Extranodal Diffuse Large B-cell Lymphoma Research Articles

Specific expression of miR-17-5p and miR-127 in testicular and central nervous system diffuse large B-cell lymphoma

Recent studies have shown that certain non-coding short RNAs, called miRNAs, play an important role in diffuse large B-cell lymphomas. Patients with diffuse large B-cell lymphoma have great diversity in both clinical characteristics, site of presentation and outcome. The aim of our study is to validate the differential expression in germinal center and non-germinal center diffuse large B-cell lymphoma,s and to study to the extent to which the primary site of differentiation is associated with the miRNA expression profile. We studied 50 cases of de novo diffuse large B-cell lymphoma for the expression of 15 miRNAs (miR-15a, miR-15b, miR-16, miR-17-3p, miR-17-5p, miR-18a, miR-19a, miR-19b, miR-20a, miR-21, miR-92, miR-127, miR-155, miR-181a and miR-221). Apart from 19 nodal cases without extranodal dissemination (stages I and II), we selected two groups with unambiguous stages I and II extranodal presentation; 9 cases of primary central nervous system, 11 cases of primary testicular and 11 cases of other primary extranodal diffuse large B-cell lymphomas. All cases were analyzed with qRT-PCR. In situ hybridization for the most differentially expressed miRNAs was performed to show miRNA expression in tumor cells, but not in background cells. MiR-21 and miR-19b showed the highest expression levels. No significant differences were seen between germinal center and non-germinal center diffuse large B-cell lymphomas in either the total or the nodal group for any of the 15 miRNAs. Two miRNAs showed significant differences in expression levels for diffuse large B-cell lymphoma subgroups according to the site of presentation. MiR-17-5p showed a significant higher expression level in the central nervous system compared with testicular and nodal diffuse large B-cell lymphomas (P<0.05). MiR-127 levels were significantly higher in testicular than in central nervous system and in nodal diffuse large B-cell lymphomas (P<0.05). We conclude that the location of diffuse large B-cell lymphoma is an important factor in determining the differential expression of miRNAs.

Treatment outcomes of extranodal diffuse large B-cell lymphoma

Objective To analyze the clinical features and treatment outcomes of extranodal diffuse large B-cell lymphoma(DLBCL). Methods Ninety-nine consecutively diagnosed patients with extranodal DLBCL were reviewed. All patients were confirmed by a combination of morphologic and immunohistochemi-cal evaluation. The primary sites of extranodal DLBCL were the gastrointestine(n = 32) ,central nerve system (CNS)/testis(n=14) ,and other sites (n = 53). Results Extranodal DLBCL was characterized by a pre-dominance in old males,less frequency of B symptorns,a large proportion of stage Ⅰ-Ⅱ disease and low in-ternational prognostic factor(IP1) score. The 5-year overall survival(OS) rate for all patients was 78.9%. The corresponding OS rate was 82.5% for gastrointestinal origin, 37.0% for CNS and testis origin and 74.6% for other organ origin, respectively. On univariate analysis, performance status, IPI score and more than one extranedal site involvement were the prognostic predictors for 5-year OS. Conclusions Being a heterogeneous group of lymphomas, extranedal DLBCL has good prognosis except those derived from the CNS and testis. Key words: Lymphoma; diffuse large B-cell ; Lymphoma; extranedal ; Treatment outcome

Patients with localized primary non‐tonsillar oral diffuse large B‐cell lymphoma exhibit favorable prognosis despite a non‐germinal center B‐cell‐like phenotype

Diffuse large B-cell lymphomas are detected frequently in the oral cavity. Although tonsillar lymphomas have been rather well characterized, lymphomas originating from non-tonsillar regions, such as the gingiva, palate, and tongue, have not been well studied. We examined the pathology of clinical samples obtained from 21 patients with localized primary non-tonsillar oral diffuse large B-cell lymphoma. Immunohistological examination of CD10, Bcl-6, and MUM1 determined that 17 of 21 (81%) samples exhibited non-germinal center B-cell type, an increased proportion of non-germinal center B-cell type compared with previous reports in samples of tonsillar origin (P<0.05). The four remaining samples exhibited germinal center B-cell type, although one sample expressed MUM1. Follow-up clinical survival data were obtained from the 17 patients over a range from 4 to 173 months (mean 52 months). All patients were treated with chemotherapies, irradiation, or surgical resection. Sixteen patients achieved complete remission and two patients relapsed, but no patient has died of disease. Extranodal diffuse large B-cell lymphomas of non-germinal center B-cell type are generally characterized by poor prognosis, regardless of localized disease. Interestingly, our results indicate that, unlike similar lymphomas of tonsillar origin, localized primary non-tonsillar oral diffuse large B-cell lymphomas exhibit favorable prognosis, suggesting that these lymphomas may be clinicopathologically distinct.

