Bcl-2, Bcl-6, and the International Prognostic Index are prognostic indicators in patients with diffuse large B-cell lymphoma treated with rituximab-containing chemotherapy

Bcl-6-dependent risk stratification by nuclear expression of Peli1 in diffuse large B-cell lymphoma

Background/Aim: Peli1 is an E3 ubiquitin ligase involving lymphomagenesis by lysine 63 ubiquitination-mediated stabilization of Bcl-6 with in diffuse large B-cell lymphoma (DLBCL). Materials and Methods: We categorized nuclear expression of Peli1 according to Bcl-6 status by immunohistochemistry in DLBCL (n=100), and analyzed clinicopathologic association with prognosis. Results: We established Bcl-6/Peli1 risk model composed of high risk (Bcl-6+/Peli1+ or Bcl-6-/Peli1-; n=64) and low risk (Bcl-6+/Peli1- or Bcl-6-/Peli1+; n=36). High risk group had more frequent non-GCB subtype (83% vs 64%; p=0.033) and Bcl-6-negativity (69% vs 28%; p<0.001) than low risk group. Univariate survival analysis for progression-free survival (PFS) and overall survival (OS) revealed Bcl-6/Peli1 risk group (p=0.026 and p=0.021) and other conventional variables including international prognostic index (IPI), stage, ECOG performance status, number of extranodal sites were significant prognostic factors, along with B symptoms for OS. In multivariate analysis for PFS, Bcl-6/Peli1 risk group (p=0.032; HR=3.29), IPI (p=0.013; HR=3.39) and ECOG PS (p=0.035; HR=3.08) were independent prognostic factors. In multivariate analysis for OS, Bcl-6/Peli1 risk group (p=0.048; HR=7.87) and IPI (p=0.001; HR=12.15) were associated with prognosis. Conclusions: DLBCL had distinctive risk groups according to pairs of nuclear Peli1 and Bcl-6 expression. These results suggest the potential role of Peli1 and Bcl-6 in risk assessment in DLBCL.

Machine Learning Provides an Accurate Classification of Diffuse Large B-Cell Lymphoma from Immunohistochemical Data

Background:

The classification of diffuse large B-cell lymphomas into Germinal Center (GCB) and non-GC subtypes defines disease subgroups which are different both in terms of gene expression and prognosis. Given their clinical significance, several classification algorithms have been designed, some by making use of widely availability immunohistochemical techniques. Despite their high concordance with gene expression profiles (GEP) and prognostic value, these algorithms were based on technical and biological assumptions that could be improved in terms of performance for classification.

Methods:

In order to overcome this limitation, a new algorithm was obtained by analyzing a previously published dataset of 475 patients by using an automatic classification tree method.

Results:

The resulting algorithm classifies correctly 91.6% of the cases when compared to GEP, displaying a Receiver-Operator Characteristic (ROC) area under the curve of 0.934. Noteworthy features of this algorithm include the capability to classify GEP-unclassifiable cases and a significant prognostic value, both in terms of overall survival (60 months for non-GC vs not reached for GCB, P = 0.007) and progression-free survival (61.9 months vs not reached, P = 0.017).

Conclusion:

By using a machine learning classification method that avoids most pre-assumptions, the novel algorithm obtained is accurate and maintains relevant features for clinical implementation.

PATZ1 expression correlates positively with BAX and negatively with BCL6 and survival in human diffuse large B cell lymphomas

Non-Hodgkin lymphomas (NHLs) include a heterogeneous group of diseases, which differ in both cellular origin and clinical behavior. Among the aggressive malignancies of this group, the diffuse large B-cell lymphomas (DLBCLs) are the most frequently observed. They are themselves clinically and molecularly heterogeneous and have been further sub-divided in three sub-types according to different cell of origin, mechanisms of oncogenesis and clinical outcome. Among them, the germinal center B-cell-like (GCB) derives from the germinal center and expresses the BCL6 oncogene. We have previously shown that Patz1-knockout mice develop B-cell neoplasias, suggesting a tumor suppressor role for PATZ1 in human NHLs. Here, by immunohistochemical analysis of a tissue-microarray including 170 NHLs, we found that PATZ1 nuclear expression is down-regulated in follicular lymphomas and DLBCLs. Moreover, consistent with our previous results showing a PATZ1-dependent regulation of BCL6 and BAX transcription, we show that low PATZ1 nuclear expression significantly correlates with high BCL6 expression, mainly in DLBCLs, and with low BAX expression, also considering separately follicular lymphomas and DLBCLs. Finally, by analyzing overall and progression-free survival in DLBCL patients that underwent rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy, low levels of PATZ1 were significantly associated to a worst outcome and demonstrated an independent prognostic factor in multivariate analysis, including known prognostic factors of DLBCL, IPI score and cell of origin (GCB/non-GCB). Therefore, we propose PATZ1 as a new prognostic marker of DLBCLs, which may act as a tumor suppressor by enhancing apoptosis through inhibiting and enhancing transcription of BCL6 and BAX, respectively.

