Burkitt's lymphoma: molecular pathogenesis and treatment

Hub genes and their key effects on prognosis of Burkitt lymphoma

BACKGROUND

Burkitt lymphoma (BL) is an exceptionally aggressive malignant neoplasm that arises from either the germinal center or post-germinal center B cells. Patients with BL often present with rapid tumor growth and require high-intensity multi-drug therapy combined with adequate intrathecal chemotherapy prophylaxis, however, a standard treatment program for BL has not yet been established. It is important to identify biomarkers for predicting the prognosis of BLs and discriminating patients who might benefit from the therapy. Microarray data and sequencing information from public databases could offer opportunities for the discovery of new diagnostic or therapeutic targets.

AIM

To identify hub genes and perform gene ontology (GO) and survival analysis in BL.

METHODS

Gene expression profiles and clinical traits of BL patients were collected from the Gene Expression Omnibus database. Weighted gene co-expression network analysis (WGCNA) was applied to construct gene co-expression modules, and the cytoHubba tool was used to find the hub genes. Then, the hub genes were analyzed using GO and Kyoto Encyclopedia of Genes and Genomes analysis. Additionally, a Protein-Protein Interaction network and a Genetic Interaction network were constructed. Prognostic candidate genes were identified through overall survival analysis. Finally, a nomogram was established to assess the predictive value of hub genes, and drug-gene interactions were also constructed.

RESULTS

In this study, we obtained 8 modules through WGCNA analysis, and there was a significant correlation between the yellow module and age. Then we identified 10 hub genes (SRC, TLR4, CD40, STAT3, SELL, CXCL10, IL2RA, IL10RA, CCR7 and FCGR2B) by cytoHubba tool. Within these hubs, two genes were found to be associated with OS (CXCL10, P = 0.029 and IL2RA, P = 0.0066) by survival analysis. Additionally, we combined these two hub genes and age to build a nomogram. Moreover, the drugs related to IL2RA and CXCL10 might have a potential therapeutic role in relapsed and refractory BL.

CONCLUSION

From WGCNA and survival analysis, we identified CXCL10 and IL2RA that might be prognostic markers for BL.

A Rare Finding of Pancreatic Involvement in a Case of Burkitt's Lymphoma

Burkitt's lymphoma (BL) is a highly aggressive type of B-cell non-Hodgkin lymphoma. BL commonly occurs in children of age 4-7 years and is uncommon in adults, with a worse prognosis. Patients often present with a rapidly growing mass typically involving the abdomen (liver and spleen) and head and neck (nodes, jaw, and facial bones). Pancreas involvement is very rare and very few case reports have been documented so far. Fluorine-18 positron emission tomography/computed tomography (F-18 PET/CT) is a whole-body survey commonly used for initial staging evaluation. Here, we present an interesting case of BL in an adult female of 43 years, who presented with swelling in the left submandibular region after tooth extraction with multiorgan involvement found on F-18 fluorodeoxyglucose PET/CT.

Primary epidural sporadic Burkitt lymphoma in a 3-year-old: Case report and literature review

Background:

Burkitt lymphoma (BL) is a common tumor of childhood that usually arises in the abdomen or pelvis in its sporadic form. In a minority of cases, BL can present with CNS involvement, usually as a secondary site. Rarely, BL can arise primarily in the epidural space and present with back pain, or less commonly, acute myelopathy. This presentation is a surgical emergency and requires vigilant management.

Case Description:

We describe a case of pediatric BL arising primarily within the epidural space and presenting with progressive difficulty walking in a 3-year-old boy. Progression to complete inability to walk, absent lower extremity deep tendon reflexes, and new urinary incontinence prompted MRI of the spine, which showed a lesion extending from T5 to T10 and wrapping around the anterior and posterior portions of the spine with evidence of spinal cord compression. The patient underwent decompressive laminectomies from T5 to T10 and partial debulking of the posterior portions of the tumor. Microscopic examination showed a prominent “starry sky” pattern with abundant mitotic figures. Immunohistochemistry confirmed the diagnosis of BL. The patient is 10 months post-op and continues to undergo chemotherapy with partial neurologic improvement. He was free of recurrence 10 months post-operative.

Conclusion:

This appears to be the youngest described patient presenting with acute myelopathy in primary paraspinal BL. Management should include surgical decompression of the spinal cord followed by one of the various described chemotherapeutic regimens. Preoperative staging and neurologic function correlate with prognosis.

Tomentosin a Sesquiterpene Lactone Induces Antiproliferative and Proapoptotic Effects in Human Burkitt Lymphoma by Deregulation of Anti- and Pro-Apoptotic Genes

(1) Tomentosin is the most representative sesquiterpene lactone extracted by I. viscosa. Recently, it has gained particular attention in therapeutic oncologic fields due to its anti-tumor properties. (2) In this study, the potential anticancer features of tomentosin were evaluated on human Burkitt’s lymphoma (BL) cell line, treated with increasing tomentosin concentration for cytotoxicity screening. (3) Our data showed that both cell cycle arrest and cell apoptosis induction are responsible of the antiproliferative effects of tomentosin and may end in the inhibition of BL cell viability. Moreover, a microarray gene expression profile was performed to assess differentially expressed genes contributing to tomentosin activity. Seventy-five genes deregulated by tomentosin have been identified. Downregulated genes are enriched in immune-system pathways, and PI3K/AKT and JAK/STAT pathways which favor proliferation and growth processes. Importantly, different deregulated genes identified in tomentosin-treated BL cells are prevalent in molecular pathways known to lead to cellular death, specifically by apoptosis. Tomentosin-treatment in BL cells induces the downregulation of antiapoptotic genes such as BCL2A1 and CDKN1A and upregulation of the proapoptotic PMAIP1 gene. (4) Overall, our results suggest that tomentosin could be taken into consideration as a potential natural product with limited toxicity and relevant anti-tumoral activity in the therapeutic options available to BL patients.

