Michael Boe Møller

Immunohistochemical Double-Hit Score is a Strong Predictor of Outcome in Patients with Diffuse Large B-Cell Lymphoma Treated with Rituximab Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone

PURPOSE Approximately 5% of diffuse large B-cell lymphomas (DLBCLs) are double-hit lymphomas (DHLs) with translocations of both MYC and BCL2. DHLs are characterized by poor outcome. We tested whether DLBCLs with high expression of MYC protein and BCL2 protein share the clinical features and poor prognosis of DHLs. PATIENTS AND METHODS Paraffin-embedded lymphoma samples from 193 patients with de novo DLBCL who were uniformly treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were studied using immunohistochemistry for MYC, BCL2, CD10, BCL6, and MUM1/interferon regulatory factor 4, and fluorescent in situ hybridization (FISH) for MYC and BCL2. RESULTS FISH analysis identified DHL in 6% of patients, who showed the expected poor overall survival (OS; P = .002). On the basis of immunohistochemical MYC and BCL2 expression, a double-hit score (DHS) was assigned to all patients with DLBCL. The DHS-2 group, defined by high expression of both MYC and BCL2 protein, comprised 29% of the patients. DHS 2 was significantly associated with lower complete response rate (P = .004), shorter OS (P < .001), and shorter progression-free survival (PFS; P < .001). The highly significant correlation with OS and PFS was maintained in multivariate models that controlled for the International Prognostic Index and the cell-of-origin subtype (OS, P < .001; PFS, P < .001). DHS was validated in an independent cohort of 116 patients who were treated with R-CHOP. CONCLUSION The immunohistochemical DHS defined a large subset of DLBCLs with double-hit biology and was strongly associated with poor outcome in patients treated with R-CHOP.

MYC/BCL2 protein coexpression contributes to the inferior survival of activated B-cell subtype of diffuse large B-cell lymphoma and demonstrates high-risk gene expression signatures: a report from The International DLBCL Rituximab-CHOP Consortium Program

Diffuse large B-cell lymphoma (DLBCL) is stratified into prognostically favorable germinal center B-cell (GCB)-like and unfavorable activated B-cell (ABC)-like subtypes based on gene expression signatures. In this study, we analyzed 893 de novo DLBCL patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). We show that MYC/BCL2 protein coexpression occurred significantly more commonly in the ABC subtype. Patients with the ABC or GCB subtype of DLBCL had similar prognoses with MYC/BCL2 coexpression and without MYC/BCL2 coexpression. Consistent with the notion that the prognostic difference between the 2 subtypes is attributable to MYC/BCL2 coexpression, there is no difference in gene expression signatures between the 2 subtypes in the absence of MYC/BCL2 coexpression. DLBCL with MYC/BCL2 coexpression demonstrated a signature of marked downregulation of genes encoding extracellular matrix proteins, those involving matrix deposition/remodeling and cell adhesion, and upregulation of proliferation-associated genes. We conclude that MYC/BCL2 coexpression in DLBCL is associated with an aggressive clinical course, is more common in the ABC subtype, and contributes to the overall inferior prognosis of patients with ABC-DLBCL. In conclusion, the data suggest that MYC/BCL2 coexpression, rather than cell-of-origin classification, is a better predictor of prognosis in patients with DLBCL treated with R-CHOP.

Malignant Transformation of Neurofibromas in Neurofibromatosis 1 Is Associated with CDKN2A/p16 Inactivation

Patients with neurofibromatosis 1 (NF1) are predisposed to develop multiple neurofibromas (NFs) and are at risk for transformation of NFs to malignant peripheral nerve sheath tumors (MPNSTs). Little is known, however, about the biological events involved in the malignant transformation of NFs. We examined the CDKN2A/p16 gene and p16 protein in NFs and MPNSTs from patients with NF1. On immunohistochemical analysis, all NFs expressed p16 protein. The MPNSTs, however, were essentially immunonegative for p16, with striking transitions in cases that contained both benign and malignant elements. None of the benign tumors had CDKN2A/p16 deletions, whereas three of six MPNSTs appeared to have homozygous CDKN2A/p16 deletions. Methylation analysis and mutation analysis of CDKN2A/p16 in MPNSTs did not reveal any abnormalities. These results show that malignant transformation of NF is associated with loss of p16 expression, which is often secondary to homozygous deletion of the CDKN2A/p16 gene. The findings suggest that CDKN2A/p16 inactivation occurs during the malignant transformation of NFs in NF1 patients and raises the possibility that p16 immunohistochemistry may provide ancillary information in the distinction of NF from MPNST.

