AIDS-related Burkitt's lymphoma. Morphologic and immunophenotypic study of biopsy specimens

Human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV) related lymphomas, pathology view point

The contribution of Epstein Barr virus (EBV) and Kaposi sarcoma herpes virus (KSHV) to the development of specific types of malignant lymphomas occurring in the human immunodeficiency virus (HIV) setting has been extensively studied since the beginning of the HIV epidemic 35 years ago. The introduction of highly active antiretroviral therapies (HAART) in 1996 has changed dramatically the incidence of HIV-related malignancies. Nevertheless, malignant lymphomas continue to be the major group of malignances observed in HIV infected individuals, and the most common cause of cancer related-deaths. Common features of the predominant B-cell lymphomas in the HIV⁺ setting are the frequent plasmacytoid morphology of the neoplastic cells, advanced stage, aggressive disease and frequent extranodal involvement. In this article, we review the evolving concepts and definitions of the various EBV-associated lymphomas in HIV⁺ patients, including diffuse large B-cell lymphoma, Burkitt lymphoma, classical Hodgkin lymphoma, plasmablastic lymphoma and primary effusion lymphoma. The current knowledge regarding the pathogenesis of these malignancies, the interplay between HIV and EBV co-infection in the development of certain HIV related lymphomas, and the emerging paradigm that suggests that HIV may play a direct role in lymphomagenesis are explored as well.

AMC 048: modified CODOX-M/IVAC-rituximab is safe and effective for HIV-associated Burkitt lymphoma

The toxicity of dose-intensive regimens used for Burkitt lymphoma prompted modification of cyclophosphamide, vincristine, doxorubicin, high-dose methotrexate/ifosfamide, etoposide, and high-dose cytarabine (CODOX-M/IVAC) for HIV-positive patients. We added rituximab, reduced and/or rescheduled cyclophosphamide and methotrexate, capped vincristine, and used combination intrathecal chemotherapy. Antibiotic prophylaxis and growth factor support were required; highly active antiretroviral therapy (HAART) was discretionary. Thirteen AIDS Malignancy Consortium centers enrolled 34 patients from 2007 to 2010. Median age was 42 years (range, 19-55 years), 32 of 34 patients were high risk, 74% had stage III to IV BL and CD4 count of 195 cells per μL (range, 0-721 cells per μL), and 5 patients (15%) had CD4 <100 cells per μL. Twenty-six patients were receiving HAART; viral load was <100 copies per mL in 12 patients. Twenty-seven patients had at least one grade 3 to 5 toxicity, including 20 hematologic, 14 infectious, and 6 metabolic. None had grade 3 to 4 mucositis. Five patients did not complete treatments because of adverse events. Eleven patients died, including 1 treatment-related and 8 disease-related deaths. The 1-year progression-free survival was 69% (95% confidence interval [CI], 51%-82%) and overall survival was 72% (95% CI, 53%-84%); 2-year overall survival was 69% (95% CI, 50%-82%). Modifications of the CODOX-M/IVAC regimen resulted in a grade 3 to 4 toxicity rate of 79%, which was lower than that in the parent regimen (100%), without grade 3 to 4 mucositis. Despite a 68% protocol completion rate, the 1-year survival rate compares favorably with 2 studies that excluded HIV-positive patients. This trial was registered at http://clinicaltrials.gov as #NCT00392834.

Controversies in the treatment of Burkitt lymphoma in AIDS

PURPOSE OF REVIEW

The success of combined antiretroviral therapy (cART) has transformed HIV infection into a survivable chronic disease in developed countries. Increasingly then, the risks of HIV associated cancers become paramount. Burkitt lymphoma is one of the cancer subtypes highly disproportionately affecting HIV infected patients.

RECENT FINDINGS

Recent conference proceedings appear to corroborate early reports that intensive therapy of HIV-Burkitt lymphoma is feasible and effective. An optimal approach is not defined due to the small numbers of patients in current trials and the absence of comparison studies. Moreover, as breakthroughs in the pathogenesis of lymphoma in general and Burkitt lymphoma in particular suggest that HIV infection plays a significant role, the opportunity for targeted therapy based on differences in biology are wholly untapped.

SUMMARY

Advances are being made in HIV-Burkitt lymphoma, but future studies need to incorporate our expanding understanding of biology to improve efficacy and reduce toxicity, preferably by integrating a biologic approach to this curable disease.

Diffuse aggressive B-cell lymphomas

Diffuse aggressive B-cell lymphomas comprise a relatively common and increasingly diverse group of neoplasms. Newer modalities including gene expression profiling and an increasing panel of immunohistochemical markers have contributed to greater accuracy in defining these entities. Attention is paid not only to the neoplastic cells but also to the cellular and stromal milieu in which they proliferate. These distinctions may have therapeutic implications as well, with improved outcome related to newer and sometimes targeted therapies. At the same time there is increasing understanding of the overlap, which occurs in the grey zone between diffuse large B-cell lymphoma and Burkitt lymphoma as well as between diffuse large B-cell lymphoma and Hodgkin lymphoma. This review aims to provide practical insights in the correct identification and differential diagnosis of these lymphomas, with emphasis on the changes that have occurred with the publication of the 2008 World Health Organization updated classification.