Xenograft models for pediatric cancer therapies

The prognosis for childhood cancer has improved considerably over the past 50 years. This improvement is attributed to well-designed clinical trials which have incorporated chemotherapy, surgery, and radiation. With an increased understanding of cancer biology and genetics, we have entered an era of precision medicine and immunotherapy that provides potential for improved cure rates. However, preclinical evaluation of these therapies is more nuanced, requiring more robust animal models. Evaluation of targeted treatments requires molecularly defined xenograft models that can capture the diversity within pediatric cancer. The development of novel immunotherapies ideally involves the use of animal models that can accurately recapitulate the human immune response. In this review, we provide an overview of xenograft models for childhood cancers, review successful examples of novel therapies translated from xenograft models to the clinic, and describe the modern tools of xenograft biobanks and humanized xenograft models for the study of immunotherapies.

Outcomes of treatment with CHOP and EPOCH in patients with HIV associated NHL in a low resource setting

Background

The optimal chemotherapy regimen for treating HIV associated NHL in low resource settings is unknown. We conducted a retrospective study to describe survival rates, treatment response rates and adverse events in patients with HIV associated NHL treated with CHOP and dose adjusted-EPOCH regimens at the Uganda Cancer Institute.

Methods

A retrospective study of patients diagnosed with HIV and lymphoma and treated at the Uganda Cancer Institute from 2016 to 2018 was done.

Results

One hundred eight patients treated with CHOP and 12 patients treated with DA-EPOCH were analysed. Patients completing 6 or more cycles of chemotherapy were 51 (47%) in the CHOP group and 8 (67%) in the DA-EPOCH group. One year overall survival (OS) rate in patients treated with CHOP was 54.5% (95% CI, 42.8–64.8) and 80.2% (95% CI, 40.3–94.8) in those treated with DA-EPOCH. Factors associated with favourable survival were BMI 18.5–24.9 kg/m², (p = 0.03) and completion of 6 or more cycles of chemotherapy, (p < 0.001). The overall response rate was 40% in the CHOP group and 59% in the DA-EPOCH group. Severe adverse events occurred in 19 (18%) patients in the CHOP group and 3 (25%) in the DA-EPOCH group; these were neutropenia (CHOP = 13, 12%; DA-EPOCH = 2, 17%), anaemia (CHOP = 12, 12%; DA-EPOCH = 1, 8%), thrombocytopenia (CHOP = 7, 6%; DA-EPOCH = 0), sepsis (CHOP = 1), treatment related death (DA-EPOCH = 1) and hepatic encephalopathy (CHOP = 1).

Conclusion

Treatment of HIV associated NHL with curative intent using CHOP and infusional DA-EPOCH is feasible in low resource settings and associated with > 50% 1 year survival.

Bptf determines oncogenic addiction in aggressive B-cell lymphomas

Chromatin remodeling factors contribute to establish aberrant gene expression programs in cancer cells and therefore represent valuable targets for therapeutic intervention. BPTF (Bromodomain PhD Transcription Factor), a core subunit of the nucleosome remodeling factor (NURF), modulates c-MYC oncogenic activity in pancreatic cancer. Here, we analyze the role of BPTF in c-MYC-driven B-cell lymphomagenesis using the Eμ-Myc transgenic mouse model of aggressive B-cell lymphoma. We find that BPTF is required for normal B-cell differentiation without evidence of haploinsufficiency. In contrast, deletion of one Bptf allele is sufficient to delay lymphomagenesis in Eμ-Myc mice. Tumors arising in a Bptf heterozygous background display decreased c-MYC levels and pathway activity, together with increased activation of the NF-κB pathway, a molecular signature characteristic of human diffuse large B-cell lymphoma (DLBCL). In human B-cell lymphoma samples, we find a strong correlation between BPTF and c-MYC mRNA and protein levels, together with an anti-correlation between BPTF and NF-κB pathway activity. Our results indicate that BPTF is a relevant therapeutic target in B-cell lymphomas and that, upon its inhibition, cells acquire distinct oncogenic dependencies.

Burkitt and Burkitt-Like Lymphomas: a Systematic Review

PURPOSE OF REVIEW

Burkitt's lymphoma and its leukemic form (Burkitt cell acute lymphoblastic leukemia) are a highly aggressive disease. We review the classification, clinical presentation, histology, cytogenetics, and the treatment of the disease.

RECENT FINDINGS

Burkitt's lymphoma might be associated with tumor lysis syndrome which is a potentially fatal complication that occurs spontaneously or upon initiation of chemotherapy. Major improvements were made in the treatment of pediatric and adults population using short-course dose-intensive chemotherapy regimens, usually 1 week after a prephase induction. Addition of Rituximab to chemotherapy has become a standard of care. Relapsed/refractory disease has a very poor prognosis and the benefit from autologous/allogeneic hematopoietic stem cell transplant remains uncertain. Rituximab-based short-course dose-intensive chemotherapy is the standard of care of Burkitt's lymphoma even in the immunodeficiency-related form.

Molecular characteristics of terminal deoxynucleotidyl transferase negative precursor B-cell phenotype Burkitt leukemia with IGH-MYC rearrangement

Precursor B cell phenotype Burkitt lymphoma/leukemia with IGH-MYC is a rare subtype of Burkitt lymphoma (BL). BL and B lymphoblastic leukemia/lymphoma (B-ALL/LBL) differ as regards treatment and the distinction between these two entities is crucial. Patients demonstrating a terminal deoxynucleotidyl transferase (TdT)-positive precursor B cell phenotype with IGH-MYC rearrangement have been reported to be molecularly distinct from BL and closer to B-ALL/LBL. We investigated the molecular characteristics of two cases of a rare but distinct TdT-negative precursor B cell phenotype BL. Both patients showed FAB L3 morphology with IGH-MYC translocation, but had precursor B cell immunophenotypes including dim to moderate expression of CD45 and absence of BCL6, CD20, monoclonal kappa, and lambda light chain expression. To characterize the molecular features, we performed exome sequencing and analyzed the breakpoint junction of the IGH-MYC rearrangement. We detected KMT2D mutations in both cases, a rarely acquired chromatin modifying gene mutation in BL. The breakpoint analysis revealed that the IGH-MYC rearrangement occurred due to an aberrant VDJ recombination in one case. The treatment protocols differed, including high-grade lymphoma treatment and standard B-ALL treatment. Complete remission was achieved in the patient who received B-ALL treatment. The degree of resemblance of BL and B-ALL differed between two cases, but the molecular pathogenesis and manifesting features of both TdT-negative precursor B cell phenotype BL case were distinct from classic BL, which indicates the need for a better understanding of this uncommon entity that does not fit in current diagnostic and classification categories.

