Primary mediastinal large B-cell lymphoma

Prognostic factors and clinical survival outcome in patients with primary mediastinal diffuse large B-cell lymphoma in rituximab era: A population-based study

The goal of this study was to investigate the clinical characteristics, prognostic variables, and survival of patients with primary mediastinal diffuse large B cell lymphoma (PMBCL) in the rituximab era. The Surveillance, Epidemiology, and End Results (SEER) database was used to identify PMBCL patients diagnosed between 2000 and 2019. The Kaplan-Meier (K-M) technique and log-rank test were used to assess overall survival (OS) and disease-specific survival (DSS). The independent prognostic variables for OS and DSS were identified using univariate and multivariate Cox regression analysis. Nomograms were created to predict survival prospects according to identified prognostic indicators. Totally, 841 patients were enrolled with PMBCL. One-year, 5-year, and 10-year OS rates were 93.99%, 85.04%, and 81.76%, and the corresponding DSS rates were 95.27%, 87.37%, and 85.98%. The results of multivariate Cox regression analysis demonstrated that age, years of diagnosis, Ann arbor staging, and chemotherapy were independent prognostic factors for survival. Nomograms designed exclusively for PMBCL were created to forecast the likelihood of 1-year, 5-year, and 10-year OS and DSS, respectively. The Harrell concordance index (C-index) for the nomograms predictions of OS and DSS were 0.704 and 0.733, respectively, which showed the established model harboring powerful and accurate performance. The present study revealed that incidence of PMBCL has been consistently rising over the last 20 years. Simultaneously, survival rates have improved tremendously. Rituximab based immunochemotherapy has emerged as an effective treatment option, leading to enhanced OS and DSS outcomes. Furthermore, the nomograms specifically developed for PMBCL have demonstrated robustness and accuracy in forecasting OS and DSS rates at 1, 5, and 10 years. These predictive tools can be valuable for clinicians in accurately estimating prognosis and establishing personalized treatment plans and follow-up protocols.

A case of suspected primary mediastinal large B-cell lymphoma: An uncommon cause of sudden death

Primary mediastinal large B-cell lymphoma (PMLBCL) is an aggressive tumor originating from thymic B-cells. Clinically, it presents with general signs such as cough, chest pain and dyspnea. Although these symptoms are not specific, they are severe enough to reveal the disease. We report an autopsy case of a 25-year-old man, with a recent past history of cough and dyspnea, for which he consulted twice the emergency department and no diagnosis was made. He presented to the Emergency Unit, with a sudden onset of a dyspnea followed by a loss of consciousness. He was shortly declared dead after, a medico-legal autopsy was requested. On external examination, no traumatic lesions on the body were found, an important cyanosis of the face and ears, was, however, found. On autopsy, a mediastinal mass was found, measuring 19 cm × 25 cm and weighing 600 g, extending to the infra-hyoid region and to the thoracic cage and infiltrating the pericardium. Trachea had a necrotic mucosa with a partially obstructive lymph node mass. The diagnosis of a primary mediastinal large B-cell lymphoma was suspected based on pathological and immunohistochemical findings. The cause of death was finally attributed to respiratory failure due to this tumor.

Flow cytometric immunophenotyping in a liquid-based cytology sample of pleural fluid: Connecting the dots

Primary mediastinal large B-cell lymphoma (PMBCL) is an uncommon non-Hodgkin lymphoma that is rarely described in cytology samples. The present study highlights the importance of flowcytometric immunophenotyping and immunocytochemistry in an effusion sample of an uncommon case of PMBCL.

Expecting the unexpected - Primary mediastinal large B cell lymphoma presenting as huge lung parenchymal mass

The first possibility considered in the etiology of large lung masses is neoplastic lesions. The differential diagnoses of these masses include bronchogenic carcinoma, pulmonary sarcoma, primitive neuroectodermal tumor etc. Primary or secondary pulmonary parenchymal lymphomas presenting as large mass is distinctly rare. We share the case of a young lady who presented with a large left lung mass almost entirely replacing the left lung parenchyma, with associated intrathoracic lymphadenopathy. On evaluation she was proved to have primary mediastinal large B-cell lymphoma. Treatment with an aggressive chemotherapy regimen led to complete remission of the parenchymal and nodal disease. The uncommon radiological presentation and the excellent therapeutic response despite huge tumor load merit clinical attention.

Primary Mediastinal Large B-Cell Lymphoma: A Review for Radiologists

OBJECTIVE. The purpose of this article is to provide a primer for radiologists focused on integrating the radiologic, pathologic, and clinical features of primary mediastinal large B-cell lymphoma (PMLBCL). CONCLUSION. PMLBCL is a unique subtype of lymphoma that poses diagnostic and therapeutic challenges to the fields of radiology and oncology. Knowledge of this distinctive clinical-pathologic entity and its associated imaging and clinical features is critical for radiologists.

