Insights into the molecular pathogenesis of follicular lymphoma arising from analysis of geographic variation

The treatment of follicular lymphoma with CD19-directed chimeric antigen receptor T-cell therapy

Follicular lymphoma (FL) is the most common indolent non-Hodgkin lymphoma. Significant unmet need remains for patients with relapsed/refractory FL after ≥3 lines of prior therapy. While recent advancements have likely improved the survival of patients with FL, most patients will eventually relapse. The treatment of patients with FL after multiple relapses or those with refractory disease has historically led to lower overall response rates (ORR) and shorter progression-free survival (PFS) with each subsequent line of therapy. New treatments with high ORR and durable PFS are needed in this setting, particularly in patients that progress within 2 years of first line chemoimmunotherapy (POD24) and/or those refractory chemoimmunotherapy. Chimeric antigen receptor T-cell therapies targeting the B-cell antigen CD-19 have shown to be an efficacious treatment option for both heavily pretreated patients and/or patients with refractory FL, resulting in a high ORR and durable remissions.

Mutational, immune microenvironment, and clinicopathological profiles of diffuse large B-cell lymphoma and follicular lymphoma with BCL6 rearrangement

BCL6-rearrangement (BCL6-R) is associated with a favorable prognosis of follicular lymphoma (FL), but the mechanism is unknown. We analyzed the clinicopathological, immune microenvironment (immune checkpoint, immuno-oncology markers), and mutational profiles of 10 BCL6-R-positive FL, and 19 BCL6-R-positive diffuse large B-cell lymphoma (DLBCL) cases (both BCL2-R and MYC-R negative). A custom-made panel included 168 genes related to aggressive B-cell lymphomas and FL. FL cases were nodal, histological grade 3A in 70%, low Ki67; and had a favorable overall and progression-free survival. DLBCL cases were extranodal in 60%, IPI high in 63%, non-GCB in 60%, EBER-negative; and had a progression-free survival comparable to that of DLBCL NOS. The microenvironment had variable infiltration of M2-like tumor-associated macrophages (TAMs) that were CD163, CSF1R, LAIR1, PD-L1, and CD85A (LILRB3) positive; but had low IL10 and PTX3 expression. In comparison to FL, DLBCL had higher TAMs, IL10, and PTX3 expression. Both lymphoma subtypes shared a common mutational profile with mutations in relevant pathogenic genes such as KMT2D, OSBPL10, CREBBP, and HLA-B (related to chromatin remodeling, metabolism, epigenetic modification, and antigen presentation). FL cases were characterized by a higher frequency of mutations of ARID1B, ATM, CD36, RHOA, PLOD2, and PRPRD (p < 0.05). DLBCL cases were characterized by mutations of BTG2, and PIM1; and mutations of HIST1H1E and MFHAS1 to disease progression (p < 0.05). Interestingly, mutations of genes usually associated with poor prognosis, such as NOTCH1/2 and CDKN2A, were infrequent in both lymphoma subtypes. Some high-confidence variant calls were likely oncogenic, loss-of-function. MYD88 L265P gain-of-function was found in 32% of DLBCL. In conclusion, both BCL6-R-positive FL and BCL6-R-positive DLBCL had a common mutational profile; but also, differences. DLBCL cases had a higher density of microenvironment markers.

High frequency of BCL2 gene rearrangement-negative follicular lymphoma in northwestern Italy

BCL2 rearrangement is reported to be an early pathogenetic event in follicular lymphoma (FL) and it is considered as a reliable marker in the follow up of the disease. We aimed to investigate the frequency of BCL2 rearrangement in FLs from northwestern Italy, to evaluate their clinicopathological features, and to investigate alternative genetic aberrations in BCL2-negative FLs. We collected a series of 76 consecutive FLs diagnosed between 2013 and 2016. All lymphomas underwent histopathological review. Interphasic fluorescent in situ hybridization (FISH) was performed with break apart probes targeting BCL2, IGH, BCL6 and MYC on paraffin embedded (PE) and fresh frozen (FF) specimens. 1p36 region and p53 locus in BLC2-negative cases were investigated using dual color probes. Karyotype analysis was available in a subset of cases. BCL2 rearrangements were detected in 39 cases (51,3%). Of the remaining 37, 6 showed IGH rearrangement, and were further tested: 1 showed variant BCL2 translocation, 1 had BCL6 rearrangement, and the other 4 were negative for further gene rearrangements. FISH on FF specimens detected small BCL2+ clones in cases otherwise categorized as BCL2-. 1p36 and p53 deletion were observed in 1 and 8 BCL2- FLs, respectively. Karyotype analysis documented 3q, 1p and BCL6 alternative abnormalities in 3 cases. In conclusion, BCL2 rearrangement is not a constant finding in FL, its frequency being probably affected by geographical factors. Thus, it should not be considered as a reliable molecular marker in the follow up of the disease, unless it is found to be present at the initial diagnosis of FL. Alternative genetic aberrations exist in BCL2-negative cases.

t(14;18) Translocations in Dioxin-Exposed Workers

OBJECTIVE

To determine if occupational exposure to dioxins is associated with an increased frequency of t(14;18) translocations.

METHODS

A cross-sectional analysis of serum dioxin levels and t(14;18) frequencies in peripheral blood mononuclear cells in 218 former chemical plant workers and 150 population controls.

RESULTS

The workers had significantly higher geometric mean serum levels of 2,3,7,8-TCDD (26.2 vs 2.5 ppt) and TEQ (73.8 vs 17.7 ppt) than controls. There were no significant differences in the prevalence or frequency of t(14;18) translocations in the workers compared to controls. Among former workers with current or past chloracne who were t(14;18) positive, the frequency of translocations significantly increased with quartiles of 2,3,7,8-TCDD and TEQ.

CONCLUSION

Chloracne appears to modulate the association between dioxin exposure and increased frequency of t(14;18) translocations.

Clinicopathological analysis of follicular lymphoma with BCL2, BCL6, and MYC rearrangements

Most follicular lymphomas (FL) show t(14;18)/IGH-BCL2 translocation, but rearrangement (R) negative cases exist. A series of 140 FL patients with a BCL2, BCL6, and MYC gene status examined by fluorescence in situ hybridization (FISH) were classified into five groups: (a) BCL2-R group (BCL2-R/BCL6-G/MYC-G) (G, germline), 77 cases; (b) BCL2/BCL6 double-R group (BCL2-R/BCL6-R/MYC-G), 16 cases; (c) BCL6-R group (BCL2-G/BCL6-R/MYC-G), 16 cases; (d) MYC-R group (BCL2-R or G/BCL6-R or G/MYC-R), three cases; (e) Triple-G group (BCL2-G/BCL6-G/MYC-G), 28 cases. The BCL6-R group had different clinicopathological characteristics. It showed lower rates of an advanced clinical stage and bone marrow invasion, less disease progression (p = 0.036), and a 'trend' toward a favorable progression-free survival (PFS) (p = 0.06). It also showed higher rates of grade 3A and MUM1-expression, and when analyzing the interfollicular spread pattern of CD20-positive cells, had fewer cases showing the IF3+ pattern (high interfollicular spread). Moreover, cases with BCL6-R and/or BCL6 gain (with cases of BCL2 rearrangement and/or of copy number gain excluded) correlated with favorable PFS (p = 0.014) and less IF3+ pattern (p = 0.007). We demonstrated that BCL6-R FLs showed unique clinicopathological findings, and FISH of BCL2, BCL6, and MYC is useful for FL diagnosis and clinical management.

Investigation of the incidence trend of follicular lymphoma from 2008 to 2017 in Taiwan and the United States using population-based data

Background

The incidence of follicular lymphoma (FL) in Taiwan has not been well investigated since its inclusion as a histological subtype in the Taiwan Cancer Registry in 2008. The purpose of this study was to describe the incidence patterns of FL in Taiwan and compare the trends with those in other racial groups in the United States.

