What Is Burkitt’s Lymphoma and When Is It Endemic?

Incidence of Burkitt lymphoma in the United States during 2000 to 2019

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that occurs worldwide. A study of BL in the US National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program during 1973 to 2005 (n = 3043) revealed three age-specific incidence peaks of BL and rates that were rising. We studied BL cases diagnosed in SEER 22 during 2000 to 2019 (n = 11 626) to investigate age-specific BL incidence rates and temporal trends. The age-standardized BL incidence rate was 3.96/million person-years, with a 2.85:1 male-to-female ratio. The BL rate among both Hispanic and White individuals was higher than in Black individuals (4.52, 4.12 vs 3.14). Age-specific BL rates showed peaks during pediatric, adult and elderly years in males and pediatric and elderly peaks in females. Based on 4524 BL cases with HIV status (SEER 13), only one peak in adult males (45 years) was observed. Overall age-standardized BL incidence rates rose 1.2%/year (not significant) up to 2009 then fell significantly by 2.4%/year thereafter. Temporal trends in BL rates during 2000 to 2019 varied with age group as pediatric BL rates rose 1.1%/year, while elderly BL rates fell 1.7%/year and adult BL rates rose 3.4%/year until 2007 before falling 3.1%/year thereafter. Overall survival from BL was 64% at 2 years, being highest in pediatric patients and lowest in Black and elderly individuals vs other subgroups. Survival improved by 20% between 2000 and 2019. Our data suggest that BL age-specific incidence rates are multimodal and that overall BL rates rose up to 2009 and then fell, suggesting changes in etiological factors or diagnosis.

Epstein-Barr virus and Burkitt's lymphoma. Associations in Iraqi Kurdistan and twenty-two countries assessed in the International Incidence of Childhood Cancer

Background

Burkitt's lymphoma (BL) has worldwide variations in incidence that are related to the age of Epstein-Barr virus (EBV) infection. This study examined the age-specific incidence rate (ASIR) of BL and community EBV seropositivity in Iraqi Kurdistan and compared results with data from countries tabulated in the International Incidence of Childhood Cancer volume 3 (IICC-3).

Methods

The ASIR (95% confidence intervals) of BL in Sulaimani Governorate of Iraqi Kurdistan were calculated for the years 2010–2020. Specimens from 515 outpatients were tested for IgG and IgM antibodies to EBV viral capsid antigen.

Results

In Sulaimani, 84% of BL occurred under 20 years of age, with an ASIR of 6.2 (4.7–7.7) per million children. This ASIR was not significantly different than that of Egypt, Morocco, Israel, Spain, or France. It was slightly higher than the ASIR of the United States, the United Kingdom, and Germany and markedly higher than for Asia and South Africa. In Africa and much of Asia, early childhood EBV exposure predominates, with nearly all children being infected by 5 years of age. In Sulaimani, just over 50% of children were EBV seropositive at 3 years old and 90% seropositivity was reached at 15 years of age. In Europe and North America, seropositivity is commonly delayed until adolescence or young adulthood and adult predominates over childhood BL.

Conclusion

In the Middle East, childhood BL is relatively common and adult BL is rare. In Sulaimani, EBV seropositivity increases progressively throughout childhood and reaches 92% at mid-adolescence. This may reflect the Mid East more widely. We suggest that the high childhood and low adult BL rates may be a regional effect of a pattern of EBV exposure intermediate between early childhood and adolescent and young adult infections.

Microbiome in human cancers

A microbiome is defined as the aggregate of all microbiota that reside in human digestive system and other tissues. This microbiota includes viruses, bacteria, fungi that live in various human organs and tissues like stomach, guts, oesophagus, mouth cavity, urinary tract, vagina, lungs, and skin. Almost 20 % of malignant cancers worldwide are related to microbial infections including bacteria, parasites, and viruses. The human body is constantly being attacked by microbes during its lifetime and microbial pathogens that have tumorigenic effects in 15-20 % of reported cancer cases. Recent scientific advances and the discovery of the effect of microbes on cancer as a pathogen or as a drug have significantly contributed to our understanding of the complex relationship between microbiome and cancer. The aim of this study is to overview some microbiomes that reside in the human body and their roles in cancer.