No Benefit from Rituximab Containing Regimens in Patients with Primary Extranodal Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous category of lymphoid tumors that comprises different clinical forms not fully recognized in the WHO classification. In this regard, extranodal (EN) DLBCLs have particular clinicobiological features and outcome, sometimes related to the specific site where the lymphoma arises. Nowadays, rituximab plus chemotherapy (CT) is the gold-standard in the treatment of DLBCL. However, the superiority of rituximab-CT (R-CT) over CT alone has not been addressed for all the clinical subsets of the disease and, in fact, the clinical role of the new therapies might be different for primary nodal or EN DLBCLs. The aim of this study was to assess the impact of rituximab in patients suffering from nodal or EN DLBCL. Two-hundred and thirty non-immunocompromised patients (112M/118F; median age, 61 years) diagnosed with CD20+DLBCL in a single institution between 1997 and 2006 (five years before and after establishing R-CT as the standard treatment in DLBCL) and treated with adriamycin-containing regimens were the subject of the present study. The series included 148 primary nodal and 82 EN DLBCL. Patients with primary CNS lymphoma were excluded and lymphomas arising at Waldeyer ring were considered as nodal DLBCL. The main EN sites were GI (n=26), bone (n=13), soft tissue (n=13), lung/pleura (n=9), liver (n=9), and other (n=12). Main clinico-biological and evolutive variables were analyzed. One hundred nineteen patients received only CT and 111 R-CT. Eighty-seven cases with available information were assigned to germinal center B-cell-like (GCB) (41%) or non-GCB (59%) groups according to the Hans method (Blood 2004; 103:275–82) based on CD10, BCL6 and MUM1 expression. Main initial features, including the primary nodal or EN origin, international prognostic index (IPI), and GCB/non-GCB categories were similar for CT and R-CT groups. No correlation was observed between the GCB/non-GCB groups and the primary site of the tumor, although nodal lymphomas more frequently expressed MUM1 than EN (69% vs. 31%, respectively; p=0.01). CR rate and 5-year overall survival (OS) according to the treatment arm (CT vs. R-CT) is detailed for the whole series and for the nodal and EN groups in the table and OS curves depicted in the figure. In the whole series, variables predicting poor OS in the multivariate analysis were high-risk IPI (RR 2.5; p<0.001), primary nodal involvement (RR 1.6; p=0.04) and no R-CT treatment (RR 1.9; p=0.002). In the nodal group, IPI and no R-CT maintained the prognostic value, whereas in the primary EN only IPI predicted OS. Moreover, no difference in OS was observed according to the nodal or EN origin in those patients receiving R-CT. Biological subtypes GCB vs. non-GCB did not add predictive information neither in the whole series nor in the nodal or EN groups. In conclusion, patients with primary EN DLBCL seem to have little benefit from the use of R-CT. Nevertheless, this intriguing observation should be confirmed in further prospective studies.Complete response CR (%)5-years OS (%)CTR-CTCTR-CTAll cases (n=230)5979*4670*Primary nodal (n=148)5478*3471*Primary extranodal (n=82)68787069*p<0.002 R-CT vs. CT [Display omitted]

Relapsed MALT Lymphomas Are Associated with a Restricted VH3-30.3 Immunoglobulin VH Gene Repertoire and Are Targeted by Aberrant Somatic Hypermutation

