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Background: Paediatric tumours are often characterised by the presence of recurrent DNA copy number alterations (CNAs). These DNA copy number profiles, obtained from a tissue biopsy, can aid in the correct prognostic classification and therapeutic stratification of several paediatric cancer entities (e.g. MYCN amplification in neuroblastoma) and are part of the routine diagnostic practice. Liquid biopsies (LQBs) offer a potentially safer alternative for such invasive tumour tissue biopsies and can provide deeper insight into tumour heterogeneity. Procedure: The robustness and reliability of LQB CNA analyses was evaluated. We performed retrospective CNA profiling using shallow whole-genome sequencing (sWGS) on paired plasma circulating cell-free DNA (cfDNA) and tissue DNA samples from routinely collected samples from paediatric patients (n = 128) representing different tumour entities, including osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, Wilms tumour, brain tumours and neuroblastoma. Results: Overall, we observed a good concordance between CNAs in tissue DNA and cfDNA. The main cause of CNA discordance was found to be low cfDNA sample quality (i.e. the ratio of cfDNA (700 bp)). Furthermore, CNAs were observed that were present in cfDNA and not in tissue DNA, or vice-versa. In neuroblastoma samples, no false-positives or false-negatives were identified for the detection of the prognostic marker MYCN amplification. Conclusion: In future prospective studies, CNA analysis on LQBs that are of sufficient quality can serve as a complementary assay for CNA analysis on tissue biopsies, as either cfDNA or tissue DNA can contain CNAs that cannot be identified in the other biomaterial.

Head and neck squamous cell carcinomas (HNSCCs) belong to a group of diverse tumors, which can be induced by infection with human papillomavirus (HPV) or tobacco and alcohol consumption. The viral etiology of HNSCC relates to better clinical outcomes reflecting a different immune system response. Here, we retrospectively analyzed 97 tissue samples from oral and oropharyngeal carcinomas associated and non-associated with HPV infection using multispectral fluorescent immunohistochemistry. To evaluate the immune cell infiltration in tumor and stroma compartments, we designed four panels of four to five antibodies. We detected more T lymphocytes in the stroma, compared to the tumor parenchyma. In HPV positive (HPV

Plasmacytoid dendritic cells (pDCs) are the most potent type I interferon-producing cells and play an important role in antiviral immunity. Tumor-infiltrating pDCs were shown to be predominantly pro-tumorigenic, with reduced ability to produce interferon alpha (IFNα) and confirmed capacity to prime regulatory T cells (Tregs) by the ICOS/ICOS-L pathway. Because a significant number of HNSCCs are induced by human papillomaviruses and show markedly different immune profiles than non-virally induced tumors, we compared the phenotype and functional capacity of HNSCC-infiltrating pDCs to the HPV status of the tumor. We observed a reduced capacity of pDCs to produce IFNα upon toll-like receptor activation in HPV-negative samples and a rather uncompromised functionality in HPV-associated tumors. Additionally, supernatants from non-virally induced but not HPV-associated tumor cell suspensions significantly inhibited IFNα production by peripheral blood-derived pDCs. We identified IL-10 and TNFα as the soluble pDC-suppressive factors with the highest variability between HPV-negative and HPV-positive tumor-derived supernatants. Additionally, we observed a positive correlation of tumor-infiltrating pDCs with Tregs in HPV-negative samples but not in virally induced tumors. Overall, our study indicates that the immunosuppressive cytokine milieu rich in IL-10 and TNFα in HPV-negative but not in HPV-positive HNSCC significantly affects the functional capacity of tumor-infiltrating pDCs, and such dysfunctional pDCs may further support the immunosuppressive tumor microenvironment by promoting the expansion of Tregs in the tumor tissue.