AIDS-associated Burkitt or Burkitt-like lymphoma: Short intensive polychemotherapy is feasible and effective

The objective was to evaluate the feasibility and efficacy of a short-term, multi-agent and dose intensive regimen in AIDS patients with Burkitt or Burkitt-like lymphoma (BL/BLL) and to compare its efficacy with that of a conventional regimen. This was a retrospective, multi-center cohort study of all HIV-1-infected patients diagnosed with BL/BLL between 1990 - 2004. Patients were assigned to two different chemotherapy approaches. Group A received a protocol which was adapted from the German multi-center study group for adult acute lymphoblastic leukemia (GMALL). Group B received a conventional CHOP-based chemotherapy. Fifty-one patients were included in the analysis. In group A (n = 20), significantly more patients achieved complete remission (75% vs 40%, P = 0.02) than in group B (n = 31). One-year survival in group A was 65% compared to 44% in group B (P = 0.17). In a multi-variable Cox regression analysis, treatment according to the GMALL protocol was significantly associated with prolonged survival with a relative hazard rate of 0.13 (95% CI 0.03 - 0.63, P = 0.01). In conclusion, the short and intensive GMALL protocol for B-ALL/NHL is feasible in patients with AIDS-BL/BLL. Outcome may be improved compared to patients treated with CHOP-based regimens. In the era of HAART, more intensive chemotherapy regimens should be considered in patients with highly aggressive lymphomas.

The role of Epstein-Barr virus in cancer

Epstein-Barr virus (EBV), discovered > 40 years ago from a Burkitt's lymphoma biopsy, was the first virus to be directly associated with human cancer. EBV has two distinct life cycles in the human host; a lytic form of infection that produces new infectious virions, and a latent form of infection that allows the virus to persist in a dormant state for the lifetime of the host. EBV has evolved a life cycle that mimics the natural differentiation pathway of antigen-activated B cells, giving the virus access to its site of latent infection, the resting memory B cell. By steering infected cells through the various stages of lymphocyte differentiation, EBV is able to enter a cell type suitable for long-term latent persistence and periodic reactivation. However, its presence in various stages of B-cell development, and its ability to infect certain epithelial cells, can have pathogenic consequences, and can contribute to the development of a diverse group of lymphomas and carcinomas. The presence of EBV in the tumour cells of EBV-associated cancers might provide a basis for specific therapy. This article focuses on the contributions that the virus may play in different types of human cancer, particularly Burkitt's lymphoma, Hodgkin's lymphoma, lymphomas and lymphoproliferative diseases in the immunocompromised, and nasopharyngeal and gastric carcinoma.

Plasmablastic lymphoma in HIV-positive patients: an aggressive Epstein-Barr virus-associated extramedullary plasmacytic neoplasm

AIDS-associated aggressive B-cell lymphomas often have plasmacytoid features. Plasma cell neoplasms in HIV patients were commonly described to have atypical morphology and an aggressive clinical course in the literature. We reviewed 14 cases of neoplasms with marked plasmacytic differentiation in HIV-positive patients to determine their clinicopathologic features. Of these, 13 of 14 had homogeneous morphology and were generally CD45(+), CD20-, PAX-5-, and CD138(+). All were positive for Epstein-Barr virus-encoded RNA (EBER) but lacked EBV late membrane proteins (LMP). Human herpes virus 8 (HHV8) DNA was detected in 6 of 10 cases by nested PCR, but HHV8 latent nuclear antigen (LNA) was absent. The 13 patients ranged in age from 28 to 44 years (median, 41 years) (11 male patients; 2 female patients). All patients had extramedullary and 11 of 13 had extranodal tumor at the initial presentation; 2 had distant marrow involvement. The most commonly involved location was the oral cavity (6 of 13 cases), followed by bone and soft tissue (4 of 13), and the gastrointestinal tract (3 of 13). All 11 patients with follow-up died within 34 months (median, 7 months). The 14th patient who had a nodal disease with more undifferentiated morphology and expression of the HHV8 LNA protein was alive without disease at last follow-up (>72 months), probably representing a novel HHV8(+) lymphoma. We conclude that most plasmacytic tumors in HIV-positive individuals are extramedullary, clinically aggressive EBV(+) tumors identical to plasmablastic lymphoma that does not have the clinical features of plasma cell myeloma.

Plasmablastic lymphoma of the oral cavity in an HIV-positive child

A 7-year-old boy with a positive history of vertical HIV transmission presented with a painful swelling over the left upper jaw of 20 days' duration. A provisional diagnosis of non-Hodgkin's lymphoma or embryonal rhabdomyosarcoma was made. Fine-needle aspiration cytology findings were inconclusive, and incisional biopsy tissue on routine stains gave an impression of small round cell tumor with plasmacytoid features. A series of histochemical stains and immunohistochemical studies was carried out to differentiate and characterize this tumor. The salient immunostaining was negativity with all routine small round cell tumor markers and positivity with CD138 and lambda light chain restriction. The heterogeneous presentation of plasmablastic lymphoma as a variant of diffuse large B-cell lymphoma and its histogenesis is documented. Potential pitfalls and differential characterization of AIDS-plasmablastic lymphoma from other closely related tumors are addressed. The importance of excluding other common pediatric small round cell tumors by immunohistochemistry is highlighted. To the best of our knowledge, this is the first report of this entity in a vertically transmitted HIV-positive child.

Latent membrane protein 1 deletion mutants accumulate in reed-sternberg cells of human immunodeficiency virus-related Hodgkin's lymphoma

The origin and biological significance of deletions at the 3' end of the Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP-1) gene are still controversial. We herein demonstrate that LMP-1 deletion mutants are highly associated with human immunodeficiency virus-related Hodgkin's lymphoma (HIV-HL) of Italian patients (29 of 31 cases; 93.5%), a phenomenon that is not due to a peculiar distribution of EBV strains in this area. In fact, although HIV-HL patients are infected by multiple EBV variants, we demonstrate that LMP-1 deletion mutants preferentially accumulate within neoplastic tissues. Subcloning and sequencing of the 3' LMP-1 ends of two HIV-HL genes in which both variants were present showed the presence of molecular signatures suggestive of a likely derivation of the LMP-1 deletion mutant from a nondeletion ancestor. This phenomenon likely occurs within tumor cells in vivo, as shown by the detection of both LMP-1 variants in single microdissected Reed-Sternberg cells, and may at least in part explain the high prevalence of LMP-1 deletions associated with HIV-HL.

