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The similarities between sporadic basal-like breast cancer (BLBC) and BRCA1-mutated breast tumours raise the possibility that deregulation of the same pathway may underlie these tumour types. The aim of this study was to determine if PTEN aberrations are characteristic of both BRCA1 tumours and sporadic TN breast carcinomas with low BRCA1 expression, and can thus be used to identify sporadic tumours potentially sensitive to PARP inhibitors. Twelve BRCA1 tumours, 19 non-BRCA familial breast tumours and 71 unselected TN breast carcinomas were screened for PTEN mutations and assessed for PTEN expression and BRCA1 mRNA expression. Loss of PTEN expression was observed in 67% of BRCA1 tumours and more specifically in 89% of TN BRCA1 tumours highlighting the link between PTEN loss and BLBC in the context of germline BRCA1 mutations. Regarding unselected TN tumours, 56% showed PTEN expression loss and 35% displayed low BRCA1 mRNA expression. Unlike familial breast cancers with low BRCA1 mRNA expression, no significant correlation was observed between the loss of PTEN expression and low BRCA1 mRNA expression in this unselected TN tumours panel. Our data suggest that, unlike the germinal context, PTEN and BRCA1 alterations in sporadic TN breast tumours are independent events.

In several instances, our group has reported opposite findings to others when analyzing the genetic features of primary cutaneous T-cell or B-cell lymphomas (CTCL or CBCL). This was especially the case for the absence of NAV3 rearrangements in CTCL, the low rate of BCL2 or MYC rearrangement in primary cutaneous follicle center lymphomas (CFCL) or primary cutaneous large B-cell lymphomas, leg-type (CLBCL, LT), respectively. Here, we review bias accounting for such discrepancies. Primary cutaneous lymphoma usually present with characteristic clinical and pathological features which serve as universal criteria for initial diagnosis and treatment. When required, extensive staging including CT scan, blood analysis and for some groups bone marrow staging, is mandatory to eliminate a secondary CTCL or CBCL. Early spreading may change the initial diagnosis and a long-term follow-up is also necessary to determine the risk for extracutaneous involvement. Non-uniform inclusion criteria and follow-up time may contribute to discrepancies, especially for studies claiming for a high rate of BCL2 rearrangement in CBCL. Most CBCL or CTCL usually display an indolent course except for aggressive subtypes arising de novo such as Sezary syndrome (SS), tumor or transformed mycosis fungoides (T-MF) or CLBCL-LT. Borderline cases between indolent and aggressive cutaneous lymphomas exist and may be called for example as leukemic CTCL or CBCL, not-otherwise specified (NOS) leading to heterogeneous terminology between centers. Moreover, aggressive CL are rare occurring mainly in adults or elderly that limits therapeutic options and comparison of small groups in retrospective series. The distribution of diagnosis between the three main primary CBCL including marginal-zone lymphoma (MZL), CFCL and CLBCL, LT has considerably evolved and its heterogeneity between centers may also hamper uniform findings. Our proposal to classify large CBCL according to germinal center or non-germinal center origin has so far not been validated by others while in systemic lymphomas genomic profiling appears mandatory to identify patients with impaired prognosis. In the most frequent cutaneous lymphomas, no highly recurrent genetic mutation is commonly used for diagnosis purpose. Some genetic lesion such as CCND1 rearrangement in mantle cell lymphoma can serve a positive criteria of secondary skin involvement. Alternatively, exceptional primary anaplastic large cell lymphoma (ALCL) bear ALK rearrangement preventing to use such criteria as a hallmark of secondary skin ALCL. BCL2 rearrangement in primary CFCL contributes to identify patients at risk for extracutaneous spreading. Most reports found negative data for NAV3 rearrangement in CTCL that may not be a primary oncogenic driver but a secondary event. Interestingly, MYC rearrangement or double-hits may have a low impact on prognosis in CBCL while they are usually associated with impaired prognosis in systemic or nodal lymphomas. Alternatively, some highly recurrent mutation such as those of MYD88 in CLBCL, LT should be routinely assessed. While clinical presentation will remain a basis for CL diagnosis and treatment, it is now time to integrate molecular profiling in research studies or clinical trials to standardize diagnosis and to identify patients which will exhibit therapeutic resistance to conventional first-line treatment.

International audience; In nodal diffuse large B-cell lymphoma, the search for double-hit with MYC and BCL2 and/or BCL6 rearrangements or for dual expression of BCL2 and MYC defines subgroups of patients with altered prognosis that has not been evaluated in primary cutaneous large B-cell lymphoma. Our objectives were to assess the double-hit and dual expressor status in a cohort of 44 patients with primary cutaneous large B-cell lymphoma according to the histological subtype and to evaluate their prognosis relevance. The 44 cases defined by the presence of more than 80% of large B-cells in the dermis corresponded to 21 primary cutaneous follicle centre lymphoma with large cell morphology and 23 primary cutaneous diffuse large B-cell lymphoma, leg type. Thirty-one cases (70%) expressed BCL2 and 29 (66%) expressed MYC. Dual expressor profile was observed in 25 cases (57%) of either subtypes (n = 6 or n = 19, respectively). Only one primary cutaneous follicle centre lymphoma, large-cell case had a double-hit status (2%). Specific survival was significantly worse in primary cutaneous diffuse large B-cell lymphoma, leg type than in primary cutaneous follicle centre lymphoma, large cell (p = 0.021) and for the dual expressor primary cutaneous large B-cell lymphoma group (p = 0.030). Both overall survival and specific survival were worse for patients belonging to the dual expressor primary cutaneous diffuse large B-cell lymphoma, leg type subgroup (p = 0.001 and p = 0.046, respectively). Expression of either MYC and/or BCL2 negatively impacted overall survival (p = 0.017 and p = 0.018 respectively). As the differential diagnosis between primary cutaneous follicle centre lymphoma, large cell and primary cutaneous diffuse large B-cell lymphoma, leg type has a major impact on prognosis, dual-expression of BCL2 and MYC may represent a new diagnostic criterion for primary cutaneous diffuse large B-cell lymphoma, leg type subtype and further identifies patients with impaired survival. Finally, the double-hit assessment does not appear clinically relevant in primary cutaneous large B-cell lymphoma.