Prognostic role of ΔMTV and ΔTLG in Burkitt lymphoma

OBJECTIVE

Burkitt's lymphoma (BL) is an aggressive lymphoma sub-type with high 18F-FDG avidity, but no well established evidence of PET/CT's role in treatment evaluation or prognosis is currently available. The prognostic role of visual analysis and Deauville criteria for BL have already been demonstrated, while the potential usefulness of semi-quantitative PET/CT features remains unclear, especially the value of the rate of reduction in metabolic tumor volume (MTV) and total lesion glycolysis (TLG). The aim of this retrospective study was to investigate whether ΔMTV and ΔTLG can predict treatment response at the end of therapy and prognosis in BL.

METHODS

We retrospectively included 61 patients (mean age 61; 40 male, 21 female) who underwent baseline, interim and end-of-treatment 18F-FDG PET/CT. The PET/CT images were analyzed visually and semi-quantitatively by measuring total metabolic tumor volume (MTV) and total lesion glycolysis (TLG) for every scan. Then we calculated volume changes based on the percentage of MTV and TLG reduction between the baseline and interim PET (ΔMTVi and ΔTLGi) and between baseline and end-of-treatment PET/CT (ΔMTVeot and ΔTLGeot) and correlated them with clinical response and progression-free survival (PFS) and overall survival (OS). Survival curves were plotted according to the Kaplan-Meier method.

RESULTS

Forty patients had a complete response and 21 patients a partial response on interim 18F-FDG PET/CT. At end of treatment, 45 had a complete response, 11 partial response and 5 disease progression. At a median follow-up of 43 months, relapse/progression occurred in 18 patients and death in 11. ΔMTV and ΔTLG values were significantly higher in patients with complete response compared to no complete response. ΔMTVeot and ΔTLGeot were demonstrated to be independent prognostic factors for both PFS and OS, while ΔMTVi and ΔTLGi were not related to survival.

CONCLUSIONS

Metabolic tumor features (ΔMTV and ΔTLG) were significantly correlated with response to treatment and long-term outcome in BL.

Trends in survival of patients with stage I/II Burkitt lymphoma in the United States: A SEER database analysis

The treatment strategy for management of Burkitt lymphoma (BL) has evolved during the past decades and the clinical outcome for this disease as a whole has also improved. Due to limited information reported on survival trends of patients with stage I/II (limited‐stage) BL, here we used the Surveillance, Epidemiology, and End Results (SEER) database to conduct our study. The time period was divided into two eras (1983‐2001 and 2002‐2014) as the recent era reflected more intensive chemotherapy regimens, the availability of rituximab, the widespread use of antiretroviral therapy (ART) and improvements in supportive care. Patients with limited‐stage BL had a significantly better 5‐year overall survival (OS) in the 2002‐2014 era in both univariate analysis and multivariate analysis, compared with those in the 1983‐2001 era (64.1% vs 57.4%). However, clinical outcomes of elderly patients (≥60 years) and children patients (0‐19 years) did not significantly improve. Older age and race of black were correlated with poorer OS in multivariate analysis, whereas sex, primary sites, and application of radiotherapy did not significantly influence OS. In conclusion, the prognosis of patients with limited‐stage BL has improved in the 2002‐2014 era, but the outcome was still much poorer in elderly patients, which needs to be improved by identifying newly molecular‐targeted drugs and developing novel personalized therapeutic approaches.

Midostaurin potentiates rituximab antitumor activity in Burkitt's lymphoma by inducing apoptosis

An intensive short-term chemotherapy regimen has substantially prolonged the overall survival of Burkitt’s lymphoma (BL) patients, which has been further improved by addition of rituximab. However, the inevitable development of resistance to rituximab and the toxicity of chemotherapy remain obstacles. We first prepared two BL cell lines resistant to rituximab-mediated CDC. Using a phosphorylation antibody microarray, we revealed that PI3K/AKT pathway contained the most phosphorylated proteins/hits, while apoptosis pathway that may be regulated by PKC displayed the greatest fold enrichment in the resistant cells. The PI3K/AKT inhibitor IPI-145 failed to reverse the resistance. In contrast, the pan-PKC inhibitor midostaurin exhibited potent antitumor activity in both original and resistant cells, alone or in combination with rituximab. Notably, midostaurin promoted apoptosis by reducing the phosphorylation of PKC and consequently of downstream Bad, Bcl-2 and NF-κB. Therefore, midostaurin improved rituximab activity by supplementing pro-apoptotic effects. In vivo, midostaurin alone powerfully prolonged the survival of mice bearing the resistant BL cells compared to rituximab alone treatments. Addition of midostaurin to rituximab led to dramatically improved survival compared to rituximab but not midostaurin monotherapy. Our findings call for further evaluation of midostaurin alone or in combination with rituximab in treating resistant BL in particular.

Adult multicentric burkitt lymphoma with bowel obstruction due to intussusception

Primary malignant tumors of the small intestine are very rare, accounting for 2%-3% of all gastrointestinal malignancies. Lymphoma constitutes about 15%-20% of all small intestine neoplasms and 20%-30% of all primary gastrointestinal lymphomas. The ileum is the most common site for gastrointestinal lymphomas. Because the symptoms and physical findings are non-specific, the preoperative diagnosis is usually difficult. In this case report, we describe the highly unusual case of sporadic Burkitt lymphoma with complete intestinal obstruction due to intussusception of the proximal jejunum and discuss the treatment options.