Head and neck squamous cell carcinomas (HNSCC) belong among severe and highly complex malignant diseases showing a high level of heterogeneity and consequently also a variance in therapeutic response, regardless of clinical stage. Our study implies that the progression of HNSCC may be supported by cancer-associated fibroblasts (CAFs) in the tumour microenvironment (TME) and the heterogeneity of this disease may lie in the level of cooperation between CAFs and epithelial cancer cells, as communication between CAFs and epithelial cancer cells seems to be a key factor for the sustained growth of the tumour mass. In this study, we investigated how CAFs derived from tumours of different mRNA subtypes influence the proliferation of cancer cells and their metabolic and biomechanical reprogramming. We also investigated the clinicopathological significance of the expression of these metabolism-related genes in tissue samples of HNSCC patients to identify a possible gene signature typical for HNSCC progression. We found that the right kind of cooperation between cancer cells and CAFs is needed for tumour growth and progression, and only specific mRNA subtypes can support the growth of primary cancer cells or metastases. Specifically, during coculture, cancer cell colony supporting effect and effect of CAFs on cell stiffness of cancer cells are driven by the mRNA subtype of the tumour from which the CAFs are derived. The degree of colony-forming support is reflected in cancer cell glycolysis levels and lactate shuttle-related transporters.

Symplastic haemangioma is a rare vascular tumor presented with regressive and degenerative atypia in stromal cells. Its morphology represents a challenge in classification of vascular tumors, regarding their biological behaviour in particular. We present a case report of a 47-years-old female with a history of left-sided breast adenocarcinoma treated by resection followed by adjuvant chemotherapy and radiotherapy. Three years after the primary diagnosis a tumorous mass appeared in the region of upper margin of left scapula, in subcutaneous tissues and the trapezius muscle. Histologically, the tumor was formed by multiple blood vessels of varied diameter and wall thickness. Endothelial lining was bland, without atypia; thromboses were observed in vascular spaces. In the interstitium, a population of spindle and pleomorphic cells with distinctive atypia and bizarre nuclei was found. These cells showed positivity in immunohistochemical expression of smooth muscle actin, further extensive immunohistochemistry including cytokeratines was negative. Mitoses were absent, proliferating activity was minimal. Signs of infiltrative growth pattern were not found and the tumor lacked hallmarks of malignant behaviour. A diagnosis of symplastic haemangioma was established. Above mentioned atypical stromal cells show myofibroblastic and sporadically smooth muscle differentiation. Their atypical appearence is associated with degenerative alterations similar to changes in leiomyomas with bizarre nuclei or ancient schwannomas. Etiopathogenesis of these changes is not clear, there are hypotheses considering long-lasting persistence of the lesion, regression of ischaemic or postinflammatory origin, or, like in our case, postirradiative degeneration. Differential diagnosis of symplastic haemangioma is widespred and contains many histological entities of variant histogenesis and biological potential. For proper classification, an extensive investigation including immunohistochemistry, clinical and anamnestic data and imaging methods is necessary.

Supplementary Materials: The following supporting information can be downloaded at: www.mdpi.com/xxx/s1, Table S1: Cell counts/Mpx in the parenchyma and stroma of HNSCC tumors; Table S2: Models of DSS and OS., Funding: This research was funded by the Czech Health Research Council, grant number 17-28055A; and the European Regional Development Fund and the Ministry of Education, Youth and Sports of the Czech Republic, grant numbers CZ.1.05/2.1.00/19.0400 and CZ.02.1.01/0.0/0.0/16_019/0000785, and by the Charles University, grant number SVV 260568.

Head and neck squamous cell carcinomas (HNSCC) can be induced by smoking or alcohol consumption, but a growing part of cases relate to a persistent high-risk papillomavirus (HPV) infection. Viral etiology has a beneficial impact on the prognosis, which may be explained by a specific immune response. Tumor associated macrophages (TAMs) represent the main immune population of the tumor microenvironment with a controversial influence on the prognosis. In this study, the level, phenotype, and spatial distribution of TAMs were evaluated, and the expression of TAM-associated markers was compared in HPV positive (HPV+) and HPV negative (HPV−) tumors. Seventy-three formalin and embedded in paraffin (FFPE) tumor specimens were examined using multispectral immunohistochemistry for the detection of TAM subpopulations in the tumor parenchyma and stroma. Moreover, the mRNA expression of TAM markers was evaluated using RT-qPCR. Results were compared with respect to tumor etiology, and the prognostic significance was evaluated. In HPV− tumors, we observed more pro-tumorigenic M2 in the stroma and a non-macrophage arginase 1 (ARG1)-expressing population in both compartments. Moreover, higher mRNA expression of M2 markers—cluster of differentiation 163 (CD163), ARG1, and prostaglandin-endoperoxide synthase 2 (PTGS2)—was detected in HPV− patients, and of M1 marker nitric oxide synthase 2 (NOS2) in HPV+ group. The expression of ARG1 mRNA was revealed as a negative prognostic factor for overall survival of HNSCC patients.

