MYC protein is a high-risk factor in mantle cell lymphoma and identifies cases beyond morphology, proliferation and TP53/p53 - a Nordic Lymphoma Group study.

The transcription factor MYC is a well-described oncogene with an important role in lymphomagenesis, but its significance for clinical outcome in mantle cell lymphoma (MCL) remains to be determined. We performed an investigation of the expression of MYC protein in a cohort of 251 MCL patients complemented by analyses of structural aberrations and mRNA, in a sub-cohort of patients. Fourteen percent (n=35) of patients showed high MYC protein expression with >20% positive cells (MYChigh), among whom only one translocation was identified, and 86% (n=216) of patients showed low MYC protein expression. Low copy number gains of MYC were detected in ten patients, but with no correlation to MYC protein levels. However, MYC mRNA levels correlated significantly to MYC protein levels with a R2 value of 0.76. Patients with a MYChigh tumor had both an independent inferior overall survival and an inferior progression-free survival (hazard ratio [HR]=2.03, 95% confidence interval [95% CI]: 1.2-3.4 and HR=2.2, 95% CI: 1.04-4.6, respectively) when adjusted for additional high-risk features. Patients with MYChigh tumors also tended to have additional high-risk features and to be older at diagnosis. A subgroup of 13 patients had concomitant MYChigh expression and TP53/p53 alterations and a substantially increased risk of progression (HR=16.9, 95% CI: 7.4-38.3) and death (HR=7.8, 95% CI: 4.4-14.1) with an average overall survival of only 0.9 years. In summary, we found that at diagnosis a subset of MCL patients (14%) overexpressed MYC protein, and had a poor prognosis but that MYC rearrangements were rare. Tumors with concurrent MYC overexpression and TP53/p53 alterations pinpointed MCL patients with a dismal prognosis with a median overall survival of less than 3 years. We propose that MYC needs to be assessed beyond the current high-risk factors in MCL in order to identify cases in need of alternative treatment.

B-cell receptor reactivity against Rothia mucilaginosa in nodular lymphocyte-predominant Hodgkin lymphoma.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a Hodgkin lymphoma expressing functional B-cell receptors (BCR). Recently, we described a dual stimulation model of IgD+ lymphocyte-predominant cells by Moraxella catarrhalis antigen RpoC and its superantigen MID/hag, associated with extralong CDR3 and HLA-DRB1*04 or HLADRB1* 07 haplotype. The aim of the present study was to extend the antigen screening to further bacteria and viruses. The fragment antibody-binding (Fab) regions of seven new and 15 previously reported cases were analyzed. The reactivity of non-Moraxella spp.-reactive Fab regions against lysates of Rothia mucilaginosa was observed in 5/22 (22.7%) cases. Galactofuranosyl transferase (Gltf) and 2,3-butanediol dehydrogenase (Bdh) of R. mucilaginosa were identified by comparative silver- and immuno-staining in two-dimensional gels, with subsequent mass spectrometry and validation by western blots and enzyme-linked immunosorbent assay. Both R. mucilaginosa Gltf and Bdh induced BCR pathway activation and proliferation in vitro. Apoptosis was induced by recombinant Gltf/ETA'-immunotoxin conjugates in DEV cells expressing recombinant R. mucilaginosa-reactive BCR. Reactivity against M. catarrhalis RpoC was confirmed in 3/7 newly expressed BCR (total 10/22 reactive to Moraxella spp.), resulting in 15/22 (68.2%) cases with BCR reactivity against defined bacterial antigens. These findings strengthen the hypothesis of bacterial trigger contributing to subsets of NLPHL.

Lymphoma risks in patients with rheumatoid arthritis treated with biological drugs-a Swedish cohort study of risks by time, drug and lymphoma subtype.

