Prognostic clinicopathologic factors, including immunologic expression in diffuse large B-cell lymphomas

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.

Identification of FCER1G related to Activated Memory CD4+ T Cells Infiltration by Gene Co-expression Network and Construction of a Risk Prediction Module in Diffuse Large B-Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) is a group of biologically heterogeneous tumors with different prognoses. The tumor microenvironment plays a vital role in the tumorigenesis and development of DLBCL, and activated memory CD4⁺ T cells are an essential component of immunological cells in the lymphoma microenvironment. So far, there are few reports about activated memory CD4+T cells infiltration and related genes in the DLBCL tumor microenvironment. This study obtained the mRNA expression profile information of the testing GSE87371 dataset and another six validation datasets (GSE53786, GSE181063, GSE10846, GSE32918, GSE32018, GSE9327, GSE3892, TCGA-DLBC) from the GEO and TCGA databases. Weighted Gene Co-expression Network Analysis (WGCNA) screened gene module associated with activated memory CD4⁺ T cells infiltration. CIBERSORT and TIMER (immune cells infiltrating estimation analysis tools) were used to identify the relationship between activated memory CD4⁺ T cells and genes associated with immune infiltrating cells in the tumor microenvironment. The least absolute shrinkage and selection operator (LASSO) built the risk prediction model and verified it using nomogram and Kaplan-Meier analysis. Further functional characterization includes Gene Ontology, KEGG pathway analysis and Gene Set Enrichment Analysis (GSEA) to investigate the role and underlying mechanisms of these genes. These results suggest that the expression of FCER1G can reflect the invasion of activated memory CD4⁺ T cells in DLBCL, which provides a new idea for studying the tumor microenvironment and may become a potential predictive biomarker for the assessment of DLBCL.

Probability calibration-based prediction of recurrence rate in patients with diffuse large B-cell lymphoma

Background

Although many patients receive good prognoses with standard therapy, 30–50% of diffuse large B-cell lymphoma (DLBCL) cases may relapse after treatment. Statistical or computational intelligent models are powerful tools for assessing prognoses; however, many cannot generate accurate risk (probability) estimates. Thus, probability calibration-based versions of traditional machine learning algorithms are developed in this paper to predict the risk of relapse in patients with DLBCL.

Methods

Five machine learning algorithms were assessed, namely, naïve Bayes (NB), logistic regression (LR), random forest (RF), support vector machine (SVM) and feedforward neural network (FFNN), and three methods were used to develop probability calibration-based versions of each of the above algorithms, namely, Platt scaling (Platt), isotonic regression (IsoReg) and shape-restricted polynomial regression (RPR). Performance comparisons were based on the average results of the stratified hold-out test, which was repeated 500 times. We used the AUC to evaluate the discrimination ability (i.e., classification ability) of the model and assessed the model calibration (i.e., risk prediction accuracy) using the H-L goodness-of-fit test, ECE, MCE and BS.

Results

Sex, stage, IPI, KPS, GCB, CD10 and rituximab were significant factors predicting the 3-year recurrence rate of patients with DLBCL. For the 5 uncalibrated algorithms, the LR (ECE = 8.517, MCE = 20.100, BS = 0.188) and FFNN (ECE = 8.238, MCE = 20.150, BS = 0.184) models were well-calibrated. The errors of the initial risk estimate of the NB (ECE = 15.711, MCE = 34.350, BS = 0.212), RF (ECE = 12.740, MCE = 27.200, BS = 0.201) and SVM (ECE = 9.872, MCE = 23.800, BS = 0.194) models were large. With probability calibration, the biased NB, RF and SVM models were well-corrected. The calibration errors of the LR and FFNN models were not further improved regardless of the probability calibration method. Among the 3 calibration methods, RPR achieved the best calibration for both the RF and SVM models. The power of IsoReg was not obvious for the NB, RF or SVM models.

Conclusions

Although these algorithms all have good classification ability, several cannot generate accurate risk estimates. Probability calibration is an effective method of improving the accuracy of these poorly calibrated algorithms. Our risk model of DLBCL demonstrates good discrimination and calibration ability and has the potential to help clinicians make optimal therapeutic decisions to achieve precision medicine.

Applying probability calibration to ensemble methods to predict 2-year mortality in patients with DLBCL

BACKGROUND

Under the influences of chemotherapy regimens, clinical staging, immunologic expressions and other factors, the survival rates of patients with diffuse large B-cell lymphoma (DLBCL) are different. The accurate prediction of mortality hazards is key to precision medicine, which can help clinicians make optimal therapeutic decisions to extend the survival times of individual patients with DLBCL. Thus, we have developed a predictive model to predict the mortality hazard of DLBCL patients within 2 years of treatment.

METHODS

We evaluated 406 patients with DLBCL and collected 17 variables from each patient. The predictive variables were selected by the Cox model, the logistic model and the random forest algorithm. Five classifiers were chosen as the base models for ensemble learning: the naïve Bayes, logistic regression, random forest, support vector machine and feedforward neural network models. We first calibrated the biased outputs from the five base models by using probability calibration methods (including shape-restricted polynomial regression, Platt scaling and isotonic regression). Then, we aggregated the outputs from the various base models to predict the 2-year mortality of DLBCL patients by using three strategies (stacking, simple averaging and weighted averaging). Finally, we assessed model performance over 300 hold-out tests.

RESULTS

Gender, stage, IPI, KPS and rituximab were significant factors for predicting the deaths of DLBCL patients within 2 years of treatment. The stacking model that first calibrated the base model by shape-restricted polynomial regression performed best (AUC = 0.820, ECE = 8.983, MCE = 21.265) in all methods. In contrast, the performance of the stacking model without undergoing probability calibration is inferior (AUC = 0.806, ECE = 9.866, MCE = 24.850). In the simple averaging model and weighted averaging model, the prediction error of the ensemble model also decreased with probability calibration.

CONCLUSIONS

Among all the methods compared, the proposed model has the lowest prediction error when predicting the 2-year mortality of DLBCL patients. These promising results may indicate that our modeling strategy of applying probability calibration to ensemble learning is successful.

An epigenetic regulator-related score (EpiScore) predicts survival in patients with diffuse large B cell lymphoma and identifies patients who may benefit from epigenetic therapy

Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma and shows considerable clinical and biological heterogeneity. Much research is currently focused on the identification of prognostic markers for more specific patients’ risk stratification and on the development of therapeutic approaches to improve the long-term outcome. Epigenetic alterations are involved in various cancers, including lymphoma. Interestingly, epigenetic alterations are reversible and drugs to target some of them have been developed. In this study, we demonstrated that the gene expression profile of epigenetic regulators has a prognostic value in DLBCL and identified pathways that could be involved in DLBCL poor outcome. We then designed a new risk score (EpiScore) based on the gene expression level of the epigenetic regulators DNMT3A, DOT1L, SETD8. EpiScore was predictive of overall survival in DLBCL and allowed splitting patients with DLBCL from two independent cohorts (n = 414 and n = 69) in three groups (high, intermediate and low risk). EpiScore was an independent predictor of survival when compared with previously described prognostic factors, such as the International Prognostic Index (IPI), germinal center B cell and activated B cell molecular subgroups, gene expression-based risk score (GERS) and DNA repair score. Immunohistochemistry analysis of DNMT3A in 31 DLBCL samples showed that DNMT3A overexpression (>42% of positive tumor cells) correlated with reduced overall and event-free survival. Finally, an HDAC gene signature was significantly enriched in the DLBCL samples included in the EpiScore high-risk group. We conclude that EpiScore identifies high-risk patients with DLBCL who could benefit from epigenetic therapy.

Prognostic efficacy of the human B-cell lymphoma prognostic genes in predicting disease-free survival (DFS) in the canine counterpart

Background

Canine B-cell lymphoma is deemed an ideal model of human non-Hodgkin’s lymphoma where the lymphomas of both species share similar clinical features and biological behaviors. However there are some differences between tumor features in both species. In the current study, we sought to evaluate the prognostic efficacy of human B-cell lymphoma prognostic gene signatures in canine B-cell lymphoma.

Methods

The corresponding probe sets of 36 human B-cell lymphoma prognostic genes were retrieved from 2 canine B-cell lymphoma microarray datasets (GSE43664 and GSE39365) (76 samples), and prognostic probe sets were thereafter detected using the univariate and multivariate Cox proportional-hazard model and the Kaplan–Meier analysis. The two datasets were employed both as training sets and as external validation sets for each other. Results were confirmed using quantitative real-time PCR (qRT-PCR) analysis.

