Juan F. García

Outcome in Hodgkin's lymphoma can be predicted from the presence of accompanying cytotoxic and regulatory T cells.

Purpose: Recent studies of Hodgkins lymphoma (HL) have suggested that the presence of regulatory T cells in the reactive background may explain the inhibition of the antitumoral host immune response observed in these patients. This study aimed to assess the relevance of regulatory T cells and CTLs present in the background of HL samples in the prognosis of a series of classic HL (cHL) patients. Experimental Design: Expression of granzyme B and TIA-1 (markers for CTL) and FOXP3 (a marker for regulatory T cells) were evaluated independently by immunohistochemistry in tissue microarrays of 257 cHL patients and correlated with patient outcome. Results: The combined influence of the presence of FOXP3+ and TIA-1+ cells distinguished three risk groups of patients with 5-year overall survival of 100%, 88%, and 73%. The presence of a small number of FOXP3+ cells and a high proportion of TIA-1+ cells in the infiltrate represent an independent prognostic factor that negatively influenced event-free survival and disease-free survival in cHL. Compared with the features at diagnosis, relapsed samples tended to have more TIA-1+ cells and a lower proportion of FOXP3+ cells in the reactive background. Conclusions: These data suggest that low infiltration of FOXP3+ cells in conjunction with high infiltration of TIA-1+ cells in cHL may represent biological markers predicting an unfavorable outcome. Moreover, the variation of these markers over the course of the disease implies a possible role for them in the progression of HL cases.

Primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma expresses follicular T-cell markers.

Cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma (CSTCL) is a cutaneous T-cell lymphoma defined by a predominance of small-to-medium–sized CD4+ pleomorphic T cells, with a favorable clinical course. Cases are also characterized by the presence of a rich infiltrate of reactive B cells. Recently, it has been reported that follicular helper T cells (TFH cells) display a distinct gene expression profile, positive for PD-1, CXCL13, and BCL-6. We report for the first time the expression of PD-1 and other TFH cell markers in CSTCLs and discuss its biologic significance. Sixteen CSTCLs were included in this study, and also 20 reactive inflammatory conditions, 10 primary cutaneous marginal zone, 10 follicular center lymphomas, and 5 primary CD30+ cutaneous lymphomas. They were immunohistochemically analyzed for a large panel of markers. Double immunoperoxidase labeling of paraffin sections was performed for PD-1, OCT-2, and BCL-6. Clonal Ig and T-cell receptor rearrangements and Epstein-Barr virus-encoded RNA expression were also evaluated. Morphologic and clinical data were reviewed. Histologic examination showed a dense polymorphic lymphoid infiltrate throughout the dermis. Atypical large CD4+ cells were positive for PD-1, CXCL13, and BCL-6 in all cases, and were attached in small clusters, or formed rosettes around CD30/OCT-2+ B blast cells. Epstein-Barr virus was not apparent in any of the cases. A dominant T-cell clone was identified in 14 cases, whereas polymerase chain reaction IgH gene rearrangement studies showed that all cases were polyclonal. None of the patients had lymphadenopathy or showed any evidence of systemic disease, nor did they have any previous history of mycosis fungoides or drug reactions. FTH cell markers are not exclusive to angioimmunoblastic lymphadenopathy but may also be seen in neoplastic cells of CSTCLs. Moreover, these findings suggest that B-cell stimulation by FTH could also take place in some cutaneous T-cell lymphomas.

Expression of the NF‐κB targets BCL2 and BIRC5/Survivin characterizes small B‐cell and aggressive B‐cell lymphomas, respectively

Nuclear factor kappa B (NF‐κB) activation has been proposed as a cardinal feature of tumourigenesis, although the precise mechanism, frequency, relevance, and extent of NF‐κB activation in lymphomas remain to be fully elucidated. In this study, expression profiling and tissue microarray studies of 209 and 323 non‐Hodgkins lymphomas (NHLs) respectively, including the most frequent sub‐types of NHL, were employed to generate a hypothesis concerning the most common NF‐κB targets in NHL. These analyses showed that NF‐κB activation is a common phenomenon in NHL, resulting in the expression of distinct sets of NF‐κB target genes, depending on the cell context. BCL2 and BIRC5/Survivin were identified as key NF‐κB targets and their expression distinguished small and aggressive B‐cell lymphomas, respectively. Interestingly, in the vast majority of B‐cell lymphomas, the expression of these markers was mutually exclusive. A set of genes was identified whose expression correlates either with BIRC5/Survivin or with BCL2. BIRC5/Survivin expression, in contrast to BCL2, was associated with a signature of cell proliferation (overexpression of cell cycle control, DNA repair, and polymerase genes), which may contribute to the aggressive phenotype and poor prognosis of these lymphomas. Strikingly, mantle cell lymphoma and chronic lymphocytic leukaemia expressed highly elevated levels of BCL2 protein and mRNA, higher than that observed in reactive mantle zone cells or even in follicular lymphomas, where BCL2 expression is deregulated through the t(14;18) translocation. In parallel with this observation, BIRC5/Survivin expression was higher in Burkitts lymphoma and diffuse large B‐cell lymphoma than in non‐tumoural germinal centre cells. In vitro studies confirmed that NF‐κB activation contributes to the expression of both markers. In cell lines representing aggressive lymphomas, NF‐κB inhibition resulted in a decrease in BIRC5/Survivin expression. Meanwhile, in chronic lymphocytic leukaemia (CLL)‐derived lymphocytes, NF‐κB inhibition resulted in a marked decrease in BCL2 expression. Copyright

EBV-positive diffuse large B-cell lymphoma of the elderly is an aggressive post-germinal center B-cell neoplasm characterized by prominent nuclear factor-kB activation.