OBJECTIVES: To estimate the association between biological DMARDs (bDMARDs; overall and by drug) as used in RA and the risk of malignant lymphomas including subtypes. METHODS: By linking nationwide Swedish registers we identified cohorts of patients with RA initiating treatment with a bDMARD (n = 16 392), bDMARD-naïve (n = 55 253), an age- and sex-matched general population comparator cohort (n = 229 047), and all incident lymphomas 2001-16. We used Cox regression to calculate hazard ratios (HRs) of lymphoma taking calendar period and other factors into account. RESULTS: There were 82 lymphomas among the bDMARD-treated patients with RA, crude incidence rate 76/100 000 person-years, and 310 lymphomas among the bDMARD-naïve patients with RA, crude incidence rate 90/100 000 person-years. This resulted in an adjusted HR (aHR) associated with bDMARD treatment (vs not) of 1.08 (95% CI: 0.83, 1.41). The corresponding aHR for bDMARD-treated and bDMARD-naïve vs the general population was 1.65 (95% CI: 1.31, 2.08) and 1.56 (95% CI: 1.37, 1.78) respectively. Restricting follow-up period to after 2006, the aHR of lymphoma for patients with RA starting a first bDMARD vs bDMARD-naïve was 0.69 (95% CI: 0.47, 1.00), and for bDMARD treated vs patients with RA switching from one conventional synthetic DMARDs to another, aHR was 0.46 (95% CI: 0.28, 0.73). There were no signals of different risks with any particular TNF inhibitor (TNFi) agent. We found no different lymphoma subtype pattern following bDMARD therapy. CONCLUSION: Treatment with bDMARDs, including both TNFi and non-TNFi bDMARDs, does not further increase the lymphoma risk in RA; instead, bDMARD treatment may actually reduce the excess lymphoma risk in RA.

Prior antithymocyte globulin therapy and survival in post-transplant lymphoproliferative disorders.

Background: Treatment with antithymocyte globulin (ATG) is a well-recognized risk factor for the development of post-transplant lymphoproliferative disorders (PTLD) after solid organ transplantation, but it is unknown how its use affects overall survival after PTLD.Methods: A total of 114 patients with PTLD and available data on immunosuppressive regimen were included from a nation-wide case series of solid organ transplant recipients in Sweden. Prior use of ATG was correlated to clinical features, PTLD subtype, and survival.Results: A total of 47 (41%) patients had received ATG prior to the diagnosis of PTLD. The ATG-treated patients were more likely to be recipients of hearts or lungs, and less likely of kidneys (p < 0.01). They had experienced more acute rejections (p = 0.02). The PTLDs arose earlier, median 2.0 vs. 6.6 years post-transplant (p = 0.002) and were more often situated in the allograft (32% vs. 7%, p < 0.001) in patients with prior ATG vs. no ATG treatment. The PTLDs in the ATG group were more often Epstein-Barr virus-positive (80% vs. 40%, p < 0.001). There were more polymorphic PTLDs (17% vs. 1.5%, p = 0.004) and less T-cell PTLDs (4% vs. 19%, p = 0.02) in the ATG group than in the no ATG group. Diffuse large B-cell lymphoma was equally common in patients with and without prior ATG therapy, but the non-germinal center subtype was more frequent in the ATG group (p = 0.001). In an adjusted Cox proportional hazards regression model, prior ATG treatment and better performance status were associated with superior overall survival, whereas older age, T-cell subtype of PTLD, presence of B symptoms, and elevated lactate dehydrogenase were associated with inferior overall survival. Patients receiving ATG solely as rejection therapy had superior overall survival compared with those receiving ATG as induction therapy or both (p = 0.03).Conclusions: ATG therapy, especially rejection therapy, prior to PTLD development is an independent prognostic factor for superior overall survival after PTLD diagnosis.

PD-L1 and IDO1 are potential targets for treatment in patients with primary diffuse large B-cell lymphoma of the CNS.