Immunoglobulin gene analysis reveals 2 distinct cells of origin for EBV-positive and EBV-negative Burkitt lymphomas

The normal counterpart of the neoplastic B cells in Burkitt lymphoma (BL) is still unclear. Based on immunoglobulin gene rearrangement studies, some authors suggest an origin from germinal center cells and others from memory B cells. However, most of these studies rely on cell lines or on a small series of cases. To help clarify the cell of origin of BL, semi-nested polymerase chain reaction (PCR) was performed to amplify the VDJ rearrangements of the immunoglobulin heavy chain (VH) genes, and the resultant amplificates were sequenced for comparison with known germline VH segments. The results of this approach revealed that all cases (15 endemic BL [eBL], 10 sporadic BL [sBL], and 6 AIDS-related BL) harbor mutated VH genes, with different mutation ranges among the 3 types of BL. The eBL and AIDS-related forms showed considerably higher mutation rates than the sBL form (5.1%, 5.4%, and 1.5%, respectively). The mutations in eBL and AIDS-related BL also showed signs of antigen selection, whereas no signs of antigen selection were found in sBL. Finally, after subcloning the amplificates, sequence analysis revealed no signs of ongoing mutations in any of the cases analyzed. Given that one of the main differences between eBL and AIDS-related BL on the one hand and sBL on the other hand is the association with Epstein-Barr virus (EBV), we compared EBV-positive and EBV-negative BLs independently of their geographic origin and HIV status. The differences in the number of somatic mutations and antigen selection were even more evident when this approach was used. According to our molecular results, it appears that EBV-positive and EBV-negative BL may originate from 2 distinct subsets of B cells, pointing to a particular role for the germinal-center reaction in the pathogenesis of these tumors. The different types of C-MYC translocation reported in BL may also be related to the different stages of B-cell maturation.

Cutaneous plasmablastic lymphoma in an HIV-positive male: an unrecognized cutaneous manifestation

Plasmablastic lymphoma (PBL) is a rare and relatively new entity originally described in HIV-infected individuals. This subset of Epstein-Barr-virus (EBV)-related non-Hodgkin lymphomas is now regarded as a distinct clinicopathological category of AIDS-associated lymphomas occurring preferentially in the oral cavity and showing a poor prognosis. We describe for the first time an EBV-associated PBL with an isolated cutaneous distribution on the lower extremities in an HIV-infected heterosexual male and point to the unique clinical, morphological and immunophenotypic characteristics of this lymphoma. The patient presented with fast growing solid and livid nodules on both legs. The large, blastic tumor cells showed the following immunophenotype: CD138+, CD45+, CD20-, CD10-, CD3-, CD30-, bcl-2-, bcl-6-, LMP-1- and EMA-. The proliferation fraction (Mib-1) was >90%. EBV association was demonstrated by in situ hybridization (EBV-encoded RNAs 1/2). Polymerase-chain-reaction-based DNA analysis demonstrated a clonal IgH rearrangement in the absence of a bcl-2/IgH translocation. PBL in HIV patients may occur not only in the oral cavity, but can probably involve any other organs including the skin.

Therapeutic approaches to AIDS-related malignancies

The introduction of highly active antiretroviral therapy (HAART) has changed dramatically the landscape of HIV disease. Deaths from AIDS-related diseases have been reduced by 75% since protease inhibitor therapy and combination antiretroviral therapy came into use in late 1995. While KS is declining, the situation for non-Hodgkin's lymphoma is more complex with a reduced incidence of primary central nervous system lymphoma, but a relatively stability in the number of patients developing systemic NHL. AIDS related NHL appears not to be markedly decreased by the introduction of HAART and it is the greatest therapeutic challenge in the area of AIDS oncology. The emphasis has now shifted to cure while maintaining vigilance regarding the unique vulnerability of HIV-infected hosts. Furthermore, also for the prolongation of the survival expectancy of these patients, other non AIDS-defining tumors, such as Hodgkin's disease, anal and head and neck, lung and testicular cancer, and melanoma have been recently reported with increased frequency in patients with HIV infection.

Intensive chemotherapy with cyclophosphamide, doxorubicin, high-dose methotrexate/ifosfamide, etoposide, and high-dose cytarabine (CODOX-M/IVAC) for human immunodeficiency virus-associated Burkitt lymphoma

BACKGROUND

In the era of highly active antiretroviral therapy (HAART), standard-dose chemotherapy for human immunodeficiency virus (HIV)-associated diffuse large B-cell lymphoma is becoming the standard of care. In contrast, the safety and efficacy of intensive regimens have not been established for Burkitt lymphoma (BL), a highly aggressive lymphoma for which moderate-dose chemotherapy is substandard in the HIV-negative population.

METHODS

To evaluate the feasibility of intensive chemotherapy in HIV-associated BL, the authors retrospectively reviewed 14 HIV-positive adults with BL treated at their center between 1988 and 2000. Eight patients were treated between 1996 and 2000 with cyclophosphamide, doxorubicin, high-dose methotrexate/ifosfamide, etoposide, and high-dose cytarabine (CODOX-M/IVAC), one of the currently preferred intensive-dose chemotherapy regimens for BL. Six received other chemotherapy. Outcomes were compared with those of 24 HIV-negative adult patients with BL who had similar patient characteristics and were treated concomitantly (13 with CODOX-M/IVAC; 11 with other regimens).