Sézary Syndrome (SS) is a rare aggressive epidermotropic cutaneous T-cell lymphoma (CTCL) defined by erythroderma, pruritis, and a circulating atypical CD4 + T-cell clonal population. The diversity of Sézary cell (SC) phenotype and genotype may reflect either plasticity or heterogeneity, which was difficult to evaluate dynamically until the achievement of long-term SC expansion. Therefore, we developed six defined culture conditions allowing for the expansion of SC defined by their phenotype and monoclonality in four of seven SS cases. Engraftment of SC through the intrafemoral route into immunodeficient NOD.Cg-Prkdc(scid)Il2rg(tm1Wjll)/SzJ (NSG) mice was achieved in 2 of 14 SS cases. Secondary xenograft by percutaneous injection mimicked most of the features of SS with dermal infiltration, epidermotropism, and blood spreading. These models also allowed assessing the intra-individual heterogeneity of patient SC. Subclones sharing the same TCR gene rearrangement evolved independently according to culture conditions and/or after xenografting. This clonal selection was associated with some immunophenotypic plasticity and limited genomic evolution both in vitro and in vivo. The long-term amplification of SC allowed us to develop eight new SC lines derived from four different patients. These lines represent the cell of origin diversity of SC and provide new tools to evaluate their functional hallmarks and response to therapy.

Le lymphome cutane primitif B diffus a grandes cellules type jambe (LBC-TJ), le plus agressif des lymphomes B cutanes, presente des caracteristiques proches des lymphomes B diffus a grandes cellules (LBDGC) de type « Activated B- Cell-like » (ABC) avec une activation constitutive de la voie NF-κB (nuclear factor-kappa B). Initialement, notre equipe a demontre la haute prevalence de la mutation MYD88L265P dans les LBC-TJ, puis associee a l’equipe du Pr Jardin (INSERM UMR1245, Rouen), nous avons confirme par exome sequencing la tres haute prevalence des mutations MYD88, PIM1 et CD79B [1] . La prise en charge de ces patients demeure un enjeu therapeutique malgre l’amelioration de la survie a 5 ans de 38 % a 74 % par l’association du Rituximab (anti-CD20) avec une polychimiotherapie adaptee a l’âge mais environ 50 % de non reponse sont observees sans facteur predictif connu. Nous souhaitons identifier un profil moleculaire predictif de reponse therapeutique permettant une meilleure prise en charge de ces patients. Nous avons analyse 14 patients repondeurs et 18 non repondeurs a la R-polychimiotherapie par NGS via un panel de 36 genes importants dans la lymphomagenese. Pour 14 patients, nous avons egalement analyse la biopsie a la progression/rechute afin d’identifier les alterations genetiques selectionnees lors de l’echappement therapeutique. Les patients presentant une mutation de la voie du BCR (CD79A/B ou CARD11) ont une survie sans progression et une survie specifique diminuee (p = 0,002 et p = 0,03 respectivement) [2] . L’analyse des echantillons au diagnostic et a la rechute montre que les mutations des genes MYD88 et CD79B sont les plus conservees et que la frequence allelique de ces mutations est superieure a la progression/rechute. La caracterisation d’une mutation dans la voie du BCR chez les patients atteints d’un LBTJ laisse presager une resistance a la polychimiotherapie conventionnelle. Ces patients pourraient beneficier d’un traitement adjuvant ou d’une seconde ligne d’emblee afin d’ameliorer leur prise en charge.

Introduction Aggressive B-cell lymphomas are heterogeneous in their clinical course and biological characteristics. They include diffuse large B-cell lymphoma not otherwise specified (DLBCL-NOS), high grade-B-cell lymphoma with double/triple-hit or NOS (HGBL), primary mediastinal B-cell lymphoma (PMBL). In order to better differentiate these entities, the WHO classification recommends using immunohistochemistry (IHC), FISH, targeted sequencing and gene expression profiles (GEP). However, these techniques are most often performed retrospectively in clinical trials, which is not representative of real life. In order to use these information to improve the current standard of treatment with targeted therapies adapted to lymphoma biology, we have set up a national network on behalf of the LYSA called RT3 (for Real-time tailored therapy) to demonstrate that we are able to comprehensively characterize aggressive B cell lymphomas in a clinically relevant timeline. Materials and methods Patients > 18 years of age with untreated aggressive B-cell lymphoma were included prospectively from 21 LYSA centers. FFPE specimens were analyzed and classified according to WHO classification, benefiting from an IHC profile (Hans algorithm, BCL2, MYC), FISH analysis (BCL6, BCL2, MYC break apart and MYC-IGH/IGL/IGK fusion probes), targeted NGS analysis and a targeted GEP using RT-MLPA (Bobée et al. J Mol diagn 2017). A first part of the study phase was carried out in an oligocentric manner with only 2 referral platforms for pathological analysis and molecular characterization. The second phase was the implementation of 7 RT3 platforms spread over France. The main objective was to evaluate the capacity of the network to provide an exhaustive histopathological and molecular characterization 4 days before theoretical R-CHOP21 C3 administration (within 38 days after D1 cycle 1). Results The oligocentric cohort 1 prospectively included 72 patients in 6 months: 19 had insufficient material or inappropriate diagnosis to be qualified and 53 benefited from the complete analysis on referral platforms. A complete characterization 4 days before RCHOP-C3 was provided to the clinician in 47 cases (88.7%), allowing to further implement the network with 7 platforms and 23 clinical investigation centers. 183 patients were included in the second phase in 9 months, 35 were excluded for inadequate diagnosis/material. On this population, 143 (96.6%) complete patient-reports were provided with a median time of 32 days (1-50). Finally, 201 cases were retained in the Full Analysis Set for which tumor samples fulfilled all prerequisites and diagnosis of DLBCL was confirmed by RT3 platforms. The clinical characteristics were as follows: median age of 61 y (20-92), with 45.2% of pts with aaIPI 2-3and 67.1% with Ann Arbor stage III-IV; 1L treatment consisted mainly of RCHOP (RCHOP14/21 = 136, 72.3%). 7% of patients were treated with experimental drugs. 76% presented with extranodal involvement. After pathological review, 139 (69%) patients were classified as DLBCL-NOS (41% GCB; 58% nGCB), 11 (5%) as HGBL-NOS, 8 (4%) as HGBL-DH and 18 (9%) as PMBL, 3 (1%) as EBV+ DLBCL-NOS, 9 (4%) as FL-3B, 7 (3%) transformed DLBCL, 2 (1%) plasmablastic, 1 (0.5%) unclassified, 1 (0.5%) DLBCL with IRF4 rearrangement. By immunohistochemistry, 22 cases were CD5+, 74% were BCL2+, and 53% MYC+ and 49% as double expressors. BCL2/18q21, BCL6/3q27 and MYC/8q24 breaks were observed in 14% (29/201), 25% (50/201) and 12% (25/201) of the cases respectively. MYC partner gene was available in 10/29 cases (5 MYC-IG, 5 non-IG). At the molecular level, PIM1 was the most frequently mutated gene in the entire cohort (36%). In the ABC subtype, MYD88 was mutated in 48% of cases. In the GCB cohort, SOCS1 was the most frequently mutated gene (30%). In the HGBL cohort, MYC was the most mutated gene (43%). Conclusion This study demonstrates that this RT3 LYSA network allowed a real time pathological and molecular characterization of aggressive B-cell lymphomas according to the WHO recommendations. The RT3 network provides relevant informations to the clinician before R-CHOP21 C3, that might contribute to modify the treatment eventually adding targeted therapies or tailor a second line treatment. This network should be used as a basis for future clinical trials. Inter platforms reproducibility and prognostic relevance of the RT3 project will be presented. Disclosures Haioun: Gilead: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Takeda: Honoraria; Miltenyi: Honoraria; Servier: Honoraria; Roche: Honoraria; Celgene: Honoraria. Le Gouill:Roche Genentech, Janssen-Cilag and Abbvie, Celgene, Jazz pharmaceutical, Gilead-kite, Loxo, Daiichi-Sankyo and Servier: Honoraria; Loxo Oncology at Lilly: Consultancy. Ribrag:arGEN-X-BVBA: Research Funding; BAY1000394 studies on MCL: Patents & Royalties; Institut Gustave Roussy: Current Employment; argenX: Current equity holder in publicly-traded company, Research Funding; Epizyme: Consultancy, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Infinity: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; Nanostring: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Honoraria; Pharmamar: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AZD: Honoraria, Other; Eisai: Honoraria; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees. Salles:Takeda: Honoraria; Karyopharm: Honoraria; Genmab: Honoraria, Other; Debiopharm: Consultancy, Honoraria, Other: consultancy or advisory role; Autolos: Other: consultancy or advisory role; Abbvie: Other: consultancy or advisory role; Roche: Honoraria, Other: consultancy or advisory role; Novartis: Honoraria, Other: consultancy or advisory role; MorphoSys: Honoraria, Other: consultancy or advisory role; Janssen: Honoraria, Other: consultancy or advisory role; Epizyme: Honoraria, Other: consultancy or advisory role; Kite, a Gilead Company: Honoraria, Other: consultancy or advisory role ; BMS/Celgene: Honoraria, Other: consultancy or advisory role. Sujobert:Sunesis: Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead/Kyte: Membership on an entity's Board of Directors or advisory committees. Bouabdallah:Gilead Sciences: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Roche: Consultancy, Honoraria. Sibon:takeda france: Consultancy.