Materials and methods

We conducted an epidemiological study using population-based data from the Taiwan Cancer Registry, Ministry of Health and Welfare, and the 18 Surveillance, Epidemiology, and End Results (SEER) registries to evaluate the FL incidence from 2008 to 2017. We calculated the annual percent change (APC) to describe the trends in the incidence of FL in subpopulations defined by race and sex over time.

Results

The annual age-adjusted incidence rate of FL in Taiwan increased significantly from 0.59 per 100,000 persons in 2008 to 0.82 per 100,000 persons in 2017, with an APC of 3.2. By contrast, the incidence rate in whites in the United States during the same period decreased from 3.42 to 2.74 per 100,000 persons, with an APC of −2.1. We found no significant change for the blacks (APC, −1.5%), Hispanics (APC, −0.7%), and Asians or Pacific Islanders (APC, +0.7%). The temporal trend was similar between the males and females. The relative frequency of FL among the incident non-Hodgkin lymphoma (NHL) cases also increased significantly in Taiwan from 7.64% in 2008 to 11.11% in 2017 (APC = 3.8). The relative frequency of FL among the incident NHL cases in the whites decreased from 2008 to 2012 (APC, −3.8%) and then stabilized after 2012 (APC, −0.2%). By contrast, little change in relative frequency of FL among the incident NHL cases was observed in the blacks, Hispanics, and APIs between 2008 and 2017.

Conclusion

We found increases in the incidence of FL and the relative frequency of FL among the incident NHL cases in both males and females in Taiwan from 2008 to 2017. The FL incidence rates were unchanged for all races and sex groups in the United States, except for the decreases in the whites.

Upward trend in follicular lymphoma among the Korean population: 10-year experience at a large tertiary institution

Background

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma (NHL) in Western countries. However, it is relatively rare in Asia. This study examined epidemiologic characteristics of FL in South Korea, with an emphasis on recent trends of increase in cases.

Methods

We retrospectively examined 239 cases of newly diagnosed FL at a large tertiary institution in Korea (Asan Medical Center, Seoul, Republic of Korea) between 2008 and 2017. Age-adjusted incidence rates and clinicopathological variables were analyzed, and joinpoint regression analysis was used to identify the changes.

Results

The age-adjusted incidence of FL significantly increased during the study period (p = .034), and the ratio of (relative incidence) patients with FL to patients with NHL increased from 4.28% to 9.35% in the same period. Over the 10-year study assessment duration, the proportion of patients with stage III/IV FL (p = .035) and expression of BCL2 (p = .022) or BCL6 (p = .039) significantly increased. From 2013–2017, the proportion of patients with highrisk Follicular Lymphoma International Prognostic Index (FLIPI) score increased (21.5% to 28.7%), whereas that of low-risk FLIPI decreased (55.4% to 38.6%), although those results were not statistically significant (p = .066).

Conclusions

We found an increasing incidence of FL, with a disproportionate increase in the incidence of high-stage disease and recent changes in the clinicopathologic features of the Korean patient population.

Hepatitis B surface antigen positivity is associated with progression of disease within 24 months in follicular lymphoma

PURPOSE

Studies have reported a positive association between hepatitis B surface antigen (HBsAg)-positive hepatitis B virus (HBV) infection and follicular lymphoma (FL). Nevertheless, clinical information concerning chronic HBV infection in FL is sparse.

METHODS

This retrospective cohort study investigated the prognostic impact of HBsAg in immunocompetent patients with FL treated with frontline rituximab-containing chemoimmunotherapy in an HBV-endemic area between 2006 and 2016.

RESULTS

Among the 149 analyzed patients, 32 (21.5%) were HBsAg-positive. HBsAg positivity was positively associated with symptomatic splenomegaly, significant serous effusions, and peritreatment hepatic dysfunction. HBsAg-positive patients had a trend of lower complete remission rate (59.4% vs. 76.9%, P = 0.07), significantly poorer overall survival (hazard ratio for death, 2.68; 95% confidence interval, 1.21-5.92), and shorter progression-free survival than had HBsAg-negative patients. Multivariate analysis revealed that HBsAg is an independent adverse prognostic factor for overall survival. Intriguingly, HBsAg-positive patients had a higher incidence of progression of disease within 24 months (POD24) than had HBsAg-negative patients (cumulative incidence rate, 25.8% vs. 12.4%, P = 0.045).

CONCLUSION

This study revealed that patients with FL and chronic HBV infection represent a distinct subgroup with a markedly poor prognosis. HBsAg was positively associated with POD24 and might serve as a new prognostic predictor of the survival of FL patients in endemic regions for HBV infection.

A comprehensive retrospective cohort study of the journey of B-cell lymphoma in Taiwan

Complete disease journey and risk factors for poor outcomes are needed to facilitate effectiveness evaluations of new therapies and clinical decision-making in B-cell Non-Hodgkin lymphoma (B-NHL), particularly in Asia where such data are lacking. This retrospective cohort study used electronic medical records from a regional medical centre in southern Taiwan to follow-up 441 patients newly diagnosed with common B-NHL subtypes: Diffuse Large B-cell Lymphoma (DLBCL), Follicular Lymphoma (FL), Chronic Lymphocytic Leukaemia/Small Lymphocytic Lymphoma (CLL/SLL), Marginal Zone Lymphoma (MZL), Mantle Cell Lymphoma (MCL), and Waldenström macroglobulinemia (WM), between 01-Jan-2008 and 31-Dec-2013, until 31-Dec-2017. Treatment pathways were modelled using a Markov approach. Stage III/IV disease at diagnosis was frequent for patients with DLBCL, FL, MCL and WM. Hepatitis B surface antigen/hepatitis C virus seropositivity was 18.6%/12.3%. Clinical responses to 1st-line treatment were observed in 76.0% (DLBCL), 87.3% (FL), 86.0% (MZL), 60.0% (MCL), and 42.9% (WM) of patients. For DLBCL, disease control was achieved by ~ 50% after 1st-line, ~ 24% after 2nd-line, ~ 17% after 3rd-line. Patients with Stage III/IV DLBCL or age > 65 years at diagnosis had lower rates of active treatment, poorer disease control and higher mortality than patients with early stage disease or age ≤ 65 years. Disease flare < 6 months after 1st-line treatment was significantly associated with mortality. Despite good clinical response rates for some sub-types, survival remains poor. New treatments are needed to improve the outcome of B-NHL.

High-Grade B-Cell Lymphoma (HGBL) with MYC and BCL2 and/or BCL6 Rearrangements Is Predominantly BCL6-Rearranged and BCL6-Expressing in Taiwan

Simple Summary

This study highlights the epidemiological, cytogenetic and clinical difference between patients with multiple hit diffuse large B-cell lymphoma in Taiwan and those from western countries. Unlike in the West, the majority of patients with multiple hit lymphoma in Taiwan harbor a BCL6 rearrangement. Almost three in every five BCL6-rearranged double hit lymphoma cases in Taiwan are non-GCB phenotype, indicating, at least in part, that the preferential screening for double hit with BCL6 rearrangement may be a clinically-informative modality for patients with non-GCB phenotype DLBCL in Taiwan. This also suggests the need for a different treatment approach than is obtained in the West where BCL6 double hit lymphomas are seemingly GCB. Consistent with our present findings, mandatory screening for BCL6-rearrangement in suspected DLBCL cases in Taiwan may aid early diagnosis, therapy decision, and clinical outcome forecast.

Abstract

This study investigated the epidemiological and clinical peculiarities of BCL2 and BCL6 rearrangement in patients with high grade B-cell lymphoma (HGBL) from Taiwan, compared with data from Western countries. Two hundred and eighty-two DLBCL cases from Taipei Medical University-affiliated hospitals (n = 179) and Tri-Service General Hospital (n = 103) were enrolled for this study. From the 282, 47 (16.7%) had MYC translocation; 24 of these harbored concurrent BCL2 and/or BCL6 translocation (double-hit, DH or triple-hit, TH). Twelve DH-HGBL cases had simultaneous MYC and BCL6 translocations, 8 harbored MYC and BCL2 rearrangement, while the remaining 4 patients exhibited TH. Together, 66.7% of DH/TH-HGBL patients were BCL6 rearrangement positive. Among these BCL6-rearranged DH/TH-HGBL patients, only 6 (37.5%) overexpressed MYC and BCL6 proteins simultaneously, indicating that MYC-BCL6 co-overexpression may not be plausible surrogate biomarker for screening BCL6-rearranged DH-HGBL. By the end of year 5, all patients with TH-HGBL, BCL2 DH-HGBL and all but one BCL6 DH-HGBL cases had expired or were lost to follow-up. Progression-free survival (PFS) was longer for the non-DH/TH-HGBL group compared with the DH/TH-HGBL group. While the patients with BCL2 DH-HGBL were lost to follow-up by day 800, their remaining TH-HGBL and BCL6 DH-HGBL peers exhibited very poor PFS, regardless of age strata. More so, patients with BCL6 rearrangement were 5.5-fold more likely associated with extranodal involvement compared with their BCL2-rearranged peers. Moreover, ~60.0% of the BCL6-rearranged DH-HGBL cases were non-GCB, suggesting that including screening for BCL6 rearrangement in patients with the non-GCB phenotype may aid medical decision-making and therapeutic strategy. Contrary to contemporary data from western countries, 2 in every 3 patients with DH/TH-HGBL in Taiwan harbor BCL6 rearrangement. Consistent with present findings, we recommend mandatory screening for BCL6 rearrangement in patients with aggressive HGBL in Taiwan.

Orbital and Eyelid B-Cell Lymphoma: A Multicenter Retrospective Study

Simple Summary

The treatment of orbital and eyelid B-cell lymphoma remains a field of progress. The aim of our study was to analyze patients diagnosed, staged and treated for orbital and eyelid B-cell lymphoma to assess clinical characteristics, treatment outcomes and recurrence patterns. We included in this study 141 cases of orbital and eyelid B-cell lymphoma. We found five lymphoma subtypes and we confirmed that the histopathologic subtype and the type of treatment were found to be the main factors influencing treatment outcome.

Abstract

Background: The aim of this study was to analyze patients diagnosed, staged and treated for orbital and eyelid B-cell lymphoma (OEL). Methods: One hundred and forty-one cases of OEL were included in this study. Primary endpoints were to analyze the histopathologic findings, the main risk factors and the type of treatment and to correlate them with recurrence of OEL. The secondary endpoint was to determine the progression-free survival (PFS) time. Results: Extranodal marginal zone B-cell lymphoma was the most frequent subtype (66%), followed by small lymphocytic lymphoma (12.7%), diffuse large B-cell lymphoma (DLBCL) (9.2%), follicular lymphoma (6.6%), mantle cell lymphoma (4.3%) and Burkitt lymphoma (1.2%). The probability of relapse was influenced by the histopathologic subtype DLBCL (OR = 7.7, 95% CI 1.8–32.3) and treatment with chemotherapy (OR = 14.9, 95% CI 2.6–83.7). Multivariate analysis showed that the histopathologic subtype DLBCL and chemotherapy treatment retained statistical significance for a poorer PFS, with hazard ratios of 8.581 (p = 0.0112) and 9.239 (p = 0.0094), respectively. Conclusions: Five lymphoma subtypes were found in patients with OEL. The histopathologic subtype and the type of treatment were found to be the main factors influencing treatment outcome.

Treatment Patterns and Health Care Costs in Commercially Insured Patients with Follicular Lymphoma

BACKGROUND

Few studies have estimated the real-world economic burden such as all-cause and follicular lymphoma (FL)-related costs and health care resource utilization (HCRU) in patients with FL.

OBJECTIVES

This study evaluated outcomes in patients who were newly initiated with FL indicated regimens by line of therapy with real-world data.

METHODS

A retrospective study was conducted among patients with FL from MarketScan^® databases between January 1, 2010 and December 31, 2013. Patients were selected if they were ≥18 years old when initiated on a FL indicated therapy, had at least 1 FL-related diagnosis, ≥1 FL commonly prescribed systemic anti-cancer therapy after diagnosis, and did not use any FL indicated regimen in the 24 months prior to the first agent. These patients were followed up at least 48 months and the outcomes, including the distribution of regimens by line of therapy, the treatment duration by line of therapy, all-cause and FL-related costs, and HCRU by line of therapy were evaluated.

RESULTS

This study identified 598 patients who initiated FL indicated treatment. The average follow-up time was approximately 5.7 years. Of these patients, 50.2% (n=300) were female, with a mean age of 60.7 years (SD=13.1 years) when initiating their treatment with FL indicated regimens. Overall, 598 (100%) patients received first-line therapy, 180 (43.6%) received second-line therapy, 51 received third-line therapy, 21 received fourth-line therapy, and 10 received fifth-line therapy. Duration of treatment by each line of therapy was 370 days, 392 days, 162 days, 148 days, and 88 days, respectively. The most common first-line regimens received by patients were rituximab (n=201, 33.6%), R-CHOP (combination of rituximab, cyclophosphamide, doxorubicin hydrochloride [hydroxydaunomycin]; n=143, 24.0%), BR (combination of bendamustine and rituximab; n=143, 24.0%), and R-CVP (combination of rituximab, cyclophosphamide, vincristine, and prednisone; n=71, 11.9%). The most common second-line treatment regimens were (N=180): rituximab (n=78, 43.3%) and BR (n=41, 22.8%). Annualized all-cause health care costs per patient ranged from US$97 141 (SD: US$144 730) for first-line to US$424 758 (SD: US$715 028) for fifth-line therapy.

CONCLUSIONS

The primary regimens used across treatment lines conform to those recommended by the National Comprehensive Cancer Network clinical practice guidelines. The economic burden for patients with FL is high and grows with subsequent lines of therapy.

Increasing Incidence of B-Cell Non-Hodgkin Lymphoma and Occurrence of Second Primary Malignancies in South Korea: 10-Year Follow-up Using the Korean National Health Information Database

Purpose

The epidemiology of B-cell non-Hodgkin lymphoma (BNHL) in Asia is not well described, and rates of second primary malignancies (SPM) in these patients are not known. We aimed to describe temporal changes in BNHL epidemiology and SPM incidence in Korea.

Materials and Methods

A retrospective cohort study used claims data from the National Health Insurance Service that provides universal healthcare coverage in Korea. Newly diagnosed patients aged at least 19 years with a confirmed diagnosis of one of six BNHL subtypes (diffuse large cell B-cell lymphoma [DLBCL], small lymphocytic and chronic lymphocytic [CLL/SLL], follicular lymphoma [FL], mantle cell lymphoma [MCL], marginal zone lymphoma [MZL], and lymphoplasmacytic lymphoma/Waldenström’s macroglobulinemia [WM]) during the period 2006-2015 were enrolled and followed up until death, dis-enrolment, or study end, whichever occurred first. Patients with pre-existing primary cancers prior to the diagnosis of BNHL were excluded.

Results

A total of 19,500 patients with newly diagnosed BNHL were identified out of 27,866 with non-Hodgkin lymphoma (NHL). DLBCL was the most frequently diagnosed subtype (41.9%-48.4% of NHL patients annually, 2011-2015). Standardized incidence of the six subtypes studied per 100,000 population increased from 5.74 in 2011 to 6.96 in 2015, with most increases in DLBCL, FL, and MZL. The incidence (95% confidence interval) of SPM per 100 person-years was 2.74 (2.26-3.29) for CLL/SLL, 2.43 (1.57-3.58) for MCL, 2.41 (2.10-2.76) for MZL, 2.23 (2.07-2.40) for DLBCL, 1.97 (1.61-2.38) for FL, and 1.41 (0.69-2.59) for WM.

Conclusion

BNHL has been increasingly diagnosed in Korea. High rates of SPM highlight the need for continued close monitoring to ensure early diagnosis and treatment.

High-grade B-cell Lymphoma with MYC and BCL2 Rearrangement Arising from Follicular Lymphoma: Presentation as a Large Peripancreatic Mass

Follicular lymphoma, the second most common non-Hodgkin lymphoma (NHL), primarily affects adults and shows an indolent clinical course. Rare cases of follicular lymphoma transform to a high-grade B-cell lymphoma with MYC and BCL2 rearrangements or “double-hit lymphoma”. Transformation to a “double-hit lymphoma” portends a worse prognosis and requires aggressive treatment. We report a comprehensive clinical, pathologic and radiographic review of a patient with previously undiagnosed low-grade follicular lymphoma that transformed into a “double-hit lymphoma”. The patient presented with a large heterogeneous mass 16 x 19 cm involving pancreatic head and neck and a mildly enlarged inguinal lymph node. Positron emission tomography (PET) study demonstrated Fluorodeoxyglucose (¹⁸F) (FDG)-avid peripancreatic mass. Tissue biopsy demonstrated a high-grade B-cell lymphoma with rearrangements t(14;18) and MYC, leading to the diagnosis of high-grade B-cell lymphoma with MYC and BCL2 rearrangements. Excisional biopsy of an inguinal lymph node demonstrated low-grade follicular lymphoma. Clonality studies demonstrated the same immunoglobulin clone V7-4 in inguinal lymph node and peripancreatic mass. Therefore, diagnosis of a high-grade B-cell lymphoma with MYC and BCL2 rearrangements that transformed from a low-grade follicular lymphoma was rendered. It is ultimately important to establish a tissue-based diagnosis at the different sites that are involved with lymphoma. Patient proceeded with the aggressive treatment with dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (EPOCH-R) treatment.

Unraveling Tumor Heterogeneity in an Apparently Monolithic Disease: BCL2 and Other Players in the Genetic Landscape of Nodal Follicular Lymphoma

Follicular lymphoma (FL) is the most common form of non-Hodgkin lymphoma in Western countries. Although traditionally considered a well-defined, easy to diagnose lymphoproliferative disorder, in the last few years it has become clear that it is in fact composed of many different clinicopathological entities, encompassing a variegated and complex genetic background. This has led to the inclusion of specific FL variants and separate entities in the latest update of the WHO classification. However, even in the context of classical FL, many aspects of intra- and inter-tumoral heterogeneity have been recognized, with a major influence on diagnosis and clinical practice at different time points during the course of the disease. This review focuses on the molecular cytogenetic heterogeneity in classical FL from precursors and early development to progression and transformation, in terms of both clonal heterogeneity and unusual genetic features. Several factors have been investigated and suggested to contribute to the broad spectrum of clinicopathological, phenotypic, and genetic features observed in otherwise morphologically classical cases. Among them, deregulation of the epigenetic machinery and interactions with tumor microenvironment seem to play a pivotal role, together with genetic aberrations involving well-known molecular pathways and mechanisms physiologically operating in the germinal center. In the era of personalized medicine, precision diagnostics based both on understanding of the complex interplay among all these factors and on novel developments will become crucial to predict the outcome and guide the treatment of FL patients.

Distinctive incidence patterns of follicular lymphoma in Taiwan: Implications of ethnic differences

BACKGROUND

Follicular lymphoma (FL) is less prevalent in Asians, but detailed epidemiological analyses were not available. This study aimed to characterize the epidemiologic features of FL in Taiwan to explore the factors relevant to disease development and prognosis.

METHODS

We obtained epidemiological data for Taiwanese citizens during 1990-2012 from Taiwan's National Cancer Registry Database, and the corresponding data for US Caucasians from the Surveillance, Epidemiology, and End Results Program. Changes in incidence rates were evaluated with age-period-cohort (APC) analyses. Patient outcomes were compared with 5-year relative survival rates (RS) estimates.

RESULTS

Incidence rates of FL in Taiwan increased continuously during the study period (0.34 to 0.91 per 100 000 person-year from 1993-1997 to 2008-2012 in men, and from 0.29 [1993-1997] to 0.81 [2008-2012] in women), while rates in the US remained stable in both sexes, ranging between 3.73 and 3.96 in men and between 3.24 and 3.55 in women. Estimates of average annual percentage changes in incidence were significantly positive in Taiwan, but not in US Caucasians. Notably, the APC analysis identified a strong birth-cohort effect in Taiwan, corresponding to environmental alterations present during the study period. The estimated 5-year RS rates in both populations showed steady improvement, but the RS in Taiwanese patients was consistently 10% lower than in US Caucasians.

CONCLUSION

A distinct increasing trend of incidence with a strong birth-cohort effect was identified in Taiwan, providing evidence of the association between environmental factors and disease development.

A Great Mimicker in Thoracic Spine: Spinal Double Expressor Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is one of the most common causes of non-Hodgkin’s lymphoma (NHL). Some of these DLBCLs can have genetic mutations as well as protein overexpression. The genes involved are MYC, BCL-2 and BCL-6. These are very aggressive and do not respond well to standard chemotherapy regiment. Lymphomas usually show classic signs and symptoms but rarely can present with little or no symptoms or even mimic other disease processes. Here we will present a case where a spinal lymphoma mimicked a hematoma and the patient developed signs and symptoms only after mechanical fall and hitting his back.

Health Disparities and the Global Landscape of Lymphoma Care Today

Lymphoma encompass a wide variety of distinct disease entities, including, but not limited to, subtypes of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL). In the last 3 decades, therapeutic advancements have resulted in substantial improvements in lymphoma outcome. In most high-income regions, HL is a largely curable disease and for patients with two frequent subtypes of NHL, diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), survival has dramatically improved with the incorporation of rituximab as a standard treatment approach. Despite these advances, outcomes vary between and across populations. This review will provide updated information about health disparities in lymphoma in the United States and across the globe.

A Study of Clinical Profile of Primary Extranodal Lymphomas in a Tertiary Care Institute in South India

Context:

Primary extranodal lymphoma (pENL) refers to group of disorders arising from tissues other than lymph nodes. The incidence of pENL is increasing and is probably due to better diagnostic immunophenotyping and imaging modalities. Hence, this study was undertaken to ascertain the incidence, distribution, and histological subtypes of extranodal non-Hodgkin lymphoma (NHL) in a tertiary care institute in South India.

Subjects and Methods:

This was a retrospective study of patients diagnosed to have histologically proven NHL. The demographic and clinical features, laboratory parameters, imaging findings, histopathology, and immunophenotyping were documented. The lymphomas were grouped as extranodal and nodal. The data were tabulated in a Microsoft Excel sheet, and descriptive analysis was done.

Results:

Primary extranodal NHLs constituted 35.96% (41/114) of all NHLs. The B symptoms were less common in pENL compared to nodal NHL. Gastrointestinal tract (GIT) constituted the most common extranodal site (19/41, 46.34%), and diffuse large B-cell lymphoma (DLBCL) was the most common histological subtype. Majority (40/41, 97%) of the patients with pENL were immunocompetent. 31/41 (75%) patients were in Stage I–II compared to 58/73 (79.4%) patients in Stage III–IV in nodal NHL.

Conclusions:

Primary extranodal NHL constituted about one-third of patients diagnosed to have NHL at our center with the GIT being the most common site of presentation and DLBCL being the most common histology. A strong suspicion of NHL at an extranodal site with appropriate pathological and immunophenotyping evidence is needed to establish the diagnosis of a pENL.

Lack of TERT Promoter Mutations in Human B-Cell Non-Hodgkin Lymphoma

Non-Hodgkin lymphomas (NHL) are a heterogeneous group of immune cell neoplasms that comprise molecularly distinct lymphoma subtypes. Recent work has identified high frequency promoter point mutations in the telomerase reverse transcriptase (TERT) gene of different cancer types, including melanoma, glioma, liver and bladder cancer. TERT promoter mutations appear to correlate with increased TERT expression and telomerase activity in these cancers. In contrast, breast, pancreatic, and prostate cancer rarely demonstrate mutations in this region of the gene. TERT promoter mutation prevalence in NHL has not been thoroughly tested thus far. We screened 105 B-cell lymphoid malignancies encompassing nine NHL subtypes and acute lymphoblastic leukemia, for TERT promoter mutations. Our results suggest that TERT promoter mutations are rare or absent in most NHL. Thus, the classical TERT promoter mutations may not play a major oncogenic role in TERT expression and telomerase activation in NHL.

Nodal Follicular Lymphomas: A Clinicopathological Study from a Tertiary Care Centre in South India

The aim of this study was to assess the distribution of nodal follicular lymphomas (FL) among various subtypes of non- Hodgkin lymphoma and to study their clinico-pathological features. Clinical details, histomorphology including grading & patterns and immunoprofile of 44 cases were studied. Majority of the cases were grade 1 (61 %) FL. BCL2 positivity was higher in low grade FLs (97 %). An associated diffuse large B cell lymphoma component was seen in 18 % and was present only in conjunction with grade 3 FL. Majority of our patients (76 %) had a high FLIPI score and belonged to the high risk group. Our study showed that the incidence of FLs is much lower in the Indian population (14.5 %) when compared to western studies and majority were of low grade. Although there was complete initial response to treatment, relapse was common and was much higher in low grade FLs with diffuse areas on histology, Ann Arbor stage III/IV and FLIPI scores of 3-5.

Current challenges and novel treatment strategies in double hit lymphomas

High-grade B-cell lymphomas with recurrent chromosomal break points have been termed 'double hit lymphoma' (DHL). The most commonly seen DHL is diffuse large B-cell lymphoma (DLBCL) with t(14;18) and t(8;14) or t(8;22) resulting in overexpression of BCL2 and MYC, respectively. The increased proliferation due to MYC overexpression, without the ability for an apoptotic brake as a result of BCL2 overexpression, results in 'the perfect storm of oncogenesis'. Thus this disease presents a number of diagnostic and therapeutic challenges for the hematologist. The first and foremost challenge is to recognize the DHL. As different morphological entities can be affected it is incumbent on pathologists and clinicians to maintain a high index of suspicion especially in disease that appears unusually aggressive or refractory to therapy. Diagnosis by fluorescence in situ hybridization (FISH) is a sensitive and specific method for detection of the disease but is time-consuming and expensive. While detection by immunohistochemistry (IHC) is sensitive and correlates with survival, standardized methods for this are not widely agreed upon. The second and equally important challenge in DHL is optimizing clinical outcome in a group of patients for whom the prognosis is widely regarded as poor. While improvements have been achieved by dose escalating standard chemotherapeutic regimens, many patients continue to do badly. Furthermore as a disease of aging many patients are unsuitable for dose-intensive chemotherapy regimens. There are now multiple novel targeted agents in various stages of clinical development that offer hope for better outcomes without undue toxicity. Among the most exciting of these developments include specific inhibitors of both BCL2 and MYC.

Subtype distribution of lymphomas in South of Iran, analysis of 1085 cases based on World Health Organization classification

Lymphoma is one of the most common malignancies worldwide. Subtype distribution is different throughout the world. Some reports from the Middle East are in record. This article is trying to report the subtype distribution of lymphoma in Iran and compare it to that of Western, Far East Asian and Middle Eastern countries. A retrospective study was done on all lymphomas diagnosed in a large referral center in the South of Iran during a time period between 2009 and 2014. All diagnoses have been made according to 2008 WHO classification. A total number of 1085 cases with diagnoses of lymphoma retrieved. Twenty-nine cases (2.6 % of all) were precursor lymphoid neoplasm, 608 cases (56 % of all) were mature B cell neoplasm, 115 cases (10.5 % of all) were mature T and NK cell neoplasm, and 333 cases (30.6 % of all) were Hodgkin lymphoma. The six most frequent subtypes of mature B cell neoplasm were diffuse large B cell lymphoma, NOS (57 %), Burkitt lymphoma (7 %), small lymphocytic lymphoma (6.9 %), mantle cell lymphoma (5.7 %), extranodal marginal zone B cell lymphoma (5.2 %) and follicular lymphoma (3.6 %). Among mature T and NK cell neoplasm, mycosis fungoides was the most common type (43.4 %) followed by peripheral T cell lymphoma, NOS (20 %) and angioimmunoblastic T cell lymphoma (9.9 %). Of Hodgkin lymphoma cases, 90.6 % were classical type and 9.3 % were nodular lymphocyte predominant Hodgkin lymphoma. Extranodal involvement was seen in 42.2 % and GI tract was the most common site. Lymphoma frequencies were similar to that of Middle Eastern countries except for lower rate of follicular lymphoma and higher incidence of diffuse large B cell lymphoma, NOS and small lymphocytic lymphoma.

Clinical Features and Survival of Patients With Follicular Lymphoma in Korea

BACKGROUND

The incidence of follicular lymphoma (FL) varies according to geographic location. It is the second most common non-Hodgkin lymphoma in Western countries but has a very low incidence in Asia. Thus, no representative data are available for FL. Therefore, we gathered our own data to build a foundation for FL research.

PATIENTS AND METHODS

We collected a total of 343 patient records. The median age was 53 years, and the ratio of male to female patients was 1.4:1. Most patients received chemotherapy with or without rituximab.

RESULTS

The incidence of grade 1 and 2 FL was 64.9% (n = 205) and of stage III and IV was 51.2% (n = 171). The grade tended to be higher and the stage to be lower compared with Western data. In the chemotherapy group, the complete response rate was 76.0%, and the partial response rate was 17.1%. The median follow-up duration was 38.1 months. The estimated 5- and 10-year progression-free survival and overall survival rates were 68.3% and 84.9% and 63.0% and 71.3%, respectively.

CONCLUSION

We could not find definitive differences between our Korean data and the Western data, although we found some trends in the baseline characteristics. Therefore, we hope to develop an understanding of FL and perform more qualitative studies in the future.

CD5-positive follicular lymphoma: clinicopathologic correlations and outcome in 88 cases

Follicular lymphoma is a low-grade B-cell lymphoma of germinal center B-cell origin that typically lacks CD5 expression. We describe the clinicopathologic features of 88 cases of CD5+ follicular lymphoma (53 men, 35 women; median age, 60 years; range, 31-86). Follicular lymphoma was diagnosed initially in lymph nodes in 66 and extranodal sites in 22 patients. Eighty-one patients had lymphadenopathy, 66 had more than one involved site, 46 had bone marrow involvement, and 7 had splenomegaly. Staging information was available for 84 patients: 52 stage IV, 18 stage III, 12 stage II, and 2 stage I. Sixty-one cases were grade 1 or 2 and 27 were grade 3. The median proliferation index (Ki-67) was 30%. CD5 expression was detected by flow cytometry in 69, immunohistochemistry in 8, and both methods in 11 cases. The presence of t(14;18)(q32;q21)/IGH-BCL2 or other BCL2 translocation was detected in 28/44 (64%) cases. A total of 38 (43%) patients also had diffuse large B-cell lymphoma, concurrent with (n=20), subsequent to (n=13), or developing before CD5+ follicular lymphoma (n=5). All patients received chemotherapy; 12 also received stem-cell transplantation. With a median follow-up of 55 months (range, 0.5-207), 15 patients died, 46 were alive with disease, and 20 were in clinical remission. Compared with a matched group of patients with CD5- follicular lymphoma, patients with CD5+ follicular lymphoma more commonly had an International Prognostic Index >2 (35/80 vs 10/99, P<0.001), more often developed diffuse large B-cell lymphoma (38/88 vs 17/99; P<0.001), and had a shorter median progression-free survival (44 vs 89 months, P=0.0042). Higher Ki-67 and International Prognostic Index were identified as poor prognostic factors in both the groups. We conclude that CD5 expression in follicular lymphoma is associated with a higher International Prognostic Index, higher rate of transformation to diffuse large B-cell lymphoma, and shorter progression-free survival.

Influence of reproductive history and exogenous hormone use on prevalence and frequency of circulating t(14;18)-positive cells in a population-based cross-sectional study

Purpose

The t(14;18) translocation might represent an intermediate step in the pathogenesis of follicular lymphoma (FL), one of the most common subtypes of non-Hodgkin lymphoma. Circulating t(14;18)-positive cells can also be detected in 30–60 % of healthy individuals at low frequencies. Some studies found a negative association between reproductive factors or use of menopausal hormone therapy (MHT) with FL. The objective of this study was to evaluate whether there is an association between number of frequencies, oral contraceptive (OC) use, menopausal status and MHT, and t(14;18) prevalence and frequency in a representative population analysis based on an epidemiologic study in the northeastern part of Germany.

Methods

The analysis is based on results of buffy coat samples from 1,981 women of the Study of Health in Pomerania (SHIP-0) and data obtained in standardized face-to-face interviews. For prevalence, odds ratios (OR) and 95 % confidence intervals (CI) were calculated using unconditional logistic regression. Frequency data were analyzed using negative binomial regression. The multivariable models included age, number of pregnancies, menopausal status (premenopausal, natural, medical/surgical menopause), OC use and MHT as a measure for exogenous hormone exposure use.

Results

We found no association between reproductive history and combined exogenous hormone use on the prevalence of circulating t(14;18)-positive cells. Modeling MHT and OC use separately in a sensitivity analysis, the MHT parameter yielded statistical significance [OR 1.37 (95 % CI 1.04;1.81)]. t(14;18) frequency was associated with use of OC [incidence rate ratio (IRR) for ever use 3.18 (95 % CI 1.54;6.54)], current use [IRR 3.86 (1.56;9.54)], >10 years use [IRR 3.93 (1.67;9.23)] and MHT [restricted to postmenopausal women; IRR 2.63 (95 % CI 1.01;6.85)] in bivariate age-adjusted analyses. In the multivariable model, medical/surgical menopause [IRR 2.46 (1.11;5.44)] and the category ever use of OC and MHT were statistically significant [IRR 2.41 (1.09;5.33)].

Conclusions

Exogenous hormone use might be a risk factor for t(14;18) frequency rather than for t(14;18) prevalence. Further research on healthy individuals carrying a t(14;18) translocation and possible risk factors for malignant lymphoma is necessary to determine the additional molecular or immunological events that have to occur to develop FL.

Electronic supplementary material

The online version of this article (doi:10.1007/s10552-015-0525-4) contains supplementary material, which is available to authorized users.

Epidemiology and etiology of non-hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) consists of many histologically and biologically distinct lymphoid malignancies with poorly understood, but possibly distinct, etiologies. The patterns of incidence and time trend vary not only by age, sex, and race/ethnicity in the USA, but also show significant geographic differences, suggesting the potential role of infectious agents, environmental factors, and lifestyle factors in addition to host genetic status in the development of NHL. Important pathogenetic mechanisms include immune modulation and chronic antigen stimulation. Epidemiologic studies in the past two decades have provided intriguing new insights on the possible causes of lymphoma and support the idea that there is some mechanistic commonality of lymphomagenesis, but significant etiologic heterogeneity clearly exists. This review presents a summary of the current understanding of the descriptive epidemiology and etiology of NHL and suggests areas of focus for future epidemiologic research.

Clinicopathological characteristics of follicular lymphoma with peripheral blood involvement

This study aimed to indicate patient outcomes and pathological characteristics of follicular lymphoma (FL) with peripheral blood (PB) involvement. Of 533 patients with FL, 56 (11%) had PB involvement. Of the patients treated with rituximab, 39 patients with PB involvement had significantly shorter progression-free survival than 107 patients with stage IV disease without PB involvement (p = 0.021), but the overall survival was not different (p = 0.804). The histopathology of the primary sites was usually nodal (95%) low-grade (86%) FL with IGH/BCL2 fusion (75%). Flow cytometric and immunohistochemical analyses revealed that the incidence of CD10 positivity was lower in the bone marrow (55% and 58%) and PB (41% and not available) than in the primary site (86% and 93%) (p = 0.004 and p = 0.0001, respectively). Therefore, even if small lymphoma cells in the bone marrow and PB are negative for CD10, FL cannot be ruled out.

MYC expression in concert with BCL2 and BCL6 expression predicts outcome in Chinese patients with diffuse large B-cell lymphoma, not otherwise specified

Recent studies provide convincing evidence that a combined immunohistochemical or fluorescence in situ hybridization (FISH) score of MYC, BCL2, BCL6 proteins and MYC translocations predicted outcome in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). However, by far, all these researches are based on Western populations. Therefore, we investigate the prognostic relevance of MYC-, BCL2- and BCL6-rearrangements and protein expression by immunohistochemistry and FISH from 336 de novo DLBCL, NOS treated with CHOP or R-CHOP. Breaks in MYC and BCL6, and fusion in IGH/BCL2 were detected in 9.7%, 20.0%, and 11.1% of the cases, respectively, and were not significantly associated with clinical outcomes. Protein overexpression of MYC (≥40%), BCL2 (≥70%) and BCL6 (≥50%) was encountered in 51%, 51% and 36% of the tumors, respectively. On the basis of MYC, BCL2 and BCL6 expression, double-hit scores (DHSs) and triple-hit score (THS) were assigned to all patients with DLBCL. Patients with high MYC/BCL2 DHS, high MYC/BCL6 DHS and high THS had multiple adverse prognostic factors including high LDH level, poor performance status, advanced clinical stage, high International Prognostic Index (IPI) score, and non-germinal center B-cell. In univariate analysis, high MYC/BCL2 DHS, high MYC/BCL6 DHS and high THS were associated with inferior OS and PFS in both CHOP and R-CHOP cohorts (P<0.05). The highly significant correlations with OS and PFS were maintained in multivariate models that controlled for IPI (P<0.05). DLBCLs with high DHSs and high THS share the clinical features and poor prognosis of double-hit lymphoma (P>0.05). These data together suggest that the immunohistochemical DHSs and THS defined a large subset of DLBCLs with double-hit biology and was strongly associated with poor outcome in patients treated with R-CHOP or CHOP.

Role of molecular studies in the classification of lymphoma

The classification of lymphomas has historically lacked both precision and accuracy, potentially compromising both optimal diagnosis and therapy. The genetic characterization of key oncogenic events and the advent of expression profiling have afforded the opportunity to understand, diagnose and treat these diseases in a much more rational and targeted manner. As exciting as these new and testable data are, it is also worth noting that molecular genetic analysis of the tumor in isolation will not be the sole arbiter of patient outcome. It is likely that we will remain reliant on traditional and sometimes subjective technologies, albeit probably to a lesser degree, with molecular studies significantly complementing, but certainly not replacing, microscopic, immunophenotypic and cytogenetic approaches. Furthermore, we will perhaps need to extend genotyping to the tumor milieu (the patient) in order to molecularly dissect drug metabolic pathways and the immune response.

Management of B-cell non-Hodgkin lymphoma in Asia: resource-stratified guidelines

Treatment of B-cell non-Hodgkin lymphomas has undergone substantial developments in the past 10 years. The introduction of rituximab has greatly improved survival outcomes in patients. Clinical practice guidelines based on current evidence have been developed to provide recommendations for standard treatment approaches. However, guidelines do not take into account resource limitations in resource-poor countries. The huge disparities in economy, health-care infrastructure, and access to novel drugs between Asian countries can hinder the delivery of optimum care to patients with lymphoma in Asia. We outline guidelines appropriate to different levels of health-care resources and expertise, aiming to provide advice on diagnosis and treatment, unify interpretation of results, and allow the design of future studies in Asia. In this resource-adapted consensus, we summarise recommendations for diagnosis, staging, risk stratification, and treatment of common B-cell non-Hodgkin lymphomas in Asia.

Single molecule quantitation and sequencing of rare translocations using microfluidic nested digital PCR

Cancers are heterogeneous and genetically unstable. New methods are needed that provide the sensitivity and specificity to query single cells at the genetic loci that drive cancer progression, thereby enabling researchers to study the progression of individual tumors. Here, we report the development and application of a bead-based hemi-nested microfluidic droplet digital PCR (dPCR) technology to achieve ‘quantitative’ measurement and single-molecule sequencing of somatically acquired carcinogenic translocations at extremely low levels (<10⁻⁶) in healthy subjects. We use this technique in our healthy study population to determine the overall concentration of the t(14;18) translocation, which is strongly associated with follicular lymphoma. The nested dPCR approach improves the detection limit to 1 × 10⁻⁷ or lower while maintaining the analysis efficiency and specificity. Further, the bead-based dPCR enabled us to isolate and quantify the relative amounts of the various clonal forms of t(14;18) translocation in these subjects, and the single-molecule sensitivity and resolution of dPCR led to the discovery of new clonal forms of t(14;18) that were otherwise masked by the conventional quantitative PCR measurements. In this manner, we created a quantitative map for this carcinogenic mutation in this healthy population and identified the positions on chromosomes 14 and 18 where the vast majority of these t(14;18) events occur.

Primary extra nodal non Hodgkin lymphoma: a 5 year retrospective analysis

BACKGROUND AND AIM

The incidence of extra nodal non Hodgkin lymphoma (ENL) is rising throughout the world. However, data regarding ENL as a group is limited. The aim was to study the epidemiological and histomorphological trends of primary ENL (pENL) in India.

MATERIAL AND METHODS

The biopsy materials from sixty eight patients with pENL (45 male, 23 female, M:F= 1.9:1), diagnosed over a five year period (2005-2009), were analysed and pathologically reclassified according to the World Health Organization (WHO) classification, 2008 criteria.

RESULTS

Primary extra nodal non Hodgkin lymphomas constituted 22.0% (68/308) of all non Hodgkin lymphomas (NHL). The mean age at presentation for pENL and primary nodal NHL was 43 years and 58 years, respectively with a male predilection (M: F=2:1). Central nervous system (CNS) constituted the most common extranodal site (20/68, 29.5%) followed by gastrointestinal tract (17/68, 25%), and nose/nasopharynx (8/68, 11.8%). Diffuse large B-cell lymphoma (DLBCL, not otherwise specified), extranodal marginal lymphoma of mucosa associated lymphoid tissue (MALT) type, and B cell NHL unclassified (U) were the three most common histological types observed. T-cell phenotype was rarely noted (4%). Follicular lymphomas and anaplastic large cell lymphoma, seen among nodal NHL, were absent at extra nodal sites. Majority (41/68, 60%) of the patients with pENL were immunocompetent and 55% were in stage I-II with favorable prognosis.

CONCLUSION

Central nervous system was the most common site of ENL, followed by gastrointestinal tract. Majority of pENL occurred in immunocompetent hosts with a favorable prognosis.

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.

Frequencies of BCL2 and BCL6 translocations in representative Chinese follicular lymphoma patients: morphologic, immunohistochemical, and FISH analyses

The most common genetic aberration in follicular lymphoma (FL) is the t(14;18)(q32;q21) translocation that juxtaposes the antiapoptotic BCL2 gene with the promoter of the immunoglobulin heavy-chain (IgH) gene, which is the molecular hallmark of FL, whereas a subset of cases harbor translocations involving the BCL6 gene locus. To date, there has been no integrated analysis based on grade, phenotype, and genotype from large numbers of FL cases in a representative Chinese population. In this study, we graded 98 FL cases; fluorescence in situ hybridization was used to determine the BCL2 and BCL6 translocation statuses, and these were compared with morphologic and immunohistochemical parameters. The expressions of the 4 antigens were B-cell leukemia/lymphoma (BCL)-2(88.8%), BCL-6(80.6%), CD10(62.2%), and Ki67(50.0%), respectively. The frequencies of BCL2 and BCL6 translocations were 58.5% and 16.3%. In conclusion, the incidence of IgH/BCL2-positive FL in Chinese patients is relatively lower compared with that in western countries. BCL2 translocation strongly correlated with CD10 and Ki67 expression. Our data confirm the presence of a relationship between the translocation status and the FL histologic grade. All BCL6 translocations occurred in high-grade FL, and this suggests that FL carrying BCL6 translocation probably constitute a special biological subtype.

Chromosomal translocations among the healthy human population: implications in oncogenesis

Chromosomal translocations are characteristic features of many cancers, especially lymphoma and leukemia. However, recent reports suggest that many chromosomal translocations can be found in healthy individuals, although the significance of this observation is still not clear. In this review, we summarize recent studies on chromosomal translocations in healthy individuals carried out in different geographical areas of the world and discuss the relevance of the observation with respect to oncogenesis.

High levels of bcl-2 protein expression do not correlate with genetic abnormalities but predict worse prognosis in patients with lymphoblastic lymphoma

We aimed to investigate bcl-2, bcl-6, and c-myc rearrangements in patients with lymphoblastic lymphoma (LBL), especially focus on the correlation of protein expression with genetic abnormalities. Moreover, their prognostic significance was further analyzed in LBL. Protein expression and genetic abnormalities of bcl-2, bcl-6, and c-myc were investigated in microarrayed tumors from 33 cases of T cell LBL and eight cases of B cell lineage. Immunohistochemical (IHC) staining was performed to evaluate protein expression, including bcl-2, bcl-6, c-myc, TdT, CD1α, CD34, Ki-67, PAX-5, CD2, CD3, CD4, CD8, and CD20. Genetic abnormalities of bcl-2, bcl-6, and c-myc were detected by dual color fluorescence in situ hybridization (FISH). Bcl-2 protein was positive in 51.2 % (21/41) of the patients, bcl-6 protein in 7.3 % (three out of 41), and c-myc protein in 78.0 % (32/41). Bcl-2 breakpoint was found in two cases by FISH analysis. There was no evidence of bcl-6 or c-myc rearrangement in patients with LBL. However, both gene gain and loss events occurred in bcl-2, bcl-6, and c-myc. A univariate analysis showed that stage III or IV, elevated lactate dehydrogenase (LDH), and positivity for bcl-2 protein were associated with shorter survival (p<0.05). Enhanced protein expression and detectable genetic abnormalities of bcl-2, bcl-6, and c-myc were observed in patients with LBL. No statistical correlation was found between IHC results and cytogenetic findings. Stage III or IV, elevated LDH, and positivity for bcl-2 protein were identified as adverse prognostic factors. The patients with more adverse factors would have increasingly worse prognosis.

Expression of BAFF and BAFF-R in follicular lymphoma: correlation with clinicopathologic characteristics and survival outcomes

BACKGROUND

B-cell activation factor (BAFF) and BAFF-receptor (BAFF-R) play crucial roles in the viability and proliferation of malignant lymphoma cells. Limited information exists regarding expression profiles and the prognostic role of BAFF and BAFF-R in follicular lymphoma (FL). We sought to determine the expression profiles of BAFF and BAFF-R in FL and to evaluate the correlation of BAFF and BAFF-R expression with clinicopathologic characteristics and outcome of FL. Correlation between expression levels of BAFF detected by immunohistochemical (IHC) and serum levels of BAFF was also evaluated.

METHODS

Paraffin-embedded specimens from 115 patients were immunohistochemically examined for BAFF and BAFF-R expression. Expression levels were dichotomized into low versus high categories based on immunostaining intensity. The correlation of BAFF and BAFF-R expression with clinicopathologic characteristics and patient outcome was assessed. Serum levels of BAFF in 35 of the 115 patients with IHC data were measured by Enzyme-linked Immunosorbent assay (ELISA).

RESULTS

BAFF and BAFF-R were expressed in 88.7% (102/115) and 87.8% (101/115) of the cases, respectively. BAFF expression was significantly correlated with only one clinicopathologic feature: Ann Arbor stage. No significant correlation was found between expression levels of BAFF detected by IHC and serum levels of BAFF detected by ELISA. High expression of BAFF-R, but not BAFF, was significantly correlated with inferior progression-free survival (PFS; P = 0.013) and overall survival (OS; P = 0.03). High expression of BAFF-R, bulky disease, and elevated lactate dehydrogenase were correlated with inferior PFS and OS in multivariate analysis. A prognostic scoring system incorporating these 3 risk factors identified 3 distinct prognostic groups with 5-year PFS of 59.4%, 41.9%, and 10.7% and OS of 91.3%, 79.7%, and 45.8%, respectively.

CONCLUSIONS

Most patients with FL variably express BAFF and BAFF-R. High expression of BAFF-R, but not BAFF, may be an independent risk factor for PFS and OS in FL.

Follicular lymphoma: 2012 update on diagnosis and management

DISEASE OVERVIEW

Follicular lymphoma (FL) is generally an indolent B-cell lymphoproliferative disorder of transformed follicular center B cells. FL is characterized by diffuse lymphoadenopathy, involvement of bone marrow, splenomegaly, and less commonly other extranodal sites of involvement. In general, cytopenias can occur but constitutional symptoms of fever, night sweats, and weight loss are uncommon.

DIAGNOSIS

Diagnosis is based on histology of preferably a biopsy of a lymph node. Immunohistochemical staining is positive in virtually all cases for cell surface CD19, CD20, CD10, and monoclonal immunoglobulin, as well as cytoplasmic expression of bcl-2 protein. The overwhelming majority of cases have the characteristic t(14;18) translocation involving the IgH/bcl-2 genes.

RISK STRATIFICATION

The FL International Prognostic Index prognostic model for FL uses five independent predictors of inferior survival: age > 60 years, hemoglobin < 12 g/dL, serum lactate dehydrogenase > normal, Ann Arbor stage III/IV, number of involved nodal areas > 4. The presence of 0, 1, 2, and ≥ 3 adverse factors defines low, intermediate, and high-risk disease with median 10-year survivals in the pre-rituximab era of ~71, 51, and 36 months, respectively. With the use of more modern therapies, specifically anti-CD20 monoclonal antibody, the outcome has improved.

RISK-ADAPTED THERAPY

Observation continues to be adequate for asymptomatic patients with low bulk disease and no cytopenias. For patients needing therapy, most patients are treated with chemotherapy plus rituximab, which has improved response rates, duration of response, and overall survival. Randomized studies have shown additional benefit for maintenance rituximab both following chemotherapy-rituximab and single-agent rituximab. Autologous stem cell transplantation (SCT) has not shown a survival benefit in first remission patients. SCT including both autologous and allogeneic SCT or experimental agent therapy is considered for recurrent disease.

Cernunnos influences human immunoglobulin class switch recombination and may be associated with B cell lymphomagenesis

B cells from Cernunnos-deficient patients contain aberrant class switch recombination junctions, and a dominant-negative Cernunnos mutation was detected in a diffuse large B cell lymphoma sample.

Cernunnos is involved in the nonhomologous end-joining (NHEJ) process during DNA double-strand break (DSB) repair. Here, we studied immunoglobulin (Ig) class switch recombination (CSR), a physiological process which relies on proper repair of the DSBs, in B cells from Cernunnos-deficient patients. The pattern of in vivo generated CSR junctions is altered in these cells, with unusually long microhomologies and a lack of direct end-joining. The CSR junctions from Cernunnos-deficient patients largely resemble those from patients lacking DNA ligase IV, Artemis, or ATM, suggesting that these factors are involved in the same end-joining pathway during CSR. By screening 269 mature B cell lymphoma biopsies, we also identified a somatic missense Cernunnos mutation in a diffuse large B cell lymphoma sample. This mutation has a dominant-negative effect on joining of a subset of DNA ends in an in vitro NHEJ assay. Translocations involving both Ig heavy chain loci and clonal-like, dynamic IgA switching activities were observed in this tumor. Collectively, our results suggest a link between defects in the Cernunnos-dependent NHEJ pathway and aberrant CSR or switch translocations during the development of B cell malignancies.

Follicular lymphoma: 2011 update on diagnosis and management

DISEASE OVERVIEW

Follicular lymphoma (FL) is generally an indolent B-cell lymphoproliferative disorder of transformed follicular center B cells. FL is characterized by diffuse lymphoadenopathy, bone marrow involvement, splenomegaly, and less commonly other extranodal sites of involvement. In general, cytopenias can occur but constitutional symptoms of fever, nightsweats, and weight loss are uncommon.

DIAGNOSIS

Diagnosis is based on histology of preferably biopsy of a lymph node. Immunohistochemical staining is positive in virtually all cases for cell surface CD19, CD20, CD10 and monoclonal immunoglobulin, as well as cytoplasmic expression of bcl-2 protein. The overwhelming majority of cases have the characteristic t(14;18) translocation involving the IgH/bcl-2 genes.

RISK STRATIFICATION

The Follicular Lymphoma International Prognostic Index prognostic model for FL uses five independent predictors of inferior survival: age > 60 years, hemoglobin <12 g/dL, serum LDH > normal, Ann Arbor stage III/IV, number of involved nodal areas > 4. The presence of 0-1, 2, and ≥3 adverse factors defines low, intermediate, and high-risk disease with median 10 year survivals in the pre-rituximab era of approximately 71, 51, and 36 months, respectively. With the use of more modern therapies, specifically anti-CD20 monoclonal antibody, the outcome has improved.

RISK-ADAPTED THERAPY

Observation continues to be adequate for asymptomatic patients with low bulk disease and no cytopenias. For patients needing therapy, most patients are treated with chemotherapy plus rituximab, which has improved response rates, duration of response, and overall survival. Randomized studies have shown additional benefit for maintenance rituximab both following chemotherapy-rituximab and single agent rituximab. Autologous stem cell transplantation has not shown a survival benefit in first remission patients. Stem cell transplantation (SCT) including both autologous and allogeneic SCT or experimental agent therapy is considered for recurrent disease.

Follicular lymphoma: stillSix characters in search of an author?

Follicular lymphoma (FL) is regarded as a distinct entity in the literature as well as in the 2008 edition of the WHO classification of tumours of haematopoietic and lymphoid tissues. Nevertheless, there are still several issues that are matters of controversy such as the grading system or the exact biological location of grade 3B FL. This makes FL somewhat like the Six characters in search of an author of Pirandello's comedy. Here, we revise the morphology and pathobiology of FL by highlighting both the areas remaining critical and future perspectives. This review was inspired by the reappraisal of Professor Lennert's personal archive that represents a unique legacy for the entire scientific community.