RESULTS

Of the 14 HIV-positive patients, 63% had a complete response after CODOX-M/IVAC treatment, compared with 67% of patients receiving other chemotherapy. The 2-year event-free survival (EFS) rates were 60% and 60% after CODOX-M/IVAC or other regimens, respectively. Similar outcomes were seen despite the fact that 88% of CODOX-M/IVAC-treated HIV-positive patients had Stage IV disease, compared with one-third of HIV-positive patients treated with other chemotherapy. HIV status did not adversely affect long-term EFS independent of the treatment regimen (P = 0.88). When EFS was evaluated according to chemotherapy regimen independent of HIV status, CODOX-M/IVAC was found to be associated with improved EFS (P = 0.05) in all patients, and particularly those at high risk. HIV-positive patients treated with CODOX-M/IVAC tolerated chemotherapy well with similar rates of myelosuppression and infectious complications as HIV-negative patients.

CONCLUSIONS

The current nonrandomized retrospective study suggested that intensive chemotherapy with CODOX-M/IVAC is feasible and well tolerated in HIV-positive adults with BL. In the post-HAART era, intensive chemotherapy such as CODOX-M/IVAC may be appropriate in all adult patients with BL, and especially those with poor prognostic factors, regardless of HIV status.

Etiology and pathogenesis of AIDS-related non-Hodgkin's lymphoma

The incidence of NHL is greatly increased in HIV-infected individuals; malignant lymphoma is the second most common neoplasm that occurs in association with AIDS. The vast majority of neoplasms are clinically aggressive, monoclonal B-cell neoplasms that exhibit Burkitt's, immunoblastic, large cell, or transitional histopathology. Approximately 80% arise systemically (nodal or extranodal) and 20% arise as primary CNS lymphomas. A small proportion of neoplasms are body cavity-based, primary effusion lymphomas that are uniquely associated with KSHV infection. Recently, HIV-associated polymorphic lymphoproliferative disorders have been described as well. AIDS-related NHLs appear to exhibit distinctive clinical characteristics according to their histopathology and anatomic site of origin. Factors that contribute to lymphoma development include HIV-induced immunosuppression, impaired immune surveillance, cytokine release and deregulation, and chronic antigenic stimulation. This environment is associated with the development of oligoclonal B-cell expansions. The appearance of NHL is characterized by the presence of a monoclonal B-cell population that displays a variety of genetic lesions, including, for example, EBV infection, MYC gene rearrangement, BCL6 gene rearrangement, P53 mutations and deletions, and RAS gene mutations. The number and type of genetic lesions vary somewhat among AIDS-related NHLs according to their histopathologic category and anatomic site of origin. These findings suggest that more than one pathogenetic mechanism is operational in the development and progression of AIDS-related NHLs. Further work is necessary to develop a complete understanding of the etiology and pathogenesis of NHL in the setting of HIV infection. AIDS-related NHL is an important biologic model for investigating the development and progression of high-grade NHLs and NHLs that develop in immunedeficient hosts.

Burkitt lymphoma arising in organ transplant recipients: a clinicopathologic study of five cases

We report five cases of Burkitt lymphoma arising in organ transplant recipients. There were four men and one woman with a mean age of 35 years. All were solid organ recipients with three renal, one liver, and one double lung transplantation. The time interval between organ transplantation and lymphoma averaged 4.5 years. Patients typically presented with high-stage disease with generalized lymphadenopathy and bone marrow involvement. Histology showed classic Burkitt lymphoma or atypical variant/Burkitt-like morphology. C-MYC rearrangement, including three cases with immunoglobulin heavy chain and two cases with lambda light chain, and Epstein-Barr virus were detected in all the cases. Additional chromosomal abnormalities were present in two of three cases and p53 mutation was found in one of three cases. Aberrant genotype and phenotype were frequently encountered, including minor monoclonal or oligoclonal T-cell populations and undetectable surface immunoglobulin light chain expression. Four patients received antilymphoma regimens, with combination chemotherapy (three patients) and/or Rituximab (three patients), in addition to reduction of immunosuppression. All four patients achieved complete remission. We conclude that posttransplant Burkitt lymphoma represents a characteristic clinicopathologic entity and occurs later after transplantation. Genotypic and phenotypic aberrations are often present. Rituximab may be an effective alternative to conventional combination chemotherapy in the treatment of a posttransplant Burkitt lymphoma.

Burkitt's lymphoma: new insights into molecular pathogenesis

The World Health Organisation classification reports three subcategories of Burkitt's lymphoma (BL)--endemic, non-endemic, and immunodeficiency associated--proposed to reflect the major clinical and genetic subtypes of this disease. These different types of BL have been reviewed and studied by immunohistochemistry and molecular methods. The results point out the heterogeneity of BL and suggest that AIDS related BL may have a different pathogenesis from that of classic BL.

Long-term survival in patients with human immunodeficiency virus-associated small non-cleaved cell lymphoma: the role for short course intensive chemotherapy

While intensive chemotherapy is recommended for the treatment of non-HIV related adult small non-cleaved lymphoma (SNCL), including Burkitt's and Burkitt-like lymphoma, optimal treatment for patients with HIV-associated SNCL is not known. We assessed remissions and survival in a cohort of 44 consecutive HIV positive patients diagnosed with SNCL at our hospital between June 2000 and November 2001 using chart and pathology data. Median follow-up, survival and survival at the median follow-up time were 4.5 months, 4 months and 49% respectively. Of this cohort 39% were complete responders (CR) and 36% were long-term lymphoma-free survivors. Two patients relapsed from CR. Short course intensive chemotherapy (McMaster) was administered to 23 patients; 17 received less intensive conventional combination chemotherapy; and four received single-agent chemotherapy or no treatment. In the McMaster group, 38% (9/23) achieved CR with no relapses. Seven patients (30%) died of toxicity compared with one (6%) in the less intensively treated group. Of the stage I patients, 75% (6/8) achieved long-term CR with half being treated conventionally. Conventional chemotherapy may be curative for early stage HIV-SNCL. In advanced disease, McMaster chemotherapy was found to be associated with substantial early mortality but was curative in a significant number of patients.