The neoplastic nature of pulmonary Langerhans cell histiocytosis (PLCH) is still debated. As the detection of BRAF V600E and MAP2K1 mutations in patients with PCLH is now considered for such assessment, the aim of our study was to evaluate digital droplet polymerase chain reaction (ddPCR) in PCLH diagnosis. We retrospectively analyzed BRAFV600E detection in a cohort of 42 PCLH tissues and 18 bronchoalveolar lavages (BALs) by ddPCR, immunohistochemistry, high-resolution melting PCR (HRM), and next-generation sequencing (NGS). The presence of BRAFV600E mutation was assessed by at least two concordant techniques to further evaluate specificity and sensitivity of each method. The BRAF V600E mutation prevalence was detected in 18 out of 41 cases by ddPCR, 10 out of 36 cases by HRM PCR, and 16 out of 31 cases by NGS. BRAFV600E immunohistochemistry sensitivity was 94%, and specificity was 79%. HRM PCR sensitivity was only 59%, and specificity was 100%. NGS sensitivity and specificity were 100% for interpretable cases (n = 31), but in 11 cases, this technique was non-contributive. The analysis of BAL samples by ddPCR revealed a BRAFV600E mutation both in tissue and in BAL samples in one patient, a wild-type status both in tissue and in BAL samples in two patients, and a wild-type BRAF status in BAL and a BRAFV600E mutation in tissue samples in four patients. The study supports the usefulness of ddPCR for BRAF status assessment in either tissue or BAL samples to increase the accuracy of PLCH diagnosis.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT) preferentially involves the lower limb in elderly subjects. A combination of polychemotherapy and rituximab has improved prognosis. However, about 50% of patients will experience progression or relapse without any predictive biologic marker of therapeutic response. The mutational profile of PCLBCL-LT has highlighted mutations contributing to constitutive NF-κB and B-cell receptor (BCR) signaling pathways but has not demonstrated clinical utility. Therefore, the mutational status of 32 patients with PCLBCL-LT (14 patients with complete durable response and 18 patients with relapsing or refractory disease) was determined with a dedicated lymphopanel. Tumor pairs at diagnosis and relapse or progression were analyzed in 14 relapsing or refractory patients. Patients with PCLBCL-LT harboring one mutation that targets one of the BCR signaling genes, CD79A/B or CARD11, displayed a reduced progression-free survival and specific survival (median 18 months, P = 0.002 and 51 months, P = 0.03, respectively, whereas median duration in the wild-type group was not reached) and were associated with therapeutic resistance (P = 0.0006). Longitudinal analyses revealed that MYD88 and CD79B were the earliest and among the most mutated genes. Our data suggest that evaluating BCR mutations in patients with PCLBCL-LT may help to predict first-line therapeutic response and to select targeted therapies.

International audience; Supplemental Digital Content is available in the text.

International audience; no abstract

Sequencing of genes encoding mitogen-activated protein kinase (MAPK) pathway proteins in colorectal cancer (CRC) has established as dogma that of the genes in a pathway only a single one is ever mutated. We searched for cases with a mutation in more than one MAPK pathway gene (co-mutations). Tumor tissue samples of all patients presenting with CRC, and referred between 01/01/2008 and 01/06/2015 to three French cancer centers for determination of mutation status of RAS/RAF+/-PIK3CA, were retrospectively screened for co-mutations using Sanger sequencing or next-generation sequencing. We found that of 1791 colorectal patients with mutations in the MAPK pathway, 20 had a co-mutation, 8 of KRAS/NRAS, and some even with a third mutation. More than half of the mutations were in codons 12 and 13. We also found 3 cases with a co-mutation of NRAS/BRAF and 9 with a co-mutation of KRAS/BRAF. In 2 patients with a co-mutation of KRAS/NRAS, the co-mutation existed in the primary as well as in a metastasis, which suggests that co-mutations occur early during carcinogenesis and are maintained when a tumor disseminates. We conclude that co-mutations exist in the MAPK genes but with low frequency and as yet with unknown outcome implications.