Comprehensive gene expression profiling and immunohistochemical studies support application of immunophenotypic algorithm for molecular subtype classification in diffuse large B-cell lymphoma: a report from the International DLBCL Rituximab-CHOP Consortium Program Study

Gene expression profiling (GEP) has stratified diffuse large B-cell lymphoma (DLBCL) into molecular subgroups that correspond to different stages of lymphocyte development–namely germinal center B-cell like and activated B-cell like. This classification has prognostic significance, but GEP is expensive and not readily applicable into daily practice, which has lead to immunohistochemical algorithms proposed as a surrogate for GEP analysis. We assembled tissue microarrays from 475 de novo DLBCL patients who were treated with rituximab-CHOP chemotherapy. All cases were successfully profiled by GEP on formalin-fixed, paraffin-embedded tissue samples. Sections were stained with antibodies reactive with CD10, GCET1, FOXP1, MUM1 and BCL6 and cases were classified following a rationale of sequential steps of differentiation of B cells. Cutoffs for each marker were obtained using receiver-operating characteristic curves, obviating the need for any arbitrary method. An algorithm based on the expression of CD10, FOXP1 and BCL6 was developed that had a simpler structure than other recently proposed algorithms and 92.6% concordance with GEP. In multivariate analysis, both the International Prognostic Index and our proposed algorithm were significant independent predictors of progression-free and overall survival. In conclusion, this algorithm effectively predicts prognosis of DLBCL patients matching GEP subgroups in the era of rituximab therapy.

Diffuse large B-cell lymphoma: clinical implications of extranodal versus nodal presentation – a population-based study of 1575 cases

Differences in genetic origin between nodal and extranodal diffuse large B‐cell lymphomas (DLBCL) exist. Using population‐based data from the registry of the Danish Lymphoma Group, the present study is the first to analyse clinical implications of nodal versus extranodal presentation of DLBCL. Of 4786 newly diagnosed non‐Hodgkins lymphoma patients in a 16‐year period, 1575 (33%) had DLBCL. The annual incidence rate was 2·9 per 100 000; 40% were extranodal. The clinical profile of patients with extranodal DLBCL was different from the nodal DLBCL patients. Extranodal DLBCL was associated with older age and poorer performance score, but also lower tumour burden. In extranodal DLBCL, 51% of the cases were stage I and 36% were stage IV, whereas the patients were relatively equally distributed between the four stages in nodal DLBCL. For stage I patients, extranodal DLBCL was independently associated with poor survival (P = 0·003). In contrast, among stage IV patients those with extranodal DLBCL survived longer (P = 0·009). We conclude that there are important clinical differences between nodal and extranodal DLBCL. The addition of these clinical results to the existing aetiological and genetic data suggests that the distinction between nodal and extranodal DLBCL is not only pathogenetically but also clinically important.

Mutational profile and prognostic significance of TP53 in diffuse large B-cell lymphoma patients treated with R-CHOP: Report from an International DLBCL Rituximab-CHOP Consortium Program Study

TP53 mutation is an independent marker of poor prognosis in patients with diffuse large B-cell lymphoma (DLBCL) treated with cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone (CHOP) therapy. However, its prognostic value in the rituximab immunochemotherapy era remains undefined. In the present study of a large cohort of DLBCL patients treated with rituximab plus CHOP (R-CHOP), we show that those with TP53 mutations had worse overall and progression-free survival compared with those without. Unlike earlier studies of patients treated with CHOP, TP53 mutation has predictive value for R-CHOP-treated patients with either the germinal center B-cell or activated B-cell DLBCL subtypes. Furthermore, we identified the loop-sheet-helix and L3 motifs in the DNA-binding domain to be the most critical structures for maintaining p53 function. In contrast, TP53 deletion and loss of heterozygosity did not confer worse survival. If gene mutation data are not available, immunohistochemical analysis showing > 50% cells expressing p53 protein is a useful surrogate and was able to stratify patients with significantly different prognoses. We conclude that assessment of TP53 mutation status is important for stratifying R-CHOP-treated patients into distinct prognostic subsets and has significant value in the design of future therapeutic strategies.