The changing clinical pattern of endemic Burkitt lymphoma in Western Africa: Experience from a tertiary center in Ghana

BACKGROUND

Burkitt lymphoma (BL) is the most common childhood cancer in Ghana, where the endemic variant is the predominant subtype and historically presents as a highly chemo-sensitive jaw tumor. This study aimed to update the current epidemiological characteristics of childhood BL in our institution.

PROCEDURE

Patient data for all children diagnosed with BL and seen at Korle Bu Teaching Hospital between January 2007 and December 2012 were retrospectively analyzed.

RESULTS

BL was diagnosed in 173 children (<13 years) during the study period, with the abdomen as the most common tumor site (46%) followed by the jaw (31%). Abdominal tumors were associated with advanced/disseminated disease (P = 0.002), and were more likely to occur in females irrespective of tumor stage (relative risk = 1.56 [95% CI; 1.1-12.3]). Twenty-five percent (43/173) of the study cohort died and mortality was influenced by increasing age (P = 0.02) and advanced disease (P = 0.03). Treatment delay was experienced by nine in ten patients primarily due to familial financial constraint (75%). Treatment abandonment was observed as a first event in 94% of patients and two thirds of children in the study were eventually lost to follow-up.

CONCLUSION

The predominance of primary abdominal tumors in our study cohort may indicate a changing epidemiological pattern of BL in Ghana. High rates of treatment delay and abandonment were evident and are likely to be contributing factors to the poor childhood cancer survival outcomes seen in resource-limited countries in Africa.

Burkitt lymphoma expresses oncofetal chondroitin sulfate without being a reservoir for placental malaria sequestration

Burkitt lymphoma (BL) is a malignant disease, which is frequently found in areas with holoendemic Plasmodium falciparum malaria. We have previously found that the VAR2CSA protein is present on malaria-infected erythrocytes and facilitates a highly specific binding to the placenta. ofCS is absent in other non-malignant tissues and thus VAR2CSA generally facilitates parasite sequestration and accumulation in pregnant women. In this study, we show that the specific receptor for VAR2CSA, the oncofetal chondroitin sulfate (ofCS), is likewise present in BL tissue and cell lines. We therefore explored whether ofCS in BL could act as anchor site for VAR2CSA-expressing infected erythrocytes. In contrast to the placenta, we found no evidence of in vivo sequestering of infected erythrocytes in the BL tissue. Furthermore, we found VAR2CSA-specific antibody titers in children with endemic BL to be lower than in control children from the same malaria endemic region. The abundant presence of ofCS in BL tissue and the absence of ofCS in non-malignant tissue encouraged us to examine whether recombinant VAR2CSA could be used to target BL. We confirmed the binding of VAR2CSA to BL-derived cells and showed that a VAR2CSA drug conjugate efficiently killed the BL-derived cell lines in vitro. These results identify ofCS as a novel therapeutic BL target and highlight how VAR2CSA could be used as a tool for the discovery of novel approaches for directing BL therapy.

Medical history, lifestyle, family history, and occupational risk factors for sporadic Burkitt lymphoma/leukemia: the Interlymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

The etiologic role of medical history, lifestyle, family history, and occupational risk factors in sporadic Burkitt lymphoma (BL) is unknown, but epidemiologic and clinical evidence suggests that risk factors may vary by age.

METHODS

We investigated risk factors for sporadic BL in 295 cases compared with 21818 controls in a pooled analysis of 18 case-control studies in the International Lymphoma Epidemiology Consortium (InterLymph). Cases were defined to include typical BL or Burkitt-like lymphoma. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations were calculated separately for younger (<50 years) and older (≥ 50 years) BL using multivariate logistic regression.