Prognostic role of baseline 18F-FDG PET/CT metabolic parameters in Burkitt lymphoma

PURPOSE

Burkitt's lymphoma (BL) is an aggressive lymphoma subtype with high 18F-FDG avidity at 18F-FDG-PET/CT, but no validated criteria for PET/CT in treatment evaluation or prediction of outcome in BL are available. The aim of our study was to investigate whether the metabolic baseline PET/CT parameters can predict treatment response and prognosis in BL.

MATERIALS AND METHODS

We retrospectively enrolled 65 patients who underwent baseline 18F-FDG-PET/CT, interim and end of treatment PET/CT. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value body weight (SUVbw), the maximum standardized uptake value lean body mass (SUVlbm), the maximum standardized uptake value body surface area (SUVbsa), lesion to liver SUVmax ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), total metabolic tumor volume (tMTV) and total lesion glycolysis (TLG). Survival curves were plotted according to the Kaplan-Meier method.

RESULTS

At a median follow-up of 40 months, the median PFS and OS were 34 and 39 months. MTV and TLG were significantly higher in patients with partial response compared to complete response group at end of treatment, while no significant differences were found at interim. Other metabolic PET/CT parameters were not related to treatment response. MTV and TLG were demonstrated to be independent prognostic factors for both PFS and OS; instead SUVbw, SUVlbm, SUVbsa, L-L SUV R and L-BP SUV R were not related to outcome survival.

CONCLUSIONS

Metabolic tumour features (MTV and TLG) were significantly correlated with response to treatment and long-term outcome.

Metabolic behavior and prognostic value of early and end of treatment 18F-FDG PET/CT in adult Burkitt's lymphoma: the role of Deauville and IHP criteria

Burkitt's lymphoma is a lymphoma with unclear metabolic behavior at 18F-FDG-PET/CT and no validated criteria in treatment evaluation and prediction of outcome exist. Sixty-five patients were retrospectively included: all underwent baseline 18F-FDG-PET/CT, 56 interim PET/CT (iPET/CT) and 54 end of treatment PET/CT (eotPET/CT) after chemotherapy. Interim and eotPET/CT results were visually interpreted according to the criteria of the IHP and Deauville-five-point-scale. Results were correlated with PFS and OS to assess and to compare the predictive value of iPET and eotPET according to each criterion. All baseline PET/CT showed increased 18F-FDG uptake in nodal and extranodal lesions. The median PFS and OS were 44.6 and 48.2 months with 3-year and 5-year PFS of 76% and 62% and 3-year and 5-year OS of 71% and 57%, respectively. EotPET/CT results using DC and IHP significantly correlate with OS and PFS; while iPET/CT did not correlated with OS and PFS.

Malignant lymphoma in the HIV-positive patient

The introduction of combination antiretroviral therapy (cART) drastically improved performance status, immune function, and life expectancy of HIV-infected individuals. In addition, incidence of opportunistic infections and of AIDS-defining malignancies declined. Nevertheless, aggressive non-Hodgkin's lymphoma still remains the leading cause of AIDS-related deaths. The availability of cART, however, significantly improved the therapeutic options for HIV-positive patients with lymphomas. Diffuse large B-cell lymphoma, Burkitt's lymphoma, or Hodgkin lymphoma has increasingly become curable diseases. In light of these favorable developments in the treatment of HIV and HIV-associated lymphomas, reduction in treatment-associated toxicities and further improvement of outcome of patients with advanced immune suppression are major requirements for future clinical trials. This review summarizes the current treatment landscape and gives an overview on future needs in HIV-positive patients with lymphoma.

Rituximab and dose-dense chemotherapy for adults with Burkitt's lymphoma: a randomised, controlled, open-label, phase 3 trial

BACKGROUND

Short intensive chemotherapy is the standard of care for adult patients with Burkitt's leukaemia or lymphoma. Findings from single-arm studies suggest that addition of rituximab to these regimens could improve patient outcomes. Our objective was to test this possibility in a randomised trial.

METHODS

In this randomised, controlled, open-label, phase 3 trial, we recruited patients older than 18 years with untreated HIV-negative Burkitt's lymphoma (including Burkitt's leukaemia) from 45 haematological centres in France. Exclusion criteria were contraindications to any drug included in the chemotherapy regimens, any serious comorbidity, poor renal (creatinine concentration >150 μmol/L) or hepatic (cirrhosis or previous hepatitis B or C) function, pregnancy, and any history of cancer except for non-melanoma skin tumours or stage 0 (in situ) cervical carcinoma. Patients were stratified into two groups based on disease extension (absence [group B] or presence [group C] of bone marrow or central nervous system involvement). Patients were further stratified in group C according to age (<40 years, 40-60 years, and >60 years) and central nervous system involvement. Participants were randomly assigned in each group to either intravenous rituximab injections and chemotherapy (lymphome malin B [LMB]) or chemotherapy alone by the Groupe d'Etude des Lymphomes de l'Adulte datacentre. Randomisation was stratified by treatment group and centre using computer-assisted permuted-block randomisation (block size of four; allocation ratio 1:1). We gave rituximab (375 mg/m(2)) on day 1 and day 6 during the first two courses of chemotherapy (total of four infusions). The primary endpoint is 3 year event-free survival (EFS). We analysed all patients who had data available according to their originally assigned group. This trial is registered with ClinicalTrials.gov, number NCT00180882.

RESULTS

Between Oct 14, 2004, and Sept 7, 2010, we randomly allocated 260 patients to rituximab or no rituximab (group B 124 patients [64 no rituximab; 60 rituximab]; group C 136 patients [66 no rituximab; 70 rituximab]). With a median follow-up of 38 months (IQR 24-59), patients in the rituximab group achieved better 3 year EFS (75% [95% CI 66-82]) than did those in the no rituximab group (62% [53-70]; log-rank p stratified by treatment group=0·024). The hazard ratio estimated with a Cox model stratified by treatment group, assuming proportionality, was 0·59 for EFS (95% CI 0·38-0·94; p=0·025). Adverse events did not differ between the two treatment groups. The most common adverse events were infectious (grade 3-4 in 137 [17%] treatment cycles in the rituximab group vs 115 [15%] in the no rituximab group) and haematological (mean duration of grade 4 neutropenia of 3·31 days per cycle [95% CI 3·01-3·61] vs 3·38 days per cycle [3·05-3·70]) events.

