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Key resource identifiers (RRIDs), antibodies, methods, and scoring systems used for immunohistochemistry analyses

Excel spreadsheets showing: (S1a) the differential expression analysis between mesenchymal vs proneural tumors; (S1b) the differential expression analysis between classical vs mesenchymal tumors; (S1c) the differential expression analysis between classical vs proneural tumors; (S1d) classification of tumor samples based on the RNA-Seq results into the three TCGA molecular subtypes (according to the GlioVis algorithms KNN, SVM, and ssGSEA) and classification according to the IGS clusters; (S1e) immunohistochemical results of samples classified in the three TCGA molecular subtypes (according to the GlioVis algorithms KNN, SVM, and ssGSEA) and IGS clusters; and (S1f) results of the gene fusion analysis in the tumor samples, the molecular subtype of the tumor (according to the GlioVis algorithms KNN, SVM, and ssGSEA), and the tumor IGS clusters

Patient characteristics and molecular subtypes

In 38 sequenced samples classified according to the Support Vector Machine (SVM) algorithm, heatmaps were plotted to compare the expression of the top 50 genes between (A) classical and mesenchymal, (B) mesenchymal and proneural, and (C) classical and proneural subtypes.

Purpose:Molecular subtype classifications in glioblastoma may detect therapy sensitivities. IHC would potentially allow the identification of molecular subtypes in routine clinical practice.Experimental Design:Formalin-fixed, paraffin-embedded tumor samples of 124 uniformly treated, newly diagnosed patients with glioblastoma were submitted to RNA sequencing, IHC, and immune-phenotyping to identify differences in molecular subtypes associated with treatment sensitivities.Results:We detected high molecular and IHC overlapping of the The Cancer Genome Atlas (TCGA) mesenchymal subtype with instrinsic glioma subtypes (IGS) cluster 23 and of the TCGA classical subtype with IGS cluster 18. IHC patterns, gene fusion profiles, and immune-phenotypes varied across subtypes. IHC revealed that the TCGA classical subtype was identified by high expression of EGFR and low expression of PTEN, while the mesenchymal subtype was identified by low expression of SOX2 and high expression of two antibodies, SHC1 and TCIRG1, selected on the basis of RNA differential transcriptomic expression. The proneural subtype was identified by frequent positive IDH1 expression and high Olig2 and Ki67 expression. Immune-phenotyping showed that mesenchymal and IGS 23 tumors exhibited a higher positive effector cell score, a higher negative suppressor cell score, and lower levels of immune checkpoint molecules. The cell-type deconvolution analysis revealed that these tumors are highly enriched in M2 macrophages, resting memory CD4+ T cells, and activated dendritic cells, indicating that they may be ideal candidates for immunotherapy, especially with anti-M2 and/or dendritic cell vaccination.Conclusions:There is a subset of tumors, frequently classified as mesenchymal or IGS cluster 23, that may be identified with IHC and could well be optimal candidates for immunotherapy.

Epithelial to mesenchymal transition (EMT) is an important mechanism of invasion in cutaneous squamous cell carcinomas (cSCCs) and has been found to be enhanced in tumors originated from actinic keratosis with transformation limited to the basal epithelial layer -differentiated pathway-, compared to cases with invasion subsequent to complete epidermal transformation -classical pathway-. Several microRNAs and proteins can contribute to EMT modulation in cSCCs. MicroRNA21 and microRNA31 are involved in posttranscriptional regulation of protein expression and could play a relevant role in EMT and cSCC progression. Throughout the EMT process upregulation of matrix metalloproteinases (MMPs) enhances invasiveness and MMP-1 and MMP-3 contribute to local invasion, angiogenesis and metastasis in cSCCs. Additionally, cSCC development is associated with PTEN loss and NF-kappa B, NOTCH-1 and p63 activation. The aim of this work is to identify differences in the expression of those molecules between both pathways of cSCCs development. Eight tissue microarrays from 80 consecutive cSCCs were analyzed using LNA-based miRNA in situ hybridization for miRNA21 and miRNA31 evaluation, and immunohistochemistry for MMP-1, MMP-3, PTEN, NOTCH-1, NF-kappa B, p63 and CD31. Significantly higher expression of miRNA31 (p < 0.0001) and MMP-1 (p = 0.0072) and angiogenesis (p = 0.0199) were found in the differentiated pathway, whereas PTEN loss (p = 0.0430) was more marked in the classical pathway. No significant differences were found for the other markers. Our findings support a contribution of miRNA31 and MMP-1 in the differentiated pathway, associated to EMT and increased microvascularization. The greater PTEN loss in the classical pathway indicate that its relevance in cSCC is not EMT-related.

