Immunohistochemical Expression Patterns of Germinal Center and Activation B-cell Markers Correlate With Prognosis in Diffuse Large B-cell Lymphoma

Clinicopathological analysis of diffuse large B-cell lymphoma using molecular biomarkers: a retrospective analysis from 7 Hungarian centers

Background

The clinical and genetic heterogeneity of diffuse large B-cell lymphoma (DLBCL) presents distinct challenges in predicting response to therapy and overall prognosis. The main objective of this study was to assess the application of the immunohistochemistry- and interphase fluorescence in situ hybridization (FISH)-based molecular markers in the diagnosis of DLBCL and its prognostic value in patients treated with rituximab-based immunochemotherapy.

Methods

This is a multicenter, retrospective study, which analyzed data from 7 Hungarian hematology centers. Eligible patients were adults, had a histologically confirmed diagnosis of DLBCL, were treated with rituximab-based immunochemotherapy in the first line, and had available clinicopathological data including International Prognostic Index (IPI). On the specimens, immunohistochemistry and FISH methods were performed. Germinal center B-cell like (GCB) and non-GCB subtypes were classified by the Hans algorithm. Outcomes included overall survival (OS), event-free survival (EFS), and EFS at 2 years (EFS24). For survival analysis, we used Kaplan-Meier curves with the log-rank test and multivariate Cox regression.

Results

A total of 247 DLBCL cases were included. Cases were positive for MYC, BCL2, BCL6, and MUM1 expression in 52.1%, 66.2%, 72.6%, and 77.8%, respectively. BCL6 translocation, BCL2 gene copy number (GCN) gain, IGH::MYC translocation, MYC GCN gain, IGH::BCL2 translocation, and BCL6 GCN gain were detected in 21.4%, 14.1%, 7.3%, 1.8%, 7.3%, and 0.9%, respectively. At a median follow-up of 52 months, 140 patients (56.7%) had disease progression or relapse. The Kaplan-Meier estimate for EFS24 was 56.2% (CI: 50.4-62.8%). In univariate analysis, only IPI and BCL6 expression were significant predictors of both OS and EFS, whereas MUM1 predicted EFS only. In multivariate analysis, the IPI score was a significant independent negative, whereas MIB-1 and BCL6 protein expressions were significant independent positive predictors of both OS and EFS.

Conclusion

In our study, we found that only IPI, BCL6 protein expression and MIB-1 protein expression are independent predictors of survival outcomes in DLBCL. We did not find any difference in survival by GCB vs. non-GCB subtypes. These findings may improve prognostication in DLBCL and can contribute to designing further research in the area.

Primary central nervous system lymphoma of the tectal plate in adult

Background:

Primary central nervous system lymphoma (PCNSL) originating in the brainstem is uncommon. In particular, PCNSL confined to the tectal plate in adults has never been reported in the past. The case of a 53-year-old man who was diagnosed with PCNSL in the tectal plate is reported.

Case Description:

The patient was referred to our hospital with a 1-month history of disorientation and magnetic resonance imaging showed hydrocephalus with an enhancing lesion in the tectum. Preoperative blood tests showed a high serum soluble interleukin-2 receptor level of 624 U/ml. Through a single burr hole, endoscopic third ventriculostomy and biopsy of the lesion were simultaneously performed with a flexible endoscope. The histological examination confirmed diffuse large B-cell lymphoma. The patient underwent chemotherapy and radiotherapy.

Conclusion:

Malignant lymphoma of the tectum may occur in adults. By measuring the soluble interleukin-2 level preoperatively, it was possible to include malignant lymphoma in the differential diagnosis. In addition, the use of a neuroendoscope permits biopsy and hydrocephalus treatment to be performed simultaneously.

MUM1 Expression versus Hans Algorithm to Predict Prognosis in Indonesian Diffuse Large B-Cell Lymphoma Patients Receiving R-CHOP

Background

Treatment response in diffuse large B-cell lymphoma (DLBCL) is heterogenous. The Hans algorithm (using 30% cut-offs for CD10, BCL6, and MUM1 protein expression) has been the most favored method to categorize DLBCL into germinal center B-cell (GCB) and non-GCB subtypes in order to predict prognosis. However, the algorithm’s ability to prognosticate is not always consistent.

Methods

This retrospective cohort study was conducted on DLBCL patients receiving R-CHOP therapy at Dr. Cipto Mangunkusumo Hospital, Jakarta from 2014 to 2017. We aimed to compare the prognostic value of Hans algorithm as well as the protein levels of CD10, BCL6, MUM1, and Ki67 at different cut-offs. Ninety-two patients were classified based on Hans algorithm and various proteins at different cut-off values were analyzed with regard to event-free survival at 24 months using survival analysis. The cut-off values were then compared using receiver operating characteristic curves.

Results

A significant survival difference was observed with MUM1 expression cut-off of 50% or more (log rank p = 0.035). CD10, BCL6, Ki67, and Hans algorithm showed AUCs below or near 0.5 (0.405, 0.436, 0.498, and 0.413, respectively), whereas MUM1 showed an AUC of 0.835, in predicting events within 24 months. MUM-1 cut-off of 70.5% yielded an optimal trade-off for sensitivity and specificity.

Conclusion

MUM1 expression of 50% or more can help predict prognosis in DLBCL patients receiving R-CHOP therapy and can be considered as for use as a single marker to predict prognosis.

GCB-type is a favorable prognostic factor in primary CNS diffuse large B-cell lymphomas

Primary CNS lymphomas (PCNSLs) are aggressive diffuse large B-cell lymphomas (DLBCLs) limited to the CNS that generally have a poor prognosis. Classification of DLBCL into germinal center B-cell (GCB) and activated B-cell (non-GCB) subtypes has prognostic value in systemic DLBCL, with GCB-type having a better prognosis. The aim of this study was to determine whether GCB versus non-GCB classification in PCNSLs has similar prognostic value. We analyzed clinical, radiological and histologic data from 24 patients with biopsy confirmed DLBCL of the CNS with classification into GCB versus non-GCB subtypes. We found that after a median follow-up of 15 months, only 39% of patients with non-GCB-type PCNS DLBCL were alive, whereas all patients with GCB-type were alive. Non-GCB-type had a median survival of 11 months, whereas all GCB-type patients were alive after a median follow-up of 22 months. As previously reported, we also found that patients younger than 70 years had longer survival (median 29 months) compared to older patients (median 8.8 months). There was no statistically significant difference between the ages, gender, focality, size or location of lesions, or treatment of non-GCB and GCB-type patients. Our findings suggest that classifying PCNSLs into GCB versus non-GCB subtype using the Hans algorithm may help stratify patients into two groups with different prognosis.

Clinicopathological features of primary central nervous system diffuse large B cell lymphoma: Experience from a Tertiary Center in North India

BACKGROUND

Primary central nervous system-diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare extra-nodal Non-Hodgkin lymphoma. There is relative paucity of literature on PCNSL from Indian subcontinent. We aimed to analyze the clinicopathological features of PCNSL and categorize them into germinal center B cell (GCB) and non-GCB subtypes to assess their prognostic significance in Indian context.

METHODS

All patients with histopathologically diagnosed PCNSLs at our center over a period of 6 years were recruited and classified into GCB and non-GCB using Han's algorithm (immunohistochemistry for CD10, BCL6 and MUM1). In situ hybridization (ISH) for Epstein-Barr virus (EBV)-encoded RNA was performed.

RESULTS

Eighty-six cases of PCNS-DLBCL were included with median age of 55 years. Majority of them were supratentorial in location (n = 62). All patients were immunocompetent. On immunohistochemical assessment, 69 (80.2%) were of NGCB subtype, 10 (11.6%) were of GCB subtype, and 7 (8.1%) were unclassified. Overall, MUM1, BCL-6, and CD10 expressions were seen in 69 (80.2%), 28 (32.6%), and 2 cases (2.3%), respectively. Four cases (4.6%) showed C-MYC expression. The median overall survival (OS) was 675 days. None of the factors (age, sex, location, immunomarkers, and GCB vs. NGCB phenotype) showed correlation with OS; however, BCL6 positive cases showed slight better OS (P > 0.05). All cases were negative for EBV-LMP1 on ISH.