Mucosa associated lymphoid tissue (MALT) type lymphomas are B-cell neoplasms that develop out of a reactive infiltrate; Sjoegren syndrome, Hashimoto thyroiditis, and Helicobacter pylori gastritis provide the pathogenetic background. Direct antigen stimulation through surface immunoglobulin (Ig) molecules may be playing an important role in the development of MALT lymphomas. In rare cases MALT lymphomas may undergo transformation into extranodal diffuse large B-cell lymphomas (eDLBCL). Previous reports suggested salivary gland MALT lymphomas expressed a restricted Ig VH gene repertoire with over use of VH1-69 gene segments. Because knowledge about the VH gene used by MALT lymphoma of gastric and extragastric origin and by eDLBCL is limited, we sequenced the VH genes from 11 MALT lymphomas [5 of gastric and 6 of extragastric origin (3 salivary gland, 3 thyroid)] and from 10 eDLBCL, all arisen from MALT lymphoma and still exhibiting a low grade component [= so called “transformed MALT lymphoma”: 5 of gastric and 5 of extragastric origin (3 salivary gland and 2 thyroid)]. MALT lymphomas used gene segments of the VH1 (1–69: 2 salivary gland and 1 thyroid), VH3 (3–30.3: 1 thyroid), VH4 (4–34: 1 thyroid, 1 salivary gland and 2 gastric), VH5 (5–51: 2 gastric) and VH6 (6-1: 1 gastric) families. Extranodal DLBCLs used segments derived from VH1 (1–69: 1 gastric and 1 salivary gland), VH2 (2–70: 1 thyroid), VH3 (3–23: 1 gastric; 3–30: 1 gastric; 3–30.3: 1 gastric and 2 salivary glands) and VH4 (4–34: 1 gastric) families as shown in table 1. The VH1-69 gene segment was found in 3 of 6 extragastric MALT lymphomas (2 salivary glands and 1 thyroid), in one gastric and one salivary gland eDLBCL but in no gastric MALT lymphoma. Further, 4 of the 21 lymphomas relapsed, 3 eDLBCL and one MALT lymphoma – and remarkably, all of them used the VH3-30.3 gene segment. Comparing the frequency of somatic hypermutation (SHM) of the immunoglobuline locus and aberrant somatic hypermutation (ASHM) of the four proto-oncogenes PAX-5, PIM-1, Rho/TTF and c-MYC between the relapsed (n=4) and non relapsed lymphomas (n=17) a ~2.9 fold (5.8 vs 2.0 × 10−2/bp, p=0.017) and 2.1 fold (0.067 vs 0.032 × 10−2/bp, p=0.027) higher mutation rate for SHM and ASHM in relapsed lymphomas was observed. Also, the AID mRNA relative expression number was 1.7 fold higher in the group of relapsed lymphomas (4.66 vs 2.71, p=0.049). Performing immunohistochemical analysis for AID a significant positive correlation (p=0.01; correlation coefficient (Spearman rho) = 0.794) was observed when comparing protein expression with mRNA levels. These results are consistent with the model in which only certain B cells displaying specific patterns of VH immunoglobuline molecules binding to an as yet undefined antigen together with a highly aberrant somatic hypermutation process are preferentially selected for malignant transformation and determine the natural course of disease.Table1: VH gene sement used by MALT lymphomas and eDLBCLCaseTypeOriginVH geneRelapseGHM2eDLBCLstomach1–69noGHM3eDLBCLstomach3–23noGHM5eDLBCLstomach3-30-3yesGHM7eDLBCLstomach4–34noGHM8eDLBCLstomach3–30noEHM12eDLBCLthyroid6–1noEHM15eDLBCLsalivary gland3-30-3yesEHM16eDLBCLsalivary gland3-30-3yesEHM18eDLBCLthyroid2–70noEHM19eDLBCLsalivary gland1–69noENM14MALTthyroid3-30-3yesENM21MALTsalivary gland1–69noENM29MALTsalivary gland1–69noENM30MALTsalivary gland4–34noENM33MALTthyroid1–69noENM35MALTthyroid4–34noGNM36MALTstomach5–51noGNM37MALTstomach4–34noGNM38MALTstomach6–1noGNM39MALTstomach5–51noGNM41MALTstomach4–34no

Interim 18f[FDG] Positron Emission Tomography in Patients with Diffuse Large B-Cell Lymphoma

Diffuse Large B-Cell Lymphoma (DLBCL) is the most frequent aggressive non-Hodgkin's Lymphoma (NHL) in adults. Presently, prognostic stratification relies on clinical characteristics and International Prognostic Index (IPI) is currently the most useful tool to identify high-risk patients (pts). Positron Emission Tomography (PET) with fluorodeoxyglucose (18F[FDG]) has been used to assess chemosensitivity in Hodgkin's lymphoma: we investigated the role of 18F[FDG]-PET as prognostic tool in DLBCL treated with a R-CHOP-like chemotherapy. Forty-two pts with newly diagnosed DLBCL treated in our Institute from February 2006 to February 2008 were enrolled in this prospective study. Median age was 59 years (range 24–80), seventeen pts were male (40%); bulky disease was present in 20 pts (48%). Stage was I–II in 18 (43%) and III–IV in 24 pts (67%); IPI was low in 20 pts, low-intermediate in 12 pts, high-intermediate in 5 pts and high in 4 pts. Twelve pts (29%) had a primary extranodal DLBCL. Pts were treated with 6 cycles of CHOP-like treatment, associated with Rituximab in all but one patient; cycles were repeated every 21 days. An interim 18F[FDG]-PET was performed after three cycles (interim 18F[FDG]-PET) and at the completion of treatment (18F[FDG]-PET6). Interim PET result did not change the planned treatment; response was assessed with 1999 Cheson's criteria. Four pts received radiotherapy after chemotherapy. Overall, 36 pts obtained a complete response (CR), the remaining six pts failed to obtain a CR. Median follow-up was 15 months (range 5–31 months); eight pts relapsed, and six patients died, two of them in CR. Overall survival (OS) at 2 years was 78%, and event-free survival (EFS) at 2 years was 77%. Interim 18F[FDG]-PET was performed after a median interval from the last therapy of 13 days (range 3–21) and was negative in 28 pts (interval 12 days) and positive in 14 pts (interval 13 days). Six positive and two negative interim 18F[FDG]-PET pts relapsed: sensitivity was 75%, specificity was 76%, positive and negative predictive values were 43% and 93%, respectively. Overall, 18F[FDG]-PET6 was positive in eight pts and negative in 34 pts; six positive and two negative 18F[FDG]-PET6 pts relapsed: sensitivity was 75%, specificity was 94%, positive and negative predictive values were 75% and 94%, respectively. The EFS at 2 years in pts with negative interim 18F[FDG]-PET was 90%, in positive interim 18F[FDG]-PET pts was 55%, which resulted statistically significant at the univariate analysis (p=0.01), as well as 18F[FDG]-PET6 (p=0.00). In all relapsed pts but one a salvage therapy with intensified chemotherapy and autologous stem cells transplantation (ASCT) was planned: four pts progressed during treatment or shortly after ASCT, and in three pts treatment is still ongoing. Interim 18F[FDG]-PET was proposed as a prognostic tool in DLBCL. Our data showed that interim 18F[FDG]-PET was statistically associated with EFS, however, nine pts (64%) with a positive interim 18F[FDG]-PET obtained a CR after induction treatment, and eight of them (89%) did not relapse. Our findings do not support an early intensification of pts with DLBCL with a positive interim 18F[FDG]-PET because of the risk of overtreatment of a large part of these pts; however, we performed interim 18F[FDG]-PET after three cycles of therapy, and this could have influenced the results. A longer follow-up and a greater number of pts could be necessary to draw definitive conclusions.

