Double hit lymphoma: the MD Anderson Cancer Center clinical experience

We report our experience with 129 cases of double hit lymphoma (DHL), defined as B‐cell lymphoma with translocations and/or extra signals involving MYC plus BCL2 and/or BCL6. All cases were reviewed for histopathological classification. Median age was 62 years (range, 18–85), 84% of patients had advanced‐stage disease, and 87% had an International Prognostic Index score ≥2. Fourteen patients (11%) had a history of low‐grade follicular lymphoma. MYC translocation was present in 81%, and extra signals of MYC in 25% of patients. IGH‐BCL2 translocation was present in 84% and extra signals of BCL2 in 12% of patients. Two‐year event‐free survival (EFS) rates in all patients and patients who received R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), R‐EPOCH (rituximab, etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin), and R‐HyperCVAD/MA (rituximab, hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone, alternating with cytarabine plus methotrexate) were 33%, 25%, 67% and 32%, respectively. In patients achieving complete response with initial therapy (n = 71), 2‐year EFS rates in patients who did (n = 23) or did not (n = 48) receive frontline stem cell transplantation were 68% and 53%, respectively (P = 0·155). The cumulative incidence of central nervous system involvement was 13% at 3 years. Multivariate analysis identified performance status ≥2 and bone marrow involvement as independent adverse prognostic factors for EFS and OS. Further research is needed to identify predictive and/or targetable biological markers and novel therapeutic approaches for DHL patients.     

LMO2 and BCL6 are associated with improved survival in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is an aggressive sub‐variant of non‐Hodgkin lymphoma (NHL) with morphological similarities to diffuse large B‐cell lymphoma (DLBCL). While methotrexate (MTX)‐based therapies have improved patient survival, the disease remains incurable in most cases and its pathogenesis is poorly understood. We evaluated 69 cases of PCNSL for the expression of HGAL (also known as GCSAM), LMO2 and BCL6 – genes associated with DLBCL prognosis and pathobiology, and analysed their correlation to survival in 49 PCNSL patients receiving MTX‐based therapy. We demonstrate that PCNSL expresses LMO2, HGAL(also known as GCSAM) and BCL6 proteins in 52%, 65% and 56% of tumours, respectively. BCL6 protein expression was associated with longer progression‐free survival (P = 0·006) and overall survival (OS, P = 0·05), while expression of LMO2 protein was associated with longer OS (P = 0·027). Further research is needed to elucidate the function of BCL6 and LMO2 in PCNSL.     

B‐cell lymphoma,unclassifiable, with features intermediate between diffuse large B‐cell lymphoma and burkitt lymphoma: study of 39 cases

B‐cell lymphoma, unclassifiable (B‐UCL), with features intermediate between diffuse large B‐cell lymphoma and Burkitt lymphoma, is a poorly characterized entity. Therefore, we investigated cases of B‐UCL treated by the Nebraska Lymphoma Study Group (NLSG). We searched the NLSG registry for years 1985–2010 for cases of B‐UCL. Immunohistochemical stains and fluorescence in situ hybridization studies for MYC, BCL2 and BCL6 gene rearrangements were performed. Among the 39 cases studied, 54% were male and 46% were female, with a median age of 69 years. The majority of patients presented with advanced‐stage disease (62%) and had high (3–5) International Prognostic Index (IPI) scores (54%). The median overall survival (OS) was only 9 months and the 5‐year OS was 30%. Patients with low IPI scores (0–2) had a better survival than those with high scores (3–5). The cases were genetically heterogeneous and included 11 ‘double‐hit’ lymphomas with rearrangements of both MYC and BCL2 or BCL6. None of the immunohistochemical or genetic features was predictive of survival. This B‐cell lymphoma is a morphologically‐recognizable entity with a spectrum of genetic abnormalities. New and better treatments are needed for this aggressive lymphoma.     

Re‐infection of Toxoplasma gondii after HSCT presenting lymphadenopathy resembling recurrence of lymphoma

Toxoplasma gondii (T. gondii) reactivation is one of the fatal complications after hematopoietic stem cell transplantation (HSCT); however, re‐infection has not been reported. Here, we report a case of mycosis fungoides in which cervical lymphadenopathy developed after HSCT. Initially, recurrent lymphoma was suspected. However, biopsy of the lymph node showed typical histology of toxoplasmosis and serology showed re‐infection of T. gondii. Toxoplasmosis needs to be differentiated for cases with lymphoadenopthy after HSCT.     