CONCLUSION

The majority of the CNS DLBCL belongs to non-GCB phenotype and uniformly carry poor prognosis, irrespective of their phenotype. Individual markers, such as BCL-6, MUM1, or CD10, are unable to predict outcome in PCNS-DLBCL.

High Ki67 proliferation index but not cell-of-origin subtypes is associated with shorter overall survival in diffuse large B-cell lymphoma

Background:

CD10, BCL6, and MUM1 are commonly used immunohistochemical stains for classifying diffuse large B-cell lymphoma (DLBCL), which is useful in predicting outcome. Conflicting reports of the prognostic value of other markers such as BCL2, CD23, and Ki67 proliferation index have been reported. Our objective was to correlate these immunostains and Hans classification with response to therapy and overall survival.

Materials and Methods:

A retrospective study of patients diagnosed with DLBCL from 2008–2014 at a tertiary-care cancer hospital. The slides with the IHC stains were reviewed by two independent pathologists. The clinical outcomes––assessed independently––were response to therapy and overall survival. The treatment response evaluation was based on the new Lugano classification. Statistical analyses were conducted using the Fisher’s exact test and Kaplan–Meier survival curves. Significance was set at P < 0.05.

Results:

Forty-one patients were included in the study with a known Hans classification, available clinical data, and at least 5-year follow-up. CD10 immunostain was reported in all patients, whereas CD23 was the least reported in only four patients. No significant association was observed between CD10, BCL6, MUM1, BCL2, and both Response to therapy and overall survival. Owing to few cases reported CD23 immunostain, further analysis of association is not reported. High Ki67 proliferative index of >80% was statistically significantly associated with shorter overall survival and not statistically significant associated with no response to therapy. Hans classification subtypes were not predictive in regard to therapy response.

Conclusion:

High Ki67 expression (>80%) was associated with shorter overall survival in DLBCL. Hans classification subtypes were not predictive.

Primary Pancreatic lymphoma: a rare clinical entity

Primary pancreatic lymphoma is a rare clinical entity representing <0.5% of pancreatic cancers and 1% of extranodal lymphomas. Due to the paucity of cases described in the literature, its clinicopathological features, differential diagnosis, optimal therapy and outcomes are not well defined. As the clinical manifestations are often non-specific, it can create a diagnostic pitfall for the unwary physician. Preoperative distinction of adenocarcinoma and primary pancreatic lymphoma is critical since the management and prognosis of these malignancies are mutually exclusive. Due to its rarity, epidemiological studies have been difficult to conduct. Chemotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin and vincristine) has proven to be effective. The authors present the case of a 52-year-old man with epigastric pain and obstructive jaundice. Further investigation with a CT of the abdomen and pelvis showed a low attenuation mass in the head of the pancreas measuring 35×25 mm, suspicious for malignancy. The mass involved the common bile duct distally causing moderate retrograde intrahepatic and extrahepatic biliary tree dilation of 14 mm. He underwent endoscopic retrograde cholangiopancreatography, sphincterotomy and insertion of a stent. Core biopsies confirmed the diagnosis of a high-grade B cell pancreas lymphoma. He started treatment with R-CHOP and prednisolone. Due to disease progression, he started treatment with DA-EPOCH-R (etoposide phosphate, prednisone, vincristine sulfate, cyclophosphamide, doxorubicin hydrochloride and rituximab). There was no clinical response, and treatment with RICE (rituximab, ifosfamide, carboplatin and etoposide) was initiated. He showed partial response and was under consideration for chimeric antigen receptor T cell therapy. He deteriorated clinically and succumbed to his disease 5 months following his initial presentation. This paper will provide an overview of the spectrum of haematological malignancies and describe useful features in distinguishing primary lymphoma of the pancreas from an adenocarcinoma, hence avoiding its surgical resection.

Discriminant analysis and machine learning approach for evaluating and improving the performance of immunohistochemical algorithms for COO classification of DLBCL

Background

Diffuse large B-cell lymphoma (DLBCL) is classified into germinal center-like (GCB) and non-germinal center-like (non-GCB) cell-of-origin groups, entities driven by different oncogenic pathways with different clinical outcomes. DLBCL classification by immunohistochemistry (IHC)-based decision tree algorithms is a simpler reported technique than gene expression profiling (GEP). There is a significant discrepancy between IHC-decision tree algorithms when they are compared to GEP.

Methods

To address these inconsistencies, we applied the machine learning approach considering the same combinations of antibodies as in IHC-decision tree algorithms. Immunohistochemistry data from a public DLBCL database was used to perform comparisons among IHC-decision tree algorithms, and the machine learning structures based on Bayesian, Bayesian simple, Naïve Bayesian, artificial neural networks, and support vector machine to show the best diagnostic model. We implemented the linear discriminant analysis over the complete database, detecting a higher influence of BCL6 antibody for GCB classification and MUM1 for non-GCB classification.

Results

The classifier with the highest metrics was the four antibody-based Perfecto–Villela (PV) algorithm with 0.94 accuracy, 0.93 specificity, and 0.95 sensitivity, with a perfect agreement with GEP (κ = 0.88, P < 0.001). After training, a sample of 49 Mexican-mestizo DLBCL patient data was classified by COO for the first time in a testing trial.

Conclusions

Harnessing all the available immunohistochemical data without reliance on the order of examination or cut-off value, we conclude that our PV machine learning algorithm outperforms Hans and other IHC-decision tree algorithms currently in use and represents an affordable and time-saving alternative for DLBCL cell-of-origin identification.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1951-y) contains supplementary material, which is available to authorized users.

Prognostic impact of germinal center B-cell-like and non-germinal center B-cell-like subtypes of bone marrow involvement in patients with diffuse large B-cell lymphoma treated with R-CHOP

The prognostic significances of the germinal center B-cell-like (GCB) and non-germinal center B-cell-like (non-GCB) types of diffuse large B-cell lymphoma (DLBCL) have been reported to be different. We analyzed the effect of the cell of origin (COO) of bone marrow (BM) involvement in patients with DLBCL who were treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in a single institute.The subtype of BM involvement was evaluated in 633 patients who were diagnosed with primary DLBCL and had been treated with R-CHOP. BM trephine biopsies were analyzed, and immunohistochemical staining of CD20, CD79a, and CD3 was performed. Additional staining of CD10, Bcl-6, and MUM1 was performed to determine the COO based on a previously reported algorithm.BM involvement was present in 81 patients (12.8%). Among them, 30 patients (37.0%) had GCB-type BM involvement and 51 (63.0%) showed non-GCB-type involvement. Kaplan-Meier survival analysis showed that the non-GCB type had the worst progression-free survival (PFS) and overall survival (OS) (P <.001). In multivariate analysis controlled for the International Prognostic Index (IPI) score, non-GCB type was an independent predictor of PFS (P <.004) and OS (P =.042), whereas GCB type was not a prognostic factor independent of the IPI score.Further prognostication based on the COO of BM involvement is a useful indicator of PFS, independent of IPI score. Accurate staging based on the COO should be included in the examination of BM in DLBCL.