Clinical significance of 18F-FDG uptake by primary sites in patients with diffuse large B cell lymphoma in the head and neck: a pilot study

This pilot study was launched to explore the utility of positron emission tomography scans, at the time of diagnosis, for clinical outcomes in patients with primary extranodal non-Hodgkin's lymphoma (PENHL) in the head and neck, retrospectively. Twenty-two patients with a diffuse large B cell lymphoma (DLBCL) among those with a PENHL were included. We retrospectively evaluated the clinical outcomes of patients according to the maximum standardized 18F-fluoro-2-deoxy-glucose (18F-FDG) uptake value of the primary lesion (SUVp). The SUVp was initially analyzed as a continuous variable. The cut-off value of SUVp was obtained from receiver-operating characteristic analysis to predict event-free survival. Using this value, patients were divided into those with a low and high SUV. Seventeen patients (59%) were men and the median age was 50 years. Most primary sites were in Waldeyer's ring (73%). The SUVp ranged from 3.3 to 23.7. The international prognostic index (IPI<2 vs. >or=2) was associated with the SUVp (P=0.014). Patients with low SUVp showed favorable survival (P=0.015). After IPI scores were stratified, the survival difference remained significant (P=0.029). The results of this pilot investigation indicate that 18F-FDG uptake of the primary lesion may be related with survival outcomes in patients with extranodal DLBCL in the head and neck. Further studies are needed to confirm and extend these results.

Distinct Gene Expression Profiles: Nodal versus Extranodal Diffuse Large B-Cell Lymphoma

Introduction: Approximately one third of diffuse large B-cell lymphomas (DLBCL) arises from tissues different from the lymph node. Perceived differences in outcome between extranodal and nodal DLBCL raise the possibility that these subgroups may represent different biological and clinical entities. Methods: Microarray GeneChip technology was used for global gene expression profiles from nodal (n = 19) and extranodal (n = 8) DLBCL, to examine possible differences between these subgroups. Quantitative RT-PCR was employed for validation of microarray data. Differential expression levels of p16 (CDKN2A) were confirmed by means of immunohistochemistry on a tissue microarray comprising more than 200 lymphoma samples. Results: A total of 218, over (124)- and underexpressed (94) genes were found to be differentially expressed in extranodal DLBCL compared with nodal DLBCL, including cytokines/chemokines, chromosome-replication-related genes and DNA repair genes. Quantitative RT-PCR confirmed the microarray data. A higher rate of p16 positivity was found in extranodal lymphomas. However, prognostic importance of p16 was associated with nodal rather than extranodal lymphomas. Conclusion: Our data suggest that a better distinction of these subgroups based on molecular classifiers is feasible and may greatly facilitate the determination of specific relevant clinical features and therapeutic implications of DLBCL with primary extranodal or nodal location.

Distinct signatures of B‐cell homeostatic and activation‐dependent chemokine receptors in the development and progression of extragastric MALT lymphomas

Chemokine receptors mediate migration and activation of lymphocytes through binding of their ligands. Recent studies have revealed important contributions of chemokine receptors to the development, progression, and dissemination of haematopoietic neoplasms. Because the chemokine receptor expression profile in extragastric MALT lymphoma is unknown, we performed a comprehensive study on tissue samples of parotid glands, parotid glands affected by Sjögren syndrome, extragastric MALT lymphoma, and extranodal diffuse large B-cell lymphoma (eDLBCL) originating from MALT lymphoma (transformed MALT lymphoma). By investigating the expression of 19 chemokine receptors by real-time PCR using a semi-quantitative approach and of four chemokine receptors (CCR1, CCR5, CXCR6, and XCR1) by immunohistochemistry, we show that the chemokine receptor expression profiles of extragastric MALT lymphomas differ substantially from those of extranodal DBLCL, with lower expression of CCR1, CCR8, and CXCR3, and the absence of expression of CX3CR1 and XCR1 in eDLBCL. Expression of CCR6, CCR7, CXCR3, CXCR4, and CXCR5, responsible for B-cell homing to secondary lymphoid tissue, was detected in both B-cell malignancies. Expression of CCR4 was just detected in trisomy 3-positive MALT lymphoma cases. Comparing gastric with extragastric MALT lymphomas, up-regulation of CXCR1 and CXCR2 accompanied by down-regulation of CCR8 and CX3CR1 and loss of XCR1 expression in extragastric MALT lymphomas appear to be key determinants for the site of origin of MALT lymphomagenesis. Our results support a model of stepwise progression of extragastric MALT lymphoma from a non-neoplastic event to Sjögren syndrome, to MALT lymphoma, and finally to overt eDLBCL, guided by differentially expressed B-cell homeostatic and activation-dependent chemokine receptors and their ligands.