Context Lynch syndrome (LS) is the most common inherited colorectal and endometrial cancer syndrome, caused by germline mutations in DNA mismatch repair (MMR) genes. It is also characterized by an increased risk of other tumors with lower prevalence, such as adrenal cortical carcinoma (ACC), an endocrine tumor with an incidence of Evidence Acquisition The objective of this study is to determine the prevalence of ACC in a Spanish LS cohort and their molecular and histological characteristics. This retrospective study includes 634 patients from 220 LS families registered between 1999 and 2018. Evidence Synthesis During the follow-up period, 3 patients were diagnosed with ACC (0.47%); all were carriers of a MSH2 germline mutation. The 3 ACC patients presented loss of expression of MSH2 and MSH6 proteins. One tumor analysis showed loss of heterozygosity of the MSH2 wildtype allele. Our findings support previous data that considered ACC as a LS spectrum tumor. Conclusion MMR protein immunohistochemistry screening could be an efficient strategy to detect LS in patients with ACC.

Background There is growing evidence that the subventricular zone (SVZ) may be involved in both the initiation and progression of glioblastoma (GB). We aimed to assess tumor proximity to the SVZ as a potential prognostic factor in GB. Method Retrospective study of 133 patients diagnosed with primary GB who underwent surgery followed by temozolomide-based chemoradiation between 2010 and 2016. All lesions were classified according to their anatomic relation with the SVZ. We determined the effect of tumor contact with the SVZ on progression-free survival (PFS), overall survival (OS), type, and patterns of recurrence. Results At a median follow-up of 18.6 months (95% CI 15.9-21.2), PFS and OS were 7.5 (95% CI 6.7-8.3) and 13.9 (95% CI 10.9-16.9) months, respectively. On the univariate analyses, initial contact with the SVZ was a factor for poor prognosis for both PFS (6.1 vs. 8.7 months;p = 0.006) and OS (10.6 vs. 17.9 months;p = 0.037). On the multivariate analysis, tumor contact with the SVZ remained statistically significant for PFS, but not OS. Patients with SVZ-contacting tumors presented a higher rate of aggressive clinical progression (30.9% vs. 11.3%;p = 0.007) and contralateral relapse patterns (23.4% vs. 9.1%;p = 0.048). Conclusions Our results suggest that glioblastoma contact with the SVZ appears to be an independent prognostic factor for poor PFS. The presence of an SVZ-contacting tumor was associated with more aggressive recurrences and a higher rate of contralateral relapses. These findings suggest that this variable may be a new prognostic factor in glioblastoma.

Pharmacologic treatment of acromegaly is currently based upon assay-error strategy, the first-generation somatostatin receptor ligands (SRL) being the first-line treatment. However, about 50% of patients do not respond adequately to SRL. Our objective was to evaluate the potential usefulness of different molecular markers as predictors of response to SRL. We used somatotropinoma tissue obtained after surgery from a national cohort of 100 acromegalic patients. Seventy-one patients were treated with SRL during at least 6 months under maximal therapeutic doses according to IGF1 values. We analyzed the expression of SSTR2, SSTR5, AIP, CDH1 (E-cadherin), MKI67 (Ki-67), KLK10, DRD2, ARRB1, GHRL, In1-Ghrelin, PLAGL1 and PEBP1 (RKIP) by RT-qPCR and mutations in GNAS gene by Sanger sequencing. The response to SRL was categorized as complete response (CR), partial (PR) or non-response (NR) if IGF1 was normal, between >23 SDS IGF1 at 6 months of follow-up, respectively. From the 71 patients treated, there were 27 CR (38%), 18 PR (25%) and 26 NR (37%). SSTR2, Ki-67 and E-cadherin were associated with SRL response (P P P P SSTR5 expression was higher in patients pre-treated with SRL before surgery. We conclude that somatotropinomas showed heterogeneity in the expression of genes associated with SRL response. E-cadherin was the best molecular predictor of response to SRL. Thus, the inclusion of E-cadherin in subsequent treatment-decision after surgical failure may be useful in acromegaly.

INTRODUCTION AND OBJECTIVE:Lymph node (LN) status is a key prognostic factor in the decision-making process for prostate cancer (PC) management. Sectioning and haematoxylin-eosin (HE) staining tech...