Bortezomib in combination with infusional dose‐adjusted EPOCH for the treatment of plasmablastic lymphoma

Plasmablastic lymphoma (PBL) is a rare and aggressive CD20‐negative lymphoma. Despite improvements of the biology behind PBL, it still represents a challenge from the diagnostic and therapeutic perspectives for pathologists and clinicians. PBL is characterized by high rates of relapse and short median survival with standard approaches. Here, we report the use of the combination of bortezomib and infusional etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (V‐EPOCH) in three patients with PBL; two were HIV‐positive and one was HIV‐negative. All three patients obtained a durable complete response to V‐EPOCH with survival times of 24, 18 and 12 months respectively.     

Nodular lymphocyte predominant Hodgkin lymphoma in USA between 2000 and 2014: an updated analysis based on the SEER data

Plasma transfusions may result in transfusion reactions. We used the International Surveillance of Transfusion‐Associated Reactions and Events (ISTARE) database, containing yearly reported national annual aggregate data on transfusion reactions from participating countries, to investigate risks of plasma transfusion reactions and compare transfusion reaction risks for different plasma types. We calculated risks for plasma transfusion reactions and compared transfusion reaction risks between plasma types using random effects regression on repeated measures. The ISTARE database contains data from 23 countries, reporting units issued and/or transfused and transfusion reactions observed for some portion of 7 years (2006–2012). Interquartile ranges (IQRs) of plasma transfusion reaction risks were: allergic reactions (5·6–72·2 reactions/10⁵ units transfused); febrile non‐haemolytic transfusion reactions (0–9·1); transfusion‐associated circulatory overload (0–1·9); transfusion related acute lung injury (TRALI) (0–1·2); and hypotensive reactions (0–0·6). Apheresis plasma was associated with more allergic reactions [odds ratio (OR) = 1·29 (95% confidence interval: 1·19–1·40)] and hypotensive reactions [OR = 2·17 (1·38–3·41)] than whole blood‐derived plasma. Pathogen‐inactivated plasma was associated with fewer transfusion reactions than untreated plasma.     

MYD88 L265P and CXCR4 mutations in lymphoplasmacytic lymphoma identify cases with high disease activity

Recurrent mutations in MYD88 have been identified in >90% of lymphoplasmacytic lymphoma (LPL). Recently, WHIM (warts, hypogammaglobulinaemia, infections, myelokathexis) syndrome‐like mutations in CXCR4 have been described in 28% of LPL cases, and seem to impact clinical presentation and response to therapy. We investigated the presence of the MYD88 L265P mutation in 90 decalcified, formalin‐fixed, paraffin‐embedded (FFPE) bone marrow (BM) biopsies, including 51 cases of LPL, 14 cases of B‐cell chronic lymphocytic leukaemia (CLL), 13 cases of marginal zone lymphoma (MZL) and 12 normal controls. In addition, the C‐terminal domain of CXCR4 was sequenced in LPL cases. MYD88 L265P was found in 49/51 (96%) LPL cases and in 1/13 (7·6%) MZL (splenic type), whereas all CLL samples remained negative. The two MYD88 wild type LPL cases were associated with cold agglutinin disease. Mutations in CXCR4 were detected in 17/47 (36·2%) LPL cases, which showed a higher extent of BM infiltration and lower leucocyte counts (P = 0·02), haemoglobin (P = 0·05) and platelet counts (P = 0·01). In conclusion the detection of MYD88 L265P mutation in FFPE samples is reliable and useful for subtyping small B‐cell lymphomas in BM biopsies. In addition, the presence of CXCR4 mutations identifies a subgroup of LPL patients with higher disease activity.     