INTERPRETATION

Addition of rituximab to a short intensive chemotherapy programme improves EFS in adults with Burkitt's leukaemia or lymphoma.

FUNDING

Gustave Roussy Cancer Campus, Roche, Chugai, Sanofi.

Ileo-Colic Burkitt Lymphoma in a Young Adult Female- A Case Report

Burkitt's lymphoma is an uncommon and aggressive type of Non-Hodgkin's lymphoma and is one of the fastest growing cancer tumour in humans; growth fraction close to 100%. We report a case of a young adult female presented with acute pain abdomen with ileo-caecal mass. On clinical presentation, initial diagnosis was acute appendicitis with lump formation. Ultrasound reported as diffuse inflammatory changes and later CECT was done which reported as Gastro-Intestinal Stromal Tumour (GIST). On laparotomy, a huge hard mass was found on ileo-caecal region and right hemicolectomy was done. Diagnosis was confirmed as Non-Hodgkins Burkitt's Lymphoma by HPE and immunohistochemistry testing. So, careful workup is the key to initiate early treatment. This patient had complete remission after the right hemicolectomy followed by multiagent chemotherapy.

Prognostic values of interim and post-therapy 18F-FDG PET/CT scanning in adult patients with Burkitt's lymphoma

Background

The prognostic values of interim and post-therapy fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) scanning have been confirmed in several subtypes of lymphoma. However, its prognostic value in Burkitt’s lymphoma has not been clearly defined. The aim of the present study was to assess the prognostic value of PET/CT scanning during different treatment processes of Burkitt’s lymphoma.

Methods

A total of 29 adult patients with newly diagnosed Burkitt’s lymphoma were retrospectively involved in this study; of them, 23 patients underwent baseline PET/CT, 15 patients underwent mid-therapy PET/CT after 1–4 cycles of chemotherapy, and 17 patients underwent post-therapy PET/CT after all planned first-line chemotherapy cycles. Mid-therapy and post-therapy PET/CT results (positive vs. negative) were visually interpreted according to the criteria of the International Harmonization Project. The reduction in the maximum standardizes uptake values (∆SUVmax) of 25%, 50%, and 75% were regarded as cutoff points. Overall survival (OS) and progression-free survival (PFS) were regarded as the major endpoints.

Results

The median OS and PFS were 27.6 months (range 6.5–78.3 months) and 27.2 months (range 3.0–78.3 months), respectively. The median SUVmax of the baseline PET/CT was 18.3 (range 1.6–35.9), whereas the median SUVmax of the mid-therapy and post-therapy PET/CT decreased to 4.0 (range 0–17.6) and 3.0 (range 0–14.5), respectively. The patients’ Eastern Cooperative Oncology Group (ECOG) scores (<2 vs. ≥2) were significantly associated with the baseline PET/CT SUVmax. The mid-therapy and post-therapy PET/CT results (positive vs. negative) showed no significant association with OS or PFS. The optimal cutoff ∆SUVmax from the baseline to the post-therapy PET/CT that could predict a change in OS in patients with Burkitt’s lymphoma was 50% (P = 0.019).

Conclusions

¹⁸F-FDG uptake was intense in Burkitt’s lymphoma, and there was a significant reduction in SUVmax during the interim and post-therapy PET/CT procedures. A ∆SUVmax of greater than 50% was a favorable cutoff point to predict the OS of Burkitt’s lymphoma patients.

Modifying chemotherapeutic management of a patient with Burkitt's lymphoma and pre-existing motor neurone disease

WHAT IS KNOWN AND OBJECTIVE

Intensive chemotherapy for treatment of Burkitt's lymphoma (BL) - a high-grade lymphoproliferative disorder (LPD) - can cause neurotoxicity. An association between motor neurone disease (MND) and LPDs has previously been described, but there is a lack of recommendations available to guide management of such patients. This report aims to describe suitable management of BL in a patient with MND.

CASE DESCRIPTION

A 66-year-old woman with a history of MND affecting her limbs was diagnosed with bulky, extranodal, high-risk gastric BL. Standard chemotherapy is with multiple non-cross-resistant cytotoxic agents. To avoid exacerbation of neuropathy, six cycles of a modified regimen was planned, aiming to minimize exposure to the most neurotoxic agents. A PET-FDG-negative remission was obtained at 12 months, without the signs of central neurotoxicity, peripheral neuropathy or muscle weakness.

WHAT IS NEW AND CONCLUSION

High-intensity chemotherapy, minimizing known neurotoxic agents, was delivered safely and effectively in a patient with BL and pre-existing MND. More case descriptions are required to guide management decisions.

Discovery of novel small-molecule compounds with selective cytotoxicity for Burkitt's lymphoma cells using 3D ligand-based virtual screening

We describe a ligand-based approach towards compounds with more specific targeting for Burkitt's lymphoma. Using three-dimensional ligand-based similarity searches and a previously described hit compound, we have identified six compounds that are chemically different but with similar spatial conformations. Biological evaluation revealed that one compound has better growth inhibition and improved selectivity towards Burkitt's lymphoma cells than the query compound. However, initial mechanism-of-action studies show a different target profile in comparison with the previous hit compound, which does not involve the inhibition of the proteasome or the NFκB pathway. The data from this study provide a solid basis for further efforts in the search for selective agents against Burkitt's lymphoma.

Interleukin-6 and interleukin-10 gene promoter polymorphisms and risk of endemic Burkitt lymphoma

Overexpression of interleukin-6 (IL-6) and IL-10 in endemic Burkitt lymphoma (eBL) may facilitate tumorigenesis by providing a permissive cytokine milieu. Promoter polymorphisms influence interindividual differences in cytokine production. We hypothesized that children genetically predisposed for elevated cytokine levels may be more susceptible to eBL. Using case-control samples from western Kenya consisting of 117 eBL cases and 88 ethnically matched healthy controls, we tested for the association between eBL risk and IL-10 (rs1800896, rs1800871, and rs1800872) and IL-6 (rs1800795) promoter single nucleotide polymorphisms (SNPs) as well as IL-10 promoter haplotypes. In addition, the association between these variants and Epstein Barr Virus (EBV) load was examined. Results showed that selected IL-10 and IL-6 promoter SNPs and IL-10 promoter haplotypes were not associated with risk eBL or EBV levels in EBV-seropositive children. Findings from this study reveal that common variants within the IL-10 and IL-6 promoters do not independently increase eBL risk in this vulnerable population.