Primary Extranodal Lymphoma of the Thorax

Primary pulmonary lymphomas represent a pathologically heterogeneous group of disorders that often share imaging features, which include peribronchovascular nodules and masses or areas of nonresolving consolidation. Primary mediastinal B-cell lymphoma is an extranodal non-Hodgkin lymphoma seen in younger patients that has imaging and pathologic features that demonstrate some degree of overlap with Hodgkin lymphoma. Primary lymphomas of the pleural space are rare and associated with concomitant viral infections.

Primary mediastinal B-cell lymphoma - metabolic and anatomical features in 18FDG-PET/CT and response to therapy

Aim of the study

Determining the role of PET/CT imaging in the evaluation of treatment efficacy in primary mediastinal B-cell lymphoma (PMBCL).

Material and methods

Retrospective analysis of seven PMBCL patients, treated at the University Hospital in Krakow, with interim PET/CT after the third course of chemo-immunotherapy.The analysis was based on the calculation of exact tumour volume and metabolic activity, compared with initial values (directly after diagnosis).

Results

Patients (five females, two males, average age 26.2 years, range 18–40 years), in clinical stage IIBX at diagnosis, were treated with eight cycles of R-CHOP-14 regimen, with radiotherapy consolidation (7/7) and central nervous system prophylaxis (6/7). The observed decrease in tumour volume between the initial staging and the interim PET ranged 72–89%. The mean ΔSUV_max reduction between initial (when available) and interim PET was 87% (range 84–89%). In 3/7 cases in the interim PET/CT, the uptake of the tumour was higher than the liver (Deauville Criteria score 4–5), and in 4/7 it was lower than the liver but higher than mediastinal blood pool structures (score 3 according to Deauville Criteria). After a median follow-up of 58 months – OS and EFS is 100%.

Conclusions

The excellent clinical outcome in the study group corresponds with very good metabolic and volumetric response in the interim PET. The ΔSUV_max seems to be easier in implementation and has a more significant impact than other measurements.

Interobserver variability in clinical target volume delineation for primary mediastinal B-cell lymphoma

PURPOSE

The purpose of this study was to evaluate interobserver variability among radiation oncologists with experience in the field of lymphoma radiation therapy in the delineation of clinical target volume (CTV) in a challenging case of primary mediastinal B-cell lymphoma.

METHODS AND MATERIALS

Ten experienced radiation oncologists were invited to a 1-day contouring session. The case of a 56-year-old man with primary mediastinal B-cell lymphoma with complete metabolic response after chemotherapy was chosen as the sample for the study. A brief presentation of his clinical history was given, together with guidelines for contouring. The 10 CTVs obtained were then compared in terms of variation in total volume and in craniocaudal, laterolateral, and anteroposterior diameters. The CTV with the best Dice similarity coefficient (DSC) between the union of all 10 CTVs and the individual CTV was considered the reference CTV, and the DSC and the Hausdorff distance (HD) for each volume compared with the reference CTV were then calculated.

RESULTS

A significant variability was found in total volume (mean, 498.3 cm(3); range, 181.8-1003 cm(3)) and craniocaudal (median, 144.7 mm; range, 80.6-159 mm), laterolateral (median, 133.5 mm; range, 83.7-149.5 mm), and anteroposterior diameters (median, 136.2 mm; range, 84-150.5 mm). Analysis of the DSC and the HD showed a mean DSC of 0.53 (range, 0.31-0.74) and a mean HD of 6.4 cm (range, 1.8-14.8 cm).

CONCLUSIONS

Results of this study strongly indicate the need to develop and share appropriate contouring guidelines among experts and suggest the promotion of specific educational activities to improve radiation therapy quality in both clinical trials and routine clinical practice.

Bowel perforation from occult ileal involvement after diagnosis in a case of primary mediastinal large B-cell lymphoma

Primary mediastinal large B-cell lymphoma (PMBCL) is confined to the mediastinum or contiguous nodal areas in most cases. Extramediastinal and abdominal involvement, especially at diagnosis, is extremely rare. Our case describes the first case of histologically proven ileal involvement of PMBCL at diagnosis that led to ileal perforation. Positron emission tomography CT could increase the sensitivity of staging by detecting unusual sites of disease localisation, and could impact clinical management.

