primary breast carcinomas and linked to a higher Ki-67 proliferation index, as well as histological grade. Interestingly, BCAT1 was predominantly expressed in estrogen receptor-α-negative/human epidermal growth factor receptor-2-positive (ERα-negative/HER-2-positive) and triple-negative breast cancers in independent patient cohorts. The inverse relationship between BCAT1 and ERα was corroborated in various breast cancer cell lines and pharmacological long-term depletion of ERα induced BCAT1 expression in vitro. Mechanistically, BCAT1 indirectly controlled expression of the cell cycle inhibitor p27^Kip1 thereby affecting pRB. Correspondingly, phenotypic analyses using a lentiviral-mediated BCAT1 short hairpin RNA knockdown revealed that BCAT1 sustains proliferation in addition to migration and invasion and that its overexpression enhanced the capacity of antiestrogen-sensitive cells to grow in the presence of antiestrogens. Importantly, silencing of BCAT1 in an orthotopic triple-negative xenograft model resulted in a massive reduction of tumor volume in vivo, supporting our findings that BCAT1 is necessary for the growth of hormone-independent breast tumors.

[BRCA diagnostics of ovarian cancer : Molecular tumor testing since the introduction of PARP inhibitor therapy]

Approximately 9000 women are diagnosed with ovarian cancer in Germany each year. The most common subtype is high-grade serous ovarian cancer. A relevant proportion of these tumors are associated with mutations in the breast and ovarian cancer susceptibility genes (BRCA1 and BRCA2) representing highly penetrant tumor suppressor genes with autosomal inheritance and play a crucial role in DNA repair mechanisms. These patients have predominantly germline mutations and less frequently have somatic BRCA mutations. Tumors harboring BRCA mutations show a significant improvement in progression-free survival under therapy with poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors. In 2015 the first PARP inhibitor was approved for the therapy of high-grade serous ovarian cancer with BRCA mutations. Mutation analysis can be performed on formalin-fixed paraffin-embedded (FFPE) tumor tissue within a few days.

[ALK-Diagnostics in NSCLC - Immunohistochemistry (IHC) and/or Fluorescence-in-situ Hybridisation (FISH)]

The EML4-ALK pathway plays an important role in a significant subset of non-small cell lung cancer patients. Treatment options such as tyrosine kinase inhibitors directed against the EML4-ALK signalling pathway lead to improved progression free and overall survival. These therapeutic options are chosen on the basis of the identification of the underlying genetic signature of the EML-ALK translocation. Efficient and easily accessible testing tools are required to identify the patients in time. While FISH techniques have been implemented to characterize this translocation for some time, the implementation of this testing is hampered by its broad use of resources. Immunohistochemical techniques to identify and screen for EML4-ALK translocations may play an important role in the near future. This consensus paper offers recommendations of the sequence and quality of the respective test approaches which are validated on the basis of the current literature.

[Colorectal Carcinoma with Suspected Lynch Syndrome: A Multidisciplinary Algorithm]

Lynch syndrome is the most frequent hereditary cancer syndrome, accounting for approximately 3-5 % of all colorectal cancers. In addition, it is the most frequent predisposing hereditary cause of endometrial cancer and is also associated with gastric cancer, ovarian cancer, cancer of the urinary tract as well as several other cancers. In clinical practise Lynch syndrome is frequently not detected and many clinicians admit uncertainties regarding diagnostic procedures. Also, counselling of patients is considered difficult regarding therapeutic - especially prophylactic surgical and chemopreventive options and recommendations. Based on a review of available literature we discuss optimized strategies for improved detection of suspected Lynch syndrome patients. The aim of this review is to establish a clinical algorithm of how to proceed on a diagnostic level and to discuss surgical options at the time of a colorectal cancer. In order to identify patients with Lynch syndrome, family history should be ascertained and evaluated in regards to fulfilment of the Amsterdam-II- and/or the revised Bethesda criteria. Subsequently immunohistochemical staining for the mismatch-repair-genes, BRAF testing for MLH1 loss of expression, as well as testing for microsatellite instability in some, followed by genetic counselling and mutation analysis when indicated, is recommended. Pathological identification of suspected Lynch syndrome is readily feasible and straightforward. However, the need of performing these analyses in the tumor biopsy at the time of (gastroenterological) diagnosis of CRC neoplasia is essential, in order to offer patients the option of a prophylactically extended surgery and - as recommended in the German S3 guidelines - to discuss the option of a merely prophylactical hysterectomy and oophorectomy (if postmenopausal) in women. Close cooperation between gastroenterologists, pathologists and surgeons is warranted, so that patients may benefit from options of extended or prophylactically extended surgery at the time of diagnosis of a colorectal primary. Patients nowadays must be involved in informed decision-making regarding prophylactic or extended prophylactic surgery at the time of a colorectal primary. To date, however, limitations in daily clinical practise, the failure to assess family history and the lack of awareness of this important hereditary syndrome is the major asset leading to severe underdiagnosis and putting to risk the indexpatients themselves and their families to (metachronous) CRC and the associated extracolonic cancers. If at all tumors of patients fulfilling Bethesda criteria will be analysed for MSI in the surgical specimen and therefore Lynch syndrome patients are not given the opportunity to opt for extended surgery. In clinical experience the postoperative MSI-analysis is inconsistently performed - even if the Bethesda criteria are fulfilled - and in case of suspected Lynch syndrome genetically counselling is not consistently recommended. Therefore affected cancer patients are left unaware of their increased genetic risk and in average 3 high-risk gene carriers per family miss the opportunity to actively engage in the recommended screening program.