Here, we report a retrospective series of 47 EBV-positive diffuse large B-cell lymphoma associated with advanced age. Histopathology allowed to the identification of different histological patterns: cases with polymorphic diffuse large B-cell lymphoma (29 cases), Hodgkin-like (8 cases) and polymorphic lymphoproliferative disorder-like (9 cases) patterns. One case was purely monomorphic diffuse large B-cell lymphoma. We show that this lymphoma type is a neoplasm with prominent classical and alternative nuclear factor-kB pathway activation in neoplastic cells (79% of the cases showed nuclear staining for p105/p50, 74% for p100/p52 and 63% for both proteins), with higher frequency than that observed in a control series of EBV-negative diffuse large B-cell lymphoma (χ2 <0.001). Most cases showed an activated phenotype (95% non-germinal center (Hans algorithm); 78% activated B cell (Choi algorithm)). Clonality testing demonstrated IgH and/or K/Kde/L monoclonal rearrangements in 64% of cases and clonal T-cell populations in 24% of cases. C-MYC (1 case), BCL6 (2 cases) or IgH (3 cases) translocations were detected by FISH in 18% cases. These tumors had a poor overall survival and progression-free survival (the estimated 2-year overall survival was 40±10% and the estimated 2-year progression-free survival was 36±9%). Thus, alternative therapies, based on the tumor biology, need to be tested in patients with EBV-positive diffuse large B-cell lymphoma of the elderly.

Clinical outcome in diffuse large B-cell lymphoma is dependent on the relationship between different cell-cycle regulator proteins.

PURPOSE The goal of this work was to perform a comprehensive exploration of the relationship between the clinical outcome of diffuse large B-cell lymphoma (DLBCL) and the expression of a panel of tumor suppressor and oncogenic proteins, which includes some cell-cycle regulator proteins involved in the p53 pathway. PATIENTS AND METHODS To this end, we collected the clinical data of 141 patients with DLBCL and immunohistochemically analyzed diagnostic tumoral tissue from each patient for the presence of Ki67 (MIB1, Immuno-tech, Marseille, France), bcl2, p53, p21/WAF1, MDM2, and retinoblastoma (Rb) proteins. RESULTS The results show that several proteins are associated with some of the clinical traits analyzed. Multivariate analysis showed that an extended overall survival (OS) time was associated with low growth fraction, high Rb protein, and low MDM2 expression, as well as with known clinical parameters. The probability of inducing a complete remission (CR) was only associated with clinical parameters, although univariate study showed that a low growth fraction was associated with a higher probability of inducing a CR. Univariate study of disease-free survival (DFS) showed that tumors with high bcl2 expression and nodal origin have a shorter DFS time, although multivariate study only confirmed the adverse effect of bcl2 expression. CONCLUSION Taking all these results into consideration, it seems that although the overall outcome for patients with DLBCL is decided by a combination of different clinical and biologic variables, the expression of some of these cell-cycle regulator proteins appears to be specifically associated with the different clinical features of tumors.

Aggressive large B-cell lymphoma with plasma cell differentiation: immunohistochemical characterization of plasmablastic lymphoma and diffuse large B-cell lymphoma with partial plasmablastic phenotype.

Background Plasmablastic lymphoma has recently come to be considered a distinct entity among mature B cell neoplasms, although the limits with diffuse large B-cell lymphoma (DLBCL) need to be more accurately defined. Design and Methods Here we show the results of an immunohistochemical study of 35 cases of plasmablastic lymphoma compared with a set of 111 conventional DLBCLs. Results Our results demonstrate that the use of a limited combination of immunohistochemical markers (PAX5&CD20, PRDM1/BLIMP1 and XBP1s) enables the identification of a plasmablastic immunophenotype highly characteristic of plasmablastic lymphoma cases and associated with an aggressive clinical behavior. Additionally, the study shows that the acquisition of a partial plasmablastic phenotype (PRDM1/BLIMP1 expression) in DLBCL is associated with shorter survival in R-CHOP-treated patients. Conclusions The use of a restricted combination of immunohistochemical markers (PAX5&CD20, PRDM1/BLIMP1 and XBP1s) enables a more accurate definition of terminal differentiation for large B-cell lymphoma.