Circulating biomarkers in blood may provide an interesting alternative to risky tissue biopsies in the diagnosis and follow-up of glioblastoma patients. We have assessed MGMT methylation status in blood and tissue samples from unresected glioblastoma patients who had been included in the randomized GENOM-009 trial. Paired blood and tissue samples were assessed by methylation-specific PCR (MSP) and pyrosequencing (PYR). After establishing the minimum PYR cut-off that could yield a significant difference in overall survival, we assessed the sensitivity, specificity, positive predictive value and negative predictive value (NPV) of the analyses. Methylation could be detected in cfDNA by both MSP and PYR but with low concordance with results in tissue. Sensitivity was low for both methods (31% and 38%, respectively), while specificity was higher for MSP in blood than for PYR in plasma (96% vs 76%) and NPV was similar (56 vs 57%). Concordance of results in tissue by MSP and PYR was 84.3% (P < 0.001) and correlated with outcome. We conclude that detection of cfDNA in the blood of glioblastoma patients can be an alternative when tumor tissue is not available but methods for the detection of cfDNA in blood must improve before it can replace analysis in tumor tissue.

e14039 Background: Glioblastoma (GB) is the most prevalent primary brain tumor in adults. The first-line treatment is based on standard brain surgery and adjuvant radio-chemotherapy. Indoleamine 2,3-dioxygenase 1 (IDO1) is a catabolic enzyme that plays a role in the metabolism of tryptophan (Trp), thereby promoting a state of immunosuppression. New treatments inhibiting this pathway are being tested in GB. This study aims to assess the expression of IDO in GB patients to determine whether this enzyme may be an actionable target for the treatment of GB. Methods: This is a retrospective transversal study whose database comes from the GLIOCAT project. Expression of IDO protein and mRNA was evaluated in tumor specimens of newly diagnosed GB patients by immunohistochemistry (IHC) (percentage of positive tumor cells) with an antibody anti-IDO1 (Sigma-Aldrich Cat#HPA027772) and by RNA sequencing (RNA-seq). RNA-seq (IIlumina HiSeq2000) in paired-end mode with a read length of 2x76bp using TruSeq SBS Kit v4). Reads were mapped to the human reference genome version hg38 with STAR. Genes were quantified with RSEM using gencode annotation version 24. Normalization of gene expression was performed with the trimmed-mean of M values (TMM) method. IDO gene expression values of -6 logCPM were considered as not expressed. Results: From the 255 samples assessed by IHC, 199 patients (78%) did not express IDO1 protein (mean 0.8±2.73, range 0-21%). From the 139 samples assessed by RNA-seq, TMM values, were negative for 49.6%, while low expression was detected for the other samples (mean -3.36 +/- 3.15 logCPM, range -6.12-4.32). Conclusions: Although IDO1 is barely expressed in normal brain tissue, certain studies show that its expression is upregulated in GB, either by tumor cells or indirectly induced in host antigen presenting cells, leading to immune evasion. Therefore, the metabolism of Trp is an attractive pathway to be targeted for the treatment of GB; however, our results show that IDO may not be the main target to be inhibited due to its undetectable or very low levels of expression.

Purpose: Glioblastoma is the most aggressive brain tumor in adults and has few therapeutic options. The study of molecular subtype classifications may lead to improved prognostic classification and identification of new therapeutic targets. The Cancer Genome Atlas (TCGA) subtype classification has mainly been applied in U.S. clinical trials, while the intrinsic glioma subtype (IGS) has mainly been applied in European trials. Experimental Design: From paraffin-embedded tumor samples of 432 patients with uniformly treated, newly diagnosed glioblastoma, we built tissue microarrays for IHC analysis and applied RNA sequencing to the best samples to classify them according to TCGA and IGS subtypes. Results: We obtained transcriptomic results from 124 patients. There was a lack of agreement among the three TCGA classificatory algorithms employed, which was not solely attributable to intratumoral heterogeneity. There was overlapping of TCGA mesenchymal subtype with IGS cluster 23 and of TCGA classical subtype with IGS cluster 18. Molecular subtypes were not associated with prognosis, but levels of expression of 13 novel genes were identified as independent prognostic markers in glioma-CpG island methylator phenotype–negative patients, independently of clinical factors and MGMT methylation. These findings were validated in at least one external database. Three of the 13 genes were selected for IHC validation. In particular, high ZNF7 RNA expression and low ZNF7 protein expression were strongly associated with longer survival, independently of molecular subtypes. Conclusions: TCGA and IGS molecular classifications of glioblastoma have no higher prognostic value than individual genes and should be refined before being applied to clinical trials.

Objective Large somatotrophic adenomas depict poor response to somatostatin receptor ligands (SRLs). Debulking has shown to enhance SRLs effect in some but not all cases and tumour volume reduction has been proposed as the main predictor of response. No biological studies have been performed so far in this matter. We aimed to identify molecular markers of response to SRLs after surgical debulking in GH-secreting adenomas. Design We performed a multicenter retrospective study. Patients 24 patients bearing large GH-producing tumours. Measurements Clinical data and SRLs response both before and after surgical debulking were collected, and 21 molecular biomarkers of SRLs response were studied in tumour samples by gene expression. Results From the 21 molecular markers studied, only two of them predicted enhanced SRLs response after surgery. Tumours with improved response to SRLs after surgical debulking showed lower levels of Ki-67 (MKI67, FC = 0.17 and P = .008) and higher levels of RAR-related orphan receptor C (RORC) (FC = 3.1 and P < .001). When a cut-off of no detectable expression was used for Ki-67, the model provided a sensitivity of 100% and a specificity of 52.6% with an area under the curve of 65.8%. Using a cut-off of 2 units of relative expression of RORC, the prediction model showed 100% of sensitivity and specificity. Conclusions High levels of RORC and low levels of Ki-67 identify improved SRLs response after surgical debulking in large somatotropic adenomas. To determine their expression would facilitate medical treatment decision-making after surgery.