Results

In the univariate analysis, CCND1, CCND2, PAX5, CR2, LMO2, HLA-DQA1, P53, CD38, MYC-N, MYBL1, and BIRCS5 were associated with longer disease-free survival (DFS), while CD44, PLAU, and FN1 were allied to shorter DFS. However, the multivariate Cox proportional-hazard analysis confirmed CCND1 and BIRCS5 as prognostic genes for canine B-cell lymphoma. qRT-PCR used for verification of results indicated that expression level of CCND1 was significantly higher in B-cell lymphoma patients with the long DFS than ones with the short DFS, while expression level of BIRCS5 wasn’t significantly different between two groups.

Conclusion

Our results confirmed CCND1 as important gene that can be used as a potential predictor in this tumor type.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0919-x) contains supplementary material, which is available to authorized users.

PD1 and PDL1 expression in primary central nervous system diffuse large B-cell lymphoma are frequent and expression of PD1 predicts poor survival

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare and aggressive type of diffuse large B-cell lymphoma (DLBCL) whit poorly understood pathogenesis. Finding biomarkers associated with patient survival may be important for understanding its physiopathology and to develop new therapeutic approaches. We investigated 32 PCNS-DLBCL from immunocompetent patients for BCL2, CMYC, LMO2, and P53 expression and for cytogenetic aberrations of BCL2, BCL6, and MYC genes, all known for their prognostic value in systemic DLBCL (s-DLBCL). We analyzed PD1 and PDL1 protein expression in both tumor infiltrating lymphocytes (TILs) and tumor cells. Finally, we searched for correlation between biological data and clinical course. The PCNS-DLBCL expressed BCL2, CMYC, LMO2, and P53 at similar frequency than s-DLBCL but without significant prognostic on survival. None cases harbored aberrations involving BCL2 and MYC gene whereas BCL6 abnormalities were present in 20.7% of cases but without value on survival. Expression of PD1 in TILs and PDL1 in tumor cells was observed at higher rates than in s-DLBCL (58% and 37%, respectively). The PD1 expression in TILs correlated with PDL1 expression in tumor cells (P = .001). Presence of PD1 positive TILs was associated with poorer overall survival (P = .011). Patients with PDL1 overexpression tended to better response to chemotherapy (P = .23). In conclusion PCNS-DLBCL pathogenesis differs from s-DLBCL without prognostic value of the phenotypic and cytogenetic parameters known for their pejorative impact in the latter. The PD1/PDL1 pathway plays a strong role in PCNS-DLBCL and represents an attractive target for this aggressive lymphoma.

Diffuse Large B-cell lymphoma: Prognostic markers and their impact on therapy

Diffuse large B-cell lymphoma (DLBCL) is the most common type of Non-Hodgkin lymphoma (NHL). DLBCL is clinically, pathologically and molecularly heterogeneous disease. Various clinical, pathological and molecular markers have been developed to characterize the disease. Based on these characterizations, new targeted agents are being investigated to optimize the treatment and improve the outcomes of DLBCL. Enhanced molecular understanding, invention of targeted agents and immunotherapy has opened the doors for improvement in the treatment of DLBCL. In this review, we will discuss various prognostic markers of DLBCL and their potential therapeutic implications.

Detection of Critical Genes Associated with Overall Survival (OS) and Progression-Free Survival (PFS) in Reconstructed Canine B-Cell Lymphoma Gene Regulatory Network (GRN)

Canine B-cell lymphoma GRN was reconstructed from gene expression data in the STRING and MiMI databases. Critical genes of networks were identified and correlations of critical genes with overall survival (OS) and progression-free survival (PFS) were evaluated. Significant changes were detected in the expressions of GLUL, CD44, CD79A, ARF3, FOS, BLOC1S1, FYN, GZMB, GALNT3, IFI44, CD3G, GNG2, ESRP1, and CCND1 in the STRING network and of PECAM1, GLUL, CD44, GDI1, E2F4, TLE1, CD79A, UCP2, CCND1, FYN, RHOQ, BIN1, and A2M in the MiMI network. Final survival analysis highlighted CCND1 and FOS as genes with significant correlations with OS and PFS.

BCL2, BCL6, IGH, TP53, and MYC protein expression and gene rearrangements as prognostic markers in diffuse large B-cell lymphoma: a study of 44 Turkish patients

The purpose of this study was to determine the frequency of BCL2, BCL6, IGH, TP53, and MYC protein expression and rearrangements of the respective genes in diffuse large B-cell lymphoma (DLBCL) patients and to assess their prognostic values. Samples from 44 patients with DLBCL were evaluated using fluorescence in situ hybridization and immunohistochemical analyses. BCL6 was the most rearranged gene (63.6%), followed by MYC (31.8%), TP53 (22.7%), and BCL2 (18.2%). Multiple rearrangements were detected in 40.9% of the cases. BCL6 was the most expressed protein (78.6%), followed by TP53 (69.04%), BCL2 (59.5%) and MYC (14.3%). Expression of multiple proteins was detected in 67.4% of the cases. BCL2 (P = .003) expression had a significant negative influence on overall survival,whereas BCL6 (P = .014) expression had a significant positive influence. Our results with a different pattern of gene rearrangements and associated protein overexpression indicate the molecular genetic complexity of DLBCLs, which reflects the morphologic, biologic, and clinical heterogeneity of these lymphomas.

Over-expression of Thioredoxin-1 mediates growth, survival, and chemoresistance and is a druggable target in diffuse large B-cell lymphoma

Diffuse Large B cell lymphomas (DLBCL) are the most prevalent of the non-Hodgkin lymphomas and are currently initially treated fairly successfully, but frequently relapse as refractory disease, resulting in poor salvage therapy options and short survival. The greatest challenge in improving survival of DLBCL patients is overcoming chemo-resistance, whose basis is poorly understood. Among the potential mediators of DLBCL chemo-resistance is the thioredxoin (Trx) family, primarily because Trx family members play critical roles in the regulation of cellular redox homeostasis, and recent studies have indicated that dysregulated redox homeostasis also plays a key role in chemoresistance. In this study, we showed that most of the DLBCL-derived cell lines and primary DLBCL cells express higher basal levels of Trx-1 than normal B cells and that Trx-1 expression level is associated with decreased patients survival. Our functional studies showed that inhibition of Trx-1 by small interfering RNA or a Trx-1 inhibitor (PX-12) inhibited DLBCL cell growth, clonogenicity, and also sensitized DLBCL cells to doxorubicin-induced cell growth inhibition in vitro. These results indicate that Trx-1 plays a key role in cell growth and survival, as well as chemoresistance, and is a potential target to overcome drug resistance in relapsed/refractory DLBCL.

Quantitative image analysis in the assessment of diffuse large B-cell lymphoma

Proliferation rates in diffuse large B-cell lymphoma have been associated with conflicting outcomes in the literature, more often with high proliferation associated with poor prognosis. In most studies, the proliferation rate was estimated by a pathologist using an immunohistochemical stain for the monoclonal antibody Ki-67. We hypothesized that a quantitative image analysis algorithm would give a more accurate estimate of the proliferation rate, leading to better associations with survival. In all, 84 cases of diffuse large B-cell lymphoma were selected according to the World Health Organization criteria. Ki-67 percentage positivity estimated by the pathologist was recorded from the original report. The same slides were then scanned using an Aperio ImageScope, and Ki-67 percentage positivity was calculated using a computer-based quantitative immunohistochemistry nuclear algorithm. In addition, chart review was performed and survival time was recorded. The Ki-67 percentage estimated by the pathologist from the original report versus quantitative image analysis was significantly correlated (P<0.001), but pathologist Ki-67 percentages were significantly higher than quantitative image analysis (P=0.021). There was less agreement at lower Ki-67 percentages. Comparison of Ki-67 percentage positivity versus survival did not show significant association either with pathologist estimate or quantitative image analysis. However, although not significant, there was a trend of worse survival at higher proliferation rates detected by the pathologist but not by quantitative image analysis. Interestingly, our data suggest that the Ki-67 percentage positivity as assessed by the pathologist may be more closely associated with survival outcome than that identified by quantitative image analysis. This may indicate that pathologists are better at selecting appropriate areas of the slide. More cases are needed to assess whether this finding would be statistically significant. Due to the good correlation between pathologist estimate and quantitative image analysis, there is no substantial benefit to using quantitative image analysis at this point of time.