BACKGROUND: Programmed cell death 1 (PD-1) and its ligands PD-L1 and PD-L2, as well as Indoleamine 2,3-deoxygenase (IDO1) can be expressed both by tumor and microenvironmental cells and are crucial for tumor immune escape. We aimed to evaluate the role of PD-1, its ligands and IDO1 in a cohort of patients with primary diffuse large B-cell lymphoma of the CNS (PCNSL). MATERIAL AND METHODS: Tissue microarrays (TMAs) were constructed in 45 PCNSL cases. RNA extraction from whole tissue sections and RNA sequencing were successfully performed in 33 cases. Immunohistochemical stainings for PD-1, PD-L1/paired box protein 5 (PAX-5), PD-L2/PAX-5 and IDO1, and Epstein-Barr virus encoding RNA (EBER) in situ hybridization were analyzed. RESULTS: High proportions of PD-L1 and PD-L2 positive tumor cells were observed in 11% and 9% of cases, respectively. High proportions of PD-L1 and PD-L2 positive leukocytes were observed in 55% and 51% of cases, respectively. RNA sequencing revealed that gene expression of IDO1 was high in patients with high proportion of PD-L1 positive leukocytes (p = .01). Protein expression of IDO1 in leukocytes was detected in 14/45 cases, in 79% of these cases a high proportion of PD-L1 positive leukocytes was observed. Gene expression of IDO1 was high in EBER-positive cases (p = .0009) and protein expression of IDO1 was detected in five of six EBER-positive cases. CONCLUSION: Our study shows a significant association between gene and protein expression of IDO1 and protein expression of PD-L1 in the tumor microenvironment of PCNSL, possibly of importance for prediction of response to immunotherapies.

p53 is associated with high-risk and pinpoints TP53 missense mutations in mantle cell lymphoma.

Survival for patients diagnosed with mantle cell lymphoma (MCL) has improved drastically in recent years. However, patients carrying mutations in tumour protein p53 (TP53) do not benefit from modern chemotherapy-based treatments and have poor prognosis. Thus, there is a clinical need to identify missense mutations through routine analysis to enable patient stratification. Sequencing is not widely implemented in clinical practice for MCL, and immunohistochemistry (IHC) is a feasible alternative to identify high-risk patients. The aim of the present study was to investigate the accuracy of p53 as a tool to identify patients with TP53 missense mutations and the prognostic impact of overexpression and mutations in a Swedish population-based cohort. In total, 317 cases were investigated using IHC and 255 cases were sequenced, enabling analysis of p53 and TP53 status among 137 cases divided over the two-cohort investigated. The accuracy of predicting missense mutations from protein expression was 82%, with sensitivity at 82% and specificity at 100% in paired samples. We further show the impact of p53 expression and TP53 mutations on survival (hazard ratio of 3·1 in univariate analysis for both), and the association to risk factors, such as high MCL International Prognostic Index, blastoid morphology and proliferation, in a population-based setting.

Prognostic implications of the microenvironment for follicular lymphoma under immunomodulation therapy.

Follicular lymphoma (FL) constitutes a significant proportion of lymphomas and shows frequent relapses. Beyond conventional chemotherapy, new therapeutic approaches have emerged, focussing on the interplay between lymphoma cells and the microenvironment. Here we report the immunophenotypic investigation of the microenvironment of a clinically well-characterized prospective cohort (study SAKK35/10, NCT01307605) of 154 treatment-naïve FL patients in need of therapy, who have been treated with rituximab only or a combination of rituximab and the immunomodulatory drug lenalidomide/Revlimid® A high ratio of CD4- to CD8-positive T cells (P = 0·009) and increased amounts of PD1+ tumour-infiltrating T cells (P = 0·007) were associated with inferior progression-free survival in the whole cohort. Interestingly, the prognostic impact of PD1+ T cells and the CD4/CD8 ratio lost its significance in the subgroup treated with R2 . In the latter group, high amounts of GATA3+ T helper (Th2) equivalents were associated with better progression-free survival (P < 0·001). We identified tumour microenvironmental features that allow prognostic stratification with respect to immuno- and combined immuno- and immunomodulatory therapy. Our analysis indicates that lenalidomide may compensate the adverse prognostic implication of higher amounts of CD4+ and, particularly, PD1+ T cells and that it has favourable effects mainly in cases with higher amounts of Th2 equivalents. [Correction added on 11 February 2020, after online publication: The NCT-trial number was previously incorrect and has been updated in this version].