Background Head and neck carcinomas (HNC) are the world’s sixth most common cancer. Most of HNCs are associated with tobacco and other environmental factors but a growing part of oropharyngeal tumors are caused by persistent infection of human papillomavirus (HPV). Patients with HPV positive cancers have a better prognosis with fewer recurrences. This may be caused by different anti-tumor immune response and immune profile of patients. Multispectral fluorescent immunohistochemistry (fIHC) is a powerful tool for a detailed analysis of the tumor microenvironment. This method allows to access the phenotype and calculate cells in tumor parenchyma and stroma of the tumor since in comparison to flow cytometry, an architecture of the tissue remains preserved. fIHC is uniquely suited to study interaction of immune and cancer cells in situ. Materials and Methods Number of 97 formalin fixed paraffine-embedded slides of the human HNC tissue with known etiology were examined using 4 different panels of 5 antibodies each. These panels include antibodies suitable for phenotyping of immune cells (CD3e, CD4, CD8, FOXP3) or their functional description (PD1, CTLA4, ICOS, CCR4). Additionally, antibodies against Ki67, VEGF and cell cytokeratin were used. Slides were stained using Opal™ 7-Color Fluorescent IHC Kit (Akoya Biosciences). The quantity of immune cells was evaluated in stroma and tumor compartment using InForm™ 2.4.6. software (Akoya Biosciences). For all patients the demographic and clinical data were available and these patients were followed for up to 18 years. Results Our results have shown significantly higher abundance of Th and Tc in both compartments of HPV+ samples. Besides HPV etiology Th and Tc in the tumor microenvironment predict independently better survival of patients. We did not observed difference in number of Tregs (characterized as a CD3+CD4+FOXP3+ cells) in tumors of different etiology, but we detected higher number of ICOS+Tregs in stroma of HPV- tumors. We also quantified the subpopulations of Th and Tc cells expressing regulatory receptors PD1 and CTLA4. PD1 showed significantly higher expression on Th and Tc both in tumor and stroma of HPV+ tumors, but CTLA4 expression was significantly higher only on Th located in stroma of HPV- tumors. Moreover, we detected significantly higher VEGF expression in both compartments and higher proliferating activity of tumor cells in HPV- tumors. Conclusions Detailed analyses of the tumor infiltrating lymphocytes allows for selection of prognostic markers in HNC of different etiology. Our results may also help to understand the better prognosis of HPV+ patients. More detailed survival analyses with inclusion of other clinical and demographic data will be presented. Disclosure Information B. Pokrývkova: None. M. Grega: None. J. Klozar: None. O. Vencalek: None. J. Nunvar: None. R. Tachezy: None.

The emergence of cisplatin (CDDP) resistance is the main cause of treatment failure and death in patients with testicular germ cell tumors (TGCT), but its biologic background is poorly understood. To study the molecular basis of CDDP resistance in TGCT we prepared and sequenced CDDP-exposed TGCT cell lines as well as 31 primary patients’ samples. Long-term exposure to CDDP increased the CDDP resistance 10 times in the NCCIT cell line, while no major resistance was achieved in Tera-2. Development of CDDP resistance was accompanied by changes in the cell cycle (increase in G1 and decrease in S-fraction), increased number of acquired mutations, of which 3 were present within ATRX gene, as well as changes in gene expression pattern. Copy number variation analysis showed, apart from obligatory gain of 12p, several other large-scale gains (chr 1, 17, 20, 21) and losses (chr X), with additional more CNVs found in CDDP-resistant cells (e.g., further losses on chr 1, 4, 18, and gain on chr 8). In the patients’ samples, those who developed CDDP resistance and died of TGCT (2/31) showed high numbers of acquired aberrations, both SNPs and CNVs, and harbored mutations in genes potentially relevant to TGCT development (e.g., TRERF1, TFAP2C in one patient, MAP2K1 and NSD1 in another one). Among all primary tumor samples, the most commonly mutated gene was NSD1, affected in 9/31 patients. This gene encoding histone methyl transferase was also downregulated and identified among the 50 most differentially expressed genes in CDDP-resistant NCCIT cell line. Interestingly, 2/31 TGCT patients harbored mutations in the ATRX gene encoding a chromatin modifier that has been shown to have a critical function in sexual differentiation. Our research newly highlights its probable involvement also in testicular tumors. Both findings support the emerging role of altered epigenetic gene regulation in TGCT and CDDP resistance development.

International audience; Background: Human papillomavirus (HPV) type 16 infection is one of the most important etiological agents of oropharyngeal squamous cell carcinoma. Patients with HPV-associated carcinomas of the head and neck were reported to have a better clinical outcome than patients with HPV-negative tumors. Because HPV16 E6 and E7 oncoproteins are highly immunogenic and constitutively expressed, HPV-specific T cell immunity may play the key role in improving the prognosis of these patients.Methods: Tumor-derived T cells were expanded in high levels of IL-2 and stimulated with HPV16 E6/E7 peptides in the presence or absence of anti-PD-1 monoclonal antibody nivolumab and soluble Tim-3.Results: HPV16-specific tumor-infiltrating T cells were present in 73.1% of HPV-associated oropharyngeal tumors. HPV16 specific CD8+ TILs were able to produce IFNγ upon specific stimulation and predominantly expressed PD-1 but not Tim-3. Specific IFNγ production was further enhanced after a blockade of both PD-1 and Tim-3 pathways but not after a PD-1 blockade alone. Additionally, the specific stimulation of anti-HPV16 CD8+ T cells suppressed Tim-3 upregulation after the PD-1 blockade.Conclusion: Our data provide the rationale for combination cancer immunotherapy approaches, including the dual blockade of PD-1 and Tim-3 and, potentially, the use of HPV16-directed therapeutic vaccines.

Human papillomavirus (HPV) infection is associated with tonsillar cancer (TC) whose incidence in humans is increasing. Tonsillar tumours are not ordinarily preceded by clinically apparent precancerous lesions, and no markers of the early stage disease are available. Therefore, we evaluated the presence of an active HPV infection also in tumour-free tonsillar tissue. Formalin-fixed paraffin-embedded (FFPE) tonsillar specimens from 114 patients with TC and 114 age and gender matched controls were screened for the presence of HPV DNA, expression of HR-HPV E6 mRNA, and p16 overexpression. HPV DNA was identified in 3.5% of tumour-free tissues, HR-HPV16 and 58 and LR-HPV111 and 17 were each detected in a single sample. No HR HPV E6 mRNA and p16 overexpression was found. The prevalence of HPV DNA in TC was 69.3%, with HPV16 being the most common (94.9%). Eighty-four percent of HPV16-positive tumours expressed HR HPV E6 mRNA, while no E6 mRNA was present in samples positive for HPV52 and 58. The overexpression of p16 correlated well with HPV DNA in TC, but in tumour-free tonsils no overexpression of p16 was detected.Our data provide further evidence of the etiological role of HPV16 in TC. In tumour-free tissue, the presence of HR-HPVs was rare and silent, as shown by direct and indirect markers.

Integration, which leads to the disruption of the circular HPV genome, is considered as a critical, albeit not obligatory, step in carcinogenic progression. Although cervical carcinomas with extrachromosomal HPV plasmid genomes have been described, the virus is integrated in 70% of HPV16-positive cervical tumours. Limited information is available about HPV integration in head and neck tumours (HNC). In this study, we have characterised the physical status of HPV in a set of tonsillar tumour samples using different methods--the mapping of E2 integration breakpoint at the mRNA level, the 3' RACE based Amplification of Papillomavirus Oncogene Transcripts (APOT) assay and Southern blot. Furthermore, the impact of HPV integration on patients' prognosis has been evaluated in a larger set of 186 patients with head and neck cancer. Based on the analysis of E2 mRNA, HPV was integrated in the host genome in 43% of the HPV-positive samples. Extrachromosomal or mixed form was present in 57%. In fresh frozen samples, the APOT and E2 mapping results were in agreement. The results were confirmed using Southern blotting. Furthermore, the type and exact site of integration were determined. The survival analysis of 186 patients revealed HPV positivity, tumour size and lymph node positivity as factors that influence disease specific survival. However, no statistically significant difference was found in disease specific survival between patients with HPV-positive integrated vs. extrachromosomal/mixed forms of the virus.