Non-Hodgkin lymphomas in pregnancy: tackling therapeutic quandaries

Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) often present with systemic symptoms such as fatigue, shortness of breath and night sweats, mimicking pregnancy-related features which may result in delayed disease diagnosis. Furthermore, the wish to avoid investigational imaging, aiming to protect the fetus from radiation exposure, may lead to a further delay, which does not often result in significant changes in HL clinical nature and patient outcome. In contrast, a more aggressive behavior (i.e., advanced disease stage and reproductive organ involvement) of most NHL types diagnosed in pregnancy may require urgent therapeutic intervention to prevent disease progression. Current management of pregnancy-associated NHL depends on histological subtype of the disease, gestational stage at diagnosis and the urgency of treatment for a specific patient. Patients diagnosed with indolent lymphoma may often be just followed, whereas those presenting with aggressive or highly aggressive disease need to be urgently treated with chemoimmunotherapy, either after undergoing an elective pregnancy termination if diagnosed at an early gestational stage, or with pregnancy preservation, if diagnosed later. Supportive care of NHL is also important; however, granulocyte colony stimulating factor (G-CSF) which is commonly used outside of pregnancy, should be cautiously employed, considering its established teratogenicity in animals, though this is less proven in humans. In conclusion, given the paucity of studies prospectively evaluating the outcome of pregnant women with NHL, international efforts are warranted to elucidate critical issues and develop guidelines for the management of such patients.

E proteins in lymphocyte development and lymphoid diseases

As members of the basic helix-loop-helix (bHLH) family of transcription factors, E proteins function in the immune system by directing and maintaining a vast transcriptional network that regulates cell survival, proliferation, differentiation, and function. Proper activity of this network is essential to the functionality of the immune system. Aberrations in E protein expression or function can cause numerous defects, ranging from impaired lymphocyte development and immunodeficiency to aberrant function, cancer, and autoimmunity. Additionally, disruption of inhibitor of DNA-binding (Id) proteins, natural inhibitors of E proteins, can induce additional defects in development and function. Although E proteins have been investigated for several decades, their study continues to yield novel and exciting insights into the workings of the immune system. The goal of this chapter is to discuss the various classical roles of E proteins in lymphocyte development and highlight new and ongoing research into how these roles, if compromised, can lead to disease.

Phosphoinositide 3-kinase/AKT/mTORC1/2 signaling determines sensitivity of Burkitt's lymphoma cells to BH3 mimetics

Burkitt's lymphoma (BL), driven by translocation and overexpression of the c-MYC gene, is an aggressive, highly proliferative lymphoma, and novel therapeutic strategies are required to overcome drug resistance following conventional treatments. The importance of the prosurvival BCL-2 family member BCL-X(L) in BL cell survival suggests that antagonistic BH3-mimetic compounds may have therapeutic potential. Here, we show that treatment of BL cell lines with ABT-737 induces caspase-3/7 activation and apoptosis with varying potency. Using selective inhibitors, we identify phosphoinositide 3-kinase (PI3K) as a proproliferative/survival pathway in BL cells and investigate the potential of combined pharmacologic inhibition of both the BCL-2 family and PI3K signaling pathway. PI3K/AKT inhibition and ABT-737 treatment induced synergistic caspase activation, augmented BL cell apoptosis, and rendered chemoresistant cells sensitive. Targeting mTORC1/2 with PP242 was also effective, either as a monotherapy or, more generally, in combination with ABT-737. The combined use of a dual specificity PI3K/mTOR inhibitor (PI 103) with ABT-737 proved highly efficacious. PI 103 treatment of BL cells was associated with an increase in BIM/MCL-1 expression ratios and loss of c-MYC expression. Furthermore, blocking c-MYC function using the inhibitor 10058-F4 also induced apoptosis synergistically with ABT-737, suggesting that maintenance of expression of BCL-2 family members and/or c-MYC by the PI3K/AKT/mTOR pathway could contribute to BL cell survival and resistance to ABT-737. The combined use of BH3 mimetics and selective mTORC1/2 inhibitors may therefore be a useful novel therapeutic approach for the treatment of B-cell malignancy, including chemoresistant lymphomas.

How I treat HIV-associated lymphoma

Over the past 10 years, significant progress has been made in understanding HIV-associated lymphomas and improving the prognosis of these diseases. With the advent of combination antiretroviral therapy and the development of novel therapeutic strategies, most patients with HIV-associated lymphomas are cured. The outcome for the majority of patients with HIV-associated diffuse large B-cell lymphoma and Burkitt lymphoma in particular, is excellent, with recent studies supporting the role of rituximab in these diseases. Indeed, in the combination antiretroviral therapy era, the curability of many patients with HIV-associated lymphoma is similar to their HIV-negative counterparts. New treatment frontiers need to focus on improving the outcome for patients with advanced immune suppression and for those with adverse tumor biology, such as the activated B-cell type of diffuse large B-cell lymphoma and the virally driven lymphomas. Future clinical trials need to investigate novel targeted agents alone and in combination with chemotherapy.

Molecular profiling of aggressive lymphomas

In the last years, several studies of molecular profiling of aggressive lymphomas were performed. In particular, it was shown that DLBCL can be distinguished in two different entities according to GEP. Specifically, ABC and GCB subtypes were characterized by having different pathogenetic and clinical features. In addition, it was demonstrated that DLBCLs are distinct from BL. Indeed, the latter is a unique molecular entity. However, relevant pathological differences emerged among the clinical subtypes. More recently, microRNA profiling provided further information concerning BL-DLBCL distinction as well as for their subclassification. In this paper, the authors based on their own experience and the most updated literature review, the main concept on molecular profiling of aggressive lymphomas.