CD30 expression and survival in posttransplant lymphoproliferative disorders.

Background: Post-transplant lymphoproliferative disorder (PTLD) is a rare but life-threatening complication of transplantation. For refractory and relapsed PTLD new therapies are needed, such as the antibody-drug conjugate brentuximab vedotin that targets CD30. There is limited knowledge of CD30 expression in various subtypes of PTLD and its correlation to clinicopathological features. Therefore, we studied the expression of CD30 in PTLD following solid organ transplantation and correlated CD30 expression to PTLD subtype, Epstein-Barr virus (EBV)-status, intratumoral regulatory T-cells (Tregs), clinical features, and outcome.Methods: We included 50 cases of PTLD from a nation-wide study of PTLDs following solid organ transplantation in Sweden. The tumor biopsies were reevaluated, and clinical data were collected. CD30 expression on tumor cells was analyzed by immunohistochemistry with the clone Ber-H2. Thirty-one cases were stained with clone 236 A/E7 for detection of forkhead box protein 3 (FoxP3, a Treg biomarker).Results: The case series consisted of 6% polymorphic, 88% monomorphic, and 6% Hodgkin lymphoma-like PTLDs and 53% of the cases were EBV+. Overall, 70% (35/50) of the PTLDs were CD30+ (≥1% CD30+ tumor cells) and 30% (15/50) were CD30-. All polymorphic PTLDs (n = 3) and Hodgkin lymphomas (n = 3), 88% (14/16) of non-germinal center type of diffuse large B-cell lymphoma (DLBCL), and 75% (9/12) of T-cell PTLDs were CD30+ whereas all germinal center-type of DLBCL (n = 5) and Burkitt type PTLD (n = 2) were CD30-. CD30+ PTLD tended to be EBV+ more frequently (p = .07) and occurred earlier posttransplant (2.1 vs. 8.2 years, p = .01) than CD30- PTLD. Type of transplant and localization of the tumor did not differ between the groups except that CNS engagement was more common in CD30- PTLD (p = .02). CD30-status was not associated with presence of intratumoral Tregs or overall survival.Conclusion: Expression of CD30 varied with PTLD subtype. There was no association between CD30 and survival, regardless of subtype.

High tumour plasma cell infiltration reflects an important microenvironmental component in classic Hodgkin lymphoma linked to presence of B-symptoms.

Plasma cells are important prognostic actors in different malignancies. The tumour microenvironmental composition in classic Hodgkin lymphoma (cHL) is a major prognostic key element; however, clinicopathological studies regarding plasma cells in cHL are lacking. The aim of this study was to investigate CD138+ (also termed SDC1+) plasma cell and IgG4 producing (IgG4+) plasma cells infiltration in the microenvironment of cHL. Immunohistochemistry with anti-CD138 and IgG4 antibodies was performed on diagnostic tumour biopsies from 124 patients with cHL, on tissue micro array (TMA). In 120 cases, CD138+ plasma cell-infiltration was associated with the presence of B-symptoms (P = 0·028) and advanced stage, IIB-IVB (P = 0·009). In multivariate analysis, CD138+ plasma cells correlated with eosinophil infiltration (P = 0·013). The subgroup of IgG4+ plasma cells was analysed in 122 cases and only correlated to CD138+ plasma cells (P = 0·004). Patients with high proportion of tumour infiltrating CD138+ plasma cells (defined as ≥10%), had a more inferior event-free survival (P = 0·007) and overall survival (P = 0·004) than patients with a low proportion of infiltrating CD138+ plasma cells (<10%), although significance was not maintained in multivariate analysis. In summary, a high proportion of tumour-associated plasma cells in cHL reflect an important component in the microenvironment of cHL.