Expression of cyclin-dependent kinase inhibitor p27(Kip1) in AIDS-related diffuse large-cell lymphomas is associated with Epstein-Barr virus-encoded latent membrane protein 1

Knowledge of the role of cell-cycle regulators in the pathogenesis of acquired immune deficiency syndrome-related non-Hodgkin's lymphomas (AIDS-NHLs) is scarce. Here we analyzed 86 systemic AIDS-NHLs and 20 AIDS-primary central nervous system lymphomas for expression of p27(Kip1), a negative regulator of cell-cycle progression belonging to the Kip family of cyclin-dependent kinase inhibitors. In parallel, we investigated the relationship between p27(Kip1), the lymphoma proliferation index, Epstein-Barr virus status, expression of cellular cyclin D3 and cyclin D1, and B-cell differentiation stage. We report that AIDS-immunoblastic lymphomas (AIDS-IBLs), either systemic or primarily localized to the central nervous system, consistently express p27(Kip1) protein (19 of 24 and 10 of 14, respectively) despite the high proliferative rate of the lymphoma clone, suggesting a failure of p27(Kip1) to inhibit the cell cycle in AIDS-IBL. Conversely, the remaining systemic AIDS-NHLs and AIDS-primary central nervous system lymphomas preferentially fail to express p27(Kip1). Expression of p27(Kip1) in Epstein-Barr virus-positive AIDS-NHLs generally associates with latent membrane protein 1 (LMP1) expression and is related to a late stage of B-cell differentiation, characterized by the BCL-6-/MUM1+/syn-1+/- phenotypic profile, whereas it seems to be unrelated to the expression of cellular cyclins. In B cells in vitro, induction of LMP-1 expression under the control of inducible promoters up-regulates expression of p27(Kip1), thus providing a putative mechanistic explanation for the association between LMP1 and p27(Kip1) observed in vivo. Overall, these data show that AIDS-IBL pathogenesis is characterized by loss of the inverse relationship between p27(Kip1) positivity and tumor growth fraction that is otherwise generally observed in normal lymphoid tissues and in most other types of NHLs.

Hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone and highly active antiretroviral therapy for patients with acquired immunodeficiency syndrome-related Burkitt lymphoma/leukemia

BACKGROUND

Patients with acquired immunodeficiency syndrome (AIDS)-associated lymphoma/leukemia have a poor prognosis and are frequently treated with low-intensity therapy. The authors investigated the feasibility and efficacy of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD), a dose-intensive chemotherapy regimen, in patients with AIDS-associated Burkitt lymphoma/leukemia, as well as the possible impact of highly active antiretroviral therapy (HAART) in these patients.

METHODS

Thirteen patients with AIDS-associated Burkitt lymphoma (six patients) or leukemia (acute lymphoblastic leukemia; seven patients) were treated with hyper-CVAD alternating with high-dose methotrexate and ara-C for a total of eight cycles. Nine patients received HAART from the start of induction chemotherapy (seven patients) or later in the course of chemotherapy (two patients). The median patient age was 43 years (range, 32-55). Nine patients were diagnosed with human immunodeficiency virus (HIV) infection at the time of diagnosis of Burkitt lymphoma/leukemia; the other 4 patients had been diagnosed with HIV infection for a median of 37 months (range, 18-137) prior to the diagnosis of Burkitt lymphoma/leukemia. The median absolute CD4 count from the 9 patients with evaluable counts was 77 cells/microL (range, 9-544); only one patient had a count > 200/microL.

RESULTS

Twelve patients (92%) achieved a complete remission (CR) and one achieved a partial response (PR). Eight patients continued in CR after a median of 31 months (range, 7-45) at the time of writing. Five patients were alive and in CR over two years later. The median survival was 12 months, with 48% of patients alive after 2 years. Six of seven patients who received HAART from the start of chemotherapy were alive and in CR after a median of 29 months (range, 7-45). The four patients who did not receive HAART died. The regimen was universally myelosuppressive, but the toxicity profiles, recoveries from myelosuppression, and incidences of infectious complications were similar to that of non-HIV patients with Burkitt lymphoma/leukemia treated with the same regimen.

CONCLUSIONS

Hyper-CVAD is an effective regimen for patients with AIDS-associated Burkitt lymphoma/leukemia, with acceptable toxicity. The combination of hyper-CVAD and HAART is associated with long-term survival in patients with the two diseases, which, until recently, were both considered invariably fatal and almost futile to treat medically.

Human immunodeficiency virus-related lymphoma: relation between clinical features and histologic subtypes

PURPOSE

Non-Hodgkin's lymphoma occurs frequently in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). We determined the association between the clinical and histologic features of HIV-related lymphoma.

SUBJECTS AND METHODS

We reviewed the medical records of 291 patients with noncerebral HIV-related lymphoma who had been treated in multicenter trials coordinated by the Groupe d'Etude des Lymphomes de l'Adulte between 1988 and 1997. This study was performed mainly before the availability of combination antiretroviral therapy.