FOXP1 abnormalities in lymphoma: translocation breakpoint mapping reveals insights into deregulated transcriptional control

Deregulation of FOXP1 expression plays an important role in lymphoma development although the underlying molecular mechanism is poorly understood. FOXP1 is targeted by chromosome translocations in MALT lymphoma and diffuse large B-cell lymphoma, where high-level protein expression is associated with poor prognosis. Nonetheless, the incidence and nature of FOXP1 abnormalities at both the genetic and protein levels, and their correlation in these lymphomas are not well established. We investigated FOXP1 translocation, copy number change and protein expression in MALT lymphoma (n=321), MALT lymphoma with a diffuse large B-cell lymphoma component (59), nodal diffuse large B-cell lymphoma (64) and extranodal diffuse large B-cell lymphoma (151) by interphase fluorescence in situ hybridization and immunohistochemistry. FOXP1 translocation was found in eight MALT lymphomas and three MALT lymphomas with diffuse large B-cell lymphoma, with all positive cases originating in the stomach. In diffuse large B-cell lymphoma, the translocation was seen in 5 cases originating in the stomach (2), tonsil (1), large intestine (1) and lymph node (1). Immunoglobulin heavy chain gene was the translocation partner in 11 of the 16 positive cases. Fluorescence in situ hybridization mapping revealed FOXP1 breakpoints within the 5′ untranslated region of the gene (upstream of exon 6, the first coding exon of full-length FOXP1) in 14 cases, but downstream of exon 6 (most likely upstream of exon 8) in the remaining 2 cases. Three copies of the FOXP1 gene were observed in MALT lymphoma (17%), MALT lymphoma with diffuse large B-cell lymphoma (12%) and diffuse large B-cell lymphoma (32%), including cases with FOXP1 translocation (19%). Immunohistochemistry showed strong/moderate FOXP1 staining in all the cases with FOXP1 translocation. However, FOXP1 expression was independent of FOXP1 translocation or copy number changes. Our findings suggest that (1) FOXP1 translocation may disrupt the full-length FOXP1 transcript and lead to expression of FOXP1 transcript variants with alternate 5′ ends and (2) mechanisms other than translocation and copy number changes are also responsible for FOXP1 overexpression in lymphoma.

Prognostic significance of primary extranodal diffuse large B-cell lymphoma (DLBCL) in patients treated with R-CHOP

8583 Background: Previous studies in the pre-rituximab era have identified important clinical differences between nodal and primary extranodal DLBCL. We have examined the prognostic significance of primary extranodal DLBCL in the post-rituximab era. Methods: Using the Lymphoid Cancer Database of the British Columbia Cancer Agency, all patients ≥18 years of age diagnosed with DLBCL between January 1999 and May 2006 and treated with an R-CHOP regimen were included for analysis. Patients were excluded if they were HIV positive, presented with disease in the testicular or central nervous system, or had known coincident indolent lymphoma. Primary extranodal DLBCL was defined as disease confined to one or more localized extranodal sites, with no or minimal nearby nodal involvement. Results: 513 patients were identified with the following characteristics: median age 62 y (range 19–93), male 59.1%, stage III/IV 53.8%, elevated LDH 49.5%, and performance status ≥2 38.2%. While 350 (68.2%) had at least some degree of extranodal involvement, only 133 (25.9%) had primary extranodal DLBCL. Among patients with primary extranodal disease, 70 (52.6%), 37 (27.8%) and 26 (19.6%) had 1, 2 and ≥3 extranodal sites, respectively. The most commonly involved extranodal sites included bone (33.1%), soft tissue (28.6%), stomach (15.0%), intestine (12.8%), and sinus (10.5%). Thirty-two percent, 20%, 0% and 48% of patients with primary extranodal DLBCL had stage I, II, III, and IV, respectively. This is in contrast to 11%, 34%, 26% and 29% for the nodal DLBCL group. Primary extranodal DLBCL was less commonly associated with an elevated LDH (37.6% vs. 53.7%, p=0.001). The distribution of International Prognostic Index scores was similar between the two groups. With a median follow-up of 2.8 years, no significant difference in overall survival was detected between primary extranodal DLBCL and nodal DLBCL analyzed either as a group or by individual stages. Furthermore, we did not identify any specific primary extranodal sites that confer a worse prognosis. Conclusion: In the post-rituximab era, the previously identified survival difference in primary extranodal DLBCL is no longer observed in this large cohort. No significant financial relationships to disclose.