RESULTS

Cases included 133 younger BL and 159 older BL (age was missing for three cases) and they were evenly split between typical BL (n = 147) and Burkitt-like lymphoma (n = 148). BL in younger participants was inversely associated with a history of allergy (OR = 0.58; 95% CI = 0.32 to 1.05), and positively associated with a history of eczema among individuals without other atopic conditions (OR = 2.54; 95% CI = 1.20 to 5.40), taller height (OR = 2.17; 95% CI = 1.08 to 4.36), and employment as a cleaner (OR = 3.49; 95% CI = 1.13 to 10.7). BL in older participants was associated with a history of hepatitis C virus seropositivity (OR = 4.19; 95% CI = 1.05 to 16.6) based on three exposed cases. Regardless of age, BL was inversely associated with alcohol consumption and positively associated with height.

CONCLUSIONS

Our data suggest that BL in younger and older adults may be etiologically distinct.

Burkittts lymphoma revisited: series of three cases with varied clinical presentation

Burkitt's lymphoma is a form of non-Hodgkin's B-cell lymphoma with more than one identifiable variant. This tumour was first noted in Africans. The sporadic form most commonly presents with abdominal lymph node involvement. This tumour predominently affects children and is probably the fastest growing tumours in humans, with exuberant proliferation. We here in report on three patients from our experience both adult and children who presented with varied clinical features.

Burkitt Lymphoma: beyond discoveries

First described in 1958 in Uganda, Burkitt lymphoma (BL) attracted interest worldwide following reports of its uneven geographic distribution and rapidly fatal clinical course. Both suggested infectious etiology and curability. Seminal discoveries followed in quick succession. Viral etiology - due to Epstein-Barr virus (EBV) - was confirmed. Chromosomal translocations, involving cellular MYC, a protooncogene, were discovered, shown to be a hallmark of BL, and central to the genetic basis of cancer. Cure of BL using combination chemotherapy was demonstrated. Unfortunately, civil disturbance in Africa disrupted BL research and blunted its impact on education and oncology care in Africa. Important questions went unanswered. The risk of BL due to malaria or EBV was not quantified. Efforts to answer whether BL could be prevented - by preventing malaria or early EBV infection - were abandoned. The mechanism of malaria in BL is unknown. In Africa, BL remains mostly fatal and diagnosis is still made clinically. Unprecedented advances in molecular, genomics and proteomic technologies, promising to unlock mysteries of cancers, have re-awakened interest in BL. With return of stability to Africa, the unanswered questions about BL are re-attracting global interest. This interest now includes exploiting the knowledge gained about genetics, proteomics, and bioinformatics to enable the development of targeted less toxic treatment for BL; and simpler methods to diagnose BL with high accuracy and sensitivity. The articles in the Burkitt Lymphoma (BL): Beyond Discoveries in Infectious Agents and Cancer highlight BL as priority. Authors explore etiology, pathology, pathogenesis of BL, and whether knowledge gained in the studies of BL can catalyze sustainable cancer services in one of the world's poorest served regions.

Pediatric, elderly, and emerging adult-onset peaks in Burkitt's lymphoma incidence diagnosed in four continents, excluding Africa