Simple karyotype and bcl-6 expression predict a diagnosis of Burkitt lymphoma and better survival in IG-MYC rearranged high-grade B-cell lymphomas

Rearrangement of MYC with immunoglobulin genes is a hallmark of Burkitt lymphoma. However, this rearrangement is not entirely specific and is often accompanied by varying numbers of additional cytogenetic abnormalities. This study aimed to assess the impact of karyotypic complexity, in correlation with comprehensive immunophenotypic analyses on the diagnosis and clinical outcomes of 34 cases of MYC-IG rearranged lymphomas that included Burkitt lymphoma (twenty-two cases), diffuse large B-cell lymphoma (three cases), unclassifiable B-cell lymphoma with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (six cases), and plasmablastic lymphoma (three cases). Additional cytogenetic abnormalities were observed in 26 of 34 cases (76%), including four cases (12%) that harbored dual translocations involving BCL-2 or BCl-6. Burkitt lymphoma cases had a significantly lower number of additional abnormalities (mean of 1.7), compared with unclassified B-cell lymphoma (3.3), diffuse large B-cell lymphoma (21.7), and plasmablastic lymphoma (6.7). Cases with simple karyotype (< or =2 additional abnormalities) were more likely to have a diagnosis of Burkitt lymphoma (89 versus 33% in patients with >2 additional abnormalities, P<0.01) and express bcl-6 (95 versus 47%, P<0.01). In addition, Burkitt lymphoma, bcl-6 expression, and simple karyotype were individual predictors of better overall survival. However, in multivariate analyses, only bcl-6 expression remained an independent predictor, although survival could be further stratified by karyotypic complexity in bcl-6(+) patients. We conclude that simple karyotype and bcl-6 expression suggest a diagnosis of Burkitt lymphoma and may portend better overall survival. These results may be very useful in the diagnosis and stratification of MYC-IG rearranged high-grade B-cell lymphomas.

Burkitt lymphoma versus diffuse large B-cell lymphoma: a practical approach

Burkitt Lymphoma (BL) is listed in the World Health Organization (WHO) classification of lymphoid tumours as an 'aggressive B-cell non-Hodgkin's lymphoma', characterized by a high degree of proliferation of the malignant cells and deregulation of the c-MYC gene. The main diagnostic challenge in BL is to distinguish it from diffuse large B-cell lymphoma (DLBCL). While in children BL and DLBCL types probably do not differ clinically, and the differential diagnosis between BL and DLBCL may theoretically appear clear-cut, in adults daily practice shows the existence of cases that have morphological features, immunophenotypic and cytogenetics intermediate between DLBCL and BL, and cannot be classified with certainty in these categories. Distinguishing between BL and DLBCL is critical, as the two diseases require different management. This review summarizes the current practical approach, including the use of a large panel of antibodies, and cytogenetic and molecular diagnostic techniques, to distinguish between BL, DLBCL and the provisional category of 'B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma', now listed in the updated WHO classification.

Burkitt lymphoma versus diffuse large B-cell lymphoma: a practical approach

Burkitt Lymphoma (BL) is listed in the World Health Organization (WHO) classification of lymphoid tumours as an "aggressive B-cell non-Hodgkin's lymphoma", characterized by a high degree of proliferation of the malignant cells and deregulation of the c-MYC gene. The main diagnostic challenge in BL is to distinguish it from diffuse large B-cell lymphoma (DLBCL). While in children BL and DLBCL types probably do not differ clinically, and the differential diagnosis between BL and DLBCL may theoretically appear clear-cut, in adults daily practice shows the existence of cases that have morphological features, immunophenotypic and cytogenetics intermediate between DLBCL and BL, and cannot be classified with certainty in these categories. Distinguishing between BL and DLBCL is critical, as the two diseases require different management. This review summarizes the current practical approach, including the use of a large panel of antibodies, and cytogenetic and molecular diagnostic techniques, to distinguish between BL, DLBCL and the provisional category of "B-cell lymphoma, unclassificable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma", now listed in the updated WHO classification.

Complete remission of gastric Burkitt’s lymphoma after eradication of Helicobacter pylori

Burkitt’s lymphoma is a highly aggressive non-Hodgkin lymphoma, often presenting in extra-nodal sites. It generally has a poor spontaneous outcome and needs aggressive treatment with systemic and intrathecal chemotherapy. Occurrence at the gastric site is rare. We report the case of a 39-year old woman who presented with a prominent ulcerated lesion of the antrum corresponding histologically to a Burkitt’s lymphoma associated with Helicobacter pylori (H pylori) infection. Interphase fluorescence in situ hybridization (FISH) demonstrated c-MYC gene rearrangement in tumour cells without BCL2 or BCL6 gene translocations. Ulcer healing and tumour regression with a complete histological response were obtained 8 wk after H pylori eradication. In spite of this complete remission, taking into account the high risk of recurrence, the patient received systemic and intrathecal chemotherapy. Two years later, the patient remained in complete remission. This is the first report of a gastric Burkitt’s lymphoma responding to H pylori eradication. These findings raise the question of the potential role of H pylori in the pathogenesis of some gastric Burkitt’s lymphomas, and show the importance of searching for and eradicating the bacteria in combination with conventional chemotherapy regimens.

Long distance polymerase chain reaction of ascites lymphoma cells aids diagnosis establishment of abdominal Burkitt's lymphoma and Burkitt-like lymphoma

Burkitt's lymphoma (BL) and its variants, including Burkitt-like lymphoma (BLL), can be difficult to distinguish morphologically and immunophenotypically from diffuse large B-cell lymphoma (DLBCL). Because the treatment of BL differs markedly from that of other types of non-Hodgkin's lymphoma (NHL), exact pathological diagnosis is crucial. We report 2 cases of patients with BL initially diagnosed as DLBCL. Due to clinical features typical of BL, long distance polymerase chain reaction (PCR) for detecting the t(8;14) translocation involving the c-myc proto-oncogene was performed on ascites lymphoma cells. Re-evaluation by a reference hematopathologist, together with long distance PCR in both patients revealing the t(8;14) translocation, resulted in diagnosis modification to BL and BLL. Consequently, the patients were treated with intense high-dose chemotherapy regimens including central nervous system (CNS) prophylaxis, and complete remission was initially achieved in both patients. Both BL and BLL should be considered in the differential diagnosis of DLBCL if abdominal spread with ascites and metabolic disorders are present. Long distance PCR analysis of ascites lymphoma cells for the detection of the BL-typical c-myc rearrangement offers a convenient and rapid possibility of diagnosis verification in atypical or borderline cases of BL.