Clinicopathological Analysis of 320 Cases of Diffuse Large B-cell Lymphoma Using the Hans Classifier

The estimation of clinical prognosis for diffuse large B-cell lymphoma (DLBCL) with a quick, cost-efficient method is necessary because of the clinical heterogeneity of this disease, which leads to death, relapsed or refractory disease in approximately 40% of patients. We analyzed 320 cases diagnosed from 2007 to 2013 treated with R-CHOP therapy at Tokai University Hospital and associated institutions. DLBCL was classified according to the cell-of-origin using the Hans algorithm [germinal center B-cell-like (GCB) vs non-GCB subtypes], and into 6 subgroups derived from combinations of CD10, BCL6 and MUM1 markers. The percentage of GCB and non-GCB (NGCB) subtypes was 35% and 65%, respectively. GCB-DLBCL was characterized by lower BCL2 immunohistochemical expression, extranodal sites ＜1, better therapeutic response, and favorable overall survival (OS) and progression free survival (PFS) (P＜0.01). The most frequent subgroup was NGCB-1 (CD10^-BCL6⁺MUM1⁺, 51%) followed by GCB-1 (CD10⁺BCL6^+or-MUM1⁺, 21%), NGCB-2 (CD10^-BCL6^-MUM1⁺, 13%), GCB-2 (CD10⁺BCL6^+or-MUM1^-, 10%), GCB-3 (CD10^-BCL6⁺MUM1^-, 4%) and NGCB-3 (CD10^-BCL6^-MUM1^-, 2%). In comparison with GCB-2 and GCB-3 (both MUM1^-), the GCB-1 (MUM1⁺) was characterized by favorable PFS (5-year PFS 84% vs 65%, OR 0.368, P＜0.05), independent of high LDH (associated with unfavorable PFS, OR 7.04, P＜0.01) in the multivariate analysis. This predictive value of MUM1 was independent of CD10. Interestingly, triple-negative NGCB-3 tended to have a more favorable prognosis than the other NGCB subgroups. In conclusion, the Hans classifier is a valid method to evaluate the prognosis of DLBCL NOS. In the GCB subtypes, GCB subtypes, MUM1-positivity is associated with a more favorable outcome (PFS).

Immunohistochemical expression of Mum-1, Oct-2 and Bcl-6 in systemic anaplastic large cell lymphomas

Aims and backround

Several transcription factors predominantly used for B-cell lineage identification are also expressed in a small percentage of T cells within germinal centers and interfollicular areas. The aim of the study was to evaluate the expression of Mum-1, Oct-2 and Bcl-6 in systemic anaplastic large cell lymphoma.

Methods

Thirty cases of anaplastic large cell lymphoma were retrieved from our archives and tissue microarray constructed. Immunohistochemistry was carried out using an avidin-biotin peroxidase complex method.

Results

A predominance of nuclear staining was observed for all transcription factors. Mum-1 was positive in all but one case (96.7%). Half of the cases displayed Oct-2 expression (15/30 cases). A considerable number of cases also had Bcl-6 expression (9/30). Bcl-6 staining was noted to be more common in ALK positive cases.

Conclusion

Our findings emphasize that these markers are not restricted to B-cell lineage and that extensive expression can be observed in anaplastic large cell lymphoma of T/null cell phenotype.

Prognostic Significance of in situ Phenotypic Marker Expression in Diffuse Large B-cell Lymphomas

Diffuse large B-cell lymphomas (DLBCL) are the most common lymphoid malignancies, and encompass all malignant lymphomas characterized by large neoplastic cells and B-cell derivation. In the last decade, DLBCL has been subjected to intense clinical, phenotypic and molecular studies, and were found to represent a heterogeneous group of tumors. These studies suggested new disease subtypes and variants with distinct clinical characteristics, morphologies, immunophenotypes, genotypes or gene expression profiles, associated with distinct prognoses or unique sensitivities to particular therapy regimens. Unfortunately, the reliability and reproducibility of the molecular results remains unclear due to contradictory reports in the literature resulting from small sample sizes, referral and selection biases, and variable methodologies and cut-off levels used to determine positivity. Here, we review phenotypic studies on the prognostic significance of protein expression profiles in DLBCL and reconsider our own retrospective data on 301 primary DLBCL cases obtained on a previously validated tissue microarray in light of powerful statistical methods of determining optimal cut-off values of phenotypic factors for prediction of outcome.

Immunohistochemical profile and prognostic significance in primary central nervous system lymphoma: Analysis of 89 cases

The majority of primary central nervous system lymphomas (PCNSLs) are diffuse large B cell lymphoma, characterized by poor prognosis. In the present study, the expression of cluster of differentiation (CD)10, B cell lymphoma (BCL)-6, multiple myeloma-1 (MUM-1), BCL-2, CD138 and Ki-67 was analyzed by immunohistochemistry in 89 Chinese PCNSL cases, and the potential prognostic significance was evaluated. CD10, BCL-6, MUM-1, BCL-2 and CD138 were positive in 16.9 (15/89), 51.7 (46/89), 92.1 (82/89), 73.3 (63/86) and 0% (0/65) of all cases, respectively. According to the Hans algorithm, 71 patients (79.8%) were classified into the non-germinal center B cell-like (non-GCB) group, indicating a post-germinal center origin of PCNSL. The median follow-up time of 73 patients was 13 months [95% confidence interval (CI), 10.93-15.08]. The median overall survival (OS) time was 45.3 months (95% CI, 25.01-65.59) and the median progression-free survival (PFS) time was 30.0 months (95% CI, 13.43-46.57). Age (>60 years) was associated with a shorter OS time (P=0.009). Ki-67 (cutoff point 90%) was associated with shorter OS (P=0.037) and shorter PFS (P=0.039) times. No other immunohistochemical markers were associated with prognosis. On multivariate analysis, age (>60 years) was associated with shorter OS time (P=0.038), but immunophenotype and expression status of Ki-67, CD10, BCL-6 and BCL-2 did not predict prognosis. In conclusion, high Ki-67 expression may predict poor prognosis in PCNSL. The present study was limited by its sample size and short follow-up time. This requires more evidence to further clinical study.

A clinicopathological study of primary central nervous system lymphomas & their association with Epstein-Barr virus

Background & objectives:

Primary central nervous system lymphomas (PCNSLs) are relatively uncommon, accounting for 2-3 per cent of primary brain tumours. Majority of these are diffuse large B cell lymphomas (DLBCL) occurring both in immunocompromised and immunocompetent patients. We undertook this study to classify PCNSL into germinal centre (GC) and non-germinal centre (NGC) type based on Hans classification and to find the role of Epstein-Barr virus (EBV) in pathogenesis both by conventional immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH).

Methods:

The consecutive cases of PCNSL during a 10 years period were analysed by IHC for CD45, CD20, CD3, B-cell lymphoma 2 and 6 (Bcl-2 and Bcl-6), B-cell specific octamer binding protein-1 (BOB-1), multiple myeloma oncogene-1 (MUM-1), EBV latent-membrane protein 1 (LMP-1), cyclin-D1, CD10, CD5 and CD23, as well as by CISH for EBV.

Results:

During a period of 10 years, 65 PCNSL were diagnosed which comprised 0.69 per cent (65/9476) of all intracranial tumours. The mean age of presentation was 49 yr with sex ratio (M:F) of 1.4:1. Most common location was supratentorial region with predominant involvement of frontal lobe. Single lesions were seen in 38 (58.4%) and multifocal lesions in 27 (41.5%) patients. None of the patients were immunocompromised. All cases were B cell immunophenotype and were DLBCL except one case of follicular lymphoma. According to Hans classification, majority of them were NGC (n=51, 79.6%) and 13 (20.3%) were GC type. Bcl-2 expression was noted in 34 (52.3%) tumours. EBV was positive in three (4.6%) cases; two were detected both by IHC and CISH and one case by CISH only.

Interpretation & conclusions:

In Indian population, PCNSL occurs mainly in immunocompetent patients, and a decade earlier than in western population. Immunophenotyping revealed that all cases were DLBCL with predominance of NGC type. No prognostic difference was seen between GC and NGC DLBCL. Association of EBV was rare and this virus was possibly not involved in the pathogenesis of PCNSL in immunocompetent individuals. CISH was an easy, economical and less cumbersome method for detection of EBV in PCNSL.