RESULTS

The main histologic subtypes were centroblastic lymphoma in 131 patients (45%), immunoblastic lymphoma in 39 patients (13%), and Burkitt's lymphoma (including the classical form and the variant with plasmacytic differentiation) in 115 patients (40%). Burkitt's lymphoma was the most aggressive form, whereas immunoblastic lymphoma occurred in severely immunodeficient patients. Two-year survival after enrollment was 15% in immunoblastic lymphoma, 32% in Burkitt's lymphoma, and 31% in centroblastic lymphoma (P = 0.006), but multivariate analysis did not confirm the independent prognostic value of histologic subtype. Instead, five independent pretreatment factors increased the risk of mortality: age 40 years or older [relative risk (RR) = 1.5; 95% confidence interval (CI), 1.1 to 2.1; P = 0.005], elevated serum lactate dehydrogenase level (RR = 1.5; 95% CI, 1.1 to 2.1; P = 0.02), having a diagnosis of AIDS before lymphoma (RR = 1.8; 95% CI, 1.2 to 2.6; P = 0.006), CD4(+) cell count less than 100 x 10(6)/L (RR = 1.8; 95% CI, 1.3 to 2.6; P = 0.0004), and impaired performance status (RR = 2.4; 95% CI, 1.7 to 3.4; P <0.0001).

CONCLUSION

Several pretreatment characteristics of HIV-related lymphoma were linked to the histologic form, but HIV disease parameters other than those of lymphoma were the main determinants of outcome, so the histologic features of the lymphoma were not associated with prognosis.

Plasmablastic lymphoma in a patient with chronic lymphocytic leukemia heavily pretreated with cladribine (2-CdA): an unusual variant of Richter's syndrome

Patients with chronic lymphocytic leukemia (CLL) may develop a large-cell transformation known as Richter's syndrome (RS). RS usually presents as diffuse large-cell lymphoma (DLCL) or its immunoblastic variant, and it can be recognized simultaneously with CLL or even 23 yr after its diagnosis. We describe an unusual case of CLL treated with cladribine (2-CdA) in whom DLCL of the plasmablastic type (PBL) developed 4 yr after CLL (Rai IV) diagnosis and 1.5 yr after the 10th course of 2-CdA treatment. Immmunologic, cytogenetic, and molecular studies performed at the time of CLL and PBL coappearance indicated that both tumors originated from different B-cell progenitors. Both malignancies were refractory to VAD (vincristine, doxorubicin, dexamethasone)-based chemotherapy, and only partial response was achieved with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) salvage treatment. However, the patient died 6 months after the occurrence of RS due to rapid progression of PBL. This is the first description of a CLL patient who developed an unusual plasmablastic variant of RS. Recently, the PBL entity has been identified among DLCL associated with the human immunodeficiency virus (HIV) infection. We suggest that in our CLL patient heavily pretreated with 2-CdA, PBL arose as a second clone due to the prolonged and severe state of the host's immunosuppression. Overall survival with current strategies is poor, and further insight into the natural history, biology, and treatment of PBL are needed.

Plasmablastic lymphoma of the lung: report of a unique case and review of the literature

Non-Hodgkin lymphomas associated with acquired immunodeficiency syndrome are heterogeneous. Recently, a novel subtype of non-Hodgkin lymphoma occurring mostly in patients with acquired immunodeficiency syndrome has been described and designated as plasmablastic lymphoma. The histomorphologic and immunophenotypic findings of this distinct subtype of non-Hodgkin lymphoma have been characterized previously. Most patients present with oral cavity involvement. We report a case of plasmablastic lymphoma presenting as a lung tumor. To our knowledge, this is the first case report of this unusual subtype of diffuse large B-cell lymphoma in this location.

Peripheral neuropathy associated with acquired immunodeficiency syndrome (AIDS)-related Burkitt's lymphoma

Peripheral neuropathy associated with acquired immunodeficiency syndrome (AIDS)-related Burkitt's lymphoma usually occurs as a toxic effect of chemotherapeutic agents. Whereas primary peripheral nerve involvement is an unusual complication, we report on a human immunodeficiency virus (HIV)-positive patient with Burkitt's lymphoma and sciatic neuropathy due to compression by a lymphomatous mass. Therapy with radiation and chemotherapy was followed by clinical and radiological improvement, but recurrent neurological deficits in a similar distribution occurred later from lymphomatous meningitis.

Burkitt's lymphoma: historical background and recent insights into classification and pathogenesis

In this paper, the authors evaluate the historical evolution of the definition of Burkitt's lymphoma (BL) and of its clinicoepidemiological (endemic, sporadic, and acquired immunodeficiency syndrome-associated BL) and morphological variants. On the basis of the morphological, immunologic, genetic, and clinical characteristics of these tumors, the authors also emphasize the importance of precise disease definitions for biological and epidemiological studies. These principles were used in accordance with the Revised European-American classification of lymphoid neoplasms (REAL), which proposed that disease entities should be defined by a constellation of pathobiological and clinical features.