Perforin-mediated suppression of B-cell lymphoma

In the present study, we have examined the effect of perforin (pfp) deficiency in 4 models of mouse B-cell lymphomagenesis. We have examined pfp loss on the background of either Mlh1 tumor suppressor allele loss or oncogene expression [Ig heavy chain (Emu)-v-Abl, Emu-myc, and vav-bcl2]. Pfp was shown to act as a suppressor of B-cell malignancies characteristically driven by v-Abl or bcl-2, whereas Mlh loss cooperated in accelerating spontaneous B-cell lymphomas characteristic of pfp loss. No protective role for pfp was observed in the more aggressive Emu-myc model of B-cell lymphoma. These transgenic models have allowed us to distinguish the role of pfp in surveillance of B-cell lymphomagenesis, as opposed to its loss simply driving the onset of a spontaneous lymphoma characteristic of pfp deficiency.

In vivo efficacy of the Bcl-2 antagonist ABT-737 against aggressive Myc-driven lymphomas

Deregulated Myc expression drives many human cancers, including Burkitt's lymphoma and a highly aggressive subset of diffuse large cell lymphomas. Myc-driven tumors often display resistance to chemotherapeutics because of acquisition of mutations that impair the apoptosis pathway regulated by the Bcl-2 protein family. Given the need to identify new therapies for such lymphomas, we have evaluated the efficacy of ABT-737, a small molecule that mimics the action of the BH3-only proteins, natural antagonists of the prosurvival Bcl-2 proteins. ABT-737 selectively targets certain prosurvival proteins (Bcl-2, Bcl-x(L), and Bcl-w) but not others (Mcl-1 and A1). We treated mice transplanted with lymphomas derived either from Emu-myc transgenic mice or Emu-myc mice that also expressed an Emu-bcl-2 transgene. As a single agent, ABT-737 significantly prolonged the survival of mice transplanted with the myc/bcl-2 lymphomas but was ineffective for the myc lymphomas, probably because of the relatively higher Mcl-1 levels found in the latter. Strikingly, when combined with low-dose cyclophosphamide, ABT-737 produced sustained disease-free survival of all animals transplanted with two of three myc/bcl-2 lymphomas tested. The combination therapy was also more effective against some myc lymphomas than treatment with either agent alone. Our data suggest that antagonism of Bcl-2 with small organic compounds is an attractive approach to enhance the efficacy of conventional therapy for the treatment of Myc-driven lymphomas that over-express this prosurvival molecule.

Molecular diagnosis of Burkitt's lymphoma

BACKGROUND

The distinction between Burkitt's lymphoma and diffuse large-B-cell lymphoma is crucial because these two types of lymphoma require different treatments. We examined whether gene-expression profiling could reliably distinguish Burkitt's lymphoma from diffuse large-B-cell lymphoma.

METHODS

Tumor-biopsy specimens from 303 patients with aggressive lymphomas were profiled for gene expression and were also classified according to morphology, immunohistochemistry, and detection of the t(8;14) c-myc translocation.

RESULTS

A classifier based on gene expression correctly identified all 25 pathologically verified cases of classic Burkitt's lymphoma. Burkitt's lymphoma was readily distinguished from diffuse large-B-cell lymphoma by the high level of expression of c-myc target genes, the expression of a subgroup of germinal-center B-cell genes, and the low level of expression of major-histocompatibility-complex class I genes and nuclear factor-kappaB target genes. Eight specimens with a pathological diagnosis of diffuse large-B-cell lymphoma had the typical gene-expression profile of Burkitt's lymphoma, suggesting they represent cases of Burkitt's lymphoma that are difficult to diagnose by current methods. Among 28 of the patients with a molecular diagnosis of Burkitt's lymphoma, the overall survival was superior among those who had received intensive chemotherapy regimens instead of lower-dose regimens.

CONCLUSIONS

Gene-expression profiling is an accurate, quantitative method for distinguishing Burkitt's lymphoma from diffuse large-B-cell lymphoma.

Burkitt lymphoma in adults: a prospective study of 72 patients treated with an adapted pediatric LMB protocol

BACKGROUND

We conducted a phase II study to evaluate in 72 adult patients the efficacy of the intensive LMB chemotherapy regimen, previously reported by the Société Française d'Oncologie Pédiatrique for children with Burkitt lymphoma and L3 acute lymphoblastic leukemia.

PATIENTS AND METHODS

Treatment began with a prephase (low-dose steroids, vincristine and cyclophosphamide), except in patients with low tumor burden. Group A (resected stage I and abdominal stage II disease) received three courses of vincristine, cyclophosphamide, doxorubicin and prednisone. Group B (not eligible for groups A or C) received five courses of chemotherapy comprising high-dose methotrexate, infusional cytarabine and intrathecal (IT) methotrexate. Group C (patients with central nervous system and/or bone marrow involvement with < 30% of blast cells) received eight courses containing intensified high-dose methotrexate, high-dose cytarabine, etoposide and triple IT injections.

RESULTS

The 2 year event-free survival and overall survival rates for the 72 patients were 65% and 70%, respectively. Age > or = 33 years and high lactate dehydrogenase value were associated with a shorter survival. No response to COP was also associated with a poor outcome in group B.

CONCLUSION

Patients with advanced-stage Burkitt lymphoma, including those with bone marrow and/or central nervous system involvement, can be cured with a short-term intensive chemotherapy regime tailored to the tumor burden.