Recent Advances in Aggressive Large B-cell Lymphomas: A Comprehensive Review

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease with considerable heterogeneity reflected in the 2008 World Health Organization classification. In recent years, genome-wide assessment of genetic and epigenetic alterations has shed light upon distinct molecular subsets linked to dysregulation of specific genes or pathways. Besides fostering our knowledge regarding the molecular complexity of DLBCL types, these studies have unraveled previously unappreciated genetic lesions, which may be exploited for prognostic and therapeutic purposes. Following the last World Health Organization classification, we have witnessed the emergence of new variants of specific DLBCL entities, such as CD30 DLBCL, human immunodeficiency virus-related and age-related variants of plasmablastic lymphoma, and EBV DLBCL arising in young patients. In this review, we will present an update on the clinical, pathologic, and molecular features of DLBCL incorporating recently gained information with respect to their pathobiology and prognosis. We will emphasize the distinctive features of newly described or emerging variants and highlight advances in our understanding of entities presenting a diagnostic challenge, such as T-cell/histiocyte-rich large B-cell lmphoma and unclassifiable large B-cell lymphomas. Furthermore, we will discuss recent advances in the genomic characterization of DLBCL, as they may relate to prognostication and tailored therapeutic intervention. The information presented in this review derives from English language publications appearing in PubMed throughout December 2015. For a complete outline of this paper, please visit: http://links.lww.com/PAP/A12.

Primary Mediastinal Large B-Cell Lymphoma With Translocations Involving BCL6 and MYC (Double-Hit Lymphoma)

OBJECTIVES

Primary mediastinal large B-cell lymphomas (PMLBCLs) are aggressive lymphomas with characteristic clinical, morphologic, and immunophenotypic features. "Double-hit" (DH) lymphomas are B-cell neoplasms characterized by a translocation involving MYC and either BCL2 or BCL6 In the indexed literature, there are no reported cases of PMLBCL associated with DH or triple-hit events.

METHODS

Herein, we present a case of a 15-year-old girl with PMLBCL who had typical clinical, morphologic, and immunophenotypic features.

RESULTS

Fluorescent in situ hybridization studies showed rearrangements involving MYC and BCL6 We also excluded the possibility of a reciprocal t(3;8) (3q27;8q24) BCL6/MYC translocation.

CONCLUSIONS

This case expands the current spectrum of lymphomas subtypes in which DH can be found and supports the rationale for cytogenetic testing for DH abnormalities in all cases of aggressive large B-cell lymphomas regardless of subtype.

Favorable outcome of primary mediastinal large B-cell lymphoma patients treated with sequential RCHOP-RICE regimen without radiotherapy

PURPOSE

Outcomes in primary mediastinal B cell lymphoma (PMBL) improved with the introduction of dose intense treatments, consolidation radiotherapy and rituximab. DA-EPOCH-R, which omits radiotherapy has been adopted with worldwide enthusiasm, despite lack of proven superiority in randomized trials. We aimed to evaluate the course and outcome of PMBL using an alternative intensive rituximab-containing regimen, RCHOP-RICE. We also evaluated the prognostic value of (18)FDG-PET-CT (PET-CT).

METHODS

We reviewed the clinical, laboratory and imaging data of PMBL patients receiving 1st-line treatment in Hadassah Medical Center between 8/2002 and 10/2014.

RESULTS

Of 47 PMBL patients, 24 (51 %) were treated with RCHOP-RICE and 23 (49 %) with other protocols. Overall, the 5-year progression-free survival was 93 % and the overall survival was 98 % (87 and 100 %, respectively, for the RCHOP-RICE regimen). Patient characteristics and treatment toxicities were balanced among protocols. A mean of 11.1 ± 1.3 hospitalization days/patient were needed to administer RCHOP-RICE regimen compared to 37 ± 2 days/patient for DA-EPOCH-R (n = 2). Radiotherapy was given to 3 patients (12 %) treated with RCHOP-RICE compared to 18 patients (78 %) treated with other protocols (p < 0.01). For patients followed with interim and end of treatment (EOT) PET-CT, we observed a significant reduction in the uptake between the two (p < 0.0001). Using a Deauville score cutoff of 3, the negative and positive predictive values (NPV and PPV) of EOT PET-CT were 94 and 33 %, respectively.

CONCLUSIONS

The RCHOP-RICE protocol results in excellent survival outcomes, generally permits omission of RT and is simpler to administer than DA-EPOCH-R. Interim PET-CT in PMBL may be unjustified; however, EOT Deauville scores ≤3 predicts a favorable outcome.