// Sandrine Poglio 1, 2, 3, 4 , Daniel Lewandowski 2, 3, 4, 5 , Julien Calvo 1, 2, 3, 4 , Aurelie Caye 6, 7 , Audrey Gros 8, 9 , Elodie Laharanne 8, 9 , Thierry Leblanc 10 , Judith Landman-Parker 11 , Andre Baruchel 10 , Jean Soulier 6, 12, 13 , Paola Ballerini 1, 2, 3, 4, 11 , Emmanuelle Clappier 6, 12, 13 , Francoise Pflumio 1, 2, 3, 4 1 Commissariat a l’Energie Atomique et aux Energies Alternatives (CEA), DSV-IRCM-SCSR-LSHL, UMR 967, Fontenay-aux-Roses, France 2 INSERM, U967, Fontenay-aux-Roses, France 3 Universite Paris Diderot, Sorbonne Paris Cite, UMR 967, Fontenay-aux-Roses, France 4 Universite Paris-Sud, UMR 967, Fontenay-aux-Roses, France 5 CEA, DSV-IRCM-SCSR-LRTS, UMR 967, Fontenay-aux-Roses, France 6 Universite Paris Diderot, Paris, France 7 Assistance Publique-Hopitaux de Paris (AP-HP), Departement de Genetique, UF de Genetique Moleculaire, Hopital Robert Debre Paris, France 8 INSERM, UMR1053 Bordeaux Research in Translational Oncology (BaRITOn), Bordeaux, France 9 Universite de Bordeaux, Bordeaux, France 10 AP-HP, Service d’hematologie Pediatrique, Hopital Robert Debre, Paris, France 11 AP-HP, Service d’hematologie Pediatrique, Hopital Armand Trousseau, Paris, France 12 AP-HP, Laboratoire d’Hematologie, Hopital Saint-Louis, Paris, France 13 Team Genome and Cancer, U944 INSERM, Paris, France Correspondence to: Francoise Pflumio, email: francoise.pflumio@cea.fr Sandrine Poglio, email: sandrine.poglio@u-bordeaux.fr Keywords: T-ALL, leukemia initiating cells, clonal selection, CD34, xenograft Received: June 29, 2015 Accepted: April 22, 2016 Published: May 12, 2016 ABSTRACT T cell acute lymphoblastic leukemia (T-ALL) develops through accumulation of multiple genomic alterations within T-cell progenitors resulting in clonal heterogeneity among leukemic cells. Human T-ALL xeno-transplantation in immunodeficient mice is a gold standard approach to study leukemia biology and we recently uncovered that the leukemia development is more or less rapid depending on T-ALL sample. The resulting human leukemia may arise through genetic selection and we previously showed that human T-ALL development in immune-deficient mice is significantly enhanced upon CD7 + /CD34 + leukemic cell transplantations. Here we investigated the genetic characteristics of CD7 + /CD34 + and CD7 + /CD34 − cells from newly diagnosed human T-ALL and correlated it to the speed of leukemia development. We observed that CD7 + /CD34 + or CD7 + /CD34 − T-ALL cells that promote leukemia within a short-time period are genetically similar, as well as xenograft-derived leukemia resulting from both cell fractions. In the case of delayed T-ALL growth CD7 + /CD34 + or CD7 + /CD34 − cells were either genetically diverse, the resulting xenograft leukemia arising from different but branched subclones present in the original sample, or similar, indicating decreased fitness to mouse micro-environment. Altogether, our work provides new information relating the speed of leukemia development in xenografts to the genetic diversity of T-ALL cell compartments.

We report here an exceptional pattern of atypical lentiginous melanocytic proliferation within an adenoma, leading to focal lamina propria infiltration and pulmonary metastasis, which was considered as primary colonic mucosal melanoma (MM) in a Caucasian patient. Such case illustrates the diagnosis criteria required to differentiate primary MM from colonic metastasis of melanoma, including the absence of past history of other primary melanoma, a unique colonic and abdominal lesion with predominant features of in situ lentiginous MM and a very focal and unique invasive area without other digestive tract or abdominal localization. This tumor displayed a KIT exon 11 mutation leading to a unique combination of p.I571M and p.D572G deleterious amino acid changes. Such pattern also favors the diagnosis as KIT appears as a master oncogenic player in MM oncogenesis.

Although the combination of rituximab and polychemotherapy has improved prognosis of primary cutaneous diffuse large B-cell lymphoma, leg type, the advanced age of patients limits therapeutic options in relapsing/refractory cases. A multicenter, single-arm, phase II trial was conducted to assess the benefits and safety of lenalidomide in refractory/relapsing primary cutaneous diffuse large B-cell lymphoma, leg type. The primary endpoint was the 6-month overall response rate. Secondary endpoints were 12-month overall response rate, overall and specific survival, duration of response, progression-free survival, safety, and identification of prognostic factors. Among the 19 patients included, the 6-month overall response rate was 26.3% (90% confidence interval [CI] = 11–47.6), including four complete responses and one partial response. At 12 months, there were still two complete responses and one partial response. Median progression-free survival was 4 months. Median overall and specific survivals were 19.4 and 23.8 months, respectively. Reduced doses tended to be associated with higher 6-month overall response rate and progression-free survival. Absence of the MYD88L265P mutation was associated with a higher overall response under treatment (80.0% vs. 33.3%; P = 0.05). The most common grade 3 adverse events were hematologic. Two grade 5 adverse events occurred (sepsis and pulmonary embolism). Lenalidomide at reduced doses may allow prolonged responses in a few patients and represents a therapeutic option in relapsing/refractory primary cutaneous diffuse large B-cell lymphoma, leg type.

Word-final fortis / lenis contrast in English plosives: lists of words in isolation read aloud by French-speaking learners The acquisition of the word-initial fortis / lenis contrast in English by speakers of other languages has been investigated by many researchers, but empirical studies on this contrast in word-final position seems to have been conducted less extensively, and especially on speakers of languages in which word-final voicing distinction is known to be absent or neutralized (Smith et al., 2009 ; Skarnitzl & Šturm, 2016). In this study, 6 French-speaking learners of English, who have voicing contrast word-finally in their first language, pronounced 30 words each in isolation. It was observed that the previous vowel, which is described as a primary cue in native speakers' speech, was significantly shorter before fortis than lenis (Wilcoxon rank sum test) in 5 learners out of 6, but some learners also showed cases of different voicing patterns for lenis than native speakers (voiced release for lenis; end of voicing earlier than natives)., L'opposition fortis / lenis en début de mot en anglais acquise par des locuteurs d'autres langues a été étudiée par de nombreux chercheurs, mais la position finale de mot semble avoir été moins abordée dans des études empiriques et ceux qui existent portent surtout sur les locuteurs de langues caractérisées par une absence ou neutralisation de cette opposition en fin de mot (Smith et al., 2009 ; Skarnitzl & Šturm, 2016). Dans cette étude, 6 apprenantes francophones de l'anglais, qui connaissent une opposition de voisement en fin de mot dans leur première langue, ont prononcé 30 mots isolés. Il a été observé que la voyelle précédente, considérée comme indice primaire chez les anglophones natifs, était significativement plus courte devant les fortis que lenis (test de la somme des rangs de Wilcoxon) par 5 apprenantes sur 6, mais certaines d'entre elles ont montré des réalisations phonétiques de voisement différentes des natifs (relâchement voisé pour lenis; fin de voisement plus tôt que les natifs).