Neoadjuvant cisplatin-based chemotherapy followed by radical cystectomy is the recommended treatment, with the highest level of evidence, for patients with muscle-invasive bladder cancer (MIBC). However, only a minority of patients receive this treatment, mainly due to patient comorbidities, the relatively small survival benefit, and the lack of predictive biomarkers to select those patients most likely to benefit from this multimodal approach. In addition, adjuvant chemotherapy has been recommended for patients with high-risk MIBC, although randomized trials have not provided conclusive evidence on the impact of this approach. At present, however, this situation is changing, largely due to our improved knowledge of the molecular biology of bladder cancer, which has enabled us to identify new prognostic and predictive biomarkers that can be used to select the most appropriate treatment for each patient. Moreover, new active treatments, especially immunotherapy, have shown promising results in the neoadjuvant setting. In addition, the gene expression profile of bladder tumors can be used to classify them into different subtypes, which correlate with specific clinical-pathological characteristics and with treatment response or resistance. Therefore, the main objective for the near future is to introduce these translational breakthroughs into routine clinical practice in order to personalize treatment for each patient.

Glioblastoma is the most aggressive brain tumor in adults and has few therapeutic options. The study of molecular subtype classifications may lead to improved prognostic classification and identification of new therapeutic targets. The Cancer Genome Atlas (TCGA) subtype classification has mainly been applied in U.S. clinical trials, while the intrinsic glioma subtype (IGS) has mainly been applied in European trials.From paraffin-embedded tumor samples of 432 patients with uniformly treated, newly diagnosed glioblastoma, we built tissue microarrays for IHC analysis and applied RNA sequencing to the best samples to classify them according to TCGA and IGS subtypes.We obtained transcriptomic results from 124 patients. There was a lack of agreement among the three TCGA classificatory algorithms employed, which was not solely attributable to intratumoral heterogeneity. There was overlapping of TCGA mesenchymal subtype with IGS cluster 23 and of TCGA classical subtype with IGS cluster 18. Molecular subtypes were not associated with prognosis, but levels of expression of 13 novel genes were identified as independent prognostic markers in glioma-CpG island methylator phenotype-negative patients, independently of clinical factors andTCGA and IGS molecular classifications of glioblastoma have no higher prognostic value than individual genes and should be refined before being applied to clinical trials.

Background Standard treatment for glioblastoma is radiation with concomitant and adjuvant temozolomide for 6 cycles, although the optimal number of cycles of adjuvant temozolomide has long been a subject of debate. We performed a phase II randomized trial investigating whether extending adjuvant temozolomide for more than 6 cycles improved outcome. Methods Glioblastoma patients treated at 20 Spanish hospitals who had not progressed after 6 cycles of adjuvant temozolomide were centrally randomized to stop (control arm) or continue (experimental arm) temozolomide up to a total of 12 cycles at the same doses they were receiving in cycle 6. Patients were stratified by MGMT methylation and measurable disease. The primary endpoint was differences in 6-month progression-free survival (PFS). Secondary endpoints were PFS, overall survival (OS), and safety (Clinicaltrials.gov NCT02209948). Results From August 2014 to November 2018, 166 patients were screened, 7 of whom were ineligible. Seventy-nine patients were included in the stop arm and 80 in the experimental arm. All patients were included in the analyses of outcomes and of safety. There were no differences in 6-month PFS (control 55.7%; experimental 61.3%), PFS, or OS between arms. MGMT methylation and absence of measurable disease were independent factors of better outcome. Patients in the experimental arm had more lymphopenia (P Conclusions Continuing temozolomide after 6 adjuvant cycles is associated with greater toxicity but confers no additional benefit in 6-month PFS. Key Points 1. Extending adjuvant temozolomide to 12 cycles did not improve 6-month PFS. 2. Extending adjuvant temozolomide did not improve PFS or OS in any patient subset. 3. Extending adjuvant temozolomide was linked to increased toxicities.