Prevalence of Achromobacter xylosoxidans in pulmonary mucosa‐associated lymphoid tissue lymphoma in different regions of Europe

Extranodal marginal zone lymphoma of mucosa‐associated lymphoid tissue (MALT lymphoma) comprises 7–8% of B‐cell lymphomas and commonly originates from a background of long‐standing chronic inflammation. An association with distinct bacteria species has been confirmed for several anatomical sites of MALT lymphoma. For pulmonary MALT lymphoma, however, a clear link with an infectious agent or autoimmune disorder has not yet been reported. Using a 16S rRNA gene–based approach, we have recently identified Achromobacter (Alcaligenes) xylosoxidans in eight of nine cases of pulmonary MALT lymphoma. A. xylosoxidans is a gram‐negative betaproteobacterium with low virulence, but high resistance to antibiotic treatment. To further examine a potential association with A. xylosoxidans, 124 cases of pulmonary MALT lymphoma and 82 control tissues from six European countries were analysed using a specific nested PCR. Although prevalence rates for A. xylosoxidans varied significantly from country to country, they were consistently higher for MALT lymphoma as compared to controls. Overall, 57/124 (46%) pulmonary MALT lymphomas and 15/82 (18%) control tissues were positive for A. xylosoxidans (P = 0·004). Whether the significant association of A. xylosoxidans with pulmonary MALT lymphoma demonstrated in our study points to a potential causal role in the pathogenesis of this lymphoma will require further studies.     

Expression of ribosomal and actin network proteins and immunochemotherapy resistance in diffuse large B cell lymphoma patients

Diffuse large B cell lymphoma (DLBCL) patients with early relapse or refractory disease have a very poor outcome. Immunochemotherapy resistance will probably, also in the era of targeted drugs, remain the major cause of treatment failure. We used proteomic mass spectrometry to analyse the global protein expression of micro‐dissected formalin‐fixed paraffin‐embedded tumour tissues from 97 DLBCL patients: 44 with primary refractory disease or relapse within 1 year from diagnosis (REF/REL), and 53 who were progression‐free more than 5 years after diagnosis (CURED). We identified 2127 proteins: 442 were found in all patients and 102 were differentially expressed. Sixty‐five proteins were overexpressed in REF/REL patients, of which 46 were ribosomal proteins (RPs) compared with 2 of the 37 overexpressed proteins in CURED patients (P = 7·6 × 10⁻¹⁰). Twenty of 37 overexpressed proteins in CURED patients were associated with actin regulation, compared with 1 of 65 in REF/REL patients (P = 1·4 × 10⁻⁹). Immunohistochemical staining showed higher expression of RPS5 and RPL17 in REF/REL patients while MARCKS‐like protein, belonging to the actin network, was more highly expressed in CURED patients. Even though functional studies aimed at individual proteins and protein interactions to evaluate potential clinical effect are needed, our findings suggest new mechanisms behind immunochemotherapy resistance in DLBCL.     

Preclinical evaluation of the BET bromodomain inhibitor BAY 1238097 for the treatment of lymphoma

The epigenome is often deregulated in cancer and treatment with inhibitors of bromodomain and extra‐terminal proteins, the readers of epigenetic acetylation marks, represents a novel therapeutic approach. Here, we have characterized the anti‐tumour activity of the novel bromodomain and extra‐terminal (BET) inhibitor BAY 1238097 in preclinical lymphoma models. BAY 1238097 showed anti‐proliferative activity in a large panel of lymphoma‐derived cell lines, with a median 50% inhibitory concentration between 70 and 208 nmol/l. The compound showed strong anti‐tumour efficacy in vivo as a single agent in two diffuse large B cell lymphoma models. Gene expression profiling showed BAY 1238097 targeted the NFKB/TLR/JAK/STAT signalling pathways, MYC and E2F1‐regulated genes, cell cycle regulation and chromatin structure. The gene expression profiling signatures also highly overlapped with the signatures obtained with other BET Bromodomain inhibitors and partially overlapped with HDAC‐inhibitors, mTOR inhibitors and demethylating agents. Notably, BAY 1238097 presented in vitro synergism with EZH2, mTOR and BTK inhibitors. In conclusion, the BET inhibitor BAY 1238097 presented promising anti‐lymphoma preclinical activity in vitro and in vivo, mediated by the interference with biological processes driving the lymphoma cells. Our data also indicate the use of combination schemes targeting EZH2, mTOR and BTK alongside BET bromodomains.     