Primary Mediastinal Large B-cell Lymphoma Exhibiting Endobronchial Involvement

Primary mediastinal large B-cell lymphoma (PMLBCL) is one of the subtypes of diffuse large B-cell lymphoma. We experienced a rare case of PMLBCL that exhibited endobronchial involvement. A 33-year-old Japanese female with the chief complaints of epigastralgia, back pain, and nausea visited a primary care hospital. Computed tomography of the chest and abdomen demonstrated a bulky mass in the left anterior mediastinum, multiple pulmonary nodules, axillary lymph node swelling, and a pancreatic tumor. Fiberoptic bronchoscopy showed a white-tinged irregularly shaped endobronchial tumor accompanied by capillary vessel dilation in the left upper lobar bronchus. Taken together, these findings resulted in a diagnosis of PMLBCL.

Novel drug targets for personalized precision medicine in relapsed/refractory diffuse large B-cell lymphoma: a comprehensive review

Diffuse large B-cell lymphoma (DLBCL) is a clinically heterogeneous lymphoid malignancy and the most common subtype of non-Hodgkin's lymphoma in adults, with one of the highest mortality rates in most developed areas of the world. More than half of DLBLC patients can be cured with standard R-CHOP regimens, however approximately 30 to 40 % of patients will develop relapsed/refractory disease that remains a major cause of morbidity and mortality due to the limited therapeutic options.Recent advances in gene expression profiling have led to the identification of at least three distinct molecular subtypes of DLBCL: a germinal center B cell-like subtype, an activated B cell-like subtype, and a primary mediastinal B-cell lymphoma subtype. Moreover, recent findings have not only increased our understanding of the molecular basis of chemotherapy resistance but have also helped identify molecular subsets of DLBCL and rational targets for drug interventions that may allow for subtype/subset-specific molecularly targeted precision medicine and personalized combinations to both prevent and treat relapsed/refractory DLBCL. Novel agents such as lenalidomide, ibrutinib, bortezomib, CC-122, epratuzumab or pidilizumab used as single-agent or in combination with (rituximab-based) chemotherapy have already demonstrated promising activity in patients with relapsed/refractory DLBCL. Several novel potential drug targets have been recently identified such as the BET bromodomain protein (BRD)-4, phosphoribosyl-pyrophosphate synthetase (PRPS)-2, macrodomain-containing mono-ADP-ribosyltransferase (ARTD)-9 (also known as PARP9), deltex-3-like E3 ubiquitin ligase (DTX3L) (also known as BBAP), NF-kappaB inducing kinase (NIK) and transforming growth factor beta receptor (TGFβR).This review highlights the new insights into the molecular basis of relapsed/refractory DLBCL and summarizes the most promising drug targets and experimental treatments for relapsed/refractory DLBCL, including the use of novel agents such as lenalidomide, ibrutinib, bortezomib, pidilizumab, epratuzumab, brentuximab-vedotin or CAR T cells, dual inhibitors, as well as mechanism-based combinatorial experimental therapies. We also provide a comprehensive and updated list of current drugs, drug targets and preclinical and clinical experimental studies in DLBCL. A special focus is given on STAT1, ARTD9, DTX3L and ARTD8 (also known as PARP14) as novel potential drug targets in distinct molecular subsets of DLBCL.

The mRNA-binding protein HuR promotes hypoxia-induced chemoresistance through posttranscriptional regulation of the proto-oncogene PIM1 in pancreatic cancer cells

Previously, it has been shown that pancreatic ductal adenocarcinoma (PDA) tumors exhibit high levels of hypoxia, characterized by low oxygen pressure (pO2) and decreased O2 intracellular perfusion. Chronic hypoxia is strongly associated with resistance to cytotoxic chemotherapy and chemoradiation in an understudied phenomenon known as hypoxia-induced chemoresistance. The hypoxia-inducible, pro-oncogenic, serine-threonine kinase PIM1 (Proviral Integration site for Moloney murine leukemia virus 1) has emerged as a key regulator of hypoxia-induced chemoresistance in PDA and other cancers. Although its role in therapeutic resistance has been described previously, the molecular mechanism behind PIM1 overexpression in PDA is unknown. Here, we demonstrate that cis-acting AU-rich elements (ARE) present within a 38-base pair region of the PIM1 mRNA 3'-untranslated region mediate a regulatory interaction with the mRNA stability factor HuR (Hu antigen R) in the context of tumor hypoxia. Predominantly expressed in the nucleus in PDA cells, HuR translocates to the cytoplasm in response to hypoxic stress and stabilizes the PIM1 mRNA transcript, resulting in PIM1 protein overexpression. A reverse-phase protein array revealed that HuR-mediated regulation of PIM1 protects cells from hypoxic stress through phosphorylation and inactivation of the apoptotic effector BAD and activation of MEK1/2. Importantly, pharmacological inhibition of HuR by MS-444 inhibits HuR homodimerization and its cytoplasmic translocation, abrogates hypoxia-induced PIM1 overexpression and markedly enhances PDA cell sensitivity to oxaliplatin and 5-fluorouracil under physiologic low oxygen conditions. Taken together, these results support the notion that HuR has prosurvival properties in PDA cells by enabling them with growth advantages in stressful tumor microenvironment niches. Accordingly, these studies provide evidence that therapeutic disruption of HuR's regulation of PIM1 may be a key strategy in breaking an elusive chemotherapeutic resistance mechanism acquired by PDA cells that reside in hypoxic PDA microenvironments.