The use of epithelial cell adhesion molecule (EPCAM) immunohistochemistry (IHC) is not included in the colorectal cancer (CRC) screening algorithm to detect Lynch syndrome (LS) patients. The aim of the present study was to demonstrate that EPCAM IHC is a useful tool to guide the LS germ-line analysis when a loss of MSH2 expression was present. We retrospectively studied MSH2 and EPCAM IHC in a large series of 190 lesions composed of malignant neoplasms (102), precursor lesions of gastrointestinal (71) and extra-gastrointestinal origin (9), and benign neoplasms (8) from different organs of 71 patients suspicious of being LS due to MSH2 alterations. LS was confirmed in 68 patients, 53 with MSH2 mutations and 15 with EPCAM 3&prime, end deletions. Tissue microarrays were constructed with human normal tissues and their malignant counterparts to assist in the evaluation of EPCAM staining. Among 154 MSH2-negative lesions, 17 were EPCAM-negative, including 10 CRC and 7 colorectal polyps, and 5 of them showed only isolated negative glands. All lesions showing a lack of EPCAM expression belonged to patients with EPCAM 3&prime, end deletions. EPCAM IHC is a useful screening tool, with 100% specificity to identify LS patients due to EPCAM 3&prime, end deletions in MSH2-negative CRC and MSH2-negative colorectal polyps.

Purpose: Molecular subtype classifications in glioblastoma may detect therapy sensitivities. IHC would potentially allow the identification of molecular subtypes in routine clinical practice. Experimental Design: Formalin-fixed, paraffin-embedded tumor samples of 124 uniformly treated, newly diagnosed patients with glioblastoma were submitted to RNA sequencing, IHC, and immune-phenotyping to identify differences in molecular subtypes associated with treatment sensitivities. Results: We detected high molecular and IHC overlapping of the The Cancer Genome Atlas (TCGA) mesenchymal subtype with instrinsic glioma subtypes (IGS) cluster 23 and of the TCGA classical subtype with IGS cluster 18. IHC patterns, gene fusion profiles, and immune-phenotypes varied across subtypes. IHC revealed that the TCGA classical subtype was identified by high expression of EGFR and low expression of PTEN, while the mesenchymal subtype was identified by low expression of SOX2 and high expression of two antibodies, SHC1 and TCIRG1, selected on the basis of RNA differential transcriptomic expression. The proneural subtype was identified by frequent positive IDH1 expression and high Olig2 and Ki67 expression. Immune-phenotyping showed that mesenchymal and IGS 23 tumors exhibited a higher positive effector cell score, a higher negative suppressor cell score, and lower levels of immune checkpoint molecules. The cell-type deconvolution analysis revealed that these tumors are highly enriched in M2 macrophages, resting memory CD4+ T cells, and activated dendritic cells, indicating that they may be ideal candidates for immunotherapy, especially with anti-M2 and/or dendritic cell vaccination. Conclusions: There is a subset of tumors, frequently classified as mesenchymal or IGS cluster 23, that may be identified with IHC and could well be optimal candidates for immunotherapy.

Background Type B intramural hematoma (IMH) is considered a low-risk entity for aortic complications if aortic dilation, containing rupture or clinical instability are absent. However, the development of intimal disruptions (ID), present in >40% of cases, poses an unknown risk. Objectives To establish which ID characteristics imply a higher risk of aortic complications and, therefore, merit invasive treatment. Methods A systematic review and a meta-analysis were made following a search in EMBASE, MEDLINE and PsycINFO for articles published between January 1995 and December 2017. The combined endpoint was defined as aortic mortality, invasive treatment for aortic disease and/or increase in maximum aortic diameter ≥55 mm. Lesions with communicating orifice ≤3 mm were defined as tiny ID (TID) and those with >3 mm as focal ID (FID). Results Six studies with 564 participants diagnosed of type B IMH were included. Incidence of ID was 54.3% (306 individuals): 27.7% (156 individuals) initially met TID criteria; however, 13.9% of these (21 of 151 with morphologic evolution) evolved to FID within the first 6 months. Ninety-two cases suffered clinical aorta-related events (16.3%; mean follow-up range: 15–85 months; median: 52 months). Patients with TID had a similar risk of aorta-related events to those without ID (RR = 0.904; 95% CI, 0.335–2.440; P = 0.842; I2 = 42.5%), but lower than those with FID (RR = 0.299; 95% CI, 0.094–0.952; P = 0.041; I2 = 26.9%). Conclusions Tiny intimal disruption in type B IMH evolution is not related to an increased risk of complications and should not be considered an indication for invasive treatment. However, since 14% of TID evolve to FID within the first 6 months, close follow-up with imaging techniques is advisable.