Pathway analysis of primary central nervous system lymphoma

AbstractPrimary central nervous system (CNS) lymphoma (PCNSL) is a diffuse large B-cell lymphoma (DLBCL) confined to the CNS. A genome-wide gene expression comparison between PCNSL and non-CNS DLBCL was performed, the latter consisting of both nodal and extranodal DLBCL (nDLBCL and enDLBCL), to identify a “CNS signature.” Pathway analysis with the program SigPathway revealed that PCNSL is characterized notably by significant differential expression of multiple extracellular matrix (ECM) and adhesion-related pathways. The most significantly up-regulated gene is the ECM-related osteopontin (SPP1). Expression at the protein level of ECM-related SPP1 and CHI3L1 in PCNSL cells was demonstrated by immunohistochemistry. The alterations in gene expression can be interpreted within several biologic contexts with implications for PCNSL, including CNS tropism (ECM and adhesion-related pathways, SPP1, DDR1), B-cell migration (CXCL13, SPP1), activated B-cell subtype (MUM1), lymphoproliferation (SPP1, TCL1A, CHI3L1), aggressive clinical behavior (SPP1, CHI3L1, MUM1), and aggressive metastatic cancer phenotype (SPP1, CHI3L1). The gene expression signature discovered in our study may represent a true “CNS signature” because we contrasted PCNSL with wide-spectrum non-CNS DLBCL on a genomic scale and performed an in-depth bioinformatic analysis.

Activated B-cell immunophenotype might be associated with poor prognosis of primary central nervous system lymphomas

Primary central nervous system (PCNS) diffuse large B-cell lymphoma (DLBCL) is an aggressive form of non-Hodgkin's lymphoma whose growth is restricted to the central nervous system and eye. Primary CNS DLBCL has a poor prognosis relative to other extranodal DLBCL. Recently DLBCL has been subclassified as germinal and non-germinal center B-cell types using microarray. Germinal center B-cell DLBCL is associated with better prognosis compared to non-germinal center B-cell group. The objective of the study was to subcategorize the PCNS DLBCL into germinal center and non-germinal center DLBCL using immunohistochemistry and to correlate its prognostic significance. 21 immunocompetent patients were diagnosed with PCNS DLBCL over last 20 years at William Beaumont Hospital. Clinical data on outcome were collected and their specimens were retrieved. Immunohistochemical staining was done using markers, CD20, CD10, Bcl-6, MUM-1, MIB-1, Bcl-2 and by molecular analysis of the immunoglobulin heavy chain gene (IgH) variable region. Immunohistochemistry showed 1/21 (positive cases/examined cases) for CD10, 19/21 for Bcl-6, 19/21 for MUM-1 and 15/21 for Bcl-2. The expression pattern of CD10(-) MUM-1(+) is corresponded to the non-germinal center DLBCL. The MIB-1 index ranged from 40--80% with a mean of 57%, indicating a high proliferation of lymphoma cells. The IgH gene variable region analysis showed monoclonality in 15 of 21 cases (71%). Primary CNS DLBCL has a non-germinal center B-cell phenotype in majority of cases and has a high Bcl-2 positivity and MIB-1 index. These features might be associated with poor prognosis.

Improved Survival of Intravascular Large B-Cell Lymphoma (IVLBCL) by Rituximab Containing Combination Chemotherapies.

Background: Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of extranodal diffuse large B-cell lymphoma (DLBCL) with poor prognosis. Recently, the addition of rituximab to CHOP regimen has significantly improved the outcome of DLBCL. However, the efficacy of rituximab in IVLBCL remains unclear.Objective and Patients: To evaluate the usefulness of rituximab in IVLBCL, 70 patients who were diagnosed as IVLBCL between 1999 and 2007 from the 16 participating centers were retrospectively analyzed. Patient characteristics were as follows: median age, 68 yrs (range, 34 to 88 yrs); sex, M/F 56%/44%; LDH > UNL, 99%; stage III/IV, 100%; extranodal site > 1, 81%; PS > 1, 84%; IPI: H-I/H, 97%. Sixty four of 70 patients received anthracycline containing chemotherapies. In 64 patients, 43 (67%) and 21 (33%) patients received rituximab containing chemotherapies (R-chemo) and chemotherapies without rituximab (chemo), respectively. There was no significant difference between the two groups in terms of various clinical variables.Results: The complete response rate (%CR) was significantly higher in the R-chemo group than in the chemo group (90% vs. 55%, P = 0.0003). With a median follow up time of 24 months (range, 2 to 88 months) in living patients, 2-year progression-free and overall survival (OS) rates were significantly higher in the R-chemo group than in the chemo group (63% vs. 32%, 71% vs. 39%, P = 0.015 and 0.01, respectively). In univariate analysis, age, LDH, the number of extranodal site, PS and platelet count were not significant prognostic factor, while the use of rituximab was favorably associated with OS (HR, 0.33; 95% CI, 0.13 to 0.88; P = 0.015). Grade 3 hypoxia due to the infusion of rituximab was observed in one of 43 patients (2%). Grade 3 or 4 non-hematologic adverse events were observed in the 3 of 43 (7%) patients and 3 of 21 (14%) patients, respectively. Treatment related death was observed in 3 patients. Two in the R-chemo group died of HBV reactivation and tuberculosis, and one in the chemo group died of sepsis. Eight of 43 and 12 of 21 patients in the each group died at the time point of the study, respectively, and the most major cause of death was primary disease (6 and 11 patients, respectively).Conclusion: Our data strongly suggested that the addition of rituximab to chemotherapies significantly improved the %CR and survival in IVLBCL without significant increase in toxicities. Thus, prospective clinical trials of rituximab-containing chemotherapies for IVLBCL are warranted.