Background Prescribing anti-programmed death-1 (PD-1) immunotherapy for advanced melanoma is currently not restricted by any biomarker assessment. Determination of programmed death-ligand-1 (PD-L1)-expression status is technically challenging and is not mandatory, because negative tumours also achieve therapeutic responses. However, reproducible biomarkers predictive of a response to anti-PD-1 therapy could contribute to improving therapeutic decision-making. Methods This retrospective study on 70 metastatic melanoma patients was undertaken to evaluate the relationships between clinical, histological, immunohistochemical and/or molecular criteria, and the 6-month objective response rate. Results Better objective response rates were associated with metachronous metastases (P = 0.04), PD-L1 tumour- and/or immune-cell status (P = 0.01), CD163+ histiocytes at advancing edges (P = 0.009) of primary melanomas and NRAS mutation (P = 0.019). Moreover, CD163+ histiocytes at advancing edges (P = 0.04) were associated with longer progression-free survival (PFS), and metachronous metastases with longer overall survival (P = 0.02) and PFS (P = 0.049). Conclusions Combining these reproducible biomarkers could help improve therapeutic decision-making for patients with progressive disease.

National audience

Introduction La positivite du marqueur PD-L1 dans le melanome non resecable ou metastatique n’est pas obligatoire pour initier une immunotherapie. L’utilisation du statut PD-L1 est discutee car certains patients avec une tumeur PD-L1 negative ont des durees de reponse prolongee sous immunotherapie. De plus, les methodes de determination du statut PD-L1 sont tres heterogenes et les seuils de positivite different dans les etudes. L’objectif principal etait d’evaluer la correlation entre des criteres cliniques, histologiques, moleculaire et la reponse objective aux anti-PD1. Patients et methodes Etude retrospective bicentrique incluant tous les patients dont les prelevements de tumeurs primitives et metastatiques fixees et incluses en paraffine etaient disponibles avant la premiere injection d’immunotherapie. Les donnees demographiques, histologiques (statut PD-L1 tumoral et lymphocytaire, expression du CD163+), moleculaire (mutation BRAF, NRAS et cKIT), la tolerance et l’efficacite du traitement a 6 mois (taux de reponse objective, survie globale et survie sans progression) ont ete recueillies. Le seuil de positivite PD-L1 retenu etait de 5 % sur les cellules tumorales. Resultats La presence de metastases metachrones (p = 0,04), une positivite de PD-L1 de plus de 5 % de la surface tumorale globale (cellules tumorales et/ou immunes, p = 0,01), la presence de plus de 10 % d’histiocytes CD163+ au front d’invasion (p = 0,009), et le statut NRAS mute (p = 0,019) dans les melanomes primitifs etaient correles a un meilleur taux de reponse objective a 6 mois. De plus la presence de metastases metachrones etait associee a une meilleure survie globale et survie sans progression. Plus de 10 % d’histiocytes CD163+ au front d’invasion (p = 0,04) etait associe a une survie sans progression augmentee. Discussion Le PD-L1 est exprime sur les histiocytes en contact etroit avec les melanocytes de la tumeur. L’evaluation conjointe de ce statut sur les cellules tumorales et sur les cellules immunes est plus fiable que sur la tumeur seule. A notre connaissance, l’expression du CD163+ sur le front d’invasion de la tumeur n’a jamais ete evaluee dans le melanome et pourrait etre un biomarqueur utile. Conclusion Le statut PD-L1 seul ne peut pas etre utilise comme biomarqueur de la reponse therapeutique aux anti-PD1, mais doit s’interpreter avec d’autres criteres comme la presence de metastases synchrones, la presence de plus de 10 % d’histiocytes CD163+ au front d’invasion ou le statut de NRAS.

Introduction Le lymphome B cutane primitif diffus a grandes cellules de type jambe (LBCGC-MI) survient chez les sujets âges. Le traitement standard associant le rituximab et une polychimiotherapie adaptee a l’âge (R-PCT) a ameliore la survie a 5 ans de 41 a 73 %. Cependant, les non-reponses primaires et surtout secondaires (recidives) restent frequentes (40 %) et sont un veritable enjeu, en l’absence de critere clinicobiologique predictif. Notre equipe a contribue a l’identification d’alterations genetiques frequentes de la voie NF-κB et du « B-Cell Receptor » ou BCR. Notre objectif etait d’identifier des marqueurs predictifs de reponse a la R-PCT par analyse mutationnelle et proteique. Patients et methodes Etude retrospective multicentrique 1 d’une cohorte de patients traites par R-PCT (13 bons repondeurs BR et 19 non repondeurs NR) pour un LBCGC-MI, par sequencage nouvelle generation (NGS) cible sur 36 genes importants pour la lymphomagenese et par analyse proteomique realises sur des biopsies tumorales fixees par le formol (32 biopsies au diagnostic, 13 biopsies a la recidive). Resultats Le NGS realise sur 32 patients au diagnostic montrait des mutations de plusieurs genes ciblant la voie NF-κB comme PIM1 (72 %), MYD88 (69 %) et des mutations ciblant celle du BCR comme CD79B (53 %). La non-reponse a la R-PCT etait fortement correlee a la presence d’une mutation pour un des 3 genes de la voie du BCR, CARD11, CD79A ou B (p = 0,001). La non-reponse etait egalement associee aux mutations ciblant uniquement le BCR (CD79A ou B) (p = 0,01) et a une plus courte survie sans progression (mediane de 18 mois vs 45 mois, p = 0,02). L’etude proteomique comparative de 12 NR et 12 BR au diagnostic montrait une expression differentielle de plusieurs marqueurs dont une proteine de la voie du BCR permettant d’identifier les BR (sensibilite : 83 %, specificite : 92 %). L’analyse comparee du profil mutationnel de 13 patients a la recidive et au diagnostic mettait en evidence une selection de clones avec un enrichissement de mutations de genes « drivers » et de clones exempts d’autres mutations identifiees au diagnostic. Discussion Les mutations de la voie du BCR semblent etre associees au risque de recidive. Ceci pourrait justifier l’utilisation d’inhibiteurs de kinase du BCR, comme l’ibrutinib qui a montre des resultats encourageants dans les lymphomes B systemiques ganglionnaire diffus a grandes cellules de type « ABC » sauf en cas de mutation CARD11 car en aval de la cible de l’ibrutinib. Les variations du nombre de copies des genes permettraient une meilleure comprehension de l’evolution clonale entre tumeur au diagnostic et a la recidive. Conclusion Cette etude souligne la place centrale de l’activation chronique du BCR dans la reponse au traitement des patients atteints de LBCGC-MI, traites par R-PCT.