BACKGROUND Every actinic keratosis (AK) starts with atypia at the basal layers of the epidermis (AK I). Progression into invasive squamous cell carcinoma (iSCC) may occur following two main pathways, classical and differentiated. In the former, iSCC only occurs after involvement of the upper epidermal layers by atypical cells (AK III), while in the latter iSCC develops directly from AK I. In the anogenital mucosa, these two pathways are associated with differential expression of p53 and p16. OBJECTIVE To explore differences between both pathways in the pathogenesis of AK, focusing on Ki67, p53, p16 and molecules that reveal epithelial-mesenchymal transition (EMT). METHODS Tissue microarrays representative of superficial and deep portions of 80 consecutive iSCCs (53 DP/27CP) were studied immunohistochemically using antibodies against Ki67, p53, p16, vimentin, E-cadherin, β-catenin and D2-40. The evaluation was performed by three researchers and the results compared to consensus. RESULTS Invasive squamous cell carcinomas originated through the differentiated pathway exhibited significantly lower proliferative activity (Ki67) (30% vs 46%, P = 0.003) and significantly lower expression of vimentin (P < 0.001), E-cadherin (P < 0.001) and membranous β-catenin (P < 0.001) than iSCCs developed through the classical pathway. The expression of E-cadherin and membranous β-catenin was significantly correlated (Pearson's r = 0.386, Spearman's Rho < 0.001). There were no significant differences regarding the expressions of p53, p16 and D2-40. CONCLUSION Epithelial-mesenchymal transition participates in transformation from AK I into iSCC (differentiated pathway), whereas a higher proliferative capacity facilitates intraepidermal extension in the classical pathway. Podoplanin, which is also involved in tumour invasion, does not seem to play a differential role in either pathway. Finally, the absence of differences in p53 and p16 expressions is at variance with other epithelia where the classical pathway is associated with human papillomavirus infection and can be explained by the fact that both AK pathways share identical mechanisms of actinic oncogenesis.

Management of low-grade gliomas (LGG) is based on clinical and radiologic features, including the Pignatti prognostic scoring system, which classifies patients as low- or high-risk. To determine whether molecular data can offer advantages over these features, we have examined the prognostic impact of several molecular alterations in LGG. In a cohort of 58 patients with LGG, we have retrospectively analyzed clinical and molecular characteristics, including the Pignatti criteria, IDH mutations, TP53 mutations, the 1p/19q deletion, and MGMT methylation, and correlated our findings with progression-free survival (PFS) and overall survival (OS). Mean age of patients was 45 years; 71% were classified as low-risk by the Pignatti system. IDH mutations were detected in 62%, p53 mutations in 17%, the 1p/19q codeletion in 46%, and MGMT methylation in 40% of patients. Survival analyses were performed in the 49 patients without contrast enhancement. In the univariate analysis, IDH mutations, the 1p/19q codeletion, and the combination of IDH mutations with the 1p/19q codeletion were associated with both longer PFS (P = 0.006, P = 0.037, and P = 0.003, respectively) and longer OS (P < 0.001, P = 0.02, and P < 0.001, respectively). The multivariate analysis identified absence of IDH mutations as a factor for greater risk of progression [hazard ratio (HR) = 3.1; P = 0.007]and death (HR = 6.4; P < 0.001). We suggest that IDH mutations may be more effective than the Pignatti score in discriminating low- and high-risk patients with LGG.

Background/Context: Glioblastoma (GB) is the most common primary brain tumour in adults and it is associated with a high mortality rate. According to the stem cell theory, the growth, relapse and treatment response of GB is determined by the stem cell subpopulation present in the tumour. Objective: Our aim is to study the prognostic value of stem cell markers (CD44, Nestin, Olig2 and SOX2) in a series of homogeneously treated GBs. Material and methods: We study 280 GBs treated with STUPP acheme with a histologican review of the cases and TMA with a maximum of 4 spots for each case. Each slide was immunohistochemically stained and Reading. We compared the immunohistochemical results with survival tme. Results: Only SOX2 immunoexpression (IE) excedding 10% of the tumour cells was found to be related to good survival (p= 0.037) in univariate analysis. However, amultivariate analysis indicate the age, surgery and MGMT promotes methylation but no SOX2 IE are prognostic factors. Conclusions: We conclude the immunohistochemical studies of stem cell markers in GB are not useful for predicting prognosis in daily practice.