MicroRNAs Specific for Immune-Privileged Diffuse Large B-Cell Lymphoma.

Introduction Primary diffuse large B-cell lymphomas (DLBCL) constitute a heterogeneous group of tumors with a great diversity in both clinical presentation and outcome. Besides nodal DLBCL, about 40% of these tumors present in different extranodal sites, both immune privileged sites such as the testis and the central nervous system (PCNSL) but also non immune privileged sites such as bone, stomach, skin and mediastinum. Remarkably each of these sites show a marked divergence in biological behavior. Recent studies have shown that certain non-coding short RNAs (22nt) called miRNAs may play a role in the pathogenesis of DLBCL. These miRNAs posttrancriptionally down regulate expression of genes. Aim of study To examine the expression levels of selected miRNAs in different DLBCL sites.Methods and Materials 51 cases of Ann Abour stage I and II primary DLBCL were divided into 4 groups; 19 nodal cases, 11 non-immune privileged site-associated (non-IP) extranodal cases, 9 PCNSL, and 12 testicular DLBCL. Each case was classified GCB or non-GCB using the algorithm as described by Hans et al. 13 miRNAs were selected from current literature on the basis of their involvement in B-cell lymphoma (miR-15, -16, -21, -221, -155, - 181a, -18a, -19, -20a, 17-3p, -17-5p and -92). The expression levels of the mature microRNAs were determined by qRT-PCR using Taqman miRNA assays. Results were compared by using 2−ΔCt and 2−ΔΔCt. Differences in expression levels between the four groups was tested using ANOVA.Results Of the selected microRNAs, miR-127, miR-17-5p and miR-221 show a significant difference in expression level between the immune privileged site-associated DLBCL (IP-DLBCL) and nodal DLBCL. Both miR-17-5p (p=0.0003) and miR-221 (p=0.0032) show an increased expression level in PCNSL compared to nodal DLBCL and miR-127 shows a significant increased level in testicular DLBCL compared to nodal (p=0.0011) and non-IP (p=0.0393) DLBCL. Also of interest is the fact that miR-17-5p and miR-127 show a significant difference in the level of expression between both PCNSL and testicular DLBCL. MiR-155 shows no significant difference in expression levels between nodal and extranodal DLBCL. Analysis on the basis of GCB and non-GCB classification is currently being undertaken.Conclusion In PCNSL miR-17-5p and miR-221 are specifically increased whereas miR-127 shows a specifically higher expression in testicular DLBCL when compared to non-IP and nodal DLBCL. Also PCNSL and testicular DLBCL differ in expression of miR-17-5p and miR-127. In contrast to previous reports miR-155 does not show any significant difference between nodal and extranodal groups. This may be caused by the selection of stage I or II primary DLBCL in contrast to previous publications which used a more heterogeneous group of DLBCL.

Addition of Rituximab to CHOP Chemotherapy Does Not Improve Clinical Outcome in Patients with Localized Gastric Diffuse Large B-Cell Lymphoma: A Retrospective Study by Ganken Adult Lymphoma Study Group (Single Institute Analysis).

Background: In recent years, it has been reported that addition of rituximab to CHOP chemotherapy significantly improves event-free survival (EFS) and overall survival (OS) compared with standard CHOP alone in patients with diffuse large B-cell lymphoma (DLBCL). On the other hand, gastric DLBCL is a good clinical outcome without surgical excision in the group of primary extranodal DLBCL. Localized gastric DLBCL shows very good EFS and OS treated with standard CHOP plus radiation therapy without rituximab.Methods: We analyzed retrospectively the prognosis between R-CHOP and CHOP alone in patients with localized gastric DLBCL. All 24 patients diagnosed between July 1999 and July 2006 in our hospital, were included in this study. The pathology was reviewed by a hematopathologist and confirmed to be de novo DLBCL according to the WHO classification. The staging system was using by Lugano meeting classification. Patients with stage IIE and IV were excluded. All patients were initially treated with six cycles of CHOP or R-CHOP regimen consisting of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone. If we evaluated partial response after six cycles of chemothrapy, the patients have been added radiation therapy.Results: Initial characteristics of the 24 patients are summarized in Table 1. The median age of patients at time of inclusion was 67.5 yr (range 30–83 yr). The median follow up of surviving patients was 30 months. CR rates between CHOP and R-CHOP were 91.7% vs. 83.3%, p=1.000, and overall response rates were 100% vs. 83.3%, p=.478, respectively. 2 years progression-free survival and overall survival were no statistical significance difference between two groups (Log rank test: P=.138, P=.739).Conclusion: These results suggested that addition of rituximab to CHOP chemotherapy does not improve clinical outcome of localized gastric DLBCL. The patients with localized gastric DLBCL did not get the clinical benefits of rituximab. As you know, rituximab needs high costs, so we recommend standard CHOP regimen plus radiation therapy in patients with localized gastric DLBCL, without rituximab combination regimen.Characteristics of the 24 patients with localized gastric DLBCLCharacteristicCHOP (n=12)R-CHOP (n=12)PAge1.000=<6034>6098Male761.000Stage (Lugano).890I43II 179Unknown10IPI score.8670,177245Unknown10