Genetic alterations of the retinoblastoma-related gene RB2/p130 identify different pathogenetic mechanisms in and among Burkitt's lymphoma subtypes

Alterations of cell cycle-associated genes probably contribute to the pathogenesis of Burkitt's Lymphoma (BL), in addition to c-myc translocation. Mutations disrupting the nuclear localization signal of the retinoblastoma-related gene RB2/p130 have been documented recently in BL cell lines and primary tumors. Given the importance of the RB2/p130 gene in controlling cell growth, mutations of this gene may result in uncontrolled cell proliferation. We tested the expression and genomic organization of the RB2/p130 gene in relation to the proliferative features of a series of BL samples collected from the endemic and sporadic regions, regardless of whether the samples were acquired immune deficiency syndrome (AIDS)-related. The expression of the Rb2/p130, p107, and cell proliferation-related proteins (cyclin A and B) was determined by immunohistochemistry. The structures of exons 19 through 22 of the RB2/p130 gene, encoding for the B domain and C terminus, were analyzed by polymerase chain reaction (PCR) analysis and single-strand conformation polymorphism (SSCP) technique. The direct PCR products were sequenced to identify the actual mutations. Our results suggest that BL is composed of a mixture of molecular types with distinct genetic and phenotypic patterns, probably resulting from different pathogenetic mechanisms. In endemic BL, the RB2/p130 gene is mutated in most of the cases, and the protein is restricted to the cytoplasm. In AIDS-related BL, high levels of nuclear expression of the wild-type pRb2/p130, p107, and cell proliferation-related proteins were detected. This finding is in line with the molecular mechanisms observed in virus-linked oncogenesis. Sporadic BLs were mainly characterized by the low nuclear values of the wild-type pRb2/p130 and, conversely, the high values of p107. The increased cell proliferation due to different alterations of cell growth control by Rb-related proteins may be the first step in lymphomagenesis, during which additional genetic changes, including missense mutations of c-myc, may subsequently occur.

Mutation of BAX occurs infrequently in acquired immunodeficiency syndrome-related non-Hodgkin's lymphomas

Acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin's lymphomas (AIDS-NHLs) consistently derive from B cells, are histologically heterogeneous, and are associated with distinct molecular pathways depending upon histology. Recently, it has been proposed that inactivating mutations of the bax death agonist may contribute to the pathogenesis of human tumors. In particular, among B-cell malignancies, BAX mutations have been detected at a certain frequency in Burkitt lymphomas. This study is aimed at defining the status of the BAX gene throughout the clinicopathologic spectrum of AIDS-NHL (n = 54), including AIDS-related Burkitt lymphoma (n = 14), AIDS-related Burkitt-like lymphoma (n = 8), AIDS-related diffuse large cell lymphoma (n = 15), AIDS-related primary central nervous system lymphoma (n = 6), and AIDS-related primary effusion lymphoma (n = 11). All 6 BAX exons and flanking sequences were subjected to mutational analysis by polymerase chain reaction-single strand conformation polymorphism followed by DNA direct sequencing of positive cases. Mutations of BAX among AIDS-NHL were restricted to a cell line of AIDS-related primary effusion lymphoma, which harbored a frameshift mutation causing the introduction of a proximal stop codon. All other AIDS-NHL displayed wild-type BAX alleles. In order to investigate whether BAX inactivation in AIDS-NHL may occur through mechanisms other than gene mutation, bax protein expression was investigated by Western blot analysis or immunohistochemistry in selected cases. All AIDS-NHL analyzed expressed normal bax proteins. Overall, this study indicates that deregulation of apoptotic control in AIDS-NHL is not caused by BAX alterations. Genes Chromosomes Cancer 27:177-182, 2000.

AIDS-related plasmablastic lymphomas of the oral cavity and jaws: a diagnostic dilemma

Acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin's lymphomas are highly pleomorphic in their clinical, pathological, and biological features. Recent investigations have led to the identification of a particular type of AIDS-related non-Hodgkin's lymphomas presenting in the oral cavity and jaws. This novel category of AIDS-related non-Hodgkin's lymphomas derives from B-cells and has been defined as plasmablastic lymphoma on the basis of its morphological and immunophenotypic features. Clinically, AIDS-related plasmablastic lymphoma is generally limited to the oral cavity at the time of diagnosis, although extension to distant sites frequently occurs at a later stage. Histologically, AIDS-related plasmablastic lymphoma is composed of a monomorphic and cohesive pattern of plasmablasts with basophilic cytoplasm. Phenotypically, AIDS-related plasmablastic lymphoma fails to express the most common B-cell-associated surface antigens, whereas it consistently expresses high levels of plasma cell-associated markers, including VS38c and CD138/syndecan-1. For the purpose of differential diagnosis, the morphological and immunophenotypic peculiarities of AIDS-related plasmablastic lymphoma clearly distinguish these lymphomas from other categories of AIDS-related non-Hodgkin's lymphomas, as well as from undifferentiated large cell carcinomas.

Plasmablastic lymphoma: a new subcategory of human immunodeficiency virus-related non-Hodgkin's lymphoma

A patient with human immunodeficiency virus-related non-Hodgkin's lymphoma arising in the oral cavity is reported. The tumour had an unusual immunohistochemical profile that was negative for leucocyte common antigen and the B-cell antigen CD20 but positive for the plasma cell-reactive antibody VS38c. The features of this type of tumour, which has recently been categorized, are presented and discussed.

HIV-associated malignant lymphomas in Kenya (Equatorial Africa)

The clinical and pathological features of acquired immune deficiency syndrome (AIDS)-related lymphomas, including their relationship with other viruses, such as Epstein-Barr virus (EBV) and human herpes virus-8 (HHV8), have been the subject of several studies from North America and Europe. No consistent data have been reported in Africa, where AIDS runs an epidemiological and clinical course different from that observed in Western countries. We retrospectively evaluated the presence of human immunodeficiency virus (HIV), HHV8, and EBV in 146 cases of malignant lymphomas collected in Kenya (Equatorial Africa), with the use of polymerase chain reaction (PCR) and in situ hybridization (ISH). The PCR technique confirmed HIV infection in 16 HIV-seropositive subjects (11%) and showed the presence of HIV sequences in five additional cases (3%) in which the occurrence of lymphoma was the only clinical manifestation. Our findings suggest that AIDS-related lymphomas are not pathogenetically homogenous, and different mechanisms may contribute to lymphomagenesis in these severely immunocompromised patients. In our series, no association of Hodgkin's disease (HD) with HIV infection could be shown. Among non-HIV-related lymphomas, EBV was present in 94% of Burkitt lymphoma (BL) occurring in patients younger than 15 years of age, in 87% of HD independently of age, sex, and histological types, in 60% of anaplastic large cell lymphoma (ALCL), and to a lesser extent (13%) in large B-cell lymphoma (LBCL) cases. Only one tumor, a case of HD, showed HHV8 by PCR.