Background Neoadjuvant chemotherapy (NAC) followed by cystectomy is the standard of care in MIBC patients, although a limited survival benefit has been obtained compared with cystectomy alone. Pathologic response has been associated with survival, but, unfortunately, neither baseline clinical or pathological variables have demonstrated ability to predict which patients will benefit from NAC, pointing to the need of predictive biomarkers of NAC response to guide treatment decisions. The objective of this retrospective study was to identify a NAC response prediction signature integrating baseline clinical features, taxonomic subtypes, and RNA expression profile in MIBC patients. Methods Formalin-fixed paraffin-embedded pre-treatment tumor samples were collected by transurethral resection from 112 patients with MIBC stage T2-4N0/+M0 treated with NAC followed by cystectomy. Immunohistochemical-based taxonomic subtypes (BASQ-like, luminal-like, mixed) were established. Gene expression analysis was performed on the Nano String nCounter platform. A custom code set of a 41-gene panel involved in the DNA damage repair (DDR) and immune response pathways was used. Lasso and elastic net penalized logistic regression were performed to identify a predictive signature. Calculation of the area under the ROC curve (AUC) was used to assess the predictive ability of the signature. Results A nine-gene RNA expression signature (RAD51, CXCL9, PARP, 53BP1, HERC2, ERCC2, CHEK1, Ku80 and RNF 168 genes) was associated with pathologic response. The highest predictive ability was observed with the integrated clinical-taxonomical-RNA signature with an AUC of 0.66, in comparison to the clinical-taxonomical classification (AUC=0.58) or the clinical signature alone (AUC=0.52). Furthermore, the integrated signature was significantly associated with overall survival (p = 0.013). Conclusions We have identified a nine-gene RNA expression signature that can help to predict response in MIBC patients treated with NAC. Prospective studies are warranted to validate these results. Legal entity responsible for the study The authors. Funding AECC. Disclosure All authors have declared no conflicts of interest.

Background Standard treatment of glioblastoma (GBM) is focal radiation with concomitant and adjuvant temozolomide (TMZ) for 6 cycles. The GEINO-14-01 trial (NCT02209948) investigated the role of extending adjuvant TMZ to 12 cycles in a randomized multicenter study. Methods Between Aug/2014 and Nov/2018, 166 patients (p) were screened and 159 randomized to extend (80p) or not (79p) TMZ treatment to 12 cycles after proving lack of progression of the disease in the MRI performed before inclusion. The trial was stratified by MGMT status and presence or absence of residual disease (defined as a residual enhancement larger than 1cm on the MRI). The primary endpoint was differences in 6monthsPFS, secondary endpoints were differences in PFS, OS, toxicity, between arms and per stratification factors. Results Median age was 60.4 (range 29-83), all p had ECOG≤1 and 86.2% were without DXM treatment. MGMT status: Met: 97 (61%) UnMet:62 (39%). RD yes: 83 (52.2%) and no: 76 (47.8%). At the time of the abstract report 3 patients are still on treatment or control without a documented progression and 5 patients have not been yet 6m in the study: 31 patients (19.5) are still free of progression and 60 patients (37.7%) are still alive. Median (m) PFS has been reached: 7.9 months (95%CI: 6.1-9.8) as well as mOS: 20.9 (95%CI: 17.6-24.1). A methylated status was a factor of better PFS (HR = 0.29, 95% CI 0.46-0.95; p = 0.029) and better OS (HR = 0.43: 95% CI 0.28-0.66; p = 0.000) as well as the absence of residual disease (PFS: HR = 0.84: 95% CI = 0.71-1.01; p = 0.068; OS: HR = 0.77, 95%CI 0.63-0.96; p = 0.019). We didn’t find any difference in PFS (HR = 1.02, 95%CI 0.85-1.21; p = 0.82), or OS (HR = 0.90; 0.73-1.11; p = 0.34) on extending treatment with temozolomide longer than 6 cycles. Toxicity data and final results are expected for the congress. Conclusions There is no benefit of continuing TMZ treatment for more than 6 cycles in the adjuvant treatment of glioblastoma. Met status and absence of RD are factors of better SLP after adjuvant treatment. Supported by a Grant of the ISCIII: PI13/01751. Clinical trial identification NCT02209948. Legal entity responsible for the study GEINO (Grupo Espanol de Investigacion en Neurooncologia). Funding Supported by a Grant of the ISCIII. Disclosure M.A.V. Salgado: Advisory / Consultancy: Lilly; Research grant / Funding (institution): Pfizer; Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: pharmamar; Advisory / Consultancy: eisai; Advisory / Consultancy: Celgene. All other authors have declared no conflicts of interest.