Numerous Ontogenetic Roads to Mantle Cell Lymphoma: Immunogenetic and Immunohistochemical Evidence.

To obtain insight into the ontogeny of mantle cell lymphoma (MCL), we assessed 206 patients from a morphological, immunohistochemical, and immunogenetic perspective. Our series included nodal (n = 151), extranodal (n = 28), and primary splenic (n = 27) MCL cases. Skewing of the immunoglobulin heavy variable (IGHV) gene repertoire was noted, with only four IGHV genes accounting for 46% of cases and approximately 70% of cases (107/154) bearing an imprint of somatic hypermutation (SHM) ranging from minimal to pronounced. Interestingly, a distinctive immunophenotypic and immunogenetic profile was identified for primary splenic MCL, which was enriched for DBA.44-positive cases (P < 0.001) and used the IGHV1-8 gene more frequently (P = 0.02) compared to nodal or extranodal cases, alluding to distinct immunopathogenetic and antigen selection processes. Expression of CD27 (considered a marker of activated B cells) was generally dissociated from SHM and was more prevalent in cases with no or minimal/borderline SHM. These findings support the idea that antigen drive is relevant for most MCL cases, although the specific antigens and the precise location of affinity maturation remain to be elucidated. Moreover, they raise the intriguing hypothesis of multiple cellular origins for MCL.

Lenalidomide-bendamustine-rituximab in patients older than 65 years with untreated mantle cell lymphoma.

For elderly patients with mantle cell lymphoma (MCL), there is no defined standard therapy. In this multicenter, open-label phase 1/2 trial, we evaluated the addition of lenalidomide (LEN) to rituximab-bendamustine (R-B) as first-line treatment for elderly patients with MCL. Patients >65 years with untreated MCL, stages II-IV were eligible for inclusion. Primary end points were maximally tolerable dose (MTD) of LEN and progression-free survival (PFS). Patients received 6 cycles every four weeks of L-B-R (L D1-14, B 90 mg/m2 IV, days 1-2 and R 375 mg/m2 IV, day 1) followed by single LEN (days 1-21, every four weeks, cycles 7-13). Fifty-one patients (median age 71 years) were enrolled from 2009 to 2013. In phase 1, the MTD of LEN was defined as 10 mg in cycles 2 through 6, and omitted in cycle 1. After 6 cycles, the complete remission rate (CRR) was 64%, and 36% were MRD negative. At a median follow-up time of 31 months, median PFS was 42 months and 3-year overall survival was 73%. Infection was the most common nonhematologic grade 3 to 5 event and occurred in 21 (42%) patients. Opportunistic infections occurred in 3 patients: 2 Pneumocystis carinii pneumonia and 1 cytomegalovirus retinitis. Second primary malignancies (SPM) were observed in 8 patients (16%). LEN could safely be combined with R-B when added from the second cycle in patients with MCL, and was associated with a high rate of CR and molecular remission. However, we observed a high degree of severe infections and an unexpected high number of SPMs, which may limit its use. This trial is registered at www.Clinicaltrials.gov as #NCT00963534.

Genetic basis of PD-L1 overexpression in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphoma (DLBCL) is one of the most common and aggressive types of B-cell lymphoma. Deregulation of proto-oncogene expression after a translocation, most notably to the immunoglobulin heavy-chain locus (IGH), is one of the hallmarks of DLBCL. Using whole-genome sequencing analysis, we have identified the PD-L1/PD-L2 locus as a recurrent translocation partner for IGH in DLBCL. PIM1 and TP63 were also identified as novel translocation partners for PD-L1/PD-L2 Fluorescence in situ hybridization was furthermore used to rapidly screen an expanded DLBCL cohort. Collectively, a subset of samples was found to be affected by gains (12%), amplifications (3%), and translocations (4%) of the PD-L1/PD-L2 locus. RNA sequencing data coupled with immunohistochemistry revealed that these cytogenetic alterations correlated with increased expression of PD-L1 but not of PD-L2 Moreover, cytogenetic alterations affecting the PD-L1/PD-L2 locus were more frequently observed in the non-germinal center B cell-like (non-GCB) subtype of DLBCL. These findings demonstrate the genetic basis of PD-L1 overexpression in DLBCL and suggest that treatments targeting the PD-1-PD-L1/PD-L2 axis might benefit DLBCL patients, especially those belonging to the more aggressive non-GCB subtype.

U-CAN: a prospective longitudinal collection of biomaterials and clinical information from adult cancer patients in Sweden.

BACKGROUND: Progress in cancer biomarker discovery is dependent on access to high-quality biological materials and high-resolution clinical data from the same cases. To overcome current limitations, a systematic prospective longitudinal sampling of multidisciplinary clinical data, blood and tissue from cancer patients was therefore initiated in 2010 by Uppsala and Umeå Universities and involving their corresponding University Hospitals, which are referral centers for one third of the Swedish population. MATERIAL AND METHODS: Patients with cancer of selected types who are treated at one of the participating hospitals are eligible for inclusion. The healthcare-integrated sampling scheme encompasses clinical data, questionnaires, blood, fresh frozen and formalin-fixed paraffin-embedded tissue specimens, diagnostic slides and radiology bioimaging data. RESULTS: In this ongoing effort, 12,265 patients with brain tumors, breast cancers, colorectal cancers, gynecological cancers, hematological malignancies, lung cancers, neuroendocrine tumors or prostate cancers have been included until the end of 2016. From the 6914 patients included during the first five years, 98% were sampled for blood at diagnosis, 83% had paraffin-embedded and 58% had fresh frozen tissues collected. For Uppsala County, 55% of all cancer patients were included in the cohort. CONCLUSIONS: Close collaboration between participating hospitals and universities enabled prospective, longitudinal biobanking of blood and tissues and collection of multidisciplinary clinical data from cancer patients in the U-CAN cohort. Here, we summarize the first five years of operations, present U-CAN as a highly valuable cohort that will contribute to enhanced cancer research and describe the procedures to access samples and data.

TET2 mutations in B cells of patients affected by angioimmunoblastic T-cell lymphoma.

Angioimmunoblastic T-cell lymphomas (AITLs) frequently carry mutations in the TET2 and IDH2 genes. TET2 mutations represent early genetic lesions as they had already been detected in haematopoietic precursor cells of AITL patients. We show by analysis of whole-tissue sections and microdissected PD1+ cells that the frequency of TET2-mutated AITL is presumably even higher than reported (12/13 cases in our collection; 92%). In two-thirds of informative AITLs (6/9), a fraction of B cells was also TET2-mutated. Investigation of four AITLs by TET2 and IGHV gene sequencing of single microdissected B cells showed that between 10% and 60% of polyclonal B cells in AITL lymph nodes harboured the identical TET2 mutations of the respective T-cell lymphoma clone. Thus, TET2-mutated haematopoietic precursor cells in AITL patients not only give rise to the T-cell lymphoma but also generate a large population of mutated mature B cells. Future studies will show whether this is a reason why AITL patients frequently also develop B-cell lymphomas. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Molecular Monitoring after Autologous Stem Cell Transplantation and Preemptive Rituximab Treatment of Molecular Relapse; Results from the Nordic Mantle Cell Lymphoma Studies (MCL2 and MCL3) with Median Follow-Up of 8.5 Years.