CD30 expression defines a novel subgroup of diffuse large B-cell lymphoma with favorable prognosis and distinct gene expression signature: a report from the International DLBCL Rituximab-CHOP Consortium Program Study

CD30, originally identified as a cell-surface marker of Reed-Sternberg and Hodgkin cells of classical Hodgkin lymphoma, is also expressed by several types of non-Hodgkin lymphoma, including a subset of diffuse large B-cell lymphoma (DLBCL). However, the prognostic and biological importance of CD30 expression in DLBCL is unknown. Here we report that CD30 expression is a favorable prognostic factor in a cohort of 903 de novo DLBCL patients. CD30 was expressed in ∼14% of DLBCL patients. Patients with CD30(+) DLBCL had superior 5-year overall survival (CD30(+), 79% vs CD30(-), 59%; P = .001) and progression-free survival (P = .003). The favorable outcome of CD30 expression was maintained in both the germinal center B-cell and activated B-cell subtypes. Gene expression profiling revealed the upregulation of genes encoding negative regulators of nuclear factor κB activation and lymphocyte survival, and downregulation of genes encoding B-cell receptor signaling and proliferation, as well as prominent cytokine and stromal signatures in CD30(+) DLBCL patients, suggesting a distinct molecular basis for its favorable outcome. Given the superior prognostic value, unique gene expression signature, and significant value of CD30 as a therapeutic target for brentuximab vedotin in ongoing successful clinical trials, it seems appropriate to consider CD30(+) DLBCL as a distinct subgroup of DLBCL.

Structural profiles of TP53 gene mutations predict clinical outcome in diffuse large B-cell lymphoma: An international collaborative study

The purpose of this study is to correlate the presence of TP53 gene mutations with the clinical outcome of a cohort of patients with diffuse large B-cell lymphoma (DLBCL) assembled from 12 medical centers. TP53 mutations were identified in 102 of 477 patients, and the overall survival (OS) of patients with TP53 mutations was significantly worse than those with wild-type TP53 (P < .001). However, subsets of TP53 mutations were found to have different effects on OS. Mutations in the TP53 DNA-binding domains were the strongest predictors of poor OS (P < .001). Mutations in the Loop-Sheet-Helix and Loop-L3 were associated with significantly decreased OS (P = .002), but OS was not significantly affected by mutations in Loop-L2. A subset of missense mutations (His158, His175, Ser245, Gln248, His273, Arg280, and Arg282) in the DNA-binding domains had the worst prognosis. Multivariate analysis confirmed that the International Prognostic Index and mutations in the DNA-binding domains were independent predictors of OS. TP53 mutations also stratified patients with germinal center B cell-like DLBCL, but not nongerminal center B cell-like DLBCL, into molecularly distinct subsets with different survivals. This study shows the prognostic importance of mutations in the TP53 DNA-binding domains in patients with DLBCL.

The JAK2 V617F allele burden in essential thrombocythemia, polycythemia vera and primary myelofibrosis – impact on disease phenotype

Background and objectives:  The JAK2 V617F tyrosine kinase mutation is present in the great majority of patients with polycythemia vera (PV), and approximately half of the patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF). The three distinct disease entities may be considered as three phenotypic presentations of the same JAK2 V617F positive chronic myleoproliferative disorder. Together with physiological and genetic modifiers the phenotype may be determined by the JAK2 V617F allele burden. In the present study, we aimed to asses the JAK2 mutational load and its impact on phenotype.

Testicular lymphoma: a population-based study of incidence, clinicopathological correlations and prognosis

In a Danish population-based non-Hodgkins lymphoma registry, 2687 newly diagnosed patients were registered from 1983 to 1992. 39 had testicular involvement (TL) (incidence 0.26/10(5)/year). Median age was 71 years. 24 cases had localised and 15 had disseminated disease. Histologically, all cases were diffuse (65% diffuse centroblastic type). Of the 27 tested, 11% were of T- and 89% of B-immunophenotype. In localised cases, where surgery was supplemented by combination chemotherapy (CCT), the relapse rate was 15.4%. The relapse rate for cases with localised disease treated with other regimens (orchiectomy and/or radiotherapy) was 63.6% (P < 0.05). Median relapse-free survival was 28 and 14 months, respectively. Overall 5-year survival for all cases was 17%. Adverse prognostic factors at the univariate level were stage IV, constitutional symptoms, serum lactic dehydrogenase elevation and performance score (WHO 3-4). It is suggested that the treatment of stage IE/IIE TL should include early CCT and CNS prophylaxis.