Malignant effusions correlate with poorer prognosis in patients with diffuse large B-cell lymphoma

OBJECTIVES

Serous effusions are a common manifestation of diffuse large B-cell lymphoma (DLBCL). However, their prognostic significance is controversial.

METHODS

We searched for consecutive patients who had DLBCL with effusions from 1999 through 2007. Primary effusion lymphoma was excluded. The presence of tumor cells in effusions (malignant effusions) was determined by cytology supplemented by flow cytometry, cell blocks with special studies, polymerase chain reaction for clonality, or conventional cytogenetics.

RESULTS

Forty-one (18.4%) patients had effusions, with 24 (58.5%) developing at diagnosis and 17 (41.5%) during tumor course. Nineteen patients (46.0%) had malignant effusions, with six (31.6%) from local extension and 13 (68.4%) through wide dissemination. Interestingly, malignant effusion correlated with a high International Prognostic Index (IPI) score (r = 0.490, P = .002) and high tumor stage (r = 0.342, P = .031) and was a poor prognosticator (P < .001, log-rank test), even worse than stage IV disease (P = .036). In the multivariate analysis, malignant effusion (P = .056) and supportive care (P = .014) retained significance and were more powerful than IPI score and stage.

CONCLUSIONS

Patients who have DLBCL with lymphomatous effusions have a poor prognosis and should be treated as having stage IV disease. The analysis of effusions for tumor cells would be a useful addition to the routine workup.

Malignant hematopoietic cell lines: in vitro models for the study of primary mediastinal B-cell lymphomas

Primary mediastinal B-cell lymphoma (PMBL) is a highly aggressive disease with a unique set of biological, clinical, morphological, immunological and in particular genetic features that in the molecular era of defining lymphomas clearly distinguishes it as a separate entity from other diffuse large B-cell lymphomas (DLBCL). A precise molecular diagnosis of PMBL can be achieved by gene expression profiling. The signature gene expression profile of PMBL is more closely related to classic Hodgkin lymphoma (cHL) than to other DLBCL subgroups. A number of common genetic aberrations in PMBL and cHL further underscore their close relationship. To investigate the pathobiology of lymphomas in depth, many groups have turned to cell lines that are suitable models facilitating molecular studies and providing unique insights. For the purposes of the current perspective, we focus on four bona fide PMBL-derived cell lines (FARAGE, KARPAS-1106, MEDB-1, U-2940) that we identified and validated as such through hierarchical cluster analysis among a large collection of leukemia-lymphoma cell lines. These gene expression profiles showed that the four PMBL cell lines represent a distinct entity and are most similar to cHL cell lines, confirming derivation from a related cell type. A validated cell line resource for PMBL should assist those seeking druggable targets in this entity. This review aims to provide a comprehensive overview of the currently available cellular models for the study of PMBL.

Primary mediastinal large B-cell lymphoma

Primary mediastinal B-cell lymphoma (PMBCL) is a relatively rare lymphoma subtype affecting mainly young adults. Its molecular signature and clinical features resemble classical Hodgkin lymphoma. The optimal chemotherapy for this lymphoma subtype has not been established. The addition of rituximab to anthracycline based chemotherapy improved response rates and survival. Many centers use R-CHOP as standard treatment, but the role of the intensified regimens and consolidation radiotherapy has to be clarified. Recent data coming from retrospective analyses and an ongoing prospective study addressing the problem of consolidation radiotherapy will help to better identify risk groups and apply risk-adapted and effective treatment strategies. The latest research has helped to understand molecular mechanisms of PMBCL pathogenesis and indicated targets of directed therapy for the future.

Hodgkin lymphoma: pathology, pathogenesis, and a plethora of potential prognostic predictors

Hodgkin lymphoma (HL) encompasses 2 unique clinicopathologic entities, classical Hodgkin lymphoma (CHL) (∼95% of cases) and nodular lymphocyte predominant HL (∼5% of cases). Both subtypes demonstrate a paucity of surreptitious (in CHL) neoplastic B cells within a background of reactive inflammatory cells underscoring both the relatedness of these 2 entities to each other, as well as their distinction from other types of lymphoid neoplasia. Clinically, they are primarily nodal diseases that disseminate in a predictable manner to contiguous nodal regions. The biology of HL as a whole, as well as the genetic and pathologic features that distinguish CHL from nodular lymphocyte predominant HL and other lymphomas has been the subject of a wealth of investigation in recent decades. The aim of this review is to detail the pathologic features of HL and to highlight the recent insights into its molecular basis and the myriad prognostic markers being described.