AIDS-related malignancies

In the US over one million persons are currently infected with the HIV, over half a million have had AIDS, and over 300,000 have died from AIDS. Worldwide, it is estimated that more than 17 million people are currently infected with HIV, and over 1,200,000 cases of AIDS have been reported to the World Health Organization. By some estimates, up to 40% of patients with AIDS will ultimately develop some form of cancer. Non-Hodgkin's lymphoma, Kaposi's sarcoma and invasive cervical cancer have a higher incidence in persons with HIV infection and all three are AIDS-defining illnesses. In addition, several reports suggest that a number of other malignancies may occur at an increased incidence in persons with HIV infection, including squamous-cell carcinoma of the head, neck and anus, plasmacytoma, melanoma, small-cell lung cancer, basal-cell cancer, and germ-cell tumours. Clinicians should become familiar with HIV-related malignancies as their incidence is expected to further increase as more effective therapies for HIV and associated opportunistic infections allow patients to live longer in an advanced state of immunodeficiency. In the current article, we will review the clinical and therapeutic aspects of the most common AIDS-related malignancies including non-Hodgkin's and Hodgkin's lymphomas, Kaposi's sarcoma and anogenital epithelial neoplasias.

Functional analysis of the p53 protein in AIDS-related non-Hodgkin's lymphomas and polymorphic lymphoproliferations

Alteration of the tumour suppressor gene p53 is frequent in AIDS-related non-Hodgkin's lymphomas (AIDS-NHL), particularly in Burkitt's or Burkitt's-like lymphomas (BL/BLL). Since mechanisms of inactivation other than mutations have been advanced, the transcriptional activity of the p53 protein was studied in a functional assay in yeast in a series of AIDS-NHL lesions and compared with their morphology, immunohistochemistry (IHC) and single-strand conformation polymorphism (SSCP) analysis detection of other p53 abnormalities, Epstein-Barr virus (EBV) status, MDM-2 oncoprotein expression and c-MYC rearrangement. Polymorphic lymphoproliferations (PL), identified as precursors of NHL in HIV-patients, were also analysed in attempt to detect p53 modifications related to clonal progression. The functional assay detected p53 mutants in 40% (12/ 30) of the tumours: 50% (6/12) of BL/BLL, 40% (4/10) of diffuse large cell lymphomas (DLCL) and 25% (2/8) of PL. An oligoclonal or monoclonal population was identified in the two PL cases with mutant p53. An accumulation of the p53 protein was detected by IHC in 26% (8/30) of the tumours (five BL/BLL and three DLCL) and was associated with positive functional assay. In the 20 lesions tested by both of the screening methods for mutations, a p53 mutant pattern was detected in 55% of cases (11/20) and in 25% of cases (5/ 20) respectively with the functional assay and SSCP analysis of exons 5-8. There was no inverse correlation between the detection of EBV genome and the presence of p53 mutations and no overexpression of MDM-2 protein for the whole series. In conclusion, the functional assay was more sensitive than IHC and SSCP for the detection of p53 mutations in tumour samples. The mutations identified in AIDS-NHL lesions inactivate the p53 protein and in PL they could represent a selection of an aggressive clone.

EBV-associated anorectal lymphomas in patients with acquired immune deficiency syndrome

Primary lymphomas of the gastrointestinal tract represent 9% of all non-Hodgkin lymphomas, and of these only 3% arise in the rectum or anus. In contrast to their rare occurrence in the general population, the incidence of anorectal lymphomas in patients with acquired immune deficiency syndrome (AIDS), particularly homosexual patients, may be as high as 26% as reported in our own series of AIDS-associated lymphomas. To determine the characteristics of this entity, we studied 15 cases of primary anorectal lymphoma in AIDS patients and compared them with four cases of anorectal lymphoma unrelated to AIDS. The cases in our study were also compared with the reports of rectal lymphoma in the medical literature over the past 30 years. In the present series, the AIDS patients were all male with a median age of 34 years, human immunodeficiency virus (HIV)-positive, with homosexuality as the main risk factor. The four non-AIDS patients included a woman and had a median age of 66.5 years. Histologically, the anorectal lymphomas in AIDS patients were all high grade, predominantly immunoblastic, and polymorphous. In the non-AIDS patients, only two of four lymphomas were high grade, including one Burkitt type. All tumors were of B-cell phenotype. In the AIDS-associated anorectal lymphomas, the presence of Epstein-Barr virus (EBV) in a latent form was demonstrated by an abundance of Epstein-Barr-encoded RNA (EBER) in 14 of 15 cases and latent membrane protein (LMP) in four cases. All anorectal lymphomas unrelated to AIDS were negative for EBV. The unusual anorectal location of AIDS-associated lymphomas is explainable by the high incidence of preceding traumatic lesions and chronic infections in the area. As a result, EBV-carrying B cells may be attracted to the field providing the cell population that, under the conditions of immune deficiency, is able to give rise to high-grade lymphomas.

Cellular kinetic and phenotypic heterogeneity in and among Burkitt's and Burkitt-like lymphomas

This study asks whether the known genotypic heterogeneity within and between endemic or sporadