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Concurrent BCL2 and MYC translocations, so called double hit (DH), are a rare finding in large B-cell lymphoma (LBCL). Based on data from retrospective series, DH has been correlated with aggressive clinical behaviour and poor outcome. We conducted a consecutive study of DH incidence and correlation with pathologic and clinical characteristics, including response to Rituximab-containing chemotherapy and survival, in an unselected cohort of patients with LBCL. Translocations involving BCL2 and MYC loci were examined with fluorescent in situ hybridization (FISH) in 157 patients with diffuse large B-cell lymphoma (DLBCL) or B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (BCLU). The incidence of DH was 11% in the total cohort, 7% of primary LBCL and 21% of transformed LBCL. DH lymphomas were all GCB immunophenotype and were more often BCLU. No clinical characteristics were correlated with the presence of DH, which also had no impact on overall response rate (ORR), relapse rate or overall survival (OS). However, sub-stratification of DH lymphomas by FISH indicated a possible inferior survival related to immunoglobulin MYC translocation partner gene. Screening of patients with BCLU and DLBCL of GCB type for DH BCL2/MYC translocation including MYC translocation partner gene may provide important prognostic information.

In large B-cell lymphoma (LBCL) MYC- and MYC/BCL2 double-hit (DH) translocations have been associated with inferior survival. We hypothesised that the negative prognostic impact of MYC translocation was determined by an immunoglobulin MYC translocation partner gene (IG-MYC), as opposed to a non-immunoglobulin partner gene (nonIG-MYC). In a prospective, unselected cohort of 237 LBCL patients MYC and BCL2 translocations were identified by fluorescent in situ hybridisation (FISH) with split probes. MYC translocation partner gene was identified by IGH/MYC fusion probes and/or kappa/lambda split probes. Clinical data were collected from patient files. MYC translocation was identified in 28/225 patients. IG-MYC translocation partner gene was identified in 12/24 patients. DH translocation was identified in 23/228 patients. IG-MYC translocation partner gene was identified in 9/19 DH patients. Neither MYC-nor DH translocation showed correlation with survival. However, MYC translocation with IG-MYC translocation partner gene was associated with worse OS compared with both MYC translocation with nonIG-MYC translocation partner gene (P = 0.02) as well as absence of MYC translocation (P = 0.03). In patients with DH a similar, however, stronger correlation was seen (P = 0.003 and P = 0.0004 respectively). MYC - or DH translocation with nonIG-MYC translocation partner gene was not associated with worse overall survival (P = 0.2 and P = 0.3 respectively). Most patients received Rituximab (86%) and CHOP/CHOP-like chemotherapy regimes (81%). We suggest that prognostic stratification of LBCL patients by MYC and/or DH translocations should include identification of MYC translocation partner gene because approximately half of the cases harbour nonIG-MYC translocation partner genes with no or minor influence on survival.

Chromosome aberrations are frequently observed in precursor-B-acute lymphoblastic leukemias (ALL) and T-cell acute lymphoblastic leukemias (T-ALL). These translocations can form leukemia-specific chimeric fusion proteins or they can deregulate expression of an (onco)gene, resulting in aberrant expression or overexpression. Detection of chromosome aberrations is an important tool for risk classification. We developed rapid and sensitive split-signal fluorescent in situ hybridization (FISH) assays for six of the most frequent chromosome aberrations in precursor-B-ALL and T-ALL. The split-signal FISH approach uses two differentially labeled probes, located in one gene at opposite sites of the breakpoint region. Probe sets were developed for the genes TCF3 (E2A) at 19p13, MLL at 11q23, ETV6 at 12p13, BCR at 22q11, SIL-TAL1 at 1q32 and TLX3 (HOX11L2) at 5q35. In normal karyotypes, two colocalized green/red signals are visible, but a translocation results in a split of one of the colocalized signals. Split-signal FISH has three main advantages over the classical fusionsignal FISH approach, which uses two labeled probes located in two genes. First, the detection of a chromosome aberration is independent of the involved partner gene. Second, split-signal FISH allows the identification of the partner gene or chromosome region if metaphase spreads are present, and finally it reduces false-positivity. Leukemia ( Chromosome aberrations play an important role in hematological malignancies. 1 In ALL, most of these aberrations concern balanced translocations involving genes that play key roles in the development and function of lymphoid cells, such as transcription factors, cell cycle regulators, and signal transduction molecules. Balanced translocations can result in fusion of two genes that encode leukemia-specific chimeric (fusion) proteins. The fusion proteins have functional features that differ from the corresponding wild-type proteins and mostly play a role in leukemogenesis. In addition to the new features of the fusion protein, loss of wild-type activity due to the translocation (in some translocations enhanced by deletion of the second allele) might contribute to oncogenesis. Alternatively, chromosome translocations can result in deregulated expression of (onco)genes as a direct consequence of a translocation to a regulatory element, for example, an immunoglobulin (Ig) or T-cell receptor (TCR) enhancer. 2,3 The most frequent translocations in precursor-B-ALL are t(1;19)(q23;p13) t(4;11)(q21;q23), t(12;21)(p13;q22), and t(9;22)(q34;q11), all four of which result in generation of fusion genes. The t(1;19)(q23;p13) fuses the transcription factorencoding gene TCF3 (E2A) with the transcription factor PBX1. In t(4;11)(q21;q23), the MLL gene at 11q23, which encodes a putative DNA-binding protein, is translocated to the MLLT2 (AF4) gene. The MLL gene is involved in many other translocations in ALL and acute myeloid leukemia (AML). Until now, more than 30 partner genes have been identified. 4 The t(12;21)(p13;q22) involves th...

