Search

Anticancer immunotherapies have revolutionized cancer management, yet the effect of systemic anti‐programmed cell death protein 1 (PD‐1) treatment is predominantly studied in tumor‐infiltrating lymphocytes (TILs). Its impact on PD‐1 expressing cells in tumor‐draining lymph nodes (TDLNs) is not well understood and yet to be explored. Thus, further research aiming for better understanding of the PD‐1 pathway not only in tumor tissue but also in TDLNs is warranted. In this study, we investigated the expression of PD‐1, CD69, and HLA‐DR on CD4+ and CD8+ T cells by flow cytometry analysis of peripheral blood mononuclear cells (PBMCs), TDLNs, and tumor samples from patients with oral squamous cell carcinoma (OSCC). Our data showed that both helper and cytotoxic T lymphocytes in OSCC tissue were highly activated and expressed high level of PD‐1 (over 70% positivity). Lymphocytes in TDLNs and peripheral blood expressed significantly lower levels of PD‐1 and other activation markers compared to TILs. Moreover, we demonstrated that a significant fraction of PD‐1 negative TILs expressed high levels of human leukocyte antigen – DR isotype and CD69. In contrast, PD‐1 negative cells in TDLNs and PBMCs scarcely expressed the aforementioned activation markers. Furthermore, we proved that patients with a high percentage of CD3+ PD‐1+ cells in tumor‐draining lymph nodes had significantly lower disease‐free and overall survival rates (log‐rank test P = .0272 and P = .0276, respectively). Taken together, we proved that flow cytometry of lymph nodes in OSCC is feasible and may be used to investigate whether PD‐1 levels in TDLNs correspond with survival and potentially with response to anti‐PD‐1 therapy. Such knowledge may ultimately help guide anti‐PD‐1 treatment., Flow cytometry is a powerful tool that can be used in head and neck cancers to investigate immunological milieu of tumor‐draining lymph nodes. In this project, we provide a characterization of T cells within head and neck cancer tumors, tumor‐draining lymph nodes, and blood.

The debates around Chinese investment and the detrimental effects that it might have on States on the receiving end of it have led the European Union (eu) to pursue initiatives intended to protect the national interests of its countries. The emergence of populism in Italy, together with a growing Euroscepticism and political instability, decisively influenced Italy’s foreign policy on Chinese investmentrelated matters, which led its communication strategies to affect the EU at some points. Alternatively, Portugal’s internal stability and favorable opinion of the eu enabled this country to manage its relations with China while generally taking into account the preservation of the European vector’s stability.

Background: Occult metastases are common in patients with oral squamous cell carcinoma (OSCC) which is why elective neck dissection, adjuvant radiotherapy or watchful waiting have been treatment options after surgical removal of the primary tumour. Sentinel lymph node biopsy (SLNB) has lately emerged as a novel possibility in treatment planning. Objectives: To establish a reliable and clinically useful protocol for SLNB in staging/elective neck dissection in oral cancer. Methods: Fourteen consecutive patients with T1-T2 N0 oral cancer were enrolled when scheduled for elective neck dissection. Results: This study outlines various techniques for improving SLNB in head and neck cancer. After evaluation, a combination of techniques was found to constitute a reliable, clinically adaptable work concept. The suggested procedure starts with the pre-surgical injection of radioactive technetium 99Tcm carried on tilmanocept (Lymphoseek ®) at the tumour site. The radioactivity in the lymph node is then visualized preoperatively with Single Photon Emission Computed Tomography (SPECT/CT). Intraoperatively, indocyanine green (ICG) is injected and a sentinel node is visualized with near-infrared light. To support the sentinel node detection, the surgeon uses a hand-held gamma detection probe. This approach results in a reproducible and reliable detection of sentinel nodes. Conclusion: This paper presents a novel protocol for the identification of the sentinel node in the head and neck region. The protocol additionally enables the use of flow cytometry analysis of resected lymph nodes.

The leading cause of death for patients with HPV associated squamous cell carcinoma of the head and neck (SCCHN) after treatment with chemoradiotherapy (CRT) nowadays is peripheral metastasis. This study investigated whether induction chemotherapy (IC) could improve progression free survival (PFS) and impact on relapse pattern after CRT. Methods: Eligible patients in this multicenter, randomized, controlled, phase 2 trial had p16-positive locoregionally advanced SCCHN. Patients were randomized in a 1:1 ratio to either RT with cetuximab (arm B) versus the same regimen preceded by two cycles of taxotere/cisplatin/5-FU (arm A). The RT dose was escalated to 74.8 Gy for large volume primary tumors. Eligibility criteria included patients of 18–75 years, an ECOG performance status 0–1, and adequate organ functions. Results: From January 2011 to February 2016, 152 patients, all with oropharyngeal tumors were enrolled, 77 in arm A and 75 in arm B. Two patients, one in each group, withdrew their consent after randomization, leaving 150 patients for the ITT analysis. PFS at 2 years was 84.2% (95% CI 76.4–92.8) in arm A and 78.4% (95% CI 69.5–88.3) in arm B (HR 1.39, 95% CI 0.69–2.79, p = 0.40). At the time of analysis, there were 26 disease failures, 9 in arm A and 17 in arm B. In arm A, 3 patients had local, 2 regional, and 4 distant relapses as first sites of recurrence, and in arm B, 4, 4, and 9 relapses in corresponding sites. Eight out of 26 patients with disease progression had salvage therapy and 7 were alive NED (no evidence of disease), at 2 years. Locoregional control was 96% in arm A and 97.3% in arm B and OS 93% and 90.5%, respectively. Local failure as first site of recurrence was low, in 4.6% of patients and was similar for T1/T2 and T3/T4 tumors (n.s). Nevertheless, out of 7 patients with primary local failures, 4 were treated with the escalated RT dose. Toxicity was low and similar in the treatment arms. There was one fatal event in arm A where the combined effects of the drugs used in chemotherapy and cetuximab could not be ruled out. Conclusions: PFS, locoregional control and toxicity did not differ between the two arms, OS was high, and there were few local relapses. In arm B, more than twice as many patients had distant metastasis as the first site of relapse compared to arm A. The response to IC was found to define 29% of patients in arm A who did not have a tumor relapse during follow-up. An escalated dose of 74.8 Gy could mitigate the negative impact of large tumor volume but for some patients, even this intensified treatment was insufficient.

The expression patterns of stimulator of interferon genes (STING) were investigated in a cohort of 158 T- and natural killer (NK)-cell and 265 B-cell non-Hodgkin lymphomas (NHLs), as well as in control reactive lymph nodes and tonsils. STING expression was assessed by immunohistochemical methods using diagnostic biopsy specimens obtained prior to treatment. Using an arbitrary 10% cutoff, STING was differentially expressed among T/NK-cell NHLs; positive in 36 out of 38 (95%) cases of ALK+ anaplastic large cell lymphoma (ALCL), 23 out of 37 (62%) ALK-ALCLs, 1 out of 13 (7.7%) angioimmunoblastic T-cell lymphomas, 15 out of 19 (79%) peripheral T-cell lymphomas, not otherwise specified, 20 out of 36 (56%) extranodal NK/T-cell lymphomas of nasal type, 6 out of 7 (86%) T-cell lymphoblastic lymphomas, and 3 out of 4 (75%) mycosis fungoides. STING expression did not correlate with clinicopathological parameters or outcome in these patients with T/NK-cell lymphoma. By contrast, all 265 B-cell NHLs of various types were STING-negative. In addition, STING mRNA levels were very high in 6 out of 7 T-cell NHL cell lines, namely, ALK+ and ALK-ALCL cell lines, and very low or undetectable in 7 B-cell NHL cell lines, suggesting transcriptional downregulation of STING in neoplastic B-cells. At the protein level, using Western blot analysis and immunohistochemistry performed on cell blocks, STING expression was found to be restricted to T-cell NHL cell lines. Taken together, STING expression represents a novel biomarker and therapeutic target in T- and NK-cell lymphomas with direct immunotherapeutic implications since modulators of cGAS–STING activity are already available for clinical use.

The expression patterns of stimulator of interferon genes (STING) were investigated in a cohort of 158 T- and natural killer (NK)-cell and 265 B-cell non-Hodgkin lymphomas (NHLs), as well as in control reactive lymph nodes and tonsils. STING expression was assessed by immunohistochemical methods using diagnostic biopsy specimens obtained prior to treatment. Using an arbitrary 10% cutoff, STING was differentially expressed among T/NK-cell NHLs; positive in 36 out of 38 (95%) cases of ALK+ anaplastic large cell lymphoma (ALCL), 23 out of 37 (62%) ALK-ALCLs, 1 out of 13 (7.7%) angioimmunoblastic T-cell lymphomas, 15 out of 19 (79%) peripheral T-cell lymphomas, not otherwise specified, 20 out of 36 (56%) extranodal NK/T-cell lymphomas of nasal type, 6 out of 7 (86%) T-cell lymphoblastic lymphomas, and 3 out of 4 (75%) mycosis fungoides. STING expression did not correlate with clinicopathological parameters or outcome in these patients with T/NK-cell lymphoma. By contrast, all 265 B-cell NHLs of various types were STING-negative. In addition, STING mRNA levels were very high in 6 out of 7 T-cell NHL cell lines, namely, ALK+ and ALK-ALCL cell lines, and very low or undetectable in 7 B-cell NHL cell lines, suggesting transcriptional downregulation of STING in neoplastic B-cells. At the protein level, using Western blot analysis and immunohistochemistry performed on cell blocks, STING expression was found to be restricted to T-cell NHL cell lines. Taken together, STING expression represents a novel biomarker and therapeutic target in T- and NK-cell lymphomas with direct immunotherapeutic implications since modulators of cGAS-STING activity are already available for clinical use.

Resumo Os debates em torno do investimento chinês e dos efeitos negativos que este pode ter nos países que o recebem levaram a União Europeia (UE) a avançar com iniciativas para proteger os interesses dos Estados. A emergência do populismo na Itália, associada a um crescente euroceticismo e à instabilidade política do país, influenciou decisivamente a política externa da Itália em matérias ligadas ao investimento chinês, algo que levou a que as suas estratégias de comunicação afetassem, em determinados períodos, a UE. Em sentido oposto, a maior estabilidade interna de Portugal e a opinião favorável da UE levaram a que o país gerisse as suas relações com a China tendo geralmente em consideração a preservação da estabilidade do vetor europeu.

6074 Background: Patients with HPV associated squamous cell carcinoma of the oropharynx have a favorable outcome with respect to tumor control and overall survival (OS) after treatment with chemoradiotherapy (CRT). The leading cause of death in these patients is reported to be peripheral metastases. Because of the favorable outcome for these patients, the medical community tries to find methods to ameliorate treatment intensity, mainly in order to reduce long term morbidity. However, between 10 and 15 % of patients relapse locally in the primary tumor as first site of disease failure. Methods: In this multicentre, randomized, controlled, phase II trial 152 patients with locoregionally advanced oropharyngeal cancer were randomized in a 1:1 ratio to either radiotherapy with cetuximab (arm B) versus the same regimen preceded by 2 cycles of induction chemotherapy (IC) with taxotere/cisplatin/5-FU (arm A). To decrease risk of local failure, an escalated radiation (RT) dose of 74.8 Gy was delivered to T3/T4 tumors and to T2 tumors > 3 cm in the base of tongue. Eligibility criteria included patients 18-75 years, ECOG performance status 0-1 and adequate organ functions. Primary endpoint of the study was to compare PFS between the treatment arms, secondary objectives were recurrence pattern, locoregional control, OS and toxicity. Results: PFS at 2 years was 84.2% (95%CI 76.4-92.8) in arm A and 78.4 (95%CI 69.5-88.3) in arm B (p = 0.20). At the time of analysis there were 26 disease failures, 9 in arm A and 17 in arm B. In arm A there were 3 local, 2 regional and 4 distant relapses as first site of recurrence, and in arm B 4, 4 and 9 relapses in corresponding sites. Local relapse rate as first site of failure was low, i.e. in 4.7%. Local failures constituted 7 relapses out of all 26 (27%), and in 4 of these local failures (57%), the escalated dose was given. In arm B, patients who had no IC, there were more than twice as many patients who had distant metastases as first site of relapse compared to arm A (n.s.). No patient who had a response to IC in the primary tumor or in regional lymph nodes, respectively, measured with CT or MRI, of either CR+CR or CR+PR, had any recurrence, local, regional or distant. So, IC could identify 22 out of 73 evaluable patients (30%) in arm A, who never had any recurrence during follow up. Conclusions: A high incidence of distant metastases as first site of failure is recognized while local failure rate is low. However, despite a high RT dose of 74.8 Gy, delivered to the primary tumor, relapses can appear in this site. Radiological response of tumor to IC could identify patients with no tumor relapse, at least within the first years of follow up, possible candidates for de-escalation treatment protocols. Clinical trial information: 2009-013438-26.

Introduction: The SAM domain and HD domain 1 (SAMHD1) protein is a deoxynucleoside triphosphate (dNTP) triphosphohydrolase, which depletes the intracellular dNTP substrates and thus protects the host (human) cells from replication of viruses such as HIV. Mutations of SAMHD1 gene have been linked to Aicardi-Goutières syndrome (AGS). In lymphoid malignancies, SAMHD1 gene mutations have been detected in a subset of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) resulting in decreased SAMHD1 mRNA levels and also mantle cell lymphoma (MCL) among B-cell neoplasms as well as in a subset (20%) of T-prolymphocytic leukemia (T-PLL). Therefore, SAMHD1 may play a role in oncogenesis as a tumor suppressor. In addition, SAMHD1 may confer resistance to cytarabine by hydrolysing their active triphosphate metabolites and its high protein levels correlate with poorer clinical outcome in acute myeloid leukemia. The mutation status of SAMHD1 gene and its expression patterns in peripheral T-cell lymphoma types is not known yet. The purpose of this study was to investigate SAMHD1 gene alterations using next generation sequencing and SAMHD1 protein expression in common types of PTCL. Methods: The study group included 81 adult patients with peripheral T-cell lymphomas (PTCL) including 26 patients with ALK+ anaplastic large cell lymphoma (ALCL), 20 ALK- ALCL, 13 angioimmunoblastic T-cell lymphomas (AILT) and 22 PTCL, not otherwise specified (NOS) with pre-treatment, formalin-fixed, paraffin-embedded (FFPE) tumor tissues available for immunohistochemical analysis. Double immunostaining (SAMHD1/CD68) was used to distinguish CD68+ histiocytes from the neoplastic T-cells. The Ventana autostainer and a previously validated monoclonal antibody for SAMHD1 (#A303-691A; Bethyl Laboratories, San Antonio, TX, USA) was utilized. The percentage of SAMHD1-positive cells was calculated by counting at least 500 tumor cells in each case. In a subset of 28 PTCLs, next generation sequencing (NGS) was performed using FFPE tissues and an enriched custom TruSight gene panel of 52 genes relevant to lymphoma biology. In addition, 3 control tissue samples were included in the analysis. The analysis pipeline was based on GATK best practices guidelines and all variants were annotated using Ensembl VEP v94.5. Freedom from progression (FFP) and overall survival (OS), were the clinical endpoints. Survival analyses were performed using the Kaplan-Meier method (log-rank test). Results: The expression level of SAMHD1 (percentage of positive neoplastic T-cells) varied significantly with AILT showing the highest level (median percentage 80%) as compared to ALK+ ALCL that showed the lowest level (median percentage 40%) of SAMHD1 expression (p=0.019, Kruskall-Wallis test). SAMHD1 mutations were detected for the first time in a subset of PTCL including 4/11 (36%) ALK+ ALCL, 1/5 (20%) ALK- ALCL, 3/6 (50%) AILT and 2/5 (40%) PTCL, NOS. The SAMHD1 gene alterations included missense mutations, nonsense (stopcodon) and splice region mutations. Importantly, reduced level (low percentage of positive tumor cells) of SAMHD1 protein expression was significantly associated with the presence of SAMHD1 mutations. More specifically, the median percentage of SAMHD1+ neoplastic T-cells was 80% in the PTCL group with wild-type SAMHD1 gene compared to 30% in the PTCL group with mutated SAMHD1 gene (p=0.01, Mann-Whitney U test), thus suggesting that alterations of SAMHD1 gene may represent a mechanism of SAMHD1 protein downregulation in a subset of PTCL. SAMHD1 expression or gene alterations did not correlate with FFP or OS in any PTCL histologic type, although the number of patients included in each group was not adequate to draw definite conclusions for prognostic significance. Conclusions: SAMHD1 gene mutations are frequently detected in a subset of PTCL and are associated with reduced expression of SAMHD1 protein. These findings reveal a novel mechanism (SAMHD1 mutations) of SAMHD1 downregulation in PTCL, and further support the tumor suppressor function of SAMHD1 gene in lymphomas. Disclosures Rosenquist Brandell: AbbVie: Honoraria; AstraZeneca: Honoraria; Illumina: Honoraria; Janssen: Honoraria; Roche: Honoraria.

Background: Detection of metastatic spread of head and neck cancer to cervical lymph nodes is essential for optimal design of therapy. Undetected metastases lead to mortality, which can be prevented by better detection methods. Methods: We analysed 41 lymph nodes from 19 patients with oral squamous cell carcinoma (OSCC). Each lymph node was divided in two, one half processed for histopathology and the other half dissociated into single-cell suspension, stained for the carcinoma cell markers cytokeratin 5/8 (CK5/8), epithelial cell adhesion molecule (EpCAM) and epithelial mucin (MUC-1), and analysed with flow cytometry. Flow cytometry data were compared with histopathology performed on serial sections and immunohistochemistry. Six cervical lymph nodes from cancer-free patients were used to establish baseline levels in flow cytometry. Results: Flow cytometry analysis (fluorescence-activated cell sorting; FACS) detected all six metastases confirmed by histopathology as well as the histologically negative nodes. Importantly, among nine sentinel lymph nodes, FACS analysis detected

Introduction: ALK+ anaplastic large cell lymphoma (ALCL) frequently carries the t(2;5) resulting in overexpression of NPM-ALK oncoprotein, which activates many oncogenic pathways. The Jab1 (c-Jun activation domain-binding protein-1), initially discovered as a c-Jun co-activator, represents the fifth component of an evolutionary highly conserved 8-subunit protein complex, named COP9 signalosome (CSN). The Jab1/Csn5 gene operates as an oncogene in cancer through multiple mechanisms including cell cycle control via the CDK inhibitor p27. Recent evidence suggests that Jab1/Csn5 is also involved in immune checkpoint regulation through PD-L1 stabilization by inhibition of PD-L1 proteasomal degradation. Recently, we reported that the protein levels of Jab1/Csn5 are the highest in ALCL as compared to other peripheral T-cell lymphomas (PTCL) and significantly correlate with PD-L1 levels in PTCLs (Drakos et al, HemaSphere 2019; (3):p596, EHA abstract). In this study, we hypothesized that NPM-ALK may regulate Jab1/Csn5 expression and thus contributes to cell proliferation as well as PD-L1/PD1 immune checkpoint regulation. Methods: The in vitro system included 4 ALK+ (Karpas 299, DEL, SUPM2, SUDHL1) and 2 ALK- (Mac1, Mac2a) ALCL cell lines as well as murine Ba/F3 parental and Ba/F3 clones stably transfected with NPM-ALK (Ba/F3-NPM-ALK), EEF1G (Ba/F3-EEF1G-ALK) or control plasmid (Ba/F3-MIG). Transient transfections with Jab1/CSN si-RNAs and STAT3 si-RNAs were also performed in ALCL cells. In addition, ALCL cells were treated with ALK (Crizotonib) or STAT3 (XIII) inhibitors. Two animal models were used in the study: 1) in the ex vivo model, Karpas-299 clones stably transfected with Jab1/CSN5 shRNA constructs were generated and injected in both thighs of SCID-beige immunocompromised mice. The Jab1/CSN5 shRNA and the control mice were followed for tumor development and their tumors were measured and analysed by immunohistochemistry. 2) in the patient derived xenograft (PDX) model of ALK+ ALCL, the mice were treated with the ALK inhibitor Ceritinib or control vehicle and were monitored for changes in tumor characteristics over two weeks. Tumor specimens were taken at early time points (24, 48, and 72 hrs) following treatment in order to obtain viable tumor cells for protein analysis. Results: Jab1/Csn5 was substantially upregulated in the Ba/F3-NPM-ALK and Ba/F3-EEF1G-ALK stable clones as compared to paternal or control Ba/F3-MIG clones. Jab1/Csn5 upregulation was associated with high STAT3 activation (Tyr705-phosphorylation) and increased PD-L1 gene expression in this system. Inversely, inhibition of ALK activity was associated with STAT3 de-activation and decreased protein levels of Jab1/Csn5 and PD-L1 in ALK+ ALCL cells. Knocking down STAT3 by siRNA or inhibition of its activity by the XIII inhibitor resulted in decreased levels of Jab1/Csn5 protein in both ALK+ and ALK- ALCL cell lines. The SCID-beige mice that received Jab1/CSN5-shRNA clones showed significant delay in tumor development and longer survival as compared to control mice, which was associated with significantly decreased PD-L1 protein levels and p27 upregulation in the tumor cells (xenografts). Treatment of the PDX mice with Ceritinib, a potent next generation ALK inhibitor, resulted in substantial tumor necrosis after 72 hrs and decreased tumor size at day 7 post-treatment. At earlier time points, de-activation (de-phosphorylation) of ALK kinase and STAT3 was observed in the Ceritinib-treated mice, which was linked to variably lower levels of Jab1/CSN5 and PD-L1 proteins as compared to control mice. Conclusion: Jab1/CSN5 is a novel downstream target of the NPM-ALK oncogenic kinase that regulates its expression, at least in part, through STAT3 activation. The Jab1/CSN5-mediated stabilization of PD-L1 can be efficiently inhibited by Ceritinib in preclinical animal models of ALK+ ALCL. Disclosures Österborg: BeiGene: Research Funding; Janssen: Research Funding; Abbvie: Research Funding; Kancera AB: Research Funding; Gilead: Research Funding. Vega:National Cancer Institute, national Institutes of Health: Other: Grant Funding-R01CA222918.

Introduction: The SAM domain and HD domain 1 (SAMHD1) protein is a deoxynucleoside triphosphate (dNTP) triphosphohydrolase, which has been initially described to restrict human immunodeficiency virus type 1 (HIV-1) in certain cell types through depletion of intracellular dNTP substrates required for HIV-1 reverse transcription. Mutations of SAMHD1 gene have been linked to Aicardi-Goutières syndrome (AGS) and have been identified as putative drivers of chronic lymphocytic leukemia resulting in decreased SAMHD1 mRNA and protein levels. More recently, SAMHD1 mutations have been reported in T-prolymphocytic leukemia (T-PLL). Based on these findings and the fact that SAMHD1 limits the dNTP pool in the cell, it may play a role in oncogenesis as a tumor suppressor. In addition, SAMHD1 may confer resistance to nucleoside-based chemotherapies by hydrolysing their active triphosphate metabolites, with cytarabine in acute myeloid leukemia being an example (Herold et al, Nat Med 2017; 23(2):256-263). The expression patterns and the potential role of SAMHD1 in the pathogenesis of peripheral T-cell lymphomas (PTCL) are not yet known. Methods: The patient cohort included 64 PTCLs of various histologic types which were diagnosed and treated at Karolinska University Hospital (Sweden). A control group of 4 reactive lymph nodes and 2 reactive tonsils was included in the study for comparison. All tissue samples were obtained prior to therapy. SAMHD1 expression was assessed by immunohistochemistry performed on a PTCL tissue microarray (TMA) with duplicate tumor cores from each case or full tissue sections using dual immunostaining (SAMHD1 / CD68) and a monoclonal antibody against SAMHD1 (Bethyl Laboratories, San Antonio, TX). At least 500 lymphoma cells were counted to calculate the percentage of SAMHD1-positive tumor cells. Overall survival (OS) was defined as time from diagnosis to death or last follow-up. Event-free survival (EFS) was defined as time from diagnosis to relapse, death, or last follow-up. Survival analyses were performed using the Kaplan-Meier method (log-rank test) and Cox regression models. Two T-cell lymphomas cell lines (Mac1, Mac2A) were used as an in vitro system. As our preliminary findings from in silico analysis revealed potential binding sites for MYC on the SAMHD1 gene promoter, we hypothesized that MYC might regulate SAMHD1 expression. Therefore, the T-cell lymphoma cell lines were treated with the selective BET / MYC inhibitor JQ-1 or transiently transfected with a MYC-overexpressing plasmid or MYC gene-specific siRNA constructs, respectively. Western blot analysis was used to assess the protein levels. Results: SAMHD1 protein was expressed in reactive T-cells and histiocytes (CD68+) in all reactive lymphoid tissues (lymph nodes and tonsils) with strong staining intensity. SAMHD was differentially expressed among PTCL subtypes generally with weaker staining intensity as compared to normal T-cells and histiocytes, thus being positive in all (100%) angioimmunoblastic T-cell lymphomas (AILT), 67% PTCL-NOS, 45% ALK+ ALCL, 20% of ALK+ ALCL, and none (0%) of T-lymphoblastic lymphomas (p=0.0017, chi-square test). Among the SAMHD1- positive cases, the percentage of positive lymphoma cells ranged from 0 to 100% and its highest median was observed in AILT. SAMHD1 expression inversely correlated with CD30 expression (% CD30+ positive lymphoma cells) (p=0.0025, Mann-Whitney test). No significant associations between SAMHD1 levels and other clinicopathologic parameters or clinical outcome (EFS or OS) were found, however, the number of patients analyzed in each histologic subtype was limited. Inhibition of MYC activity by JQ-1 or MYC gene silencing with specific siRNA resulted in a substantial increase in the SAMHD1 protein level in T-cell lymphoma cell lines. Inversely, transient transfection of the cell lines with a MYC overexpressing plasmid resulted in decreased levels of SAMHD1. Taken together, the in vitro data suggest a possible MYC-associated regulation (repression) of SAMHD1 gene expression in T-cell lymphoma. Conclusions: SAMHD1 is shown for the first time to be differentially expressed among PTCL types and its regulation may involve MYC. Preliminary survival analysis shows no significant associations of SAMHD1 expression with EFS and OS in this cohort of PTCL, however, analysis of a larger PTCL study group is underway to draw definite conclusions. Disclosures Österborg: Gilead: Consultancy, Research Funding; Beigene: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; Abbvie: Research Funding.

Introduction: The PD-1 / PD-L1 interaction is a crucial immune checkpoint in cancer, which has been targeted by monoclonal antibodies currently used in clinical trials. The genetic basis and transcriptional regulation of PD-L1 has been previously investigated in ALK+ and ALK- anaplastic large cell lymphomas (ALCL) by our group (Atsaves et al, Leukemia 2017, (7):1633-1637), however, the regulatory mechanisms of PD-1/PD-L1 immune checkpoint in other T-cell lymphomas are not yet known. PD-L1 expression in neoplastic cells has been associated with worse clinical outcome in other hematologic malignancies including Hodgkin lymphoma, diffuse large B-cell lymphoma (DLBCL) and plasma cell myeloma, however, the clinical significance of PD-L1 expression in neoplastic cells and in the immune cells of the tumor microenvironment in PTCLs has not been studied to date. In this study, we investigated PD-L1 gene copy number alterations using a genome-wide approach and diagnostic biopsies. We also assessed for the expression patterns of PD-L1 in the neoplastic cells and histiocytes in PTCL tumors as well as for their possible associations with clinical outcome. Methods: The PTCL study group included 64 patients (median age 62 years; 61% males, various histologic types), diagnosed and treated at Karolinska University Hospital (Sweden). All tissue samples were obtained prior to therapy. PD-L1 expression was assessed by immunohistochemistry performed on tissue microarrays or full tissue sections using a PD-L1 monoclonal antibody (SP263, Ventana). At least 500 lymphoma cells were counted to calculate the percentage of PDL1-positive tumor cells. PD-L1 expression in histiocytes was scored as "high" or "low" (arbitrary) based on the number of positive infiltrating histiocytes. Overall survival (OS) defined as time from diagnosis to death or last follow-up was chosen as the endpoint for outcome. Survival analyses were performed using the Kaplan-Meier method (log-rank test) and Cox hazards models. In addition, a pilot series of 24 PTCLs were analysed by Oncoscan (Affymetrics) for PD-L1 gene copy number alterations and the results were confirmed by digital q-RT PCR at the mRNA level. Genomic DNA and total RNA were extracted from diagnostic formalin-fixed, paraffin-embedded (FFPE) biopsies using standard protocols. Associations between PD-L1 expression and PTCL type were statistically analysed with Fisher's exact, chi-square, Mann-Whitney and Kruskal-Wallis tests. Survival analysis was performed using the Kaplan-Meier method (log rank test) and Cox proportional hazards model. Results: Whole genome analysis using Oncoscan (Affymetrics) showed low-level chromosomal gains in 2 (8.3%) PTCLs, which were confirmed by digital q-RT PCR that demonstrated slightly increased PD-L1 mRNA levels (PD-L1/reference gene Conclusions: Copy number alterations of the PD-L1 gene (9p24.1 locus) are uncommon in PTCL subtypes and therefore, PD-L1 gene expression is likely regulated at the transcriptional of post-translational levels in T-cell lymphomas. PD-L1 negativity in the lymphoma cells and high PD-L1 expression in histiocytes are strong adverse prognostic factors in PTCL, however, larger series are needed to confirm these associations in each histologic type of PTCL. Disclosures Österborg: Pharmacyclics: Research Funding; Janssen: Research Funding; Gilead: Consultancy, Research Funding; Abbvie: Research Funding; Beigene: Research Funding.