The Role of c-MYC in B-Cell Lymphomas: Diagnostic and Molecular Aspects

c-MYC is one of the most essential transcriptional factors, regulating a diverse array of cellular functions, including proliferation, growth, and apoptosis. Dysregulation of c-MYC is essential in the pathogenesis of a number of B-cell lymphomas, but is rarely reported in T-cell lymphomas. c-MYC dysregulation induces lymphomagenesis by loss of the tight control of c-MYC expression, leading to overexpression of intact c-MYC protein, in contrast to the somatic mutations or fusion proteins seen in many other oncogenes. Dysregulation of c-MYC in B-cell lymphomas occurs either as a primary event in Burkitt lymphoma, or secondarily in aggressive lymphomas such as diffuse large B-cell lymphoma, plasmablastic lymphoma, mantle cell lymphoma, or double-hit lymphoma. Secondary c-MYC changes include gene translocation and gene amplification, occurring against a background of complex karyotype, and most often confer aggressive clinical behavior, as evidenced in the double-hit lymphomas. In low-grade B-cell lymphomas, acquisition of c-MYC rearrangement usually results in transformation into highly aggressive lymphomas, with some exceptions. In this review, we discuss the role that c-MYC plays in the pathogenesis of B-cell lymphomas, the molecular alterations that lead to c-MYC dysregulation, and their effect on prognosis and diagnosis in specific types of B-cell lymphoma.

Stratifying diffuse large B-cell lymphoma patients treated with chemoimmunotherapy: GCB/non-GCB by immunohistochemistry is still a robust and feasible marker

Diffuse large B cell lymphoma (DLBCL) is a heterogeneous group of aggressive lymphomas that can be classified into three molecular subtypes by gene expression profiling (GEP): GCB, ABC and unclassified. Immunohistochemistry-based cell of origin (COO) classification, as a surrogate for GEP, using three available immunohistochemical algorithms was evaluated in TMA-arranged tissue samples from 297 patients with de novo DLBCL treated by chemoimmunotherapy (R-CHOP and R-CHOP-like regimens). Additionally, the prognostic impacts of MYC, BCL2, IRF4 and BCL6 abnormalities detected by FISH, the relationship between the immunohistochemical COO classification and the immunohistochemical expression of MYC, BCL2 and pSTAT3 proteins and clinical data were evaluated. In our series, non-GCB DLBCL patients had significantly worse progression-free survival (PFS) and overall survival (OS), as calculated using the Choi, Visco-Young and Hans algorithms, indicating that any of these algorithms would be appropriate for identifying patients who require alternative therapies to R-CHOP. Whilst MYC abnormalities had no impact on clinical outcome in the non-GCB subtype, those patients with isolated MYC rearrangements and a GCB-DLBCL phenotype had worse PFS and therefore might benefit from novel treatment approaches.

Diagnostic and predictive biomarkers for lymphoma diagnosis and treatment in the era of precision medicine

Lymphomas are a group of hematological malignancies derived from lymphocytes. Lymphomas are clinically and biologically heterogeneous and have overlapping diagnostic features. With the advance of new technologies and the application of efficient and feasible detection platforms, an unprecedented number of novel biomarkers have been discovered or are under investigation at the genetic, epigenetic, and protein level as well as the tumor microenvironment. These biomarkers have enabled new clinical and pathological insights into the mechanisms underlying lymphomagenesis and also have facilitated improvements in the diagnostic workup, sub-classification, outcome stratification, and personalized therapy for lymphoma patients. However, integrating these biomarkers into clinical practice effectively and precisely in daily practice is challenging. More in-depth studies are required to further validate these novel biomarkers and to assess other parameters that can affect the reproducibility of these biomarkers such as the selection of detection methods, biological reagents, interpretation of data, and cost efficiency. Despite these challenges, there are many reasons to be optimistic that novel biomarkers will facilitate better algorithms and strategies as we enter a new era of precision medicine to better refine diagnosis, prognostication, and rational treatment design for patients with lymphomas.

The immunophenotypic spectrum of primary mediastinal large B-cell lymphoma reveals prognostic biomarkers associated with outcome

Primary mediastinal large B-cell lymphoma (PMBL) is a distinct subtype of diffuse large B-cell lymphoma (DLBCL) that shows overlap with classical Hodgkin lymphoma (CHL) and a favorable prognosis compared to mediastinal gray-zone lymphoma (MGZL). We performed immunohistochemistry on initial diagnostic specimens of 49 cases of uniformly treated PMBL to determine the frequency and clinical significance of expression of antigens commonly seen in CHL and MGZL, along with markers previously shown to be prognostic in DLBCL, not otherwise specified. The median age was 37 years with a female:male ratio of 2.3. After a median follow-up of 78 months, 24% of patients had relapsed or refractory disease and 22% had died; the 5-year PFS was 70%. Variable CD15 expression was seen in 31% of cases, but was not associated with adverse outcome. Hans cell-of-origin, proliferation index, and MYC/BCL2 coexpression were not associated with outcome, while low PDL1 (P = 0.011) and high MUM1 (P = 0.065) staining were each associated with shorter PFS. A biologic risk score (one point each for low PDL1 and high MUM1) stratified patients into three prognostic risk groups for PFS (P = 0.001) and OS (P = 0.032). On separate multivariate models, low PDL1 was independent of R-IPI risk group for PFS (HR 6.0, P = 0.023), as was a biologic risk score of 2 (HR 5.6, P = 0.011). Incorporation of the biologic risk score sub-stratified patients within R-IPI groups for both PFS (P < 0.001) and OS (P < 0.001). In summary, we characterize the immunophenotypic spectrum of PMBL and identify PDL1 and MUM1 as prognostic biomarkers for high-risk disease. Am. J. Hematol. 91:E436-E441, 2016. © 2016 Wiley Periodicals, Inc.

Primary Cutaneous Diffuse Large B-Cell Lymphoma With a MYC-IGH Rearrangement and Gain of BCL2: Expanding the Spectrum of MYC/BCL2 Double-Hit Lymphomas

Aggressive extracutaneous B-cell lymphomas span the various stages of B-cell ontogeny and include B-cell lymphoblastic lymphoma, Burkitt lymphoma, mantle cell lymphoma, and diffuse large B-cell lymphoma. Diffuse large B-cell lymphomas represent the most common histologic subtype of non-Hodgkin lymphomas, comprising 30% of adult non-Hodgkin lymphomas in the United States. A distinctive form of diffuse large B-cell lymphoma is the double-hit lymphoma, with most cases exhibiting a combined MYC and BCL2 rearrangement, leading some hematopathologists to propose the term MYC/BCL2 lymphoma. More recently, MYC rearrangement with multiple copies/gain of BCL2 or multiple copies/gain of MYC with a BCL2 rearrangement have been described and exhibit a very similar clinical course to conventional double-hit lymphomas. We report the seventh case of diffuse large B-cell lymphoma exhibiting this distinct cytogenetic abnormality and the first reported case in the skin. The patient's clinical course was aggressive, succumbing to disease 18 months after his initial presentation.

B-cell-specific conditional expression of Myd88p.L252P leads to the development of diffuse large B-cell lymphoma in mice

The adaptor protein MYD88 is critical for relaying activation of Toll-like receptor signaling to NF-κB activation. MYD88 mutations, particularly the p.L265P mutation, have been described in numerous distinct B-cell malignancies, including diffuse large B-cell lymphoma (DLBCL). Twenty-nine percent of activated B-cell-type DLBCL (ABC-DLBCL), which is characterized by constitutive activation of the NF-κB pathway, carry the p.L265P mutation. In addition, ABC-DLBCL frequently displays focal copy number gains affecting BCL2 Here, we generated a novel mouse model in which Cre-mediated recombination, specifically in B cells, leads to the conditional expression of Myd88(p.L252P) (the orthologous position of the human MYD88(p.L265P) mutation) from the endogenous locus. These mice develop a lymphoproliferative disease and occasional transformation into clonal lymphomas. The clonal disease displays the morphologic and immunophenotypical characteristics of ABC-DLBCL. Lymphomagenesis can be accelerated by crossing in a further novel allele, which mediates conditional overexpression of BCL2 Cross-validation experiments in human DLBCL samples revealed that both MYD88 and CD79B mutations are substantially enriched in ABC-DLBCL compared with germinal center B-cell DLBCL. Furthermore, analyses of human DLBCL genome sequencing data confirmed that BCL2 amplifications frequently co-occurred with MYD88 mutations, further validating our approach. Finally, in silico experiments revealed that MYD88-mutant ABC-DLBCL cells in particular display an actionable addiction to BCL2. Altogether, we generated a novel autochthonous mouse model of ABC-DLBCL that could be used as a preclinical platform for the development and validation of novel therapeutic approaches for the treatment of ABC-DLBCL.