Germline mutations in Protection of Telomeres 1 in two families with Hodgkin lymphoma

In a previous whole exome sequencing of patients from 41 families with Hodgkin lymphoma, we identified two families with distinct heterozygous rare coding variants in POT1 (D224N and Y36H), both in a highly conserved region of the gene. POT1 D224N mutant did not bind to a single‐stranded telomere oligonucleotide in vitro suggesting the mutation perturbs POT1's ability to bind to the telomeric G‐rich overhang. Human HT1080 cells expressing POT1 D224N and lymphoblastoid cells carrying Y36H both showed increased telomere length and fragility in comparison to wild type cells. This strongly suggests that mutant POT1 causes chromosome instability and may play a role in lymphomagenesis in these families.     

A single institution experience on 314 newly diagnosed advanced Hodgkin lymphoma patients: the role of ABVD in daily practice

Based on the results of clinical trials, there is no global consensus on the optimal first‐line therapy for patients with advanced Hodgkin lymphoma (HL) with both ABVD and BEACOPP currently being used. However, the results of clinical trials are usually better than those in daily practice. We thus describe here our experience on 314 advanced classical HL patients treated with ABVD at the Clinical Center of Serbia and associated centers between 1997 and 2008. The median follow‐up for all patients was 91 months; the estimated 5‐yr event‐free survival was 62% and the 5‐yr overall survival (OS) 76%. Multivariate Cox regression analysis revealed that patients with IPS ≥ 3 and extranodal disease involving more than one site have a poorer outcome. The data presented here show on overall improvement in outcome as compared to more previous data and illustrate the problems of treating advanced stage HL outside the setting of a clinical trial.     

A national study on conditional survival,excess mortality and second cancer after high dose therapy with autologous stem cell transplantation for non‐Hodgkin lymphoma

This national population‐based study aimed to investigate conditional survival and standardized mortality ratios (SMR) after high‐dose therapy with autologous stem‐cell transplantation (HDT‐ASCT) for non‐Hodgkin lymphoma (NHL), and to analyse cause of death, relapses and second malignancies. All patients ≥18 years treated with HDT‐ASCT for NHL in Norway between 1987 and 2008 were included (n = 578). Information from the Cause of Death Registry and Cancer Registry of Norway were linked with clinical data. The 5‐, 10‐ and 20‐year overall survival was 61% (95% confidence interval [CI] 56–64%), 52% (95%CI 48–56%) and 45% (95%CI 40–50%), respectively. The 5‐year survival conditional on having survived 2, 5 and 10 years after HDT‐ASCT was 81%, 86% and 93%. SMRs were 12·3 (95%CI 11·0–13·9), 4·9 (95%CI 4·1–5·9), 2·4 (95%CI 1·8–3·2) and 1·0 (95%CI 0·6–1·8) for the entire cohort and for patients having survived 2, 5 and 10 years after HDT‐ASCT respectively. Of the 281 deaths observed, 77% were relapse‐related. Treatment‐related mortality was 3·6%. The 10‐year cumulative incidence of second malignancies was 7·9% and standardized incidence ratio was 2·0 (95%CI 1·5–2·6). NHL patients treated with HDT‐ASCT were at increased risk of second cancer and premature death. The mortality was still elevated at 5 years, but after 10 years mortality equalled that of the general population.     

Common variants within 6p21.31 locus are associated with chronic lymphocytic leukaemia and,potentially, other non‐Hodgkin lymphoma subtypes

A recent meta‐analysis of three genome‐wide association studies of chronic lymphocytic leukaemia (CLL) identified two common variants at the 6p21.31 locus that are associated with CLL risk. To verify and further explore the association of these variants with other non‐Hodgkin lymphoma (NHL) subtypes, we genotyped 1196 CLL cases, 1699 NHL cases, and 2410 controls. We found significant associations between the 6p21.31 variants and CLL risk (rs210134: P = 0·01; rs210142: P = 6·8 × 10^?3). These variants also showed a trend towards association with some of the other NHL subtypes. Our results validate the prior work and support specific genetic pathways for risk among NHL subtypes.