The main objectives of the present study were to monitor minimal residual disease (MRD) in the bone marrow of patients with mantle cell lymphoma (MCL) to predict clinical relapse and guide preemptive treatment with rituximab. Among the patients enrolled in 2 prospective trials by the Nordic Lymphoma Group, 183 who had completed autologous stem cell transplantation (ASCT) and in whom an MRD marker had been obtained were included in our analysis. Fresh samples of bone marrow were analyzed for MRD by a combined standard nested and quantitative real-time PCR assay for Bcl-1/immunoglobulin heavy chain gene (IgH) and clonal IgH rearrangements. Significantly shorter progression-free survival (PFS) and overall survival (OS) was demonstrated for patients who were MRD positive pre-ASCT (54 patients) or in the first analysis post-ASCT (23 patients). The median PFS was only 20 months in those who were MRD-positive in the first sample post-ASCT, compared with 142 months in the MRD-negative group (P < .0001). OS was 75% at 10 years and median not reached in the MRD-negative group, compared with only 35 months in the MRD-positive group (P < .0001). Of the 86 patients (47%) who remained in continuous molecular remission, 73% were still in clinical remission after 10 years. For all patients, the median time from ASCT to first molecular relapse was 55 months, with a continuous occurrence of late molecular relapses. Fifty-eight patients who experienced MRD relapse received rituximab as preemptive treatment on 1 or more occasions, and in this group, the median time from first molecular relapse to clinical relapse was 55 months. In most cases, rituximab converted patients to MRD negativity (87%), but many patients became MRD-positive again later during follow-up (69%). By multivariate analysis, high-risk Mantle Cell Lymphoma International Prognostic Index score and positive MRD status pre-ASCT predicted early molecular relapse. In conclusion, preemptive rituximab treatment converts patients to MRD negativity and likely postpones clinical relapse. Molecular monitoring offers an opportunity to select some patients for therapeutic intervention and to avoid unnecessary treatment in others. MRD-positive patients in the first analysis post-ASCT have a dismal prognosis and thus are in need of novel strategies.

miR-18b overexpression identifies mantle cell lymphoma patients with poor outcome and improves the MIPI-B prognosticator.

Recent studies show that mantle cell lymphoma (MCL) express aberrant microRNA (miRNA) profiles; however, the clinical effect of miRNA expression has not previously been examined and validated in large prospective homogenously treated cohorts. We performed genome-wide miRNA microarray profiling of 74 diagnostic MCL samples from the Nordic MCL2 trial (screening cohort). Prognostic miRNAs were validated in diagnostic MCL samples from 94 patients of the independent Nordic MCL3 trial (validation cohort). Three miRNAs (miR-18b, miR-92a, and miR-378d) were significantly differentially expressed in patients who died of MCL in both cohorts. MiR-18b was superior to miR-92a and miR-378d in predicting high risk. Thus, we generated a new biological MCL International Prognostic Index (MIPI-B)-miR prognosticator, combining expression levels of miR-18b with MIPI-B data. Compared to the MIPI-B, this prognosticator improved identification of high-risk patients with regard to cause-specific, overall, and progression-free survival. Transfection of 2 MCL cell lines with miR-18b decreased their proliferation rate without inducing apoptosis, suggesting that miR-18b may render MCL cells resistant to chemotherapy by decelerating cell proliferation. We conclude that overexpression of miR-18b identifies patients with poor prognosis in 2 large prospective MCL cohorts and adds prognostic information to the MIPI-B. MiR-18b may reduce the proliferation rate of MCL cells as a mechanism of chemoresistance.

Expression of possible targets for new proteasome inhibitors in diffuse large B-cell lymphoma.