The distinct clinical features and prognosis of the CD10⁺MUM1⁺ and CD10⁻Bcl6⁻MUM1⁻ diffuse large B-cell lymphoma

Using an immunohistochemistry (IHC) based method, diffuse large B-cell lymphoma (DLBCL) can be classified into germinal center B-cell (GCB) and non-GCB subtypes. However, the prognostic value of Hans algorithm was contradictory in the literature. Using IHC and fluorescence in situ hybridization, we analyzed the antibodies applied in Hans algorithm and other genetic factors in 601 DLBCL patients and prognostic value of Hans algorithm in 306 cases who were treated with chemoimmunotherapy. The results showed that patients with GCB subtype have better overall survival (OS) and progression-free survival (PFS) than non-GCB cases. However, to some extent, double positive (CD10(+)MUM1(+), DP) and triple negative (CD10(-)Bcl6(-)MUM(-), TN) showed different clinical characteristics and prognosis to others that were assigned to the same cell-of-origin group. The DP group showed similar OS (median OS: both not reached, P = 0.3650) and PFS (median PFS: 47.0 vs. 32.7 months, P = 0.0878) with the non-GCB group while the TN group showed similar OS (median OS: both not reached, P = 0.9278) and PFS (median PFS: both not reached, P = 0.9420) with the GCB group. In conclusion, Recognition of specific entities in Hans algorithm could help us to accurately predict outcome of the patients and choose the best clinical management for them.

The novel kinesin spindle protein (KSP) inhibitor SB-743921 exhibits marked activity in in vivo and in vitro models of aggressive large B-cell lymphoma

The kinesin spindle protein (KSP) is a mitotic protein essential for cell cycle control and motility. SB-743921 (hereafter SB-921) is an inhibitor that selectively targets the ATP-binding domain of the KSP. The preclinical activity of SB-921 was evaluated in models of diffuse large B-cell lymphoma (DLBCL). The cytotoxicity of SB-921 was evaluated in a series of germinal center (GC-DLBCL) and post-germinal center (ABC-DLBCL) DLBCL cell lines and a murine lymphoma xenograft model. GC-DLBCL lines generally demonstrated greater sensitivity to SB-921. IC50 values ranged between 1 nM and 900 nM for GC-DLBCL compared to 1 nM to 10 μM for ABC lines. SB-921 demonstrated marked activity in a xenograft model of Ly-1 (GC-DLBCL). While SB-921 was relatively more active in GC derived cell lines, ABC-derived lines still underwent apoptosis at higher concentrations. These results demonstrate that SB-921 inhibits proliferation and induces apoptosis in both GC-DLBCL and ABC-DLBCL.

Pediatric non-Hodgkin lymphomas: first report from Central Africa

BACKGROUND

Information on presentation and outcome of pediatric non-Hodgkin's lymphoma is limited from Africa. The demographic characteristics, distribution of different subtypes were noted and compared with published reports from other parts of the world.

METHODS

The study was conducted in Kinshasa, the Democratic Republic of Congo between January 2002 and December 2012.

RESULTS

A total of 63 cases of pediatric non-Hodgkin's lymphoma were retrospectively analyzed. This cohort represents the largest series of pediatric non-Hodgkin's lymphoma presented from sub-Saharan Africa. Median age was 8.7±3.6 years. There were 43 (68.3%) males. A mean of 82 ± 59 days passed from detection of the first sign to referral to oncology unit. Morphology distribution showed that 42 cases (66.7%) had a diagnosis of Burkitt lymphoma, 16 cases (25.4%) had diffuse large B-cell lymphoma and 5 cases (7.9%) had NHL-not otherwise specified. The majority of patients (82.5%) had advanced stage (stage III and IV). Immunohistochemistry findings were available for 32 biopsy samples. All (100%) cases were B-cell non-Hodgkin's lymphoma and immunohistochemistry had identified 18 (56.3%) cases of Burkitt lymphoma. In our cohort, 22 of 32 cases expressed positive bcl-2 and 12 (37.5%) were found to be positive for bcl-6. Thirty-one (96.7%) cases were positive for high Ki-67 antigen expression. Assuming that cases lost to follow-up worsened and died, the mortality would be 98.4%.

CONCLUSION

In comparison to western data, we observed higher proportion of B-cell non-Hodgkin's lymphoma, Burkitt Lymphoma and patients with bcl-2 expression.

Prognostic impact of B-cell lymphoma 6 in primary CNS lymphoma

BACKGROUND

We investigated the prognostic significance of B-cell differentiation status and common B-cell differentiation markers in a post hoc analysis of 119 patients with primary CNS lymphoma (PCNSL) homogeneously receiving high-dose methotrexate (HDMTX)-based chemotherapy within the prospective G-PCNSL-SG1 trial.

METHODS

We evaluated protein expression of B-cell lymphoma 2 (BCL2), BCL6, CD10, and multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4) by immunohistochemistry and analyzed the association with survival.

RESULTS

The median follow-up of all patients was 67.5 months. Median progression-free survival (PFS) was 10.61 months (95% CI: 4.23-17.00). Median overall survival (OS) was 28.85 months (95% CI: 17.96-39.73). Eighty-nine tumors expressed BCL2 (92.7%), 24 (20.5%) expressed CD10, 60 (54.1%) expressed BCL6, and 87 (79.0%) expressed MUM1/IRF4. On the basis of the Hans algorithm, 80 tumors (73.4%) were classified to the non-germinal center B group, suggesting a post-germinal center origin of PCNSL. Expression of BCL6 (cutoff point 30%), but none of the other markers, was associated with shorter PFS (P = .047) and OS (P = .035). On multivariate analysis, BCL6 expression was associated with shorter PFS (hazard ratio: 1.95, 95% CI: 1.22-3.12, P = .005) but not OS (hazard ratio: 1.85, 95% CI: 0.71-4.80, P = .21). Classification according to Hans algorithm and expression status of the single B-cell markers BCL2, CD10, and MUM1/IRF4 did not correlate with prognosis.

CONCLUSION

The findings are limited by the fact that only 23% of all G-PCNSL-SG1 patients could be included in the analysis. If validated in an independent cohort, BCL6 may assume clinical relevance as an unfavorable prognostic biomarker in PCNSL.

Primary central nervous system diffuse large B-cell lymphoma in the immunocompetent: Immunophenotypic subtypes and Epstein-Barr virus association

INTRODUCTION

Primary central nervous system diffuse large B-cell lymphoma (PCNSL DLBCL) in the immunocompetent is an uncommon tumor that has an activated B-cell immunophenotype resembling germinal center exit B cells. They also differ from primary central nervous diffuse large B-cell lymphomas in the immunocompromised as they show no association with the Epstein-Barr virus.

OBJECTIVE

To determine if immunophenotypic subtyping of PCNS DLBCL from Asian subcontinent are also different similar to its systemic counterpart is unclear, as there are only limited studies from Asia, and none from India.

MATERIAL AND METHODS

The immunohistochemical profile of 24 South Indian patients with primary central nervous system diffuse large B-cell lymphoma was studied using germinal center markers - CD10 and Bcl-6, and activation markers - MUM1 and CD138, which are markers for late/post germinal centre B cells. Insitu hybridization for EBV genome and LMP1 by immunohistochemistry was carried out in all cases to determine association with EBV.

RESULTS

Centroblastic morphology and uniform activated B-cell phenotype with positivity for MUM1 was seen in 91.6% of tumors. Co-expression of Bcl-6 and MUM1 was evident in 50%, which is more frequent than in systemic diffuse large B-cell lymphomas. All cases were negative for Epstein-Barr virus using EBER in-situ hybridization and LMP1 immunohistochemistry.

CONCLUSION

Primary diffuse large B-cell lymphoma in the immunocompetent is a distinct clinicopathological entity with centroblastic morphology, a uniform activated B-cell immunophenotype that is not associated with the Epstein-Barr virus regardless of geographic origin.