Background Standard treatment of oropharyngeal squamous cell carcinoma (OPSCC) is associated with strong morbidity, whereas immunotherapeutic approaches using PD-1:PD-L1 checkpoint blockade only show moderate response rates in OPSCC patients. Therefore, the development of a complex therapeutic protocol combining checkpoint inhibition with other targets is needed for better responses. The significance of tumor-infiltrating B cells (TIL-Bs) in shaping antitumor immunity remains unclear; therefore, we analyzed frequency, phenotype, prognostic value and possible roles of TIL-Bs in OPSCC. Methods In this study, we evaluated the density and distribution of TIL-Bs in FFPE samples from 2 cohorts of OPSCC patients. Than we assessed the phenotype of TIL-Bs by means of flow cytometry in fresh tumor samples immediately after radical surgery. The acquired data were corelated with the clinical outcome of the patients. Results We observed that CD20+ TIL-Bs and CD8+ T cells formed non-organized clusters with clearly interacting cells and the densities of both intraepithelial CD20+ B cells and B/CD8+ T cell interactions have prognostic significance for the overall survival of OPSCC patients. Furthermore, a high density of TIL-Bs was associated with an activated B cell phenotype and a high density of direct B cell/CD8+ T cell interactions significantly correlated with the abundance of HPV16-specific CD8+ T cells. Conclusion Our results indicate that high abundance of TIL-Bs and high density of direct B cell/CD8+ T cell interactions can preselect patients with excellent prognosis who would profit from less invasive treatment. Furthermore, including B cells as an additional target in novel immunotherapeutic protocols may help to establish the desired sustained antitumor T cell responses in OPSCC patients. Legal entity responsible for the study Kamila Hladikova. Funding Sotio a.s. Disclosure All authors have declared no conflicts of interest.

Human papillomavirus (HPV) type 16 infection is one of the most important etiological agents of oropharyngeal squamous cell carcinoma. Patients with HPV-positive squamous cell carcinomas of the head and neck were reported to have a better clinical outcome than patients with HPV-negative tumors. Because HPV16 E6 and E7 oncoproteins are highly immunogenic and constitutively expressed within the tumor cells, HPV-specific T cell immunity may contribute to the better prognosis of HPV-positive tumors. We analyzed the frequency, phenotype and function of HPV16 E6/E7-specific tumor-infiltrating T cells (TILs) in oropharyngeal tumors and tested the effect of anti-PD1 mAb (nivolumab), soluble Tim-3 (sTim-3) and homeostatic in vitro expansion on these characteristics. We show that 73.1% of HPV-associated oropharyngeal tumors are positive for HPV16-specific T cells capable of producing IFNγ upon stimulation with E6/E7 peptide pools. These IFNγ-producing HPV-specific TILs were mainly PD-1+Tim-3-CD8+ T cells, identifying Tim-3 rather than PD-1 as a marker of T cell dysfunction. Consequently, specific IFNγ production was further enhanced by combined nivolumab plus sTim-3 treatment, but not with nivolumab alone. Our data provide the rationale for exploring additional setups of anti-PD-1 mAb treatment, including combinations with other check-point blockers, such as Tim-3 and/or with HPV16-directed therapeutic vaccines. Citation Format: Simona Partlova, Kamila Hladikova, Vladimir Koucky, Anna Fialova, Radek Spisek, Jan Boucek, Michal Zabrodsky, Michael Halaska, Ruth Tachezy, Marek Grega, Jean-François Fonteneau. Dysfunction of HPV16-specific CD8+ T cells derived from oropharyngeal tumors is related to the expression of Tim-3 but not PD-1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1002.