Poor outcome in patients with diffuse large B-cell lymphoma is associated with high percentage of bcl-2 and Ki 67-positive tumor cells

BACKGROUND/AIM

Newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL) tretaed with immunochemotherapy have durable remission and improved overall survival. It is important to identify high risk patients who may benefit from even more effective therapies.

METHODS

In a group of 50 newly diagnosed patients with DLBCL, treated with CHOP/R-CHOP (cyclophosphemide doxorubicine, vincristine, prednisone with or without rituximab) regimen, we analyzed the prognostic value of the expression of Ki67 and bcl-2 at diagnosis as well as other standard clinical parameters: International Prognostic Index (IPI), bulky disease, extranodal distribution and lactat dehydrogenase (LDH). Significance was tested according to response rate and overall survival.

RESULTS

Univariate survival analysis showed that high IPI had a statistically significant negative influence on overall and event free survival time (log rank, p < 0.01). The log rank test analysis signified that patients with a high proliferative fraction (Ki-67 > 60%) had a worse overall survival rate (OS5y) of 40% compared to those with low proliferation (Ki-67 < 60%) with OS5y of 80% (p < 0.01). There was a clear difference between bcl-2 positivity (treshold 50%) and the achievement of complete remission (66% vs 86% in patients with bcl-2 high and low levels respectively, p < 0.05). In survival analysis, patients with low bcl-2 expression had significantly higher OS5y - 68% compared to those with high bcl-2+ with OS5y 37% (p < 0.05). Multivariate analysis performed by Cox model revealed that IPI > 3, high Ki-67+, bcl-2 positivity had a significant independent prognostic value concerning overall survival (p < 0.05).

CONCLUSION

An initial high IPI score associated with high Ki-67+ and bcl2+ could represent possible predictive factors of poor prognosis, which would help to identify a high risk subgroup of newly diagnosed DLBCL.

Clinical characteristics and prognostic analysis of Chinese patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma in adults. As it is a highly heterogenous disease, many studies have focused on finding useful prognostic factors to help guide therapy. In this report, we examine several biological markers in 83 patients with DLBCL enrolled in our hospital, including cell origin, serum lactate dehydrogenase (LDH) levels, and international prognostic index (IPI), in order to find the best combination of prognostic factors. We also examined whether DLBCL has a significant geographic difference, since several studies have suggested that the prevalence and potential etiological factors of lymphomas in China may be different from those in other countries. Our results demonstrate that: (1) patients in China have higher extranodal tissue involvement and different extranodal organ distribution than patients reported from other countries; (2) Chinese patients have higher rates of germinal center (GC) cell origin; and (3) among nine prognostic variables, lower IPI scores, GC cell origin determined by immunohistochemical staining, and no more than 1.5 times of normal levels of LDH are statistically significant good prognostic factors in Chinese patients with DLBCL, whereas age at the time of diagnosis, clinical stage, beta(2)-microglobulin levels, extranodal tissue involvement, and expression levels of Bcl-6 protein were not useful in determining prognosis.

Prognostic significance of immunohistochemical classification of diffuse large B-cell lymphoma

AIM

To evaluate the clinical significance of immunoperoxidase staining for CD10, bcl-6, mum-1 and bcl-2 to subdivide DLBCL into prognostic subgroups, we analysed 50 DLBCL cases using immunohistochemical methods.

METHODS AND RESULTS

Fifty DLBCL patients were evaluated retrospectively. The expression of CD10 was associated with better OS (p=0.04) whereas expression of mum-1 was associated with worse OS (p=0.009). There were no significance of OS in case of expression of bcl-6 (p=0.05) and bcl-2 (p=0.3). They were subclassified using CD10, mum-1, bcl-6 as germinal center B-cell like (GCB) lymphoma (30%) and non-GCB lymphoma (70%). The OS and EFS (event free survival) were longer in GCB group (p=0.002) and 5-year OS for GCB group was 92% compared with only 44% for the non-GCB group (p=0.02). The OS of the GCB group also was longer compared to that of the non-GCB group in low IPI subgroup (p=0.01).

CONCLUSION

The existence of survival differences between GCB a non-GCB group also in the patients with low IPI score, showed the importance of prognostic classification in the risk-adaptive treatment approaches. The classification as GCB and non-GCB based immunostains may enable to define more accurate prognostic groups in DLBCL.

MUC1 and the MUCs: A Family of Human Mucins with Impact in Cancer Biology

Mucins represent a family of glycoproteins characterized by repeat domains and a dense O-glycosylation. During the last two decades, the gene and peptide structures of various mucins as well as their glycosylation states were partly elucidated. Characteristic tumor-associated alterations of the expression patterns and glycosylation profiles were observed in biochemical, immunochemical, and histological studies and are discussed in the light of efforts to use the most prominent member in this family, MUC1, as a tumor target in anti-tumor strategies. Within this context the present review, focusing on MUC1, describes recent work on the regulation of mucin biosynthesis by cytokines and hormones, the role of mucins in cell adhesion, and their interaction with the immune system. Important aspects of clinical diagnostics based on mucin antigens are discussed, including the application of tumor serum assays and the significance of numerous studies revealing correlations between the expression of peptide cores or mucin-associated carbohydrates and clinicopathological parameters like tumor progression and prognosis.

Pediatric diffuse large B-cell lymphoma demonstrates a high proliferation index, frequent c-Myc protein expression, and a high incidence of germinal center subtype: Report of the French-American-British (FAB) international study group

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) makes up 10-20% of pediatric non-Hodgkin lymphoma, and these patients have a significantly better prognosis than adults with DLBCL. The difference in prognosis may be related to clinical, phenotypic, and/or biological differences between adult and pediatric DLBCL. In adult DLBCL, the germinal center (GC) phenotype is associated with a better prognosis than the activated B-cell (ABC) phenotype. However, a high proliferative index and expression of Bcl2 and c-Myc protein have all been associated with worse outcomes. While multiple studies have addressed the phenotype and expression patterns of adult DLBCL, relatively little is known about these biological variables in pediatric DLBCL. The goal of this study was to investigate the proliferative index, the relative frequencies of the GC and non-GC subtypes, and the expression of Bcl2 and c-Myc protein in a cohort of children with DLBCL treated in a uniform manner.

PROCEDURE

We performed immunohistochemistry (IHC) for MIB1, CD10, Bcl6, MUM1, Bcl2, and c-Myc on DLBCL tissue from children treated uniformly in the FAB LMB96 trial (SFOP LMB96/CCG5961/UKCCSG/NHL 9600).

RESULTS

Compared to published adult DLBCL studies, pediatric DLBCL demonstrated moderate to high proliferation rates (83%), increased c-Myc protein expression (84%), decreased Bcl2 protein expression (28%), and an increased frequency of the GC phenotype (75%).

CONCLUSIONS

These findings suggest that there are significant biologic differences between pediatric and adult forms of DLBCL, which may contribute to the superior prognosis seen in the pediatric population relative to adult disease.

High-grade mature B-cell lymphoma with Burkitt-like morphology: results of a clinicopathological study of 72 Japanese patients

The aim of the present study was to estimate optimum chemotherapeutic regimens for high-grade mature B-cell lymphoma cases with Burkitt-like morphology (Burkitt's lymphoma [BL]/Burkitt-like lymphoma [BLL]) patients. We analyzed 72 BL/BLL, including 36 with the c-myc translocation (molecular BL [mBL]), 20 without it (mBL-like), and 16 in whom we were uncertain regarding the existence of the c-myc translocation, and compared them with 182 diffuse large B-cell lymphoma (DLBCL) cases. On clinical and immunophenotypic analysis, the typical BL immunophenotype (CD10 positive, bcl-2 negative, and Ki-67 index >or=95%) was noted in 23 (66%) and 11 (55%) of the 35 mBL and 20 mBL-like patients, respectively. The presence of the c-myc translocation and typical immunophenotype in BL did not affect the overall survival of BL/BLL. There were no significant differences between the overall survival of DLBCL (45%) and BL/BLL (50%, P = 0.85). However, the overall survival of BL/BLL patients who received cyclophosphamide, doxorubicin, vincristine, and prednisolone-related therapy (22%) was significantly lower than that of DLBCL patients (P = 0.01). In contrast, the overall survival of BL/BLL patients who received aggressive short-term chemotherapy (75%) was better than that of the patients who received cyclophosphamide, doxorubicin, vincristine, and prednisolone therapy (P < 0.01). The finding was confirmed by multivariate analysis (hazard ratio 4.4; confidence interval 2.0-9.7; P = 0.0003). We concluded that aggressive short-term chemotherapy improves survival in BL/BLL, regardless of its genetic and immunophenotypic features.