Heart of lymphoma: primary mediastinal large B-cell lymphoma with endomyocardial involvement

Primary mediastinal B-cell lymphoma (PMBCL) is an uncommon aggressive subset of diffuse large B-cell lymphomas. Although PMBCL frequently spreads locally from the thymus into the pleura or pericardium, it rarely invades directly through the heart. Herein, we report a case of a young Mexican female diagnosed with PMBCL with clear infiltration of lymphoma through the cardiac wall and into the right atrium and tricuspid valve leading to tricuspid regurgitation. This was demonstrated by cardiac MRI and transthoracic echocardiogram. In addition, cardiac MRI and CT scan of the chest revealed the large mediastinal mass completely surrounding and eroding into the superior vena cava (SVC) wall causing a collar of stokes. The cardiac and SVC infiltration created a significant therapeutic challenge as lymphomas are very responsive to chemotherapy, and treatment could potentially lead to vascular wall rupture and hemorrhage. Despite the lack of conclusive data on chemotherapy-induced hemodynamic compromise in such scenarios, her progressive severe SVC syndrome and respiratory distress necessitated urgent intervention. In addition to the unique presentation of this rare lymphoma, our case report highlights the safety of R-CHOP treatment.

Radiation therapy in primary mediastinal B-cell lymphoma with positron emission tomography positivity after rituximab chemotherapy

PURPOSE

To investigate the role of radiation therapy (RT) in patients affected with primary mediastinal B-cell lymphoma (PMBCL) with residual (18)fluorodeoxyglucose positron emission tomography ((18)FDG-PET)-positive disease after rituximab chemotherapy (R-CT).

METHODS AND MATERIALS

Thirty-seven patients treated with R-CT and RT, all with (18)FDG-PET scan at diagnosis and before RT, were included. All (18)FDG-PET scans were reviewed, and responses were classified according to the Deauville 5-point scoring system. Outcomes measures were overall survival (OS) and progression-free survival (PFS), estimated for the whole cohort and for subgroups according to (18)FDG-PET score after R-CT.

RESULTS

The median follow-up time was 40.9 months. Three patients were assigned to Deauville score 1 (8.1%), 9 to score 2 (24.3%), 7 to score 3 (19%), 14 to score 4 (37.8%), and 4 to score 5 (10.8%). After RT, all patients with score 3-4 experienced a complete response (CR). Among patients with score 5, 1 was in CR (25%), 2 had persistent positivity (50%), and 1 showed progressive disease (25%). A total of 4 patients experienced progression or relapse: 1 of 33 (3%) with scores 1-4, and 3 of 4 (75%) with score 5. The 3-year OS and PFS of the whole cohort were 89.8% and 88.7%, respectively. OS was significantly different between scores 1-3 and scores 4-5 (100% vs 77% at 3 years, P<.05). Patients with a score of 5 had a significantly worse outcome than did all other patients (OS at 2 years, 33.3% vs 100%).

CONCLUSIONS

Approximately 50% of PMBCL patients show residual disease at (18)FDG-PET scan after R-CT. RT is able to convert to CR approximately 85% of these patients, but those with a Deauville score of 5 (10%) appear at high risk of progression and death, and they might be candidates for intensified programs.

Diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy in adults accounting for 31% of all NHL in Western Countries. Following, morphological, biological and clinical studies have allowed the subdivision of DLBCLs into morphological variants, molecular and immunophenotypic subgroups and distinct disease entities. However, a large number of cases still remain biologically and clinically heterogeneous, for which there are no clear and accepted criteria for subclassification; these are collectively termed DLBCL, not otherwise specified (NOS). DLBCL-NOS occurs in adult patients, with a median age in the seventh decade, but the age range is broad, and it may also occur in children. Clinical presentation, behaviour and prognosis are variable, depending mainly of the extranodal site when they arise. These malignancies present in localized manner in approximately 20% of patients. Disseminated extranodal disease is less frequent, and one third of patients have systemic symptoms. Overall, DLBCLs are aggressive but potentially curable malignancies. Cure rate is particularly high in patients with limited disease with a 5-year PFS ranging from 80% to 85%; patients with advanced disease have a 5-year PFS ≈ 50%. The International Prognostic Index (IPI) and age adjusted IPI (aaIPI) are the benchmarks of DLBCL prognosis. First-line treatment for patients with DLBCL is based on the individual IPI score and age, and three major subgroups should be considered: elderly patients (>60 years, aaIPI=0-3); young patients with low risk (<60 years, aaIPI=0-1); young patients with high risk (<60 years, aaIPI=2-3). The combination of the anti-CD20 monoclonal antibody rituximab and CHOP chemotherapy, every 14 or 21 days, is the standard treatment for DLBCL patients. Recent randomized trials suggest that high-dose chemotherapy supported by autologous stem cell transplant (HDC/ASCT) should not be used as upfront treatment for young high-risk patients outside prospective clinical trials. HDC/ASCT is actually recommended in young patients who did not achieve CR after first-line chemotherapy. Consolidation radiotherapy should be reserved to patients with bulky disease who did not achieve CR after immunochemotherapy. Patients with high IPI score, which indicates increased LDH serum level and the involvement of more than one extranodal site, and patients with involvement of certain extranodal sites (a.e., testes and orbit) should receive CNS prophylaxis as part of first-line treatment. HDC/ASCT should be considered the standard therapy for DLBCL patients with chemotherapy-sensitive relapse. Overall results in patients who cannot be managed with HDC/ASCT due to age or comorbidity are disappointing. New effective and less toxic chemotherapy drugs or biological agents are also worth considering for this specific and broad group of patients. Several novel agents are undergoing evaluation in DLBCL; among other, immunomodulating agents (lenalidomide), m-TOR inhibitors (temsirolimus and everolimus), proteasome inhibitors (bortezomib), histone deacetylase inhibitors (vorinostat), and anti-angiogenetic agents (bevacizumab) are being investigated in prospective trials.

Randomized clinical trial to assess the efficacy of radiotherapy in primary mediastinal large B-lymphoma

PURPOSE

We developed a controlled clinical trial to assess the efficacy and toxicity of adjuvant-involved field radiotherapy (IFRT) in patients with primary mediastinal B-cell lymphoma that achieved complete response after the patients were treated with cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (R-CHOP-14).

METHODS AND MATERIALS

Between January 2001 and June 2004, 124 consecutive patients who were in complete remission after dose dense chemotherapy and rituximab administration (R-CHOP14) were randomly assigned to received IFRT (30 Gy). Sixty-three patients received IFR, and 61 patients did not (control group).

RESULTS

The study aimed to include 182 patients in each arm but was closed prematurely because in a security analysis (June 2004), progression and early relapse were more frequent in patients that did not received IFRT. Patients were followed until March 2009, at which point actuarial curves at 10 years showed that progression free-survival was 72% in patients who received IFR and 20% in the control group (p < 0.001), overall survival was 72% and 31%, respectively (p < 0.001). Acute toxicity was mild and well tolerated.

DISCUSSION

Adjuvant radiotherapy to sites of bulky disease was the only difference to have an improvement in outcome in our patients; the use of rituximab during induction did not improve complete response rates and did affect overall survival; patients who received rituximab but not IFRT had a worse prognosis.

CONCLUSIONS

The use of IFRT in patients with primary mediastinal B-cell lymphoma who achieved complete response remain as the best treatment available, even in patients that received rituximab during induction.

Aberrant expression of the dendritic cell marker TNFAIP2 by the malignant cells of Hodgkin lymphoma and primary mediastinal large B-cell lymphoma distinguishes these tumor types from morphologically and phenotypically similar lymphomas

Tumor necrosis factor-α-inducible protein-2 (TNFAIP2) is a protein upregulated in cultured cells treated with tumor necrosis factor α (TNF), but its expression in normal and neoplastic tissues remains largely unknown. Here, we use standard immunohistochemical techniques to demonstrate that TNFAIP2 is normally expressed by follicular dendritic cells, interdigitating dendritic cells, and macrophages but not by lymphoid cells in secondary lymphoid tissues. Consistent with this expression pattern, we found strong TNFAIP2 staining of tumor cells in 4 of 4 cases (100%) of follicular dendritic cell sarcoma and in 3 of 3 cases (100%) of histiocytic sarcoma. Although TNFAIP2 is not expressed by the small and intermediate-sized neoplastic B cells comprising follicular lymphoma, small lymphocytic lymphoma, mantle cell lymphoma, or marginal zone lymphoma, we observed strong TNFAIP2 staining of the large, neoplastic cells in 31 of 31 cases (100%) of classical Hodgkin lymphoma, in 12 of 12 cases (100%) of nodular lymphocyte-predominant Hodgkin lymphoma, and in 27 of 31 cases (87%) of primary mediastinal (thymic) large B-cell lymphoma. In contrast, TNFAIP2 was expressed by malignant cells in only 2 of 45 cases (4%) of diffuse large B-cell lymphoma, not otherwise specified, in 2 of 18 cases (11%) of Burkitt lymphoma, and in 1 of 19 cases (5%) of anaplastic large cell lymphoma. Further analysis indicates that TNFAIP2, as a single diagnostic marker, is more sensitive (sensitivity=87%) and specific (specificity=96%) than TRAF1, nuclear cRel, or CD23 for distinguishing the malignant B cells of primary mediastinal (thymic) large B-cell lymphoma from those of its morphologic and immunophenotypic mimic, diffuse large B-cell lymphoma, not otherwise specified. Thus, TNFAIP2 may serve as a useful new marker of dendritic and histiocytic sarcomas, the aberrant expression of which in the malignant cells of classical Hodgkin lymphoma and primary mediastinal (thymic) large B-cell lymphoma serves to distinguish these tumors from other large cell lymphomas in routine clinical practice.