Human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are widely used semiquantitative assays for selecting breast cancer patients for HER2 antibody therapy. However, both techniques have been shown to have disadvantages. Our aim was to test a recent automated technique of combined IHC and brightfield dual in situ hybridization-gene protein detection platform (GPDP)-in breast cancer HER2 protein, gene, and chromosome 17 centromere status evaluations, comparing the results in accordance to the American Society of Clinical Oncology/College of American Pathologists recommendations for HER2 testing in breast cancer from both 2007 and 2013. The GPDP technique performance was evaluated on 52 consecutive whole slide invasive breast cancer cases with HER2 IHC 2/3+ scoring results. Applying in turns the American Society of Clinical Oncology/College of American Pathologists recommendations for HER2 testing in breast cancer from 2007 and 2013 to both FISH and GPDP DISH assays, the HER2 gene amplification results showed 100% concordance among amplified/nonamplified cases, but there was a shift in 4 cases toward positive from equivocal results and toward equivocal from negative results. This might be related to the emphasis on the average HER2 copy number in the 2013 criteria. HER2 expression by IVD market IHC kit (Pathway®) has a strong correlation with GPDP HER2 protein, including a full concordance for all cases scored as 3+ and a reduction from 2+ to 1+ in 7 cases corresponding to nonamplified cases. Gene protein detection platform HER2 protein "solo" could have spared the need for 7 FISH studies. In addition, the platform offered advantages on interpretation reassurance including selecting areas for counting gene signals paralleled with protein IHC expression, on heterogeneity detection, interpretation time, technical time, and tissue expense.

Tuberculosis is a disease relatively frequent in renal transplant patients, presenting a wide variety of clinical manifestations, often involving various organs and potentially fatal. Gastrointestinal tuberculosis, although rare in the general population, is about 50 times more frequent in renal transplant patients. Intestinal tuberculosis has a very difficult investigational approach, requiring a high clinical suspicion for its diagnosis. Therapeutic options may be a problem in the context of an immunosuppressed patient, requiring adjustment of maintenance therapy. The authors report two cases of isolated gastro-intestinal tuberculosis in renal transplant recipients that illustrates the difficulty of making this diagnosis and a brief review of the literature on its clinical presentation, diagnosis, and therapeutic approach.

Auteur(s) : Aristoteles ROSMANINHO1 arisrosmaninho@gmail.com, Pedro FARRAJOTA2, Carlos PEIXOTO2, Isabel AMORIM1, Manuela SELORES1 1 Department of Dermatology, 2 Anatomopathology, Centro hospitalar do Porto-HSA, Servico Dermatologia, Edificio Consultas Externas-HSA (Ex-CICAP), Rua D. Manuel II s/no, 4099-001 Porto, Portugal A 47-year-old man presented with a 2-year history of a non-painful lesion on his right knee. The lesion had gradually enlarged overtime and a slight darkening was observed [...]

We present a florid case of remitting seronegative symmetrical synovitis with pitting edema that was actually a paraneoplastic syndrome of an asymptomatic undiagnosed adenosquamous lung cell carcinoma. The arthritis led to a screening for lung cancer and an early enough diagnosis for a curative intervention.