Nodal Marginal Zone Lymphoma: A Heterogeneous Tumor: A Comprehensive Analysis of a Series of 27 Cases

We have reviewed the clinical, morphologic, immunophenotypical, and molecular features of a series of 27 cases of nodal marginal zone lymphoma with the aim of defining this entity more precisely. The series was characterized by a relatively favorable clinical course, with a low clinical stage at diagnosis (59% patients with clinical stage I–II) and a 5-year overall survival probability of 79%. However, the disease persisted in a relatively large fraction of the patients, thus yielding a 5-year failure-free survival probability of 22%. Molecular and immunohistochemical analyses of the series revealed heterogeneity in the frequency of IgVH somatic mutation and in the expression of IgD, CD43, MUM1, and CD38. Apart from the absence of nuclear Bcl10, no clear distinction could be made from the expression profiling of other B-cell lymphomas claimed to be derived from marginal zone B cells. Additionally, the immunophenotype of the tumoral cells in all cases but one differed from that described in monocytoid B cells. It was characterized by a Bcl2−, p21+, cyclin E+ profile. The analysis of apoptosis-regulator proteins disclosed abnormalities in the expression of survivin and active caspase 3, which could partially explain the abnormal regulation of apoptosis observed in these tumors. Molecular and immunohistochemical data obtained in this study strongly imply that there is significant heterogeneity among the cases included in the category termed nodal marginal zone lymphoma.

Whole-Exome Sequencing Identifies MDH2 as a New Familial Paraganglioma Gene

Disruption of the Krebs cycle is a hallmark of cancer. IDH1 and IDH2 mutations are found in many neoplasms, and germline alterations in SDH genes and FH predispose to pheochromocytoma/paraganglioma and other cancers. We describe a paraganglioma family carrying a germline mutation in MDH2, which encodes a Krebs cycle enzyme. Whole-exome sequencing was applied to tumor DNA obtained from a man age 55 years diagnosed with multiple malignant paragangliomas. Data were analyzed with the two-sided Students t and Mann-Whitney U tests with Bonferroni correction for multiple comparisons. Between six- and 14-fold lower levels of MDH2 expression were observed in MDH2-mutated tumors compared with control patients. Knockdown (KD) of MDH2 in HeLa cells by shRNA triggered the accumulation of both malate (mean ± SD: wild-type [WT] = 1±0.18; KD = 2.24±0.17, P = .043) and fumarate (WT = 1±0.06; KD = 2.6±0.25, P = .033), which was reversed by transient introduction of WT MDH2 cDNA. Segregation of the mutation with disease and absence of MDH2 in mutated tumors revealed MDH2 as a novel pheochromocytoma/paraganglioma susceptibility gene.

MiRNA expression in diffuse large B-cell lymphoma treated with chemoimmunotherapy

Diffuse large B-cell lymphoma (DLBCL) prognostication requires additional biologic markers. miRNAs may constitute markers for cancer diagnosis, outcome, or therapy response. In the present study, we analyzed the miRNA expression profile in a retrospective multicenter series of 258 DLBCL patients uniformly treated with chemoimmunotherapy. Findings were correlated with overall survival (OS) and progression-free survival (PFS). miRNA and gene-expression profiles were studied using microarrays in an initial set of 36 cases. A selection of miRNAs associated with either DLBCL molecular subtypes (GCB/ABC) or clinical outcome were studied by multiplex RT-PCR in a test group of 240 cases with available formalin-fixed, paraffin-embedded (FFPE) diagnostic samples. The samples were divided into a training set (123 patients) and used to derive miRNA-based and combined (with IPI score) Cox regression models in an independent validation series (117 patients). Our model based on miRNA expression predicts OS and PFS and improves upon the predictions based on clinical variables. Combined models with IPI score identified a high-risk group of patients with a 2-year OS and a PFS probability of < 50%. In summary, a precise miRNA signature is associated with poor clinical outcome in chemoimmunotherapy-treated DLBCL patients. This information improves upon IPI-based predictions and identifies a subgroup of candidate patients for alternative therapeutic regimens.

Influence of Biologic Markers on the Outcome of Hodgkin's Lymphoma: A Study by the Spanish Hodgkin's Lymphoma Study Group

PURPOSE Current therapies fail to cure a significant proportion of patients with Hodgkins lymphoma (HL). Predictive systems for stratification of the disease and selection of treatment based on sets of clinical variables, such as the international prognostic score (IPS), are of relatively small practical value. The predictive use of biologic parameters has so far provided limited and inconsistent results. Here we explore the influence of a set of molecular markers on the outcome of HL. PATIENTS AND METHODS Forty molecular markers involved in B-cell differentiation and activation, signal transduction, cell cycle, and apoptosis control were analyzed in 259 classic HL patient cases by using tissue microarrays. Univariate analysis was performed to evaluate the influence of markers on favorable outcome (complete remission of > 12 months). Significant variables were included in a multivariate logistic regression analysis, and the probability of favorable outcome was estimated. RESULTS Univariate analysis revealed four molecular markers that predicted outcome, and the multivariate analysis showed p53, Bcl-X(L), and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) to have independent significance. The combination of these factors determined two groups of patients (group I, zero to one factor; group II, two to three factors) with a probability of a favorable outcome of.948 and.687, respectively. A multivariate Coxs model shows that these biologic risk groups have special predictive power in low-IPS patients. CONCLUSION The data from this exploratory study suggest that the accumulation of molecular events seems to influence the outcome of HL, particularly in the low-IPS group.