Introduction Au sein des lymphomes B diffus a grandes cellules ganglionnaires, la presence d’un « double-hit » (rearrangements de 2 oncogenes MYC et BCL2 et/ou BCL6) ainsi que la double expression de BCL2 et MYC definissent des sous-groupes de patients ayant un pronostic defavorable. La valeur clinique de ces profils n’a pas ete etudiee dans les lymphomes B a grandes cellules primitifs cutanes (LBGCC). Materiel et methodes Il s’agit d’une etude multicentrique, incluant retrospectivement des cas de LBGCC (> 80 % de grandes cellules), diagnostiques selon les criteres de la classification OMS 2017. Nous avons recherche des rearrangements de MYC, BCL2 et BCL6 par hybridation in situ en fluorescence et le statut « double expression » (> 50 % et > 40 % de cellules tumorales exprimant BCL2 et MYC) par immunohistochimie. Les resultats ont ete correles avec les donnees cliniques (recidive, survie) et une analyse statistique a la recherche de valeur diagnostique et pronostique a ete realisee. Resultats Quarante-quatre LBGCC etaient inclus : 21 lymphomes B cutanes centro-folliculaires a grandes cellules (LBCF-GC) et 23 lymphomes B diffus a grandes cellules, de type jambe (LBTJ). Deux cas (5 %) presentaient un rearrangement de MYC : 1 LBTJ ( Fig. 1A ) et 1 LBCF-GC. Un rearrangement de BCL6 etait observe dans 5 cas (12 %) : 4 cas de LBTJ et 1 cas de LBCF-GC ( Fig. 1B ). Aucun rearrangement de BCL2 n’a ete observe. Seul un cas (2 %), correspondant a un LBCF-GC, avait un statut double-hit (rearrangement de MYC et BCL6), sans lien apparent avec le pronostic (remission complete apres 29 mois de suivi). Comme attendu, les LBTJ avaient une survie globale et specifique inferieure aux LBCF-GC (respectivement p = 0,001 et p = 0,021). Trente et un cas (70 %) exprimaient BCL2 et 29 (66 %) exprimaient MYC. Un profil double expression etait present dans 25 cas (57 %) : 6 cas de LBCF-GC et 19 cas de LBTJ. Le profil double expression etait plus souvent associe au sous-type histologique LBTJ (p = 0,006) et associe a un mauvais pronostic (survie globale inferieure, p = 0,002). De plus, au sein du groupe des LBTJ, la presence d’un profil double expression impactait negativement la survie (p = 0,001) ( Fig. 2 ). Discussion Certains cas de LBGCC restent difficiles a classer selon les criteres morphologiques et phenotypiques habituellement utilises. Le profil double expression de MYC et BCL2 est associe a une survie inferieure et pourrait representer un critere diagnostique aidant a differencier les LBCF-GC des LBTJ, deux entites au pronostic et a la prise en charge therapeutique differents. Conclusion Contrairement au lymphome B diffus a grandes cellules ganglionnaires, la recherche du statut double-hit ne semble pas pertinente dans les LBGCC. Le profil double expression peut apporter une aide diagnostique parmi les LBGCC et permet d’identifier un sous-groupe de patients ayant une survie inferieure au sein des LBTJ.

International audience; BACKGROUND:The aim of this study was to assess the efficacy of neoadjuvant anastrozole and fulvestrant treatment of large operable or locally advanced hormone-receptor-positive breast cancer not eligible for initial breast-conserving surgery, and to identify genomic changes occurring after treatment.METHODS:One hundred and twenty post-menopausal patients were randomised to receive 1 mg anastrozole (61 patients) or 500 mg fulvestrant (59 patients) for 6 months. Genomic DNA copy number profiles were generated for a subgroup of 20 patients before and after treatment.RESULTS:A total of 108 patients were evaluable for efficacy and 118 for toxicity. The objective response rate determined by clinical palpation was 58.9% (95% CI=45.0-71.9) in the anastrozole arm and 53.8% (95% CI=39.5-67.8) in the fulvestrant arm. The breast-conserving surgery rate was 58.9% (95% CI=45.0-71.9) in the anastrozole arm and 50.0% (95% CI=35.8-64.2) in the fulvestrant arm. Pathological responses >50% occurred in 24 patients (42.9%) in the anastrozole arm and 13 (25.0%) in the fulvestrant arm. The Ki-67 score fell after treatment but there was no significant difference between the reduction in the two arms (anastrozole 16.7% (95% CI=13.3-21.0) before, 3.2% (95% CI=1.9-5.5) after, n=43; fulvestrant 17.1% (95%CI=13.1-22.5) before, 3.2% (95% CI=1.8-5.7) after, n=38) or between the reduction in Ki-67 in clinical responders and non-responders. Genomic analysis appeared to show a reduction of clonal diversity following treatment with selection of some clones with simpler copy number profiles.CONCLUSIONS:Both anastrozole and fulvestrant were effective and well-tolerated, enabling breast-conserving surgery in over 50% of patients. Clonal changes consistent with clonal selection by the treatment were seen in a subgroup of patients.British Journal of Cancer advance online publication 14 July 2015; doi:10.1038/bjc.2015.247 www.bjcancer.com.

The neoplastic nature of pulmonary Langerhans cell histiocytosis (PLCH) is still debated. As the detection of BRAF

Recent massive parallel sequencing data have evidenced the genetic diversity and complexity of Sézary syndrome mutational landscape with TP53 alterations being the most prevalent genetic abnormality. We analyzed a cohort of 35 patients with SS and a control group of 8 patients with chronic inflammatory dermatoses. TP53 status was analyzed at different clinical stages especially in 9 patients with a past-history of mycosis fungoides (MF), coined secondary SS. TP53 mutations were only detected in 10 patients with either primary or secondary SS (29%) corresponding to point mutations, small insertions and deletions which were unique in each case. Interestingly, TP53 mutations were both detected in sequential unselected blood mononuclear cells and in skin specimens. Cytogenetic analysis of blood specimens of 32 patients with SS showed a TP53 deletion in 27 cases (84%). Altogether 29 out of 35 cases exhibited TP53 mutation and/or deletion (83%). No difference in prognosis was observed according to TP53 status while patients with secondary SS had a worse prognosis than patients with primary SS. Interestingly, patients with TP53 alterations displayed a younger age and the presence of TP53 alteration at initial diagnosis stage supports a pivotal oncogenic role for TP53 mutation in SS as well as in erythrodermic MF making TP53 assessment an ancillary method for the diagnosis of patients with erythroderma as patients with inflammatory dermatoses did not display TP53 alteration.