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Chromosomal translocations affecting the immunoglobulin loci, particularly immunoglobulin heavy chain (IGH) genes complex at 14q32, are a hallmark of B cell malignancies.1,2 They usually result in deregulated expression of involved oncogenes (eg, BCL1, CMYC, and PAX5) juxtaposed to the regulatory elements of IGH. As some of these translocations are associated with specific subtypes of mature B cell lymphoma and have prognostic significance, their detection is of clinical importance. In daily practice, IGH translocations have been routinely analyzed by fluorescence in situ hybridization (FISH) using either a common LSI IGH dual-color, break-apart rearrangement assay or dual-color, dual-fusion oncogene-specific probe, such as LSI IGH/CCND1, IGH/ BCL2, and IGH/CMYC.The IGH-mediated translocations are relatively rare in B cell chronic lymphocytic leukemia (CLL), [3][4][5] which is the most common form of leukemia in adults and shows a highly variable clinical course. The CLL cells display a phenotype of mature activated B lymphocytes expressing CD19, CD5, and CD23 and having reduced levels of membrane IgM, IgD, and CD79b. The co-expression of CD19 and CD5, however, is also characteristic for mantle cell lymphoma (MCL), which, in contrast to CLL, is usually an aggressive disease hallmarked by the t(11;14)(q13; q32)/IGH-CCND1 rearrangement. Differential diagnosis between CLL and leukemic MCL is sometimes challenging. 5 Given that up to 30% of MCL cases have immunophenotypic features characteristic of B-CLL, albeit usually with atypical, pleomorphic morphology, 6 immunophenotyping alone is insufficient to exclude a diagnosis of MCL. Therefore, in the Belfast City Hospital (Belfast, Northern Ireland) all suspected CLL cases have been routinely examined by rapid interphase FISH with the LSI IGH/CCND1 assay to identify t(11;14)-positive MCL cases, in addition to examination for CLL typical cytogenetic aberrations. During this analysis, a subset of CLL

The role of c-myc in multiple myeloma (MM) is controversial. We conducted a retrospective study of 117 patients with MM diagnosed between 2004 and 2010 at Herlev Hospital. Immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) were performed on tissue microarrays (TMAs) made from diagnostic bone marrow aspirates. Clinical data were obtained from the Danish Multiple Myeloma Database (DMMD). Overexpression of c-myc was found in 40% of patients. MYC translocation was found in 10% of patients. Overexpression of c-myc was not associated with MYC translocation. Overexpression of c-myc was associated with hypercalcemia (p = 0.02) and extramedullary myeloma (p < 0.01). Overexpression of c-myc was associated with shorter overall survival (OS) by multivariable analysis of the entire patient cohort [HR 1.92 (1.06-3.45), p = 0.03] and univariable analysis of high-dose-therapy (HDT)-ineligible patients [HR 2.01 (1.05-3.86), p = 0.04]. Further studies of c-myc overexpression in larger cohorts of patients with MM are warranted.

This study indicated that in patients with mCRC, RAS mutations are associated with increased risk of lung and ovary metastases. BRAF V600E is associated with increased risk of skin metastases, and PIK3CA mutation with decreased risk of peritoneal metastases.