Clinical outcome of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly in the rituximab era

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of malignant lymphoma. The incidence of Epstein–Barr virus (EBV)-positive DLBCL in Asian and Latin American countries ranges from 8 to 10%. The prognosis of patients with EBV-positive DLBCL is controversial. To compare the clinical outcome of EBV-positive and EBV-negative patients with DLBCL in the rituximab era, we analyzed 239 patients with de novo DLBCL diagnosed between January 2007 and December 2011. The presence of EBV in lymphoma cells was detected using EBV-encoded RNA in situ hybridization, and it was found that 18 (6.9%) of 260 patients with diagnosed DLBCL tested positive. Among the 260 cases, 216 cases were treated with rituximab plus chemotherapy, as were 8 EBV-positive DLBCL patients. The median overall survival and progression-free survival times in patients with EBV-positive DLBCL were 8.7 months and 6.8 months, respectively. The median overall survival and progression-free survival could not be determined in EBV-negative DLBCL patients (P = 0.0002, P < 0.0001, respectively). The outcome of patients with EBV-positive DLBCL remains poor, even in the rituximab era.

Diffuse large B-cell lymphoma, not otherwise specified of the palate: A case report

Diffuse large B-cell lymphoma (DLBCL) is the most frequent type of non-Hodgkin´s lymphoma found in oral and maxillofacial regions. A large number of cases may be biologically heterogeneous, which are commonly defined as DLBCL, not otherwise specified (NOS) by the World Health Organization (WHO-2008). The present case reports on an ulcer of raised and irregular edges, found on the border between the hard and soft palate, as the first and only manifestation of an extranodal non-Hodgkin lymphoma in an 85-year-old patient. Incisional biopsy was carried out, and the specimen revealed a proliferation of large lymphoid cells suggestive of diffuse large cell lymphoma. An immunohistochemical analysis was performed. EBV-RNA was assessed by in situ hybridization that also proved to be negative. Immunohistochemical and EBV analyses are important to avoid delays and inappropriate treatment strategies. Although advanced age is considered an adverse prognostic factor, early diagnosis did prove to be a key contributory factor in the cure of non-Hodgkin lymphoma. Key words:Diffuse large B-cell lymphoma, elderly, EBV.

Tissue microarray in a subset of South African patients with DLBCL

Tissue samples from 93 de novo diffuse large B-cell lymphoma patients seen between 1995 and 2009 randomly receiving either standard combination chemotherapy (CHOP, n=48) or the identical program with rituximab (n=45) were subtyped using an investigational immunohistochemical (IHC) based tissue microarray (TMA) and contrasted to the approximately corresponding categories as defined either by Hans and associates using a three marker panel into germinal or non-germinal centre subtypes or by Choi and colleagues with two additional antibodies into germinal centre (GCB) or activated B-cells (ABC). Each of these primary subdivisions was further evaluated for expression of BCL2 and LMO2 both of which are recognised to predicate response. The addition of rituximab to the uniform drug regimen did not show any significant improvement in 5 years overall (63% versus 59%, p 0.68) or event-free survival (42% versus 39%, p 0.94), for CHOP versus R-CHOP comparisons. Similarly no differences were evident in subtype analysis. Interestingly however, when segregated on the Choi criteria, cytotoxic drugs alone showed a non-significant trend in improved survival (74% versus 55%, p 0.32) as well as event-free survival (44% versus 40%, p 0.42) for the germinal centre as opposed to the activated B-cell subtype. Nevertheless not even a small difference could be demonstrated in the presence of the anti CD 20 monoclonal antibody. According to Choi, both regimens (chemotherapy or immunotherapy antibody) revealed similar results to the Hans algorithm on 5 years OS as well as 3 year EFS when comparing GCB versus ABC or non-GCB subgroups. BCL2 and LMO2 marker expression of the respective immunohistochemical (IHC) subtype, despite small sample size, revealed the following. Analysis by Choi criteria on survival for BCL2, no matter for which subsets (GCB or ABC) or treatment modality (chemotherapy with or without the addition of rituximab) showed no difference in 5 years OS or EFS. In contrast, a significant difference for better EFS (p=0.0015) in the BCL2 positive group of the ABC subgroups subtypes treated with rituximab containing chemotherapy. For LMO2 similar results on survival outcome were seen thus showing no difference in 5 years OS or EFS - regardless of subtype or treatment modality. Also here, this was contrasted by better EFS (p=0.039) in the LMO2 positive group of ABC subtypes when treated with the rituximab containing regimen. The use of the IHC based TMA methodology has shown to be a simple, cost effective and a robust alternative to gene expression profiling (GEP) which is currently regarded as the gold standard for the classification in lymphomas. It provides a useful prognostic tool in stratifying DLBCL or other entities in future, even when frozen tissue samples are not available for GEP analysis. With the current budgetary limitations in South African public hospitals chemotherapy protocols for lymphoproliferative disorders exclude agents such as rituximab. Local therapeutic drug committees consider the approximately 15% overall survival benefit seen at 5 years for DLBCL when rituximab is added to combination chemotherapy as too marginal for justifying the arising additional expenses. Accordingly, demonstration that a specific molecular subtype accounts for superior outcome, when using these regimens, is needed. Such an option would provide convincing evidence for the use of immunochemotherapy in a resource constrained setting.

Detailed analysis of diffuse large B cell lymphoma patients: a single-center, retrospective study

The aim of this single-center, retrospective study was to investigate the impact of rituximab, reconsider the validity of International Prognostic Index (IPI), and evaluate the prognostic role of the cell of origin (CoO) in a relatively young cohort. Three hundred twelve diffuse large B cell lymphoma patients (median age: 52) were included. Rituximab significantly improved the 3- and 5-year progression free survival (PFS) (70% versus 65% and 41% versus 36%, resp.; P < 0.001) but led only to a slight, insignificant increase in 3- and 5-year overall survival (OS) (71% versus 77.3% and %67 versus 74.5%, resp.; P = 0.264). In the young, low risk patient subgroup (aaIPI = 0&1; n = 129), rituximab improved 3- and 5-year PFS and OS rates (P < 0.001 and P = 0.048, resp.). The efficacy of rituximab in young high risk patients was comparable to the literature. CoO data were available in 190 patients. The OS at 3 years was 79% for GC and 64% for non-GC subgroups (P = 0.014). To the best of our knowledge, this is the first study which investigated the impact of R-CHOP in the context of CoO and IPI in a relatively young cohort. CoO was not an independent risk factor for prognosis in the multivariate analysis although patients with GC showed a significant survival advantage in the univariate analysis. CoO was also found to be a significant determinant of response in refractory/relapsed patients. Our results confirm the efficacy of rituximab in low and high risk, young patients outside of a randomized clinical trial setting.

Evaluation of BCL-6, CD10, CD138 and MUM-1 expression in diffuse large B-cell lymphoma patients: CD138 is a marker of poor prognosis

The diffuse large B-cell lymphoma (DLBCL) encompasses two major groups of tumors with uneven survival outcomes--germinal center B-cell (GCB) and non-germinal center B-cell (non-GCB). In the present study, we investigated the expression of GCB markers (BCL-6 and CD10) and non-GCB markers (CD138 and MUM-1) in an effort to evaluate their prognostic value. Paraffin-embedded tumor biopsies of 46 Jordanian DLBCL patients were analyzed, retrospectively, by immunohistochemistry to investigate the expression of BCL-6, CD10, CD138 and MUM-1. In addition, survival curves were calculated with reference to marker expression, age, sex and nodal involvement. Positive expression of BCL-6, CD10, CD138 and MUM-1 was shown in 78%, 61%, 39% and 91% of the cases, respectively, that of BCL-6 being associated with better overall survival (p = 0.02), whereas positive CD138 was linked with poor overall survival (p = 0.01). The expression of CD10 and MUM-1 had no impact on the overall survival. Among the clinical characteristics studied, diagnosis at an early age, nodal involvement and maleness were associated with a higher overall survival for DLBCL patients. Our results underline the importance of BCL-6 as a marker of better prognosis and CD138 as a marker of poor prognosis for DLBCL patients.