Nodal versus extranodal diffuse large B-cell lymphoma: comparison of clinicopathologic features, immunophenotype and prognosis

To study the clinicopathologic features and outcome of patients with diffuse large B-cell lymphoma (DLBCL), and to compare the differences between DLBCL of nodal and extranodal origins. One hundred and forty-two cases of de novo DLBCL collected during a 10-year period were reviewed. The clinicopathologic features and follow-up (2 - 108 months) data were analyzed. Tissue microarray blocks were performed and immunohistochemical studies using antibodies against CD10, bcl-6 and MUM1 were carried out. The cases were then further categorized into germinal center B cell-like (GCB) and non-GCB subtypes. Primary gastrointestinal DLBCL often presented as early-stage disease (stage I or II) and was associated with low international prognostic index. They showed better prognosis than DLBCL of nodal and other extranodal origins. The positivity rates of CD10, bcl-6 and MUM1 were 19%, 51% and 58%, respectively. 36% of the cases belonged to GCB, while the remaining 64% were non-GCB. In general, DLBCL of extranodal origin showed more frequent bcl-6 expression than nodal DLBCL. As for extranodal DLBCL, GCB immunophenotype was often seen in thyroid and breast tumors, while testicular DLBCL usually carried a non-GCB immunophenotype. DLBCL of various origins show a diversified GCB and non-GCB differentiation. Nodal and extranodal DLBCL, as well as extranodal DLBCL from different primary sites, carry different biologic characteristics and prognostic implications.

Sind primär extranodale diffuse großzellige B-Zell-Lymphome organotypische Erkrankungen?

Roughly 30-40% of diffuse large B-cell lymphomas (DLBCL) arise primarily in extranodal sites. Most frequently, they occur in the gastrointestinal tract, especially in the gastric mucosa. They also occur in the central nervous system, as testicular lymphomas, in the lungs, or in the skin. Morphologically, they show the whole spectrum of peripheral B-blasts: centroblasts, immunoblasts, or plasmoblasts. Thus, there is no actual difference in their cytomorphological presentation compared to their nodal-and frequently systemic-counterparts. However, recent data point to profound differences in primary extranodal DLBCL compared to primary nodal tumors, as well as to each other, frequently relating to their molecular characteristics and especially implying organotypic features. These characteristics may relate to a particular organotypic site of origin, or the particular clinico-pathogenetic setting in which the tumors arise. This is exemplified in the description of the DLBCL subtypes as defined by the World Health Organization classification (mediastinal or intravascular B-cell lymphoma; primary effusion lymphoma). On the other hand, primary extranodal DLBCL are frequently characterized by a particular (cyto-)genetic constitution, often related to their site of origin. Finally, some preliminary data on gene expression profiling strongly argue in favor of particular gene signatures for primary extranodal DLBCL, and hence in favor of particular organotypic transformation pathways.

Mutations within the 5′ region of FAS/CD95 gene in nodal diffuse large B-cell lymphoma

CD95 is a cell-surface receptor that mediates apoptosis. A possible association between CD95 mutations and extranodal diffuse large B-cell lymphomas (DLBCL) has been reported. To further elucidate this question, a mutation analysis within the 5′ region and exon 9 of CD95 was performed in a series of 66 DLBCL patients, by polymerase chain reaction, single-strand conformational polymorphism, and sequencing in all cases. Four mutations, all within the 5′ region, were detected in three cases of primary nodal DLBCL (6.3% of primary DLBCL), probably originated as by-products of the somatic hypermutation process. No CD95 mutations in the two analyzed regions were detected in primary extranodal DLBCL, mediastinal large B-cell lymphoma (MLBCL), and DLBCL arising from indolent low-grade lymphomas. Because of our results, a review of published data with respect to the site of mutations was performed, which suggested a different distribution of mutations in nodal and extranodal DLBCL.

Intravascular Lymphoma: The Oncologist's “Great Imitator”

Intravascular lymphoma (IVL) is a rare subtype of extranodal diffuse large B-cell lymphoma with a distinct presentation. Anatomically the disease is characterized by the proliferation of clonal lymphocytes within small vessels with relative sparing of the surrounding tissue. The clinical symptoms of the disease are dependent on the specific organ involvement, which most often includes the central nervous system and skin. Because of the various modes of presentation and the rarity of IVL, the diagnosis is often made postmortem. The diagnosis is almost exclusively made by surgical biopsy of a suspected site of involvement. Advances in imaging and immunohistochemistry have led to increasing antemortem diagnosis of this lymphoma. Although some patients with this disease may be curable with aggressive therapy, further research into novel treatment strategies is needed to improve outcome. Some potential insights into future therapies may be drawn from the small amount of basic science literature relevant to this entity. This review provides a concise, up-to-date summary of IVL.