Primary testicular diffuse large B-cell lymphoma belongs to the nongerminal center B-cell-like subgroup: A study of 18 cases

The most common type of primary testicular lymphoma is diffuse large B-cell type, which has the potential for aggressive clinical behavior. Diffuse large B-cell lymphoma can be further subclassified into two major prognostic categories: germinal center B-cell-like and nongerminal center B-cell-like. Such distinction is made possible using the immunohistochemical expression of CD10, Bcl-6 and MUM1. The aim of this study was to stratify primary testicular lymphoma of the diffuse large B-cell type according to this scheme. Immunohistochemical stains for CD10, Bcl-6 and MUM1 were performed on 18 cases of primary testicular lymphoma of diffuse large B-cell type. Subclassification was carried out as previously described where CD10 and/or Bcl-6 positivity and negativity for MUM1 were considered indicative of germinal center B-cell-like type and the opposite expression as nongerminal center B-cell-like type. The proliferative activity was determined using immunostaining with the Ki-67 antibody. Of 18 cases, 16 (89%) were found to belong to the nongerminal center B-cell-like type. Two cases (11%) were classified as germinal center B-cell-like type; one had a CD10-positive, Bcl-6-positive and MUM1-negative profile, and the other was CD10 negative, Bcl-6 positive and MUM1 negative. The former occurred in a 38-year-old patient who was human immunodeficiency virus positive. All the cases expressed high proliferative activity (> or =50% Ki-67 labeling). We conclude that most (89%) primary testicular lymphomas of the diffuse large B-cell type belong to the nongerminal center B-cell-like subgroup and have high proliferative activity.

Prognostic immunohistologic markers in human tumors: why are so few used in clinical practice?

Technological advances in gene cloning and genome-wide analyses have greatly increased the number of new tumor markers that can be detected by immunohistologic techniques. While many of these have been evaluated with respect to prognosis, there is a striking discrepancy between the number of markers reported to confer prognostic information and those that are used in clinical practice. We argue that lessons learned from epidemiological studies are applicable to studies of immunohistologic markers; in particular, advances in both fields can be vitiated by non-causal associations. We suggest that the most valuable immunohistologic markers are those that reflect genetic abnormalities, that are linked to the cell of origin, or that reflect tumor infiltrating cells or stromal reactions. It should also be appreciated that a marker that is genuinely predictive of prognosis may nevertheless not find any application in clinical practice if it becomes obsolete through the introduction of newer therapies or because there is no choice of alternative treatment strategies.

Cyclin D1 splice variant and risk for non-Hodgkin lymphoma

To investigate the role of cell cycle gene variations in lymphomagenesis, we evaluated associations (odds ratios [OR] and 95% confidence intervals [CI]) in polymorphisms from seven candidate genes in 1,172 non-Hodgkin lymphoma (NHL) cases and 982 population-based controls. The cyclin D1 (CCND1) splice variant G870A (rs603965) increased NHL risk (OR(AA) = 1.4, 95% CI = 1.1-1.8, P-trend = 0.021), which was consistent for four B-cell subtypes. As CCND1 expression indicates poor NHL prognosis, our results, if true, would support its potentially dual importance in NHL etiology and survival.

Prognostic evaluation of nodal diffuse large B cell lymphoma by immunohistochemical profiles with emphasis on CD138 expression as a poor prognostic factor

Recently diffuse large B cell lymphoma (DLBCLs) was reported to be subdivided into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subgroups by using cDNA microarray and immunohistochemical markers. Tissue microarray blocks were created from 51 nodal DLBCLs with control tissue. Immunohistochemical staining for the above markers were performed. The median follow-up period was 26 months. Nodal DLBCLs were subclassified into GCB [CD10+ or CD10-/Bcl-6+/MUM1-, n=17 (33%)] and non-GC subgroups [CD10-/Bcl-6- or CD10-/Bcl-6+/MUM1+, n=35 (67%)], and were alternatively subclassified into pattern A [+ for GCB marker only, n=12 (23%)], B [Co-positive for both markers, n=13 (33%)], C [+ for activation marker only, n=18 (35%)], and D [- for both markers, n=9 (17%)]. Upon survival analysis, the GCB groups showed a relatively better survival than non-GC groups (p=0.0748). Also, pattern C (p=0.0055) and CD138+ (p=0.0008) patients had significantly lower survival rates. By multivariate analysis, CD138 expression alone was considered as an independent risk factor (p=0.031). In summary, our results add to the registration of prognostic implications for previously reported DLBCL subgroups. CD138 may play an important role as a poor prognostic marker. By using immunohistochemistry, a prognostically important subclassification of DLBCLs is possible.

Prognostic implications of p21 (Waf1/Cip1) immunolocalization in multiple myeloma

Protein p21 (Waf1/Cip1) plays a critical role in controlling the cell cycle especially as a check point of G1 and is intimately associated with important cellular activities including differentiation, senescence, tumorigenesis, and apoptosis. In the present study, we examined the expression of p21 in multiple myeloma (MM) cells for prognostic evaluation. The immunocytochemical localization of p21 could be categorized into nuclear and cytoplasmic types. The nuclear-type p21 localization was correlated with the severity of MM and the expression of proliferating cell nuclear antigen and p53. Patients with the nuclear-type p21 localization survived significantly shorter than those with the cytoplasmic-type localization. Thus, the present study suggests that p21-immunolocalization can be a useful prognostic marker of MM.

CASPAR: a hierarchical bayesian approach to predict survival times in cancer from gene expression data

MOTIVATION

DNA microarrays allow the simultaneous measurement of thousands of gene expression levels in any given patient sample. Gene expression data have been shown to correlate with survival in several cancers, however, analysis of the data is difficult, since typically at most a few hundred patients are available, resulting in severely underdetermined regression or classification models. Several approaches exist to classify patients in different risk classes, however, relatively little has been done with respect to the prediction of actual survival times. We introduce CASPAR, a novel method to predict true survival times for the individual patient based on microarray measurements. CASPAR is based on a multivariate Cox regression model that is embedded in a Bayesian framework. A hierarchical prior distribution on the regression parameters is specifically designed to deal with high dimensionality (large number of genes) and low sample size settings, that are typical for microarray measurements. This enables CASPAR to automatically select small, most informative subsets of genes for prediction.

RESULTS

Validity of the method is demonstrated on two publicly available datasets on diffuse large B-cell lymphoma (DLBCL) and on adenocarcinoma of the lung. The method successfully identifies long and short survivors, with high sensitivity and specificity. We compare our method with two alternative methods from the literature, demonstrating superior results of our approach. In addition, we show that CASPAR can further refine predictions made using clinical scoring systems such as the International Prognostic Index (IPI) for DLBCL and clinical staging for lung cancer, thus providing an additional tool for the clinician. An analysis of the genes identified confirms previously published results, and furthermore, new candidate genes correlated with survival are identified.

Immunohistochemical Expression of p53, bcl-2, and p21 waf1 in 48 Argentinean Children With Non-Hodgkin Lymphoma

BACKGROUND

Lymphoma accounts for 10% of all childhood cancers in developed countries. In Argentina, the incidence is 13.6%; of these, 53% are non-Hodgkin lymphomas (NHL) and 47% are Hodgkin lymphomas. Overexpression of p53, p21, and bcl-2 has been studied mainly in adults with NHL and correlated with clinical features and survival. The authors' aim was to analyze overexpression of these cellular oncogenes in children with NHL.

METHODS

Formalin-fixed paraffin-embedded lymph node biopsies from 48 children with NHL were studied by immunohistochemistry with monoclonal antibodies for p53, bcl-2, and p21.

RESULTS

Overexpression of p53 was detected in 81% of cases; bcl-2 positivity was 46% and p21 positivity was 42%. The p53/p21 expression patterns (types IV and V patterns), which correspond to the overexpression of nonfunctional p53, accounted for 46% of NHL. None of the studied oncogene patterns correlated with poor clinical patient outcome or histologic subtype.