Burkitt's lymphoma (BL) in the general population and immunosuppressed persons with AIDS in the United States was characterized by three age-specific incidence peaks near 10, 40, and 70 years. We hypothesized that BL from different geographical areas may exhibit pediatric, adult, and elderly age incidence peaks. We investigated this hypothesis using data on 3,403 cases obtained from the International Agency for Research on Cancer (1963-2002). Data from Africa were sparse or incomplete, and thus were excluded. Age-standardized rates (ASRs) and age-specific incidence rates were calculated, supplemented with the calculations performed using age-period-cohort (APC) models. The ASR rose 5.3% (95% confidence interval [CI], 5.0-5.6) per year in males and 4.6% (95% CI, 4.5-4.8) in females. The ASR increased gradually in children, steeply in adults and most rapidly in the elderly both in males and in females. Overall, BL male/female ASR ratio was 2.5, but it declined from 3.1 (95% CI, 3.0-3.3) for pediatric BL to 2.3 (95% CI, 2.2-2.4) for adult BL and 1.5 (95% CI, 1.4-1.6) for elderly BL. Age-specific incidence peaks occurred near 10 and 70 years in all regions and periods. A peak near 40 years of age emerged in the mid-1990s, particularly in men. Findings using APC models confirmed those based on the standard analyses. Our findings, based on the international BL cases, support our hypothesis that BL is multimodal and that BL peaks at different ages may be clues to differences in the etiology and/or biology of BL at those ages.

Burkitt lymphoma: pathogenesis and immune evasion

B-cell lymphomas arise at distinct stages of cellular development and maturation, potentially influencing antigen (Ag) presentation and T-cell recognition. Burkitt lymphoma (BL) is a highly malignant B-cell tumor associated with Epstein-Barr Virus (EBV) infection. Although BL can be effectively treated in adults and children, leading to high survival rates, its ability to mask itself from the immune system makes BL an intriguing disease to study. In this paper, we will provide an overview of BL and its association with EBV and the c-myc oncogene. The contributions of EBV and c-myc to B-cell transformation, proliferation, or attenuation of cellular network and immune recognition or evasion will be summarized. We will also discuss the various pathways by which BL escapes immune detection by inhibiting both HLA class I- and II-mediated Ag presentation to T cells. Finally, we will provide an overview of recent developments suggesting the existence of BL-associated inhibitory molecules that may block HLA class II-mediated Ag presentation to CD4+ T cells, facilitating immune escape of BL.

AIDS-related Burkitt lymphoma in the United States: what do age and CD4 lymphocyte patterns tell us about etiology and/or biology?

Trimodal or bimodal age-specific incidence rates for Burkitt lymphoma (BL) were observed in the United States general population, but the role of immunosuppression could not be excluded. Incidence rates, rate ratios, and 95% confidence intervals for BL and other non-Hodgkin lymphoma (NHL), by age and CD4 lymphocyte count categories, were estimated using Poisson regression models using data from the United States HIV/AIDS Cancer Match study (1980-2005). BL incidence was 22 cases per 100 000 person-years and 586 for non-BL NHL. Adjusted BL incidence rate ratio among males was 1.6× that among females and among non-Hispanic blacks, 0.4× that among non-Hispanic whites, but unrelated to HIV-transmission category. Non-BL NHL incidence increased from childhood to adulthood; in contrast, 2 age-specific incidence peaks during the pediatric and adult/geriatric years were observed for BL. Non-BL NHL incidence rose steadily with decreasing CD4 lymphocyte counts; in contrast, BL incidence was lowest among people with ≤ 50 CD4 lymphocytes/μL versus those with ≥ 250 CD4 lymphocytes/μL (incidence rate ratio 0.3 [95% confidence interval = 0.2-0.6]). The bimodal peaks for BL, in contrast to non-BL NHL, suggest effects of noncumulative risk factors at different ages. Underascertainment or biological reasons may account for BL deficit at low CD4 lymphocyte counts.