2042 Background: Malignant gliomas are heterogeneous diseases in genetic basis. The development of sequencing techniques, such as RNA-Sequencing, has identified many gene rearrangements encoding novel oncogenic fusions. Gene fusion discovery can potentially lead to the development of novel treatments, however studies of gene fusions in glioma remain limited. Methods: The GLIOCAT project studied 139 patient samples of newly diagnosed glioblastoma who had received the standard first-line treatment from 2004 to 2015, to identify gene fusion events from glioblastoma transcriptome data (RNA-Seq). The molecular subtype could be studied in 124 cases. RNA-Seq reads were mapped against the reference human genome with STAR-fusion version 0.7.0, specifically, with FusionInspector validate ( http://star-fusion.github.io ). Two other platforms, FusionHub ( https://fusionhub.persistent.co.in ) and Oncofuse ( www.unav.es/genetica/oncofuse.html ), were applied to eliminate false positives or previously described in healthy tissue and to predict of the oncogenic potential each fusion. Results: A total of61 patients showed 103 different fusions, a median of two fusions by sample. The majority of gene fusions were intrachromosomal and most frequently implied chromosome was 12 followed by 7. In addition, fusions were more common in patients with MGMT promoter methylation, TCGA classical subtype and 18 IGS subtype. There were no differences in age, sex, type of surgery or long survivors ( > 30 months). Ten fusions were already described in cancer, including three in gliomas (FRS2-KIF5A, EGFR-SEPT14 and FGFR3-TACC3). From the detected fusions, 22 of them included an oncogene or protooncogene. Conclusions: In our study, we report the landscape of gene fusions from a large data set of glioblastomas analyzed by RNA-seq. The majority of the fusions were private fusions. A minority of these recur in a low frequency but as many as a quarter of them included an oncogene or protooncogene. RNA-seq of GBM patient samples it is an important tool for the identification of patient-specific fusions that could drive personalized therapy. Furtherless, we will plan to validate this gene fusions.

Resumen La enfermedad de Behcet es una vasculitis caracterizada por ulceras bucales y genitales. La afectacion neurologica o neuro-Behcet es una manifestacion infrecuente, de predominio en el genero masculino y que aparece de 2 a 4 anos despues de la primera manifestacion clinica. El neuro-Behcet cursa ocasionalmente lesiones cerebrales pseudotumorales. Presentamos 2 casos de pacientes diagnosticados de neuro-Behcet tras la deteccion de lesiones cerebrales pseudotumorales y se realiza una revision de la literatura.

Importance Neurofibromatosis type 2 (NF2) is a devastating genetic condition characterized by the development of multiple tumors of the nervous system. An early diagnosis of individuals with NF2 would facilitate treatment and reduction of disease impact because most severe effects of the disease do not usually develop before adolescence. Little attention has traditionally been paid to dermatological signs in NF2. However, skin plaques are commonly seen in patients with NF2, normally appearing either at birth or early childhood, providing an opportunity for early NF2 detection and testing. Objective To determine the clinical utility of skin plaque identification and characterization in children for reaching an early diagnosis of patients with NF2 and to evaluate their molecular pathogenesis and their use in the genetic diagnostics of NF2. Design, Setting, and Participants Diagnostic test study by the histological and genetic characterization of skin plaques from patients with NF2. Patients were 7 individuals with NF2 or clinical suspicion of NF2 treated at the Spanish Reference Center on Phakomatoses. Main Outcomes and Measures Histological evaluation of all skin plaques was performed. Fresh skin plaques were cultured to obtain Schwann cells and theNF2gene was genetically analyzed. For all 7 patients, NF2 clinical history was reviewed. Results In all 7 patients (4 male and 3 female), all skin plaques analyzed were histologically characterized as plexiform schwannomas. Genetic analysis of primary Schwann cell cultures derived from them allowed the identification of a constitutional and a somaticNF2mutation. Genetic testing allowed the early diagnosis of NF2 in a child only exhibiting the presence of skin plaques. Most of the patients with NF2 analyzed had an early presentation of skin plaques and a severe NF2 phenotype. Conclusions and Relevance This work emphasizes the clinical utility of a careful dermatological inspection and the correct identification of skin plaques in children for an early diagnosis of NF2. We show for the first time that Schwann cells derived from skin plaque plexiform schwannomas bear the double inactivation of theNF2gene and thus constitute an excellent source of tissue for genetic testing, especially in the context of mosaicism.

Glioblastoma (GB) is the most common brain malignancy and accounts for over 50% of all high-grade gliomas. Radiotherapy (RT) with concomitant and adjuvant temozolomide (TMZ) chemotherapy is the current standard of care for patients with newly diagnosed GB up to age 70. Recently, a new standard of care has been adopted for elderly patients (≥ 65 years) based on short course of RT and TMZ. Several clinically relevant molecular markers that assist in diagnosis and prognosis have recently been identified. The treatment for recurrent GB is not well defined, and decision-making is usually based on prior strategies as well as several clinical and radiological factors. The presence of neurologic deficits and seizures can significantly impact quality of life.

Sin financiación 2.393 JCR (2018) Q3, 115/199 Clinical Neurology, 184/261 Neurosciences 0.950 SJR (2018) Q2, 134/378 Neurology (clinical), 80/188 Physiology, 45/108 Physiology (medical); Q3, 59/90 Cellular and Molecular Neuroscience No data IDR 2018 UEM