Expression of DBC1 and Androgen Receptor Predict Poor Prognosis in Diffuse Large B Cell Lymphoma

BACKGROUND

Recently, deleted in breast cancer 1 (DBC1) has been suggested as a poor prognostic indicator of various human cancers and may possibly have a role as a coactivator of androgen receptor (AR). However, their roles in lymphoma are still unknown.

MATERIALS AND METHODS

We investigated the effect of the expression of DBC1 and AR in diffuse large B cell lymphoma (DLBCL). Immunohistochemical expression of DBC1 and AR were evaluated in 101 DLBCL samples by tissue microarray.

RESULTS

Positive expression of DBC1 and AR was seen in 73% and 70% of DLBCL, respectively. In total DLBCL patients, DBC1 and AR expression were significantly associated with high clinical stage, elevated serum lactate dehydrogenase levels, and high international prognostic index scores, and they predicted shorter overall survival (OS) and relapse-free survival (RFS) by univariate analysis. DBC1 expression was also an independent prognostic indicator by multivariate analysis (OS, P = .017; RFS, P = .004). Especially, both DBC1 and AR expression significantly correlated with shorter OS and RFS in non-germinal center B cell (non-GCB)-type DLBCL by univariate analysis. In multivariate analysis, DBC1 expression was an independent prognostic predictor for OS (P = .035) and AR expression significantly correlated with RFS (P = .005).

CONCLUSION

We demonstrate that the expression of DBC1 and AR are significant prognostic indicators for DLBCL patients, especially for unfavorable non-GCB-type DLBCL.

Clinicopathologic implication of A20/TNFAIP3 deletion in diffuse large B-cell lymphoma: an analysis according to immunohistochemical subgroups and rituximab treatment

We analyzed the clinicopathologic implication of A20/tumor necrosis factor α-induced protein 3 deletion in diffuse large B-cell lymphoma (DLBCL) using fluorescence in situ hybridization, according to germinal center B-cell (GCB) versus non-GCB/activated B-cell (ABC) phenotypes and rituximab treatment. Excluding primary central nervous system (CNS) and Epstein-Barr virus (EBV)-positive lymphomas, 134 DLBCLs were analyzed. A20 was deleted in 23.1% (31/134) of DLBCLs including 21.6% (29/ 134) of monoallelic and 1.5% (2/134) of biallelic deletion, with no predilection for GCB versus non-GCB/ABC. In univariate analysis, A20 deletion was marginally associated with favorable prognosis in the rituximab-treated subgroup (n = 109; p = 0.0454), non-gastrointestinal lymphoma (n = 108; p = 0.0320) and nodal lymphoma (n = 46; p = 0.0411). In multivariate analysis in rituximab-treated DLBCL, MUM1 and international prognostic index (IPI) were independent prognostic factors (p = 0.021 [IPI]; p = 009 [MUM1]) with a marginally favorable prognostic effect for A20 deletion (p = 0.047). Taken together, A20 deletion was observed in similar frequencies in GCB and non-GCB/ABC, and was not a poor prognostic factor in DLBCL.

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.

Molecular pathology of lymphoma

Ocular lymphomas can be divided into intraocular lymphomas and ocular adnexal lymphomas. The vitreoretinal lymphoma-usually a diffuse large B-cell lymphoma (DLBCL) of high-grade malignancy-is the most common lymphoid malignancy arising in the eye, while the extranodal marginal zone B-cell lymphoma (EMZL), an indolent often recurrent tumour, occurs most frequently in the ocular adnexal tissue. The two lymphoma subtypes differ significantly in their clinical presentation, subsequent course and outcome as well as in their underlying morphological, immunophenotypical and genetic features. The molecular processes involved in DLBCL and EMZL development are complex, and include chromosomal translocations, mutations caused by aberrant somatic hypermutation, sporadic somatic mutations, and copy number alterations, characterized by deletions and amplifications. These lead to alterations in particular signalling pathways, which in turn activate transcription factors, such as nuclear factor NF-κB. This review provides an overview of the histological features of DLBCL and EMZL, and discusses the current insights into the molecular mechanisms underlying the development of these tumours, when they occur systemically and particularly when they arise in ocular tissues.

Diffuse large B-cell lymphoma of Waldeyer's ring has distinct clinicopathologic features: a GELA study

BACKGROUND

Diffuse large B-cell lymphomas (DLBCLs) arising in specific extranodal sites have peculiar clinicopathologic features.

PATIENTS AND METHODS

We analyzed a cohort of 187 primary Waldeyer's ring (WR) DLBCLs retrieved from GELA protocols using anthracyclin-based polychemotherapy.

RESULTS

Most patients (92%) had stage I-II disease. A germinal center B-cell-like (GCB) immunophenotype was observed in 61%, and BCL2 expression in 55%, of WR DLBCLs. BCL2, BCL6, IRF4 and MYC breakpoints were observed in, respectively, 3 of 42 (7%), 9 of 36 (25%), 2 of 26 (8%) and 4 of 40 (10%) contributive cases. A variable follicular pattern was evidenced in 30 of 68 (44%) large biopsy specimens. The 5-year progression-free survival (PFS) and the overall survival (OS) of 153 WR DLBCL patients with survival information were 69.5% and 77.8%, respectively. The GCB immunophenotype correlated with a better OS (P = 0.0015), while BCL2 expression predicted a worse OS (P = 0.037), an effect overcome by the GCB/non-GCB classification. Compared with matched nodal DLBCLs, WR DLBCLs with no age-adjusted international prognostic index factor disclosed a better 5-year PFS rate (77.5% versus 70.7%; P = 0.03).

CONCLUSIONS

WR DLBCLs display distinct clinicopathologic features compared with conventional DLBCLs, with usual localized-stage disease, common follicular features and a high frequency of GCB immunophenotype contrasting with a low rate of BCL2 rearrangements. In addition, they seem to be associated with a better outcome than their nodal counterpart.

The contribution of HGAL/GCET2 in immunohistological algorithms: a comparative study in 424 cases of nodal diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma can be subclassified into at least two molecular subgroups by gene expression profiling: germinal center B-cell like and activated B-cell like diffuse large B-cell lymphoma. Several immunohistological algorithms have been proposed as surrogates to gene expression profiling at the level of protein expression, but their reliability has been an issue of controversy. Furthermore, the proportion of misclassified cases of germinal center B-cell subgroup by immunohistochemistry, in all reported algorithms, is higher compared with germinal center B-cell cases defined by gene expression profiling. We analyzed 424 cases of nodal diffuse large B-cell lymphoma with the panel of markers included in the three previously described algorithms: Hans, Choi, and Tally. To test whether the sensitivity of detecting germinal center B-cell cases could be improved, the germinal center B-cell marker HGAL/GCET2 was also added to all three algorithms. Our results show that the inclusion of HGAL/GCET2 significantly increased the detection of germinal center B-cell cases in all three algorithms (P<0.001). The proportions of germinal center B-cell cases in the original algorithms were 27%, 34%, and 19% for Hans, Choi, and Tally, respectively. In the modified algorithms, with the inclusion of HGAL/GCET2, the frequencies of germinal center B-cell cases were increased to 38%, 48%, and 35%, respectively. Therefore, HGAL/GCET2 protein expression may function as a marker for germinal center B-cell type diffuse large B-cell lymphoma. Consideration should be given to the inclusion of HGAL/GCET2 analysis in algorithms to better predict the cell of origin. These findings bear further validation, from comparison to gene expression profiles and from clinical/therapeutic data.