Trimodal age-specific incidence patterns for Burkitt lymphoma in the United States, 1973-2005

Burkitt lymphoma (BL) is a unique B-cell non-Hodgkin lymphoma with 3 established clinical-epidemiological variants: endemic, sporadic and AIDS-related BL. BL variants show characteristic dysregulation of MYC gene, but the causes of MYC dysregulation or BL arising at different ages are poorly understood. Therefore, we examined population-based BL incidence patterns in the United States to determine age-related risk. BL case and population data were obtained from the NCI's Surveillance, Epidemiology and End Results Databases (1973-2005). Standard cross-sectional age-standardized and age-specific incidence rates were stratified by sex and race and supplemented with age-period-cohort models. We analyzed 3,058 BL cases diagnosed during 1,160,300,297 person-years of observation. Age-standardized incidence rates rose 6.8% per year (95% CI 4.5-9.1) for males and 7.1% (95% CI 3.2-11.1) for females during the study period. The rate among males was 3.2 times that among females, and among Whites 1.3 times that among Blacks. Male-to-female incidence rate ratios did not differ by race, but were 4.2 for pediatric (0-19 years), 4.1 for adult (20-59 years) and 2.0 for geriatric (> or = 60 years) BL. Cross-sectional age-specific rates showed 2 separate peaks among males and females, near ages 10 and 75 years, and a 3rd peak near age 40 years among males. The tri/bimodal incidence pattern was present in sensitivity analyses excluding registries with many HIV/AIDS cases and in period-specific, cohort-specific analyses. To our knowledge, tri/bimodal incidence patterns have not previously been reported for BL. Trimodal/bimodal BL suggests heterogeneity in etiology or biology of BL diagnosed at different ages in males and females.

Mechanisms involved in Burkitt's tumor formation

Burkitt's lymphoma is a rapidly fatal tumor if untreated, but it is curable with intensive polychemotherapy. Unfortunately, the toxicities reported for its treatment in adults are poorly tolerated. Novel therapies aimed at specific molecular targets might prove to be less toxic. A better knowledge of the mechanisms involved in the pathogenesis of Burkitt's lymphoma would facilitate the identification of such targets. This review explores the current knowledge on the alterations found in the three main Burkitt's lymphoma variants.

Burkitt's lymphoma of the colon and bronchi: three case reports

Introduction

Burkitt's lymphoma is a form of non-Hodgkin's B-cell lymphoma with more than one identifiable variant. The sporadic form most commonly presents with abdominal lymph node involvement.

Case reports

We herein report on three patients from our experience that presented with either endobronchial or colonic Burkitt's lymphoma. Their clinical presentation mimicked that of other syndromes. After confirmatory pathological diagnosis, the patients had complete remission through the use of an optimal treatment protocol.

Conclusion

Our review of the cases and comparable reports warrants careful workup of such presentations to ensure early diagnosis and therapeutic planning of this highly aggressive disease.

Biology and treatment of Burkitt's lymphoma

PURPOSE OF REVIEW

Burkitt's lymphoma is a unique hematological malignancy remarkable for its biological characteristics, including aberrant expression of the MYC oncogene, and its requirement for intensive treatment regimens. This review will focus on those features, and discuss recent advances in the molecular biology and advancing treatment options for the disease.

RECENT FINDINGS

Advances in molecular biology have provided many new insights into the biology and treatment options for Burkitt's lymphoma. Microarray technology has recently been used to define a molecular gene expression signature for Burkitt's lymphoma. This signature allows for the differentiation of Burkitt's lymphoma from other forms of non-Hodgkin's lymphoma such as diffuse large B-cell lymphoma. Recent advances in the use of biological agents, such as rituximab, have also allowed for a reduction in treatment toxicities while still offering comparable survival outcomes for patients.

SUMMARY

Burkitt's lymphoma is an interesting mature B-cell non-Hodgkin's lymphoma that has numerous distinct features and clinical variants depending on factors such as geographical location, immunological status and patient's age. Although the role of the MYC oncogene has been well studied, we are only now appreciating the defining molecular characteristics of this disease, and using these advances to improve treatment options for patients.

Denis Burkitt and his contribution to haematology/oncology

Denis Burkitt was motivated by Christian Evangelism from his early years. It was a critical factor not only in his personal development and decision to work in Uganda, but also in his medical achievements. The events in his life which led to his description of Burkitt lymphoma in 1958 are described together with his discovery of the endemic nature of the condition and its treatment. His research on the aetiology of the condition is also described. The endemic form of the lymphoma is still a major cause of childhood mortality in Africa due to a lack of basic resources to treat the condition. Burkitt Lymphoma has been used as a model to advance research and treatment on a wide range of conditions in haematology and oncology. Burkitt's work in later life on dietary fibre and its implications are summarised.