OBJECTIVES: Investigating expression of possible targets for proteasome inhibitors in patients with diffuse large B-cell lymphoma (DLBCL) and correlating the findings to clinical parameters and outcome. METHODS: Tumour material from 92 patients with DLBCL treated with either R-CHOP like (n = 69) or CHOP like (n = 23) regimens were stained for possible targets of proteasome inhibitors. RESULTS: The primary target molecule of bortezomib, proteasome subunit beta, type 5 (PSMB5), was not detected in the tumour cells in any of the cases but showed an abundant expression in cells in the microenvironment. However, the deubiquitinases (DUBs) of the proteasome, the ubiquitin carboxyl-terminal hydrolase L5 (UCHL5) and the ubiquitin specific peptidase 14 (USP14), were detected in the cytoplasm of the tumour cells in 77% and 74% of the cases, respectively. The adhesion regulating molecule 1 (ADRM1) was detected in 98% of the cases. There was no correlation between the expression of any of the studied markers and clinical outcome or GC/non-GC phenotype. CONCLUSIONS: We suggest that UCHL5 and/or USP14 should be further evaluated as new targets for proteasome inhibitors in DLBCL. The lack of expression of PSMB5 on the tumour cells might provide an explanation of the relatively poor results of bortezomib in DLBCL.

Population-based experience on primary central nervous system lymphoma 2000-2012: the incidence is increasing.

BACKGROUND: Primary central nervous system lymphomas (PCNSL) are rare lymphomas with a poor prognosis. Recently, an increased incidence has been reported. The present study is a population-based study of all patients with PCNSL in the Uppsala/Örebro region of middle Sweden. PATIENTS AND METHODS: All patients diagnosed with a PCNSL at Uppsala University Hospital 2000-2012 were identified. Altogether, 96 patients (50 women and 46 men) were included. The median age at diagnosis was 66 years (17-95). RESULTS: There was a statistically significant increase in age-standardized incidence during the study period, 30 patients were diagnosed in the first half and 66 in the second half of the period. No patient had an HIV-infection. Two patients had undergone kidney transplantation and were treated with immunosuppressive drugs. A high proportion of the patients, 29%, had a history of an autoimmune or inflammatory disease. The prognosis was poor with a median survival of only four months. In the 70 (73%) patients treated with curative intention the median survival was 12 months. Patients treated with high-dose methotrexate, radiotherapy and/or temozolomide appeared to have a better survival. There was no improvement in survival during the study period or after the introduction of rituximab. There also was no difference in any of the analyzed variables that could explain the increased incidence. CONCLUSION: In this population-based study we could confirm the previously described increased incidence of PCNSL. The prognosis remains poor despite the inclusion of treatment with rituximab during the study period. A high proportion of the patients had a history of an autoimmune or inflammatory disease not previously described but there was no increase during the study period.

15-year follow-up of the Second Nordic Mantle Cell Lymphoma trial (MCL2): prolonged remissions without survival plateau.

In recent decades, the prognosis of Mantle Cell Lymphoma (MCL) has been significantly improved by intensified first-line regimens containing cytarabine, rituximab and consolidation with high-dose-therapy and autologous stem cell transplantation. One such strategy is the Nordic MCL2 regimen, developed by the Nordic Lymphoma Group. We here present the 15-year updated results of the Nordic MCL2 study after a median follow-up of 11·4 years: For all patients on an intent-to-treat basis, the median overall and progression-free survival was 12·7 and 8·5 years, respectively. The MCL International Prognostic Index (MIPI), biological MIPI, including Ki67 expression (MIPI-B) and the MIPI-B including mIR-18b expression (MIPI-B-miR), in particular, significantly divided patients into distinct risk groups. Despite very long response durations of the low and intermediate risk groups, we observed a continuous pattern of relapse and the survival curves never reached a plateau. In conclusion, despite half of the patients being still alive and 40% in first remission after more than 12 years, we still see an excess disease-related mortality, even among patients experiencing long remissions. Even though we consider the Nordic regimen as a very good choice of regimen, we recommend inclusion in prospective studies to explore the benefit of novel agents in the frontline treatment of MCL.