Expression of Toll-like receptor9 in diffuse large B-cell lymphoma: further exploring CpG oligodeoxynucleotide in NFκB pathway

Human Toll-like receptors (TLRs) that recognize a variety of pathogen-associated molecular patterns are associated with activation and immunogenic response in lymphoid neoplasms, but rarely explored in diffuse large B-cell lymphoma (DLBCL). We conducted this study to evaluate the expression of TLR9 in and potential treatment of DLBCL with TLR9 agonist - CpG oligodeoxynucleotide (ODN). The real-time quantitative reverse transcription-polymerase chain reaction was carried out to detect TLR9 expression in 41 formalin-fixed paraffin-embedded samples. The transformation of immunophenotype and NFκB pathway of DLBCL upon CpG ODN stimulation were investigated by a DLBCL cell line. TLR9 was commonly detected in DLBCL with relative mRNA levels above 1.0 × 10(-2) in 35 of 41 cases (85.36%). It was suspected that a high proportion of DLBCL to be activated by CpG stimulation. In vitro study with a DLBCL cell line revealed an increased CD20, but decreased BCL-6 and MUM1/IRF4 expression after treatment with CpG ODN. The NFκB pathway was initially activated, but finally suppressed upon CpG ODN stimulation. The proliferation of tumor cells was also inhibited by long time incubation. These findings provide new insights into the role of TLR9 in DLBCL and potential implication of TLR9 agonist in the treatment of DLBCL.

The role of genotype in 104 cases of diffuse large B-cell lymphoma primary of breast

OBJECTIVES

To analyze the role of genotype in patients with diffuse large B-cell lymphoma primary of breast (DLBCL-PB) treated with chemotherapy or immunochemotherapy.

METHODS

We carried out a retrospective analysis in 104 patients with DLBCL-PB who were treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or immunochemotherapy: R-CHOP (adding rituximab) and also carried out an analysis of genotype, studied with immunohistochemistry, as a prognostic factor.

RESULTS

Seventy-seven percent of patients showed the non-GCB (germinal center B) genotype. Patients treated with CHOP had a complete response of 70%; actuarial curves at 5 years showed that disease-free survival was 66 % and overall survival was 52% and that it was not statistically different than patients treated with R-CHOP: 78%, 61%, and 53%, respectively. When genotype was analyzed to assess the impact in prognosis, no statistical differences were observed. Patients treated with R-CHOP and non-GCB genotype have a complete response of 77%, disease-free survival of 56%, and overall survival of 66% that were not statistically different than patients with GCB: 80%, 60%, and 60% respectively, (P: 0.81, 0.5, and 0.66, respectively).

CONCLUSIONS

We confirm that the non-GCB genotype is most frequent in DLBCL-PB, but the addition of rituximab did not improve outcome in primary breast lymphoma with non-GCB phenotype.

Development of multigene expression signature maps at the protein level from digitized immunohistochemistry slides

Molecular classification of diseases based on multigene expression signatures is increasingly used for diagnosis, prognosis, and prediction of response to therapy. Immunohistochemistry (IHC) is an optimal method for validating expression signatures obtained using high-throughput genomics techniques since IHC allows a pathologist to examine gene expression at the protein level within the context of histologically interpretable tissue sections. Additionally, validated IHC assays may be readily implemented as clinical tests since IHC is performed on routinely processed clinical tissue samples. However, methods have not been available for automated n-gene expression profiling at the protein level using IHC data. We have developed methods to compute expression level maps (signature maps) of multiple genes from IHC data digitized on a commercial whole slide imaging system. Areas of cancer for these expression level maps are defined by a pathologist on adjacent, co-registered H&E slides, allowing assessment of IHC statistics and heterogeneity within the diseased tissue. This novel way of representing multiple IHC assays as signature maps will allow the development of n-gene expression profiling databases in three dimensions throughout virtual whole organ reconstructions.

Immunophenotyping of chronic B-cell neoplasms: flow cytometry versus immunohistochemistry

Morphological differentiation between benign and malignant lymphoproliferative disorders (LPDs) can be challenging. Immunophenotyping (IPT) by either technique, flow cytometry or immunohistochemistry (IHC), is an important step in solving such difficulty. Thirty-five newly diagnosed patients with chronic B-cell neoplasms (11 chronic lymphocytic leukemia, 22 non Hodgkin lymphoma and 2 hairy cell leukemia) were included in this study with age range from 20 to 70 years. Monoclonal antibodies surface expression using lymphoproliferative disorders panel (CD45, CD19, CD5, CD10, CD11c, CD20, CD22, CD23, CD38, CD79b, FMC7, CD103, CD25, kappa and lambda light chains) by flow cytometry was done on bone marrow samples. CD20, CD5, CD23, Bcl-2, Bcl-6, kappa and lambda light chain immunostaining were performed on fixed bone marrow trephine biopsy specimen. The sensitivity of IHC was 81.8% in chronic lymphocytic leukemia (CLL) and 100% in non Hodgkin lymphoma (NHL) as regards CD20, 100% in both groups as regards CD5, 46% in CLL and 66.7% in NHL as regards CD23, 33.3% in CLL and 50% in NHL as regards kappa chain, 20% in CLL and 33.3% in NHL as regards lambda chain. We found that IHC and flow cytometry are equally effective in diagnosing CLL; however, IHC might be slightly more sensitive than flow cytometry in detecting bone marrow infiltration in NHL and hairy cell leukemia (HCL).

Prognostic value of immunohistochemical biomarkers at different cut-off values in patients with diffuse large B-cell lymphoma treated with CHOP chemotherapy

Many predictive models have been proposed for better stratification of diffuse large B-cell lymphoma (DLBCL). Hans' algorithm has been widely used as standard to sub-classify DLBCL into germinal center B-cell (GCB) and non-GCB origins. However, there have been disagreements in the literature regarding its prognostic significance. Here, we retrospectively analyzed Hans' algorithm and the individual immunohistochemical biomarkers at different cut-off values (5%, 30%, 50% or 75%) in 94 Korean patients with DLBCL treated with combination chemotherapy with cyclophosphamide, daunorubicin, vincristine, and prednisone. No significant differences were observed between the GCB (18 patients, 19.1%) and non-GCB (76, 80.9%) groups. Among individual biomarkers, CD10 negativity (cut point: 30%) and bcl-6 positivity (cut point: 5%) were independent good prognostic markers in progression-free survival (PFS), whereas bcl-6 (cut point: 5%) positivity was an independent good prognostic marker in overall survival irrelevant of international prognostic index. The present study showed the lack of predictability of Hans' algorithm in DLBCL patients, and that CD10, Bcl-6 may have diverse prognostic significance at different cut-off values. Our results suggest that the proposed cut-off value may not be applied universally, and that the optimal cut-off value may need to be optimized for individual laboratory.

Molecular pathogenesis of diffuse large B-cell lymphoma

In past years, substantial insight regarding the pathogenesis of diffuse large B-cell lymphoma has been obtained. Particularly, based on gene expression profile analysis, this disease can be classified into distinct phenotypic subgroups and specific transcriptional programs have been identified. New technologies like next-generation whole genome/exome sequencing and genome-wide single nucleotide polymorphism array analysis have revealed novel lesions involved in the pathogenesis of this disease. This review focuses on the diversity of genetic lesions identified in the different subtypes of diffuse large B-cell lymphoma.

Prognostic relevance of immunohistochemical subclassification of diffuse large B-cell lymphoma in two prospective phase III clinical trials

PURPOSE

Until now molecular biologic techniques have not been easily used in daily clinical practice to stratify patients for therapeutic purposes. Therefore, we have investigated the prognostic relevance of the immunohistochemical (IHC) germinal center B-cell (GCB) versus non-GCB diffuse large B-cell lymphoma (DLBCL) subtypes.

PATIENTS AND METHODS

We have analyzed tumor samples from patients treated in 2 prospective multicenter phase III trials, ie HOVON 25 (patients≥65 years, n=153) and HOVON 26 (patients<65 years, n=144) using whole sections (WS) or tissue microarray (TMA). CD10, BCL6, and MUM1 were applied in a specific IHC algorithm. The effect on clinical outcome using WS or TMA and variations in cut-off levels of these markers was also investigated.

RESULTS

The GCB subtype was not associated with a better OS in either trial. Small differences were observed in the HOVON 25 trial between techniques, with TMA showing a better outcome for GCB than did WS. Variation of cut-off levels in the specific algorithm did not improve the prediction of clinical outcome.

CONCLUSION

We did not observe a consistent predictive power of the GCB and non-GCB classification by IHC in this large series of DLBCL patients treated with CHOP. This underscores the need to determine the biologic variation and the standardization of the protein expression levels and to further study the relevance of prognostic IHC classifications, preferably in phase III clinical trials.