Homogeneous immunophenotype and paucity of secondary genomic aberrations are distinctive features of endemic but not of sporadic Burkitt's lymphoma and diffuse large B-cell lymphoma withMYC rearrangement

The present study has compared immunohistological marker expression profiles and genomic imbalances in seven African endemic Burkitt's lymphomas (eBLs) with those in ten European B-cell lymphomas with MYC rearrangement as shown by fluorescence in situ hybridization (FISH) analysis. eBLs showed a typical histomorphology and a homogeneous immuno-profile: CD10+, CD38+, CD77+, bcl-2-, and IgM+. Epstein-Barr virus (EBV) DNA was present in all cases. On comparative genomic hybridization (CGH), only three out of six eBLs showed imbalances (median number of imbalances = 2), with gains on chromosome 17 in two eBLs. The European lymphomas were all highly proliferating, with a Ki-67 index of at least 90%, and included seven with morphology typical of sporadic Burkitt's lymphoma (sBL) and three immunoblastic diffuse large B-cell lymphomas with MYC rearrangement (MYCre+DLBCL). In contrast to eBL, the immuno-profiles of the European lymphomas were less homogeneous and inconsistent for CD10, CD38, CD77, IgM and bcl-2 expression. EBV DNA was not detected. In five of seven sBLs, CGH showed a higher number of imbalances (median = 6), with recurrent gains on chromosome 1q (3/7) and losses on 12q and 17p (2/7), whereas all three MYCre+DLBCLs had fewer imbalances (median = 4), with gains on 17q in two of three lymphomas. It is concluded that eBL has a homogeneous immunohistology and few secondary genomic aberrations, whereas MYC-rearranged and highly proliferating European B-cell lymphomas are a heterogeneous group that includes sBL and a subgroup of diffuse large B-cell lymphomas.

Contrasting roles of dendritic cells and B cells in the immune control of Epstein-Barr virus

The human gamma-herpesvirus, Epstein-Barr virus (EBV), has growth-transforming potential in vivo and in vitro. Despite this, most healthy carriers remain free of EBV-associated malignancies because of effective T cell-mediated immune control of the virus. A better understanding of these highly efficient control mechanisms is important in the development of new treatment strategies for EBV-associated malignancies. A rational approach to EBV immunotherapy requires answering two questions about the initiation of the protective EBV-specific immune response. The first question is, what is the antigen-presenting cell responsible for priming EBV specific immunity? Second, which viral antigen is central to protective EBV adaptive immunity seen in healthy carriers of the virus? We provide evidence in this review that dendritic cells rather than EBV-transformed B cells are responsible for orchestrating protective EBV immunity and that the EBV nuclear antigen 1 (EBNA1)-specific CD4+ T cell response probably plays a role in resistance against all types of EBV-associated malignancies in healthy carriers. This implies that EBNA1 targeting to dendritic cells should be a component of vaccine and immunotherapy development against EBV-associated malignancies.