[A very rare cause of haemoptysis - coexistence of primary oncocytic adenoma of trachea with bronchial carcinoma]

HISTORY AND ADMISSION FINDINGS

A 70-year-old man with a past history of COPD stage GOLD D with home oxygen therapy and tracheotomy due to long-term ventilation (898 hours) 6 years ago was admitted for investigation of haemoptysis during oral anticoagulation. He suffered from peripheral arterial disease (PAD) with bypass and repeated thrombectomy due to recurrent bypass caps, despite effective warfarin therapy. He had all cardiovascular risk factors.

INVESTIGATIONS

The suspicion of a bronchial carcinoma was confirmed by CT. Bronchoscopically a 2 cm lesion in the left upper lobe was biopsied. Additionally, bronchoscopy revealed an approximately erythematous, bloody discolored lesion (diameter 7 mm) at a tracheotomy scar.

DIAGNOSIS, TREATMENT AND COURSE

The biopsies revealed an adenocarcinoma in the left upper lobe and an oncocytic adenoma of the trachea - an extremely rare adenoma. The staging result was cT1b cN0 cM0 G2 IASLC Ia. Because of his severe multiple diseases the patient was in an inoperable condition. An interdisciplinary tumor conference recommended an individualized approach with a definitive radiotherapy of the adenocarcinoma. Endoscopic control of the macroscopically completely removed oncocytic adenoma of the trachea shall be performed one year later.

CONCLUSIONS

Oncocytoma is an extremely rare adenoma (of the trachea), which in this case, has caused haemoptysis in addition to lung cancer during anticoagulation. For tumor genesis a reactive or hyperplasic response after tracheotomy 6 years ago is considered. Resection is the treatment of choice because of the potential for infiltrative growth. But the decision to treat always depends on individual benefit.

SS18-SSX fusion protein-induced Wnt/β-catenin signaling is a therapeutic target in synovial sarcoma

Synovial sarcoma is a high-grade soft tissue malignancy characterized by a specific reciprocal translocation t(X;18), which leads to the fusion of the SS18 (SYT) gene to one of three SSX genes (SSX1, SSX2 or SSX4). The resulting chimeric SS18-SSX protein is suggested to act as an oncogenic transcriptional regulator. Despite multimodal therapeutic approaches, metastatic disease is often lethal and the development of novel targeted therapeutic strategies is required. Several expression-profiling studies identified distinct gene expression signatures, implying a consistent role of Wnt/β-catenin signaling in synovial sarcoma tumorigenesis. Here we investigate the functional and therapeutic relevance of Wnt/β-catenin pathway activation in vitro and in vivo. Immunohistochemical analyses of nuclear β-catenin and Wnt downstream targets revealed activation of canonical Wnt signaling in a significant subset of 30 primary synovial sarcoma specimens. Functional aspects of Wnt signaling including dependence of Tcf/β-catenin complex activity on the SS18-SSX fusion proteins were analyzed. Efficient SS18-SSX-dependent activation of the Tcf/β-catenin transcriptional complex was confirmed by TOPflash reporter luciferase assays and immunoblotting. In five human synovial sarcoma cell lines, inhibition of the Tcf/β-catenin protein-protein interaction significantly blocked the canonical Wnt/β-catenin signaling cascade, accompanied by the effective downregulation of Wnt targets (AXIN2, CDC25A, c-MYC, DKK1, CyclinD1 and Survivin) and the specific suppression of cell viability associated with the induction of apoptosis. In SYO-1 synovial sarcoma xenografts, administration of small molecule Tcf/β-catenin complex inhibitors significantly reduced tumor growth, associated with diminished AXIN2 protein levels. In summary, SS18-SSX-induced Wnt/β-catenin signaling appears to be of crucial biological importance in synovial sarcoma tumorigenesis and progression, representing a potential molecular target for the development of novel therapeutic strategies.

[Molecular pathology of the lungs. New perspectives by next generation sequencing]

Lung cancer is one of the most frequent malignancies in the western world. Its frequent association with a wide spectrum of mutations in genes encoding various signal transducers that are often linked to therapy response, emphasizes the obvious need for improved, fast and highly efficient approaches in molecular pathology. Comprehensive analyses of the mutation status of progression and therapy relevant genes can be performed by the novel sequencing forms named next generation sequencing (NGS) providing extremely high capacities for ultra-deep sequence analyses. The 454 pyrosequencing method, the sequencing by synthesis and the semiconductor sequencing platform are now available for parallel sequencing approaches of multitudinous target genes linked to multiple tumor DNA applications. The "one molecule, one clone, one read" principle by the NGS approaches supplies not only information on allele frequencies and mutation rates but also has the advantage of a very sensitive detection of low frequency variants.

[Lung cancer. Molecular pathology and personalized therapy]

Recent advances in the treatment of non-small cell lung cancer (NSCLC) are based on the identification of so-called driver mutations, resulting in a more personalized treatment setting. Currently about 15% of NSCLC patients benefit from improved treatment protocols based on the genetic background of the tumor. In the last few years cancer immunotherapy has returned to the center of attention and comprises a variety of treatment approaches incorporating adaptive, as well as innate immunity. Current strategies involve the use of monoclonal antitumor antibodies, cancer vaccines, adoptive transfer of ex vivo activated T and NK cells as well as the blockade of so-called immune checkpoints (immune inhibitory pathways). Especially the combination of current treatments with immunotherapy seems promising to achieve highly potent antitumor effects. However, a profound understanding of the dynamic and complex interaction between lung cancer and the host immune system and especially its immune checkpoints is the foundation to identify potential biomarkers for a personalized cancer immunotherapy approach.