Primary cutaneous follicle center lymphoma (PCFCL) is the most frequent cutaneous B-cell lymphoma. A 62-year-old man presented with a solitary indolent subcutaneous nodule for 3 years duration, without other abnormalities. Histological examination showed lymphoproliferation with a nodular growth pattern characterized by fibrous collagen bands surrounding nodules. The nodules were composed of medium-sized centrocytes admixed with many large multilobulated and lacunar cells without eosinophils or granulomatous aspect. Hodgkin-like cells were CD30+, CD15+, PAX5+, OCT2+, BOB1+, MUM1+, Ki67+, Bcl6+ and focally CD20+ and EMA-, CD79a-, Bcl2- and CD10-. The medium-sized cells were CD20+, CD79a+, Bcl2+, Bcl6+ and CD10+, enmeshed in a network of CD21-positive follicular dendritic cells. Epstein-Barr virus detection was negative. Interphase fluorescence in situ hybridization showed the absence of BCL2 or BCL6 rearrangement. In such a case, the presence of Hodgkin-like cells intermixed with the tumor population may result in a pitfall diagnosis of classical Hodgkin lymphoma (CHL). Differential diagnoses to be ruled out are secondary or primary skin localization of rather CHL, or systemic follicular lymphoma. Several clinical, radiological, histological, immunohistochemical and molecular arguments indicated the diagnosis of PCFCL. To our knowledge, this is the first report of PCFCL with Hodgkin-like cells.

International audience; Introduction: Anaplastic lymphoma kinase (ALK) rearrangements occur in 1% to 7% of non-small-cell lung cancers (NSCLCs). Crizotinib, an ALK inhibitor, has been demonstrated to provide dramatic clinical benefits in ALK-positive advanced-stage NSCLC. Fluorescent in situ hybridization (FISH) has been established in clinical trials as the standard procedure method for detecting ALK rearrangements. Although the detection of ALK by immunohistochemistry (IHC) has been proposed for the screening of patients, large-scale studies are warranted to validate such a hierarchical approach. Methods: In this article, we report the largest series thus far of parallel FISH and IHC ALK testing in 3244 consecutive NSCLC cases analyzed at two independent French centers. Results: FISH-positive and/or IHC-positive results were demonstrated in 150 of 3244 cases (4.6%). An imbalanced sex ratio was detected, with women exhibiting a 2.2-fold relative risk for an alteration. Strikingly, only 80 of 150 specimens were classified as ALK positive by both techniques. The specimens with discordant FISH/IHC analyses were FISH-positive/IHC-negative (36), FISH-negative/IHC-positive (19), or FISH-noncontributive/IHC-positive (15). Thus, a single FISH or IHC analysis performed alone would have failed to detect approximately one-fourth of the ALK-positive cases with similar findings in our two centers. Conclusions: This study highlights the feasibility of systematic NSCLC testing by both FISH and IHC in routine practice. Many preanalytical factors may account for the apparent discrepancies between both methods, suggesting that hierarchical screening may underscore ALK-positive cases. This significant level of discrepancy supports the need of combined testing to optimize the detection of ALK-inhibitor-eligible patients given that some patients with discordant testing were found to respond to crizotinib.

Neurofibromatosis 1 (NF1) is one of the most common genetic disorders and is caused by mutations in the NF1 gene. NF1 gene mutational analysis presents a considerable challenge because of its large size, existence of highly homologous pseudogenes located throughout the human genome, absence of mutational hotspots, and diversity of mutations types, including deep intronic splicing mutations. We aimed to evaluate the use of hybridization capture-based next-generation sequencing to screen coding and noncoding NF1 regions. Hybridization capture-based next-generation sequencing, with genomic DNA as starting material, was used to sequence the whole NF1 gene (exons and introns) from 11 unrelated individuals and 1 relative, who all had NF1. All of them met the NF1 clinical diagnostic criteria. We showed a mutation detection rate of 91% (10 out of 11). We identified eight recurrent and two novel mutations, which were all confirmed by Sanger methodology. In the Sanger sequencing confirmation, we also included another three relatives with NF1. Splicing alterations accounted for 50% of the mutations. One of them was caused by a deep intronic mutation (c.1260 + 1604A > G). Frameshift truncation and missense mutations corresponded to 30% and 20% of the pathogenic variants, respectively. In conclusion, we show the use of a simple and fast approach to screen, at once, the entire NF1 gene (exons and introns) for different types of pathogenic variations, including the deep intronic splicing mutations.

Histologic and phenotypic analyses of splenectomy samples from 17 patients with common variable immunodeficiency (CVID) showed the following nonspecific, evocative, white-pulp lesions: white-pulp hyperplasia (WPH) with reactive follicles, giant follicles (GFs), marginal zone hyperplasia, periarteriolar T-zone hyperplasia (PATH) and/or granulomas, which enabled us to discern 2 groups: the first (n=6) composed of WPH with reactive follicles without granulomas, and the second (n=9) characterized by the presence of granulomas with or without WPH. All specimens were Epstein-Barr virus negative by in situ hybridization. Molecular analyses revealed a polyclonal immunoglobulin heavy chain gene (IGH) rearrangement (n=12). WPH-only patients were mostly female individuals and younger at CVID onset, diagnosis, and splenectomy, but their interval between the first symptom and diagnosis was longer; they had more associated infectious events, autoimmune disease, pulmonary complications, and liver regenerative nodular hyperplasia; their IgG, IgA, and IgM concentrations were also higher. Granuloma-group patients were mostly male individuals; were older at CVID onset, diagnosis, and splenectomy; had disseminated granulomatous disease, but infectious events, autoimmune disease, pulmonary complications, and liver regenerative nodular hyperplasia were less common; their immunoglobulin concentrations were lower. Histologic comparisons between the WPH-only and granuloma groups showed more intense WPH and more intense marginal zone hyperplasia and fewer GFs in the former versus more developed PATH and more common GFs in the latter. The results of this novel comparative study of the histologic patterns of 17 CVID patients' evocative splenic lesions suggested different biological and clinical profiles.