Burkitt's and Burkitt-like lymphoma

Burkitt's and Burkitt-like lymphoma (BL/BLL) are aggressive B-cell malignancies with a high proliferative rate that may be fatal within months if not treated promptly. Furthermore, treatment of BL/BLL requires comprehensive supportive care to avoid disease-related complications such as acute renal failure secondary to tumor lysis syndrome. Improvements in our understanding of the biology of BL and BLL have led to more effective therapeutic protocols. Clinical trials have demonstrated that short duration, multi-agent, dose-intensive chemotherapy regimens combined with aggressive central nervous system therapy results in long-term survival rates in children and young adults near 70% to 80%, whereas long-term disease-free survival rates in older adults remains suboptimal at 15% to 25%. Outcomes in HIV-associated BL/BLL are improved because of more effective chemotherapy regimens and enhanced HIV care. Autologous bone marrow transplantation has proven feasible in many patient populations with BL/BLL and may lead to cure in selected patients. Improved therapeutic strategies are warranted, such as integrating agents such as monoclonal antibodies to combination dose-intensive chemotherapy. Moreover, further study into the molecular biology of BL/BLL with attention to the role of c-myc dysregulation is needed to help predict prognostic factors and for the development of molecular targeted therapies. Clinical trials remain critical to determine the most effective treatment regimens that will continue to improve cure rates in this aggressive but treatable disease.

An international evaluation of CODOX-M and CODOX-M alternating with IVAC in adult Burkitt's lymphoma: results of United Kingdom Lymphoma Group LY06 study

BACKGROUND

Burkitt's lymphoma (BL) is a rare and rapidly progressive form of B-cell non-Hodgkin's lymphoma. Cyclophosphamide, vincristine, doxorubicin, high-dose methotrexate (CODOX-M)/ifosfamide, etoposide and high-dose cytarabine (IVAC) is a highly effective alternating non-cross-resistant regimen developed by Magrath et al. (Magrath I., Adde M., Shad A. et al. J Clin Oncol 1996; 14: 925-934) at the US National Cancer Institute. The aim was to confirm these results in a larger, international, multi-centre study using International Prognostic Index-based criteria to assign prognostic groups, whilst slightly simplifying the protocol.

PATIENTS AND METHODS

A phase II study where: (i) low risk (LR) patients were treated with three cycles of modified CODOX-M; and (ii) high risk (HR) patients received treatment with four cycles of alternating modified CODOX-M and IVAC chemotherapy. Target of 60 patients, fit for protocol treatment, from 16 to 60 years of age with locally diagnosed, non-HIV-related, non-organ-transplant-related BL.

RESULTS

Results are given for 52 of 72 registered patients whose pathological eligibility was confirmed by central pathology review: 12 LR plus 40 HR. The majority of patients (n = 41) completed protocol treatment, but toxicity was severe, especially myelosuppression and mucositis. Overall, 2-year event-free survival (EFS) was 64.6% (95% CI 50.4% to 78.9%) and 2-year overall survival (OS) was 72.8% (95% CI 59.4% to 86.3%). For LR, 2-year EFS was 83.3% and OS was 81.5%. For HR, 2-year EFS was 59.5% and OS was 69.9%.

CONCLUSIONS

This study confirms high cure rates with this CODOX-M/IVAC approach.

VH gene sequences from a novel tropical splenic lymphoma reveal a naive B cell as the cell of origin

The prevalence of malaria and other infections in tropical Africa provides a setting for the emergence of B-cell tumours distinct from that in Western countries. Attempts to draw comparisons with Western lymphomas have led to difficulties, with so-called African chronic lymphocytic leukaemia (CLL) having a different pattern of incidence from Western CLL. Splenomegaly is common in African CLL, and this has posed diagnostic problems in differentiating the tumour from malaria-associated hyper-reactive malarial splenomegaly (HMS). One feature of the splenomegalic form of African CLL is that the tumour cells often possess short but fine cytoplasmic projections reminiscent of those observed in Western splenic lymphoma with villous lymphocytes (SLVL). Analysis of Ig VH genes both facilitates discrimination between clonal B-cell tumours and HMS, and reveals the differentiation status of the cell of origin. This study indicated that VH genes of nine cases of clonal splenic B-cell tumours with villous lymphocytes from Ghana were relatively unmutated, consistent with an origin from a naive B cell. These features differ from SLVL which arises from a post-follicular antigen-selected B cell. One possibility is that these splenic B-cell tumours derive from a splenic T-independent B cell, with malaria infection as a potential influence.