Wilms tumor gene 1 (WT1), a zinc-finger transcription factor essential for testis development and function, along with other genes, was investigated for their role in the pathogenesis of testicular germ cell tumors (TGCT).In total, 284 TGCT and 100 control samples were investigated, including qPCR for WT1 expression and BRAF mutation, p53 immunohistochemistry detection, and massively parallel amplicon sequencing.WT1 was significantly (p 0.0001) under-expressed in TGCT, with an increased ratio of exon 5-lacking isoforms, reaching low levels in chemo-naïve relapsed TGCT patients vs. high levels in chemotherapy-pretreated relapsed patients. BRAF V600E mutation was identified in 1% of patients only. p53 protein was lowly expressed in TGCT metastases compared to the matched primary tumors. Of 9 selected TGCT-linked genes, RAS/BRAF and WT1 mutations were frequent while significant TP53 and KIT variants were not detected (p = 0.0003).WT1 has been identified as a novel factor involved in TGCT pathogenesis, with a potential prognostic impact. Distinct biologic nature of the two types of relapses occurring in TGCT has been demonstrated. Differential mutation rate of the key TGCT-related genes has been documented.

Integration, which leads to the disruption of the circular HPV genome, is considered as a critical, albeit not obligatory, step in carcinogenic progression. Although cervical carcinomas with extrachromosomal HPV plasmid genomes have been described, the virus is integrated in 70% of HPV16-positive cervical tumours. Limited information is available about HPV integration in head and neck tumours (HNC). In this study, we have characterised the physical status of HPV in a set of tonsillar tumour samples using different methods--the mapping of E2 integration breakpoint at the mRNA level, the 3' RACE based Amplification of Papillomavirus Oncogene Transcripts (APOT) assay and Southern blot. Furthermore, the impact of HPV integration on patients' prognosis has been evaluated in a larger set of 186 patients with head and neck cancer. Based on the analysis of E2 mRNA, HPV was integrated in the host genome in 43% of the HPV-positive samples. Extrachromosomal or mixed form was present in 57%. In fresh frozen samples, the APOT and E2 mapping results were in agreement. The results were confirmed using Southern blotting. Furthermore, the type and exact site of integration were determined. The survival analysis of 186 patients revealed HPV positivity, tumour size and lymph node positivity as factors that influence disease specific survival. However, no statistically significant difference was found in disease specific survival between patients with HPV-positive integrated vs. extrachromosomal/mixed forms of the virus.

Soft tissue tumors (SSTs) constitute a broad spectrum of neoplasms with diverse biological properties. Rare or unusual types are often difficult to classify. Recent studies show, that a significant subset of SSTs including many types of sarcomas are associated with specific genetic changes such as chromosomal translocations producing chimeric genes, which play a role in the pathogenesis of SSTs. Because SSTs represent a diagnostically challenging group of tumors, molecular-genetic techniques (FISH or PCR) are useful as supplementary and/or confirmatory diagnostic tools. In the present paper we demonstrate the usefulness of a combined diagnostic approach using the tools of classical histopathology and immunohistochemistry together with the molecular diagnostic approach in selected nosologic entites.

Background. Human papillomaviruses (HPVs) have been proved as one of the etiological factors of oropharyngeal squamous cell carcinoma (OPSCC). Patients with tumors of viral etiology have a lower recurrence rate and better prognosis. OPSCC is linked to an alteration in the immune system. Only a limited number of studies have correlated both the immunological parameters and HPV status with patient prognosis. The aim of this study was to determine whether HPV infection and the immunological status influence patient prognosis individually or in concurrence.Material and Methods. Sixty patients with oral and oropharyngeal carcinomas were enrolled. They were divided into HPV-positive and HPV-negative groups based on the expression of HPV 16 E6 mRNA. Basic lymphocyte subpopulations were determined in the peripheral blood by means of flow cytometry.Results. Significantly better disease-specific survival (DSS) was observed in patients with HPV-positive tumors. Nodal status, tumor grade, recurrence, and CD8+/Tregs ratio were identified as factors influencing DSS. A higher level of Tregs and a lower ratio of CD8/Tregs influenced overall survival (OS) independently of HPV status and age. Patients with HPV-positive tumors and high levels of Tregs survived significantly better than patients from the other groups.Conclusion. Better survival is associated with HPV positivity and elevated Tregs levels. Our data suggest that HPV infection and Tregs do not influence patient prognosis in concurrence.

4534 Background: Wilms’ tumor gene 1 (WT1) is a transcription factor essential for normal development of the urogenital system and male gonadal formation. Its alterations have been found in Wilms’ ...