Primary mediastinal (thymic) large B-cell lymphoma: a short review with brief discussion of mediastinal gray zone lymphoma

Primary mediastinal (thymic) large B-cell lymphoma (PMBCL) is a subtype of diffuse large B-cell lymphoma (DLBCL). It commonly presents as a bulky lesion in the anterior-superior mediastinum with symptoms related to local invasion or compression. Microscopic examination typically shows infiltration of medium-large cells surrounded by collagen fibrosis. The neoplastic cells express B-cell markers, and CD30 often shows heterogeneous staining. Comparative genomic hybridization has identified gains in loci of 9p24 and 2p15 as well as Xp11.4-21 and Xq24-26. Amplification of REL and BCL11A at 2p as well as elevated expression of JAK2, PDL1, and PDL2 at 9p has been demonstrated. Nodular sclerosis classic Hodgkin lymphoma needs to be differentiated from PMBCL and cases with overlapped features have been described as mediastinal gray zone lymphoma. Primary mediastinal (thymic) large B-cell lymphoma carries a favorable prognosis in comparison to conventional DLBCL.

Autologous transplant for primary mediastinal B-cell lymphoma

Primary mediastinal large B-cell lymphoma (PMBCL) is a subtype of lymphoma that shares similarities with diffuse large B-cell lymphoma and with classic Hodgkin's lymphoma. The current study evaluates the use of autologous stem cell transplant (ASCT) as part of initial therapy in a cohort of patients with PMBCL treated between 1985 and 2006. The study demonstrates excellent survival and progression-free survival for patients in complete remission (CR) at ASCT, and for those achieving CR after ASCT. It also shows a benefit to administration of involved-field radiation therapy. However, front-line therapy has evolved considerably since these patients were treated. Dose-dense chemotherapy regimens show excellent results without transplant and the incorporation of rituximab in the treatment may have further improved outcomes. Given these excellent results, ASCT should not currently be used in patients in first CR, but ASCT remains the treatment of choice in relapsed and refractory PMBCL. Similarly, radiotherapy is unnecessary in patients in first CR but is probably useful in patients with residual active mass.

Pim-1 kinase inhibits pathological injury by promoting cardioprotective signaling

Stem cells mediate tissue repair throughout the lifespan of an organism. However, the ability of stem cells to mitigate catastrophic damage, such as that sustained after major myocardial infarction is inadequate to rebuild the heart and restore functional capacity. However, capitalizing on the ability of these cells to attenuate damage in the myocardium, various maneuvers that enhance repair mechanisms to improve cardiac structure and function after injury are being investigated. These studies have led to discovery of various factors that mediate cardioprotection and enhance endogenous repair by 1) salvaging surviving myocardium, 2) promoting homing of stem cells and 3) increasing survival and proliferation of stem cell populations at the site of injury. Herein we report upon a downstream target of Akt kinase, named Pim-1, which promotes cardioprotective signaling and enhances cardiac structure and function after pathological injury. The compilation of studies presented here supports use of Pim-1 to enhance long-term myocardial repair after pathological damage. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure."

For better or for worse: the role of Pim oncogenes in tumorigenesis

Pim oncogenes are overexpressed in a wide range of tumours from a haematological and epithelial origin. Pim genes encode serine/threonine kinases that have been shown to counteract the increased sensitivity to apoptosis induction that is associated with MYC-driven tumorigenesis. Recently, considerable progress has been made in characterizing the pathways of PIM-mediated survival signalling. Given the unique structure of their active site and the minimal phenotype of mice mutant for all Pim family members, these oncogenes might be promising targets for highly specific and selective drugs with favourable toxicity profiles. In this Review, we discuss the physiological functions and oncogenic activities of Pim kinases.