CONCLUSIONS

Of 81% of cases with p53 overexpression, 46% exhibited a nonfunctional p53 pattern, and this may contribute to dysregulation of proliferation, bcl-2 expression in up to 46% of cases may reflect a failure of bcl-2 downregulation in pre-B and immature B cells.

Prognostic Biomarkers in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. Although it represents a curable disease, less than half of the patients are cured with conventional chemotherapy. The highly variable outcome reflects a heterogeneous group of tumors, with different genetic abnormalities and response to therapy. The International Prognostic Index (IPI) is useful in predicting the outcome of DLBCL patients. However, patients with identical IPI still exhibit marked variability in survival, suggesting the presence of significant residual heterogeneity within each IPI category. The discovery of specific genetic alterations and the assessment of protein expression led to the identification of multiple novel single molecular markers capable of predicting the outcome of DLBCL patients independently of clinical variables. The recent application of DNA microarrays and tissue array technologies allowed a better understanding of the biology of lymphoma and the development of novel diagnostic tools capable of improving the current models for outcome prediction. However, much confusion exists in the literature regarding the importance of different prognostic biomarkers and their applicability in routine practice. This review summarizes the recent advances in our understanding of prognostic biomarkers in DLBCL and discusses whether this is the right time for biomarkers-guided risk-adjusted therapy.

Expression of PKC-beta or cyclin D2 predicts for inferior survival in diffuse large B-cell lymphoma

We sought to determine whether identification of poor-risk subgroups of diffuse large B-cell lymphoma (DLBCL) using immunohistochemical stains would have practical utility with regard to prognosis and therapeutic decisions. Tissue microarray blocks were created using replicate samples of formalin-fixed, paraffin-embedded tissue from 200 cases of de novo DLBCL. The sections were stained with antibodies to proteins that are expressed by activated or proliferating B cells including MUM1, FOXP1, bcl-2, survivin, protein kinase C-beta (PKC-beta), cyclin D2, cyclin D3, and Ki-67. In univariate analysis, tumor expression of cyclin D2 (P = 0.025) or PKC-beta (P = 0.015) was associated with a worse overall survival, whereas none of the other markers was predictive of overall survival. Patients with DLBCL that expressed either cyclin D2 or PKC-beta had a 5-year overall survival of only 30% as compared to 52% for those who were negative for both markers (P = 0.0019). In multivariate analysis, the expression of cyclin D2 or PKC-beta was an independent predictor of poor overall survival (P = 0.035). Cyclin D2 and PKC-beta expression will be useful in designing a 'biological prognostic index' for patients with DLBCL.

Evaluation of immunophenotype in diffuse large B-cell lymphoma and its impact on prognosis

Diffuse large B-cell lymphoma (DLBCL) has been shown to be comprised of at least two prognostic entities, depending on its resemblance to normal germinal center or activated B cells, using global gene expression profiling. Also, the expression patterns of bcl-6, CD10 and IRF-4 (also known as MUM1) have been suggested as alternative means of identifying the germinal- and nongerminal center (activated B-cell like) groups. In the present study, we evaluated by immunohistochemistry the expression patterns of CD10, bcl-6, IRF-4 and bcl-2 in a large material of 161 DLBCL patients. Using two different approaches, patients with germinal center phenotype displayed a significantly better survival than the nongerminal center group. Positive staining for bcl-6 or CD10 predicted for superior survival, while expression of IRF-4 alone showed no association with prognosis. Furthermore, expression of bcl-2 was associated with worse event-free survival and overall survival. In a multivariate analysis, a high international prognostic index score (3-5), non-GC phenotype and bcl-2 were independent adverse prognostic factors. Here we confirm the prognostic importance of determining the germinal- or nongerminal center phenotype in patients with DLBCL.

Expression of Polo-Like Kinase (PLK1) in non-Hodgkin's lymphomas

Polo-like kinases (PLKs) are protein serine/threonine kinases that play important roles in cell division. Expression of PLK1 might, moreover, play a role in the pathogenesis of human neoplasms. The expression of PLK1 mRNA is closely correlated with survival in patients with malignant tumors. We investigated the expression of PLK1 in non-Hodgkin's lymphomas (NHLs) and analyzed the relationships between expression of PLK1, histological grade, and prognosis. We analyzed various types of NHLs from 118 patients using monoclonal antibodies against PLK1 and Ki-67. The levels of expression of PLK1 and Ki-67 were significantly lower in low-grade NHLs than in high-grade and intermediate-grade NHLs (P < 0.001). Moreover, when patients were grouped in terms of 5-year overall survival ( > 70%, group A; 50 - 70%, group B; 30 - 49%, group C; and < 30%, group D), levels of expression of PLK1 and Ki-67 were found to be significantly higher in group D than in group A and they were also significantly higher in group C than in group A (P < 0.001). Conversely, the level of expression, of Ki-67 was significantly lower in group D than in group C (P < 0.05). The labeling indices specific for PLK1 were generally higher than those specific for Ki-67. Once we divided all patients into two groups in terms of the expression levels, high-level expression group of PLK1 (PLK1 index of 70%) and Ki-67 (Ki-67 indices of 60%) and low-level expression, one of these markers (PLK1 index of >/= 70%, Ki-67 indices of >/= 60%) had a similar prognosis, an observation that can be explained by the fact that rapidly proliferating group is more drug-sensitive than the other. Our study demonstrates that expression of PLK1 might reflect the malignant potential of NHLs and that PLK1 might be more useful than Ki-67 for the detection of proliferative cells.

Cytogenetic features of de novo CD5-positive diffuse large B-cell lymphoma: Chromosome aberrations affecting 8p21 and 11q13 constitute major subgroups with different overall survival

De novo CD5-positive diffuse large B-cell lymphoma (CD5(+)DLBCL) is regarded as a different clinicopathological entity from CD5-negative DLBCL (CD5(-)DLBCL) and mantle cell lymphoma (MCL). Because only a few published cytogenetic studies of de novo CD5(+)DLBCL are available, we investigated chromosomal changes in 23 Japanese patients who had de novo CD5(+)DLBCL. A characteristic of cytogenetic abnormalities in de novo CD5(+)DLBCL was a high incidence of chromosomal aberrations affecting 8p21 and 11q13. Major chromosomal breakpoints were concentrated at 8p21, 11q13, and 3q27. Patients with 8p21 aberrations showed aggressive clinical features, including advanced stage of disease, elevated serum LDH level, poor performance status, and an inferior survival curve compared with patients who had 11q13 changes (P = .043). Chromosomal abnormalities of both 8p21 and 11q13 were not observed in the same patient, and each abnormality showed different chromosomal gains and losses. These results indicate that de novo CD5(+)DLBCL may occur in previously unidentified subgroups that differ in their chromosomal abnormalities. The conflicting results of previous studies on prognosis may thus be explained in part by the differences in chromosomal changes.

Efficacy of rituximab plus chemotherapy in follicular lymphoma depends on Ki-67 expression

Rituximab is widely used for the treatment of B-cell non-Hodgkin's lymphoma (NHL), and encouraging results have been obtained. However, some CD20-positive NHL show minimal response to rituximab, indicating that the treatment effect depends on the presence or absence of an unidentified factor. We analyzed the relationship between the effect of rituximab plus chemotherapy and expression of Ki-67, p53 and bcl-2 and several clinical variables in cases of B-NHL, particularly follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). Forty-four patients were included in the present study, and the overall treatment response rate was 68%. Twelve of 30 patients (40%) achieved a complete response, five (16%) reached an unconfirmed complete response and 13 (43%) achieved a partial response. A high serum lactate dehydrogenase level and International Prognostic Index of high or high intermediate risk were associated with a decreased response in the case of FL. Immunohistochemical assays were performed in 18 FL patients (55%) and 15 DLBCL patients (45%). Significant correlation was found between an inferior response to treatment and high Ki-67 expression in the cases of FL (P = 0.006). p53 and bcl-2 expression did not correlate significantly with the response rate. The cell cycle appears to be an important factor in the efficacy of rituximab treatment. Ki-67 expression might be a predictor of efficacy of rituximab plus chemotherapy.

Prediction of survival in diffuse large-B-cell lymphoma based on the expression of six genes

BACKGROUND

Several gene-expression signatures can be used to predict the prognosis in diffuse large-B-cell lymphoma, but the lack of practical tests for a genome-scale analysis has restricted the use of this method.

METHODS

We studied 36 genes whose expression had been reported to predict survival in diffuse large-B-cell lymphoma. We measured the expression of each of these genes in independent samples of lymphoma from 66 patients by quantitative real-time polymerase-chain-reaction analyses and related the results to overall survival.

RESULTS

In a univariate analysis, genes were ranked on the basis of their ability to predict survival. The genes that were the strongest predictors were LMO2, BCL6, FN1, CCND2, SCYA3, and BCL2. We developed a multivariate model that was based on the expression of these six genes, and we validated the model in two independent microarray data sets. The model was independent of the International Prognostic Index and added to its predictive power.

CONCLUSIONS

Measurement of the expression of six genes is sufficient to predict overall survival in diffuse large-B-cell lymphoma.

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

Recent studies with cDNA microarrays showed that diffuse large B-cell lymphoma (DLBCL) cases with gene expression profiles similar to germinal center (GC) B cells had much better prognosis than DLBCL cases with gene expression profiles resembling activated B cells. The goal of the current study is to evaluate if using a panel of GC B-cell (CD10 and Bcl-6) and activation (MUM1/IRF4 and CD138) markers by immunohistochemistry defines prognosis in patients with de novo DLBCL. Immunohistochemical stains for the above markers were performed on paraffin-embedded tissues from 42 de novo DLBCL patients. Median follow-up in all patients was 41 months (range, 1-103 months) and in surviving patients was 65 months (range, 14-103 months). These cases could be classified into three expression patterns: GC B-cell pattern (pattern A) expressing CD10 and/or Bcl-6 but not activation markers; activated GC B-cell pattern (pattern B) expressing at least one of GC B-cell markers and one of activation markers; and activated non-GC B-cell pattern (pattern C) expressing MUM1/IRF4 and/or CD138 but not GC B-cell markers. Patients with pattern A had much better overall survival than those with the other two patterns (Kaplan-Meier survival analysis, P < 0.008, log rank test). Using multivariate Cox proportional hazards regression analysis, the international prognostic index scores and the expression pattern of these markers were independent prognostic indicators. Our results suggest that expression patterns of this panel of GC B-cell and activation markers by immunohistochemistry correlate with the prognosis of patients with DLBCL. Immunohistochemical analysis on paraffin-embedded tissues is more readily available than gene expression profiling by cDNA microarray and may provide similar prognostic information.

Telomerase activity and proliferation index in aggressive mature B-cell lymphoma: comparison to germinal center phenotypic markers

Cell proliferation may be evaluated by various methods, including Ki-67 immunohistochemistry and measures of telomerase activity. Both methods would theoretically show comparable increases in a given case. To evaluate the relationship between these 2 markers of proliferation in aggressive mature B-cell lymphomas, 48 cases were studied. The study group included 5 cases of mantle cell lymphoma (MCL); 6 cases of Burkitt's/Burkitt's-like lymphoma (BL); 9 cases of follicular lymphoma, grade 3 (FLC); and 28 cases of diffuse large B-cell lymphoma (DLC). Telomerase activity was measured as total product generated (TPG) units, and TPG results for the aforementioned cases were compared to the TPG results for 10 cases of reactive follicular hyperplasia. An overlap in TPG scores between reactive cases and lymphoma cases was found. Significant differences in both log TPG (P = 0.0443) and Ki-67 (P = 0.0006) were seen in the different lymphoma types. A positive correlation between Ki-67 percentage and TPG score was identified in FLC (r = 0.9281; P = 0.0003), but a poor correlation between these 2 indicators was seen in the other lymphoma types. Cluster analysis identified distinct patterns for MCL, FLC, and BL, but heterogeneous patterns for DLC. Because increases in both Ki-67 proliferation and telomerase activity are reported in normal germinal centers (GCs), these tests were also evaluated for usefulness as markers of a GC cell phenotype. Among the FLC and DLC cases, features of a GC phenotype significantly correlated with increased Ki-67 percentage (P = 0.0152), but not with increased log TPG. An elevated log TPG correlated with CD10 expression, and elevated Ki-67 percentage correlated with both CD10 and BCL-6 expression. TPG level and Ki-67 percentage did not correlate with the presence of t(14;18) or BCL-2 protein expression. Although the proliferation patterns were fairly distinctive for MCL, FLC, and BL, these studies show that markers of cell proliferation do not by themselves,identify distinct subtypes of large cell lymphomas. With the exception of FLC, the tumors exhibited poor correlation between telomerase activity and Ki-67 proliferation index. These tests did show some correlation with expression of GC cell phenotypic markers, however.

Variability in immunophenotype in diffuse large B-cell lymphoma and its clinical relevance

Diffuse large B-cell lymphoma (DLBCL), the single largest category of lymphoma, is a clinically and biologically heterogeneous disease entity. Clinically, patients differ in their mode of presentation and respond variably to therapy. A combination of clinical parameters can be used to predict the patient's response to therapy and survival. The pathological variability of DLBCL is expressed in morphology, immunophenotype, cytogenetic and molecular genetic features. Numerous markers detectable by immunohistochemistry and linked to different aspects of tumour biology have been studied in DLBCL, including lineage-associated and immune markers, proliferation and apoptosis markers, cell adhesion molecules, and more recently stage-specific markers of B-cell differentiation. This review summarizes these studies in regard to their clinical significance and in the light of recent advances in our understanding of the molecular pathology and histogenesis of DLBCL.

c-Myc oncogene and Cdc25A cell activating phosphatase expression in non-Hodgkin's lymphoma

The product of proto-oncogene c-Myc is a potent activator of cell proliferation. The prognostic importance of the over expression of c-Myc and its transcriptional target Cdc25A in non-Hodgkin lymphoma (NHL) patients remains to be elucidated. To determine the role and the prognostic relevance of c-Myc and Cdc25A over expression in this group, we analyzed the expression of c-Myc oncoprotein by immunohistochemistry and Cdc25A mRNA by reverse-transcription polymerase chain reaction (RT-PCR) in the biopsied lymph nodes of 59 NHL patients. Over expression of c-Myc oncoprotein (P62) was observed in 32 out of 59 samples (54.2%) and Cdc25A in 36 out of 59 (60.1%). The percentage of c-Myc oncoprotein and Cdc25A mRNA over expression was significantly increased from low grade (4/12=25%, 4/16=25%) through intermediate grade (9/20=45%, 10/20=50%) to high grade lymphoma (19/23=82.6%, 22/23=95.6%) respectively (P=0.001 for both). The proportion of patients with positive c-Myc and Cdc25A over expression was significantly higher among patients with elevated serum lactic dehydrogenase (sLDH), and serum beta 2 microglobulin compared to those with normal levels (P<0.05, <0.01, respectively). Moreover, 80 and 90% of NHL patients with bone marrow infiltration at diagnosis had c-Myc and Cdc25A over expression, respectively. On the other hand, positive c-Myc, and Cdc25A over expression were not significantly related to the grade of international prognostic index, or the presence of B symptoms or to histopathological type. The expression of c-Myc and Cdc25A was significantly elevated in those who died when compared to survivors (P<0.001 for both). Moreover, positive c-Myc and Cdc25A over expression was associated with shortened overall survival.

IN CONCLUSION

over expression of c-Myc and Cdc25A may be poor prognostic factor in NHL and associated with poor outcome. Assessments of c-Myc and Cdc25A expression in NHL at diagnosis are likely to be helpful in predicting patient outcome and selecting optimal therapeutic regimen.

Prognostic significance of bcl-2, bax, and p53 expression in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLCL) exhibits heterogeneous clinical features and varies markedly in response to treatment and prognosis. Because apoptosis-related proteins may play an important role in predicting the prognosis of DLCL, the current study investigated the prognostic significance of a high level of bcl-2, bax, and p53 expression in relation to clinical characteristics in patients with DLCL. Paraffin-embedded specimens from 94 patients with de novo DLCL were analyzed immunohistochemically for bcl-2, bax, and p53 gene expression. Cases with a positive immunohistological stain in more than 50% of the tumor cells were considered to have DLCL-positive expression. Patients were treated optimally, i.e., with radiotherapy including brief cycles of CHOP or CHOP-like regimens for patients with stage 1-2A diseases and with at least 6 cycles of CHOP or CHOP-like regimens for stage 2B-4 diseases. The responses to therapy and survival were then analyzed in 94 uniformly staged patients. bcl-2 expression was identified in 24 patients (26.4%), bax expression in 35 patients (37.6 %), and p53 expression in 21 patients (22.6%). bax expression proved to be a statistically significant prognostic factor in predicting the overall survival (OS) (P = 0.0015) and disease-free survival (DFS) (P = 0.0052), regardless of other clinical factors or immunohistological results. There was no significant difference in the OS (P = 0.0682) or DFS (P = 0.088) between the bcl-2-positive (n = 24) and bcl-2-negative (n = 67) groups. However, bcl-2 expression was found to be unfavorably associated with the OS (P = 0.0054) in a confined group with low (n = 51) or low intermediate (n = 22) IPI scores. The expression of p53 exhibited no statistical correlation with the OS or DFS. A multivariate analysis revealed that IPI score, bulky mass, and bax expression were all significantly associated with the DFS or OS. bax and bcl-2 should be considered as independent biologic prognostic parameters in DLCL, thereby aiding in the identification of patient risk groups. As such, bcl-2-positive patients with a low or low intermediate IPI score, or without a high level of bax expression could be candidates for more intensive therapy or alternative therapeutic approaches.

Expression of p53, c-Myc, or Bcl-6 suggests a poor prognosis in primary central nervous system diffuse large B-cell lymphoma among immunocompetent individuals

CONTEXT

Primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) in immunocompetent individuals, although rare, has been rising in incidence. Currently, no reliable prognostic markers are available for these individuals.

OBJECTIVE

To study the implications of expression of a panel of oncogenic proteins (Bcl-2, Bcl-6, and c-Myc) and p53 for predicting clinical outcome, particularly overall survival, in immunocompetent individuals with primary CNS DLBCL.

DESIGN

Fourteen primary CNS DLBCL cases were retrospectively studied by immunohistochemistry on formalin-fixed, paraffin-embedded sections for the expression of c-Myc, Bcl-2, Bcl-6, and p53.

RESULTS

The overall frequencies of expression for p53, c-Myc, Bcl-2, and Bcl-6 in these cases were 29%, 50%, 71%, and 57%, respectively. Cases with expression of p53, c-Myc, or Bcl-6 had a poorer overall survival than those without (Kaplan-Meier survival analysis: 50% cumulative overall survival, 2 months vs 30-60 months, P =.02, log-rank test; 9-16 months vs 21-60 months, P =.03, log-rank test; and 9-16 months vs 21-60 months, P =.16, log-rank test, respectively). The expression of Bcl-2 or proliferation activity by MIB-1 showed no correlation with overall survival. Likewise, the clinical parameters, including age, location of tumors, multiplicity of tumor lesions, and lactase dehydrogenase levels revealed no impact on overall survival.

CONCLUSION

Our results suggest that patients with expression of p53, c-Myc, or Bcl-6 have a poorer overall survival than those without. Since traditional prognostic markers in non-CNS DLBCL, such as staging and International Prognostic Index scores, are not applicable to primary CNS DLBCL, evaluation of p53, c-Myc, and Bcl-6 by immunohistochemistry may be warranted as part of prognostic evaluation in immunocompetent patients with primary CNS DLBCL. Further studies are indicated to confirm our observations.

Immunohistochemical expression of CD10 and t(14;18) chromosomal translocation may be indicators of follicle centre cell origin in nodal diffuse large B-cell lymphoma

AIMS

Although diffuse large B-cell lymphoma is categorized as a distinct entity in the REAL classification of lymphomas, it represents a heterogeneous group of neoplasms. A subgroup is probably of follicle centre cell origin and may evolve from a pre-existing follicular lymphoma. The t(14;18) chromosomal translocation can be demonstrated in the majority of follicular lymphomas and the aim of this study was to investigate the prevalence of t(14;18) translocation in a series of de novo nodal diffuse large B-cell lymphomas. We correlated this with the immunohistochemical expression of CD10, bcl2 and bcl6, markers which are usually expressed by the neoplastic cells in follicular lymphomas. We also correlated these parameters with the presence or absence of p53 protein expression by the neoplastic cells.

METHODS AND RESULTS

Nodal diffuse large B-cell lymphomas (n=34) were stained immunohistochemically with monoclonal antibodies to CD10, bcl2, bcl6 and p53 (D07). Polymerase chain reaction (PCR) for the t(14;18) translocation was also performed. Fourteen, 24 and 29 (41%, 71%, 85%) cases exhibited positivity for CD10, bcl2 and bcl6, respectively. In 12 cases there was positivity with D07 (35%). By PCR, the t(14;18) translocation was identified in five cases (15%), four of which were positive for CD10 and bcl2 and all of which were positive for bcl6. One of five cases positive for the chromosomal translocation exhibited positivity with D07.

CONCLUSIONS

In this study the t(14;18) translocation was identified in 15% of diffuse large B-cell lymphomas, all but one of which exhibited positivity for CD10, bcl2 and bcl6. These may represent cases of follicle centre cell origin which may or may not have evolved from a pre-existing follicular lymphoma. It is possible that positivity for CD10 especially may identify cases which are of follicle centre cell origin and that the absence of t(14;18) translocation in some of these cases may reflect the fact that the translocation cannot normally be demonstrated in all follicular lymphomas. Whether the presence or absence of the translocation and the immunophenotype are prognostically important should be investigated further.

Prognostic value of Bcl 10 rearrangement in diffuse large B-cell lymphoma

The role of bcl 10, a recently cloned apoptosis-associated gene, in diffuse large B-cell lymphoma (DLBL) is unknown. Here we determined the role of bcl 10 gene rearrangement on prognosis. Bcl 10 rearrangement was examined by Southern blot. Bcl 10 rearrangement was detected in 20 of 137 (14.6%) samples of DLBL. The frequency of bcl 10 rearrangement was higher in extranodal (eight of 38 cases, 21%) than in nodal (12 of 99, 12%) DLBL. The survival rate in patients with bcl 10 rearrangement tended to be better than in those with germ-line bcl 10, albeit statistically insignificant probably due to the small population sample. The superior prognosis in patients with bcl 10 rearrangement might be due to bcl 10-induced enhanced apoptosis.

Pediatric non-Hodgkin's lymphoma: clinical and biologic prognostic factors and risk allocation

The use of effective combination chemotherapy for all stages and subtypes of non-Hodgkin"s lymphoma (NHL) in children has resulted in a striking improvement in cure rates. Event-free survival now ranges from 70% to 90%, depending on the stage of disease and the NHL subtype. Risk-adapted therapy has resulted in a dramatic improvement in outcome for high-risk patients, at the cost of significantly increased short-term toxicity, and a reduction of therapy and toxicity for the lower-risk patient, while maintaining the excellent cure rate. Successful risk allocation of patients is dependent on the identification and continual validation of prognostic factors. The specific treatment protocol is the single most important factor predicting outcome today. Traditional prognostic factors such as stage and tumor burden are useful in selecting the intensity and length of therapy, rather than as a major indicator of likelihood of survival. In order to further improve cure rates and decrease toxicity, new biologic prognosticators need to be found and validated. Some promising avenues for study appear to be the presence or absence of adhesion molecules and of aberrant proteins that are specific to subtypes of lymphomas, such as soluble CD30 and anaplastic lymphoma kinase (ALK), the molecular classification of lymphomas on the basis of gene expression, and the evaluation of biologic markers for measuring early response to therapy.

Germinal center phenotype and bcl-2 expression combined with the International Prognostic Index improves patient risk stratification in diffuse large B-cell lymphoma

The International Prognostic Index (IPI) identifies poor- and good-risk patients with diffuse large B cell lymphoma (DLBCL); however, the majority of patients have an intermediate IPI, with an uncertain prognosis. To determine whether cellular factors can be combined with the IPI to more accurately predict outcome, we have analyzed 177 presentation nodal DLBCLs for the expression of bcl-2 and a germinal center (GC) phenotype (defined by expression of bcl-6 and CD10). P53 gene band shifts were detected using single-stranded conformational polymorphism polymerase chain reaction analysis of exons 5-9 and were correlated with protein expression. In a Cox regression analysis, IPI (R = 0.22, P <.0001) and bcl-2 (R = 0.14, P =.0001) were independent poor prognostic factors and a GC phenotype predicted a favorable outcome (R = -0.025, P =.02). Neither p53 expression nor band shifts had a significant effect on survival. Using the IPI alone, 8% of patients were identified as high risk. Expression of bcl-2 in the intermediate IPI group identified a further 28% of patients with an overall survival comparable to the high IPI group. In the intermediate IPI, bcl-2(-) group, the presence of a GC phenotype improved overall survival to levels approaching the IPI low group. Following this analysis only 15% of patients failed to be assigned to a favorable- or poor-risk group. Sequential addition of bcl-2 expression and GC phenotype into the IPI significantly improves risk stratification in DLBCL. For the 36% of high-risk patients with a 2-year overall survival of 19%, alternative treatment strategies should be considered in future trials.

Cytogenetic characterization of diffuse large cell lymphoma using multi-color fluorescence in situ hybridization

We have employed multi-color fluorescence in situ hybridization (M-FISH) to characterize the cytogenetic changes in 20 diffuse large B-cell lymphomas (DLBCL), that contained complex and partially characterized karyotypes. The M-FISH analysis helped to delineate 94% of the unidentified abnormalities and assisted in redefining some unidentified/misidentified karyotypic changes. Recurrent breakpoints observed in approximately 20% cases included 14q32, 3p21, 3q27, 22q12, 1q25, and 18q21 (in decreasing order), and 1p22, 1q21, 4q31, 6q21, and 8q24 (in four cases each). Numerical gain of chromosomes 7, 9, 12, and X and loss of chromosomes 1, 4, 6, 17, and Y, were noted in approximately 20% of cases. The minimum deleted regions encompassed 6q21-q25, 1p22-p36, 1q32-q44, 2p23-p25, 4q31-q35, 13p13-q14, and 17p11-p13. Two cases presented with a sole structural abnormality, and one contained a der(17)t(9;17)(p21;p13), which has not been reported earlier as a sole abnormality in DLBCL. Upon completely characterizing the karyotypes, we observed with interesting that in 55% of the cases, more than one BCL gene bearing regions was involved in translocations. In the remaining 45%, where only one or none of the BCL gene regions was involved in a rearrangement, we observed the loss of chromosomes 6 and/or 17 or partial deletions of 6q and/or 17p or gain of 7 and/or 12. Our findings suggest that, although BCL2 and BCL6 are most often implicated in DLBCL, the possibility of the disruptions of BCL3, BCL8, BCL9, and BCL10 as a "primary event" in DLBCL cannot be ruled out. Most often, a combination of events may be necessary for the genesis of DLBCL or progression of follicular lymphoma to DLBCL. Overall, M-FISH has enhanced our ability to provide a comprehensive karyotypic analysis, and has helped in defining the importance of BCL3, BCL8, BCL9, and BCL10 carrying breakpoints in DLBCL.

Angiotropic lymphoma: an immunophenotypically and clinically heterogeneous lymphoma

Angiotropic lymphoma (AL) is an uncommon lymphoma often presenting with nonspecific clinical features and having a high mortality rate. Although not specifically recognized by the Revised European-American Classification of Lymphoid Neoplasms, it likely will appear as a subtype of diffuse large B-cell lymphoma in the upcoming WHO classification. Some authors may also consider it to be a subtype of cutaneous lymphomas. Recent studies have reported an immunophenotypic heterogeneity of AL, and in rare instances, an association with other NHL. To further characterize AL, we studied the immunophenotype by immunohistochemistry for CD5, CD10, CD20, bcl-2, and bcl-6 in 18 cases of B-cell AL identified at three medical centers in North America. Bcl-2 gene rearrangement status by polymerase chain reaction and Epstein Barr virus status by in situ hybridization also were evaluated. Eight men and 10 women were identified with AL (median age 71 years). Eleven patients were diagnosed in life and seven were diagnosed at autopsy. Neurologic symptoms were the most common presentation, seen in six patients. Skin was the most commonly biopsied site. All showed classic intravascular localization; in two cases, there was also a minor diffuse large cell lymphoma component observed in some organs. Most (89%) of the cases expressed bcl-2 protein; CD10, bcl-6 and CD5 were each expressed in 22% of cases. Based on CD5 and CD10 expression, three major groups were evident: CD5-, CD10- (11 cases); CD5+, CD10- (3 cases), and CD5-, CD10+ (3 cases). Even though a follicle center lymphoma preceded the AL in one patient, we did not detect bcl-2 gene rearrangement in any of these cases. All cases were negative for Epstein Barr virus. Of the five treated with chemotherapy, two achieved a complete remission. Based on these findings, we conclude that ALs are clinically and immunophenotypically heterogeneous and may represent more than one pathogenetic entity. In some instances AL may be preceded by another lymphoproliferative disorder, raising the possibility that some cases of AL may represent a transformation from another type of lymphoma. Cutaneous manifestations of AL are common; however, it appears to be a systemic lymphoma. Although often fatal, patients with AL who are diagnosed early and treated with chemotherapy may achieve remission.

Rearrangements of bcl-1, bcl-2, bcl-6, and c-myc in diffuse large B-cell lymphomas

Diffuse large B-cell lymphoma (DLBL) is characterized by a marked degree of morphologic and clinical heterogeneity. We studied 137 patients with de novo DLBL for rearrangements of the bcl-1, bcl-2, bcl-6 and c-myc oncogenes by Southern blot analysis. Structural alterations of bcl-1, bcl-2, bcl-6, and c-myc were detected in 21 of 137 (15.3%), 8 of 137 (5.8%), 22 of 137 (16.1%), 14 of 137 (10.2%) patients, respectively. Two cases showed a combination of bcl-1 and bcl-6 rearrangements. Chromosomal analysis was performed in 31 cases of the 137 DLBL. 27 of these showed karyotypic abnormalities, and two had translocations 3q27 involving bcl-6. However, one of two cases had no rearrangement of bcl-6. Patients with rearranged bcl-6 and c-myc tended to have poorer survival than patients with germ-line. Furthermore, bcl-1 and bcl-2 rearrangements tended to have a better outcome, although the above differences were not statistically significant. Rearrangements of the bcl-1, 2, 6, and c-myc gene correlated with the clinical outcome in DLBL and may thus serve as prognostic markers in patients with this form of malignant lymphoma. However, other genetic factors are probably involved in determining prognosis.

CD10 and Bcl10 expression in diffuse large B-cell lymphoma: CD10 is a marker of improved prognosis

AIMS

Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma, is clinically and pathologically heterogeneous. The Bcl10 gene was recently isolated from the breakpoint region of t(1;14)(p22;q32) in mucosa-associated lymphoid tissue (MALT) lymphomas, and is considered to be an apoptosis-associated gene. CD10 is considered to be a marker of follicular centre B-cell differentiation. To assess the clinical significance and roles of CD10 and Bcl10 in DLBCL, we analysed 138 cases, using immunohistochemical methods.

METHODS AND RESULTS

CD10 expression was limited to the cytoplasm, whereas Bcl10 expression was detected in the cytoplasm and/or nuclei. CD10 expression was detected in 39 of 138 cases (28.2%), cytoplasmic Bcl10 in 68 cases (49.2%), and nuclear Bcl10 in 34 cases (24.6%). Nuclear Bcl10 was detected in 14 of 28 cases (50%) of extranodal DLBCL, but only 20 of 110 cases (18.2%) of nodal DLBCL. Cytoplasmic Bcl10 was detected in 19 of 28 cases (67.8%) of extranodal DLBCL and 49 of 110 cases (44.5%) of nodal DLBCL. CD10 expression closely correlated with improved survival (68% overall survival (OS) vs. 48% OS), but not with site of disease. A high International Prognostic Index (IPI) was considered to be a poor prognostic factor associated with a shorter OS. CD10 expression was detected in 27 of 84 cases (32.1%) with low-risk IPIs, and in 12 of 54 cases (22.2%) with high-risk IPIs. In the low-risk group, cases expressing CD10 carried a better prognosis than CD10- cases (93% OS vs. 71% OS), whereas this was not the case in the high-risk group (25% vs. 20%).

CONCLUSIONS

Bcl10 expression was associated with extranodal DLBCL, but not with prognosis. CD10 expression was closely associated with improved survival, but not with risk as predicted by IPI. Overall, our results suggest that CD10 expression may be useful, in combination with clinical parameters, for determining the prognosis of DLBCL.