Partial deletion of the ALK gene in ALK-positive anaplastic large cell lymphoma

Anaplastic lymphoma kinase (ALK) protein is an orphan receptor tyrosine kinase that is constitutively activated by aberrant translocations of the ALK gene in anaplastic large cell lymphoma, ALK-positive and several other cancers. Additionally, aberrant mutation and amplification of the ALK gene, resulting in ALK kinase activation, were detected mainly in neuroblastoma. Recently, truncated ALK protein was also reported in neuroblastoma. Here, we describe a novel truncated form of the ALK transcript with in-frame skipping through exons 2 to 17 (ALKΔ2-17) in anaplastic large cell lymphoma, ALK-positive. The ALKΔ2-17 showed ligand-independent deregulated phosphorylation that initiated strong STAT3 signalling in NIH3T3 cells. The ALKΔ2-17-transduced NIH3T3 cells showed oncogenic potential in a colony formation assay. Our data indicate that the aberrant deletion of the ALK gene might be oncogenic, providing a novel insight into the oncogenic role of the ALK pathway.

Prognostic significance of HLA class I and II expression in patients with diffuse large B cell lymphoma treated with standard chemoimmunotherapy

Loss of tumor cell human leukocyte antigen (HLA) is an immune escape mechanism for malignancies. However, the effect of low HLA class I or class II expression in diffuse large B cell lymphoma (DLBCL) treated with chemoimmunotherapy with the monoclonal antibody rituximab is largely unknown. We retrospectively analyzed samples and other data from 144 patients with DLBCL who were newly diagnosed in our institution and treated with standard R-CHOP therapy. We used antibodies against pan-HLA class I and pan-HLA class II molecules to assess HLA expression and its effect on prognosis. In a multivariate analysis, loss of HLA class II expression was a significantly independent adverse factor for progression-free survival (PFS; hazard ratio 2.3; 95 % confidence interval 1.2-4.6; P = 0.01). Although HLA class I loss of expression did not correlate with prognosis, the combination of HLA class I(+) with either low peripheral lymphocyte count or CD3(+) lymphocyte count was an adverse prognostic factor for PFS. Loss of HLA class II is an International Prognostic Index (IPI)-independent adverse factor for PFS in patients with DLBCL treated with standard therapy. However, in contrast to other solid cancers, HLA class I loss was not solely a prognostic factor in DLBCL.

Thalidomide enhanced the efficacy of CHOP chemotherapy in the treatment of diffuse large B cell lymphoma: A phase II study

Cyclophosphamide, doxorubicin, vincristine, and prednisolone plus rituximab (R-CHOP) is the standard treatment for patients with diffuse large B cell lymphoma (DLBCL). However, rituximab cannot be popularly applied in a considerable number of patients with DLBCL because of economic reasons. To develop a new regimen to improve the outcome of these patients is extremely important. In our study, sixty five patients with DLBCL were randomly assigned to thalidomide plus CHOP group (n=32) or to CHOP alone group (n=33). Objective response rates (ORR) and complete remission rates (CRR) were 96.7% and 80.6% in T-CHOP group versus 78.9 % and 57.8 % in CHOP group, respectively (P <0.05). At a median follow-up of 96 months, median PFS for T-CHOP group was still not reached yet, and in CHOP group it was 22.9 months (95% CI [0-50.4]). (P=0.163). Median overall survival (OS) for T-CHOP group was also not reached, and the estimated median OS for CHOP group was 83.5 months, the difference of OS between the two groups is not significant (p=0.263). But, in patients with Bcl-2 positive and Bcl-6 negative, the median PFS in T-CHOP group was longer than that in CHOP group (111.0 vs 8.5 months (P=0.017). In addition, thalidomide did not significantly increase the grade 3/4 toxicity of CHOP. We concluded that the addition of thalidomide to the CHOP regimen significantly improved the CRR and showed a trend of improving clinical outcome in patients with DLBCL, especially for patients with Bcl-2 positive and Bcl-6 negative B-cell phenotype, without increased toxicity.

High expression of Bcl-2 predicts poor outcome in diffuse large B-cell lymphoma patients with low international prognostic index receiving R-CHOP chemotherapy

The prognostic significance of Bcl-2, Bcl-6, p53, topoisomerase II, and β-tubulin expression was evaluated in diffuse large B-cell lymphoma (DLBCL) patients treated with cyclophosphamide, doxorubicin, vincristine, prednisolone, and rituximab. Eight-year progression-free survival (PFS, P = 0.006) and overall survival (OS, P = 0.001) of patients with high Bcl-2 expression were significantly inferior to those of patients with low expression without prognostic significance of Bcl-6, p53, topoisomerase II, and β-tubulin expression. High expression of Bcl-2 was associated with poor PFS (P = 0.045) and OS (P = 0.004) only in patients with low international prognostic index (IPI). In multivariate analysis, high expression of Bcl-2 was a significant independent prognostic factor of poor PFS (P = 0.026) and OS (P = 0.007) along with high IPI. In conclusion, the expression of Bcl-2 may be a useful prognostic factor, especially in DLBCL patients with low IPI.

Combination of BCL-2 and MYC protein expression improves high-risk stratification in diffuse large B-cell lymphoma

Purpose

To evaluate whether the addition of two biological markers (MYC and BCL-2 protein overexpression) improves the stratification of high-risk patients with diffuse large B-cell lymphoma (DLBCL).

Method

Seven risk factors were identified at diagnosis, and a maximum of 7 points were assigned to each patient. The patients were classified according to four risk groups: low (0–1), low-intermediate (2–3), high-intermediate (4), and high (5–7). Only high-risk patients with DLBCL were included in this analysis. We retrospectively examined 20 cases from 2008 to 2013 at the Nanjing Drum Tower Hospital.

Results

The median expression of MYC protein was 60%, and 17 of 20 (65%) evaluable cases overexpressed MYC. The median expression of BCL-2 protein was also 60%. Eighteen of 20 (90%) evaluable cases showed BCL-2 overexpression. Additionally, 12 out of 20 cases (60%) demonstrated coexpression of MYC and BCL-2 proteins. The percentages of overall survival and progression-free survival at the median follow-up time (36 months) were 33.3%±16.1% and 16.9%±13.5%, respectively. By comparison, nine, four, and 20 patients were classified as high risk based on the International Prognostic Index (IPI), National Comprehensive Cancer Network(NCCN)-IPI, and revised IPI criteria, respectively. According to the IPI and NCCN-IPI stratification, the risk groups demonstrated closely overlapping survival curves. In addition, four out of 20 cases were identified as low-intermediate risk according to the NCCN-IPI criteria.

Conclusion

The addition of MYC and BCL-2 protein expression to the IPI could identify a subset of DLBCL patients with high-risk clinicopathological characteristics and poor clinical outcome.

Prognostic significance of immunophenotypes and a nodular pattern in primary mediastinal large B-cell lymphoma

To investigate the clinicopathological and prognostic significance of a nodular pattern and immunophenotypes in primary mediastinal large B-cell lymphoma (PMBL), histopathological features, including a nodular pattern and immunophenotypes, were analyzed in 58 Japanese PMBL patients. The patients were 23 men and 35 women with a median age of 31 years. The 4-year progression free survival (PFS) rate was 78%, and the 4-year overall survival (OS) rate was 89%. Among the histopathological and immunohistochemical features, Bcl6(+) (P = 0.013), MUM1(+) (P = 0.091), and pale cytoplasm (P = 0.064) were favorable prognostic indicators of PFS, and Bcl6(+) (P = 0.051) and MUM1(+) (P = 0.07) were favorable prognostic indicators of OS. Patients with Bcl2 negativity (n = 11) had 4-year PFS and OS rates of 100%. Histologically, a nodular pattern, resembling nodular sclerosis classical Hodgkin lymphoma (CHL), was observed in 22 patients (38%). However, this was not a significant prognostic indicator. In conclusion, Bcl6(+) , MUM1(+) , Bcl2(-) , and pale cytoplasm are candidate favorable prognostic indicators for PMBL and should be further examined in larger studies. We suggest that PMBL with a nodular pattern may belong to the same histological spectrum as nodular sclerosis CHL.

Poor concordance among nine immunohistochemistry classifiers of cell-of-origin for diffuse large B-cell lymphoma: implications for therapeutic strategies

PURPOSE

The opportunity to improve therapeutic choices on the basis of molecular features of the tumor cells is on the horizon in diffuse large B-cell lymphoma (DLBCL). Agents such as bortezomib exhibit selective activity against the poor outcome activated B-cell type (ABC) DLBCL. In order for targeted therapies to succeed in this disease, robust strategies that segregate patients into molecular groups with high reliability are needed. Although molecular studies are considered gold standard, several immunohistochemistry (IHC) algorithms have been published that claim to be able to stratify patients according to their cell-of-origin and to be relevant for patient outcome. However, results are poorly reproducible by independent groups.

EXPERIMENTAL DESIGN

We investigated nine IHC algorithms for molecular classification in a dataset of DLBCL diagnostic biopsies, incorporating immunostaining for CD10, BCL6, BCL2, MUM1, FOXP1, GCET1, and LMO2. IHC profiles were assessed and agreed among three expert observers. A consensus matrix based on all scoring combinations and the number of subjects for each combination allowed us to assess reliability. The survival impact of individual markers and classifiers was evaluated using Kaplan-Meier curves and the log-rank test.

RESULTS

The concordance in patient's classification across the different algorithms was low. Only 4% of the tumors have been classified as germinal center B-cell type (GCB) and 21% as ABC/non-GCB by all methods. None of the algorithms provided prognostic information in the R-CHOP (rituximab plus cyclophosphamide-adriamycin-vincristine-prednisone)-treated cohort.

CONCLUSION

Further work is required to standardize IHC algorithms for DLBCL cell-of-origin classification for these to be considered reliable alternatives to molecular-based methods to be used for clinical decisions.

Clinicopathological prognostic indicators in 107 patients with diffuse large B-cell lymphoma transformed from follicular lymphoma

Follicular lymphoma (FL) frequently transforms into diffuse large B-cell lymphoma (DLBCL). To clarify the associated clinicopathological prognostic parameters, we examined the correlation of 11 histopathological parameters with progression-free survival (PFS) and overall survival (OS) in 107 consecutive patients who had DLBCL with pre-existing (asynchronous) or synchronous FL. The patients comprised 58 men and 49 women with a median age of 56 years. For DLBCL, the complete response rate was 81%, overall response rate was 88%, and 5-year PFS and OS rates were 55% and 79%, respectively. Immunohistochemical analysis of the DLBCL component revealed the following positivity rates: CD10, 64%; Bcl-2, 83%; Bcl-6, 88%; MUM1, 42%; GCB, 82%; cMyc index ≥80%, 17%; and Ki-67 index ≥90%, 19%. IGH/BCL2 fusion was positive in 57% of DLBCL cases. In univariate analyses, asynchronous FL and DLBCL (24%, P = 0.021), 100% proportion of DLBCL (29%, P = 0.004), Bcl-2 positivity (P = 0.04), and high Ki-67 index (P = 0.003) were significantly correlated with shorter PFS. Asynchronous FL and DLBCL (P = 0.003), 100% proportion of DLBCL (P = 0.001), and high Ki-67 index (P = 0.004) were significantly correlated with shorter OS. In a multivariate analysis, asynchronous FL and DLBCL (P = 0.035) and 100% proportion of DLBCL (P = 0.016) were significantly correlated with shorter OS. Thus, asynchronism and 100% proportion of DLBCL, that is, FL relapsed as pure DLBCL, or FL and DLBCL at different sites, were significant predictors of unfavorable outcome of patients with DLBCL transformed from FL.