De recentes analyses de sequencage massif [1] , [2] ont permis de mettre en evidence la diversite et la complexite du profil mutationnel du syndrome de Sezary (SS). Ces differentes etudes ont cependant definit l’alteration de TP53 comme anomalie la plus frequente. Dans ce contexte, nous avons analyse le statut TP53 dans une cohorte de 35 patients SS ainsi qu’un groupe temoin compose de 8 patients presentant une dermatose inflammatoire chronique. Le statut TP53 a ete analyse a differents stades cliniques, notamment pour 9 patients appeles « SS secondaire » car ayant developpe un syndrome de Sezary apres un mycosis fongoides (MF). Une mutation du gene TP53 de type mutation ponctuelle ou petite insertion/deletion a ete caracterisee chez 10 (29 %) patients SS d’emblee ou secondaire. Aucune mutation n’est commune a plusieurs patients. A noter que ces mutations sont presentes a la fois dans les cellules mononuclees du sang et dans les echantillons de peau. Des analyses cytogenetiques realisees en parallele sur les cellules mononuclees du sang de 32 patients ont rapporte 27 (84 %) cas de deletion. Au total, une mutation et/ou une deletion de TP53 a ete caracterisee sur 29 (83 %) des 35 cas testes. Aucune difference de pronostique n’a ete observee selon le statut TP53 mais les patients presentant un SS secondaire ont un pronostic plus sombre que les patients presentant un SS d’emblee. Il est interessant de souligner que la presence de l’alteration de TP53 au diagnostic de SS (ou de MF s’il s’agit d’un SS secondaire) supporte l’hypothese que la mutation de TP53 jouerait un role pivot dans l’oncogenese du SS et du MF, et que l’etude du statut de TP53 et notamment l’absence d’alteration de TP53 pourrait etre utile au diagnostic differentiel des patients atteints de dermatoses inflammatoires.

Anaplastic lymphoma kinase (ALK) gene rearrangements in lung adenocarcinoma result in kinase activity targetable by crizotinib. Although fluorescence in situ hybridisation (FISH) is the reference diagnostic technique, immunohistochemistry (IHC) could be useful for pre-screening.Diagnostic yields of ALK IHC, FISH and quantitative reverse transcriptase PCR performed in 14 French pathology/molecular genetics platforms were compared. 547 lung adenocarcinoma specimens were analysed using 5A4 and D5F3 antibodies, two break-apart FISH probes and TaqMan kits. Clinicopathological data were recorded.140 tumours were ALK rearranged (FISH with ≥15% of rearranged cells) and 400 were ALK FISH negative (ALK patients were young (p=0.003), mostly females (p=0.007) and light/nonsmokers (p20%. Variants were undetected in 36% of ALK tumours.Discordances predominated with FISH ranging from 10% to 20% of rearranged cells and were centre dependent. IHC remains a reliable pre-screening method for ALK rearrangement detection.

Background It can be useful to assess the NRAS mutation status in patients with metastatic melanoma because NRAS -activating mutations confer resistance to RAF inhibitors, and NRAS- mutated patients appear to be sensitive to mitogen-activated protein kinase (MEK) inhibitors. Objective We aimed to assess the diagnostic accuracy of an immunohistochemistry (IHC) approach using a novel anti-NRAS (Q61R) monoclonal antibody on formalin-fixed paraffin-embedded tissue samples from patients with metastatic melanoma. Methods We conducted a retrospective multicenter cohort study on 170 patients with metastatic melanoma. The automated IHC assay was performed using the SP174 clone, and compared with results of the molecular testing. Results Evaluation of a test cohort with knowledge of the mutation status established a specific IHC pattern for the mutation. In the independent blinded analysis of the remaining cases, the anti-NRAS (Q61R) antibody accurately identified all NRAS Q61R-mutated tumors, and demonstrated 100% sensitivity and specificity. Limitations Limitations include retrospective design and lack of multicenter interobserver reproducibility. Conclusion The NRAS (Q61R) IHC assay is reliable and specific for the evaluation of the Q61R mutation status in metastatic melanoma and may be an alternative to molecular biology in evaluation of metastatic melanoma in routine practice.

Contexte Les rearrangements du gene ALK dans les adenocarcinomes pulmonaires (ADK) induisent une activation constitutive de la kinase ALK, ciblable par le crizotinib [1] , [2] . Bien que la FISH (hybridation in situ fluorescente) soit la technique de reference pour le diagnostic de ces rearrangements, l’immunohistochimie (IHC) pourrait etre utile en tant qu’outil de pre-screening. But de l’etude Comparer les techniques d’IHC, FISH et RT-qPCR ALK realisees par 14 plateformes de genetique moleculaire des cancers (PGMC). Materiel et methodes Pour cette etude methodologique, 547 ADK, enrichis en prelevements chirurgicaux et en cas positifs, ont ete analyses, en utilisant les anticorps 5A4 et D5F3 (IHC), 2 sondes break-apart (FISH), et des kits TaqMan (RT-qPCR), et les donnees clinicopathologiques des patients renseignees. Resultats Au total, 140 tumeurs presentaient un rearrangement du gene ALK par FISH (≥ 15 % de cellules rearrangees) et 400 etaient negatives ( 20 %. Aucun variant de transcription n’a ete detecte dans 36 % des cas ALK-positifs. Conclusion L’analyse des resultats a mis en evidence que les discordances IHC/FISH sont plus frequentes pour les cas « borderline » (FISH entre 10 et 20 %), et qu’elles sont PGMC-dependantes. L’IHC est donc un outil de prescreening fiable pour la detection des rearrangements du gene ALK.

Summary Oculocutaneous albinism (OCA) is caused by mutations in six different genes, and their molecular diagnosis encompasses the search for point mutations and intragenic rearrangements. Here, we used high-resolution array-comparative genome hybridization (CGH) to search for rearrangements across exons, introns and regulatory sequences of four OCA genes: TYR, OCA2, TYRP1, and SLC45A2. We identified a total of ten new deletions in TYR, OCA2, and SLC45A2. A complex rearrangement of OCA2 was found in two unrelated patients. Whole-genome sequencing showed deletion of a 184-kb fragment (identical to a deletion previously found in Polish patients), whereby a large portion of the deleted sequence was re-inserted after severe reshuffling into intron 1 of OCA2. The high-resolution array-CGH presented here is a powerful tool to detect gene rearrangements. Finally, we review all known deletions of the OCA1–4 genes reported so far in the literature and show that deletions or duplications account for 5.6% of all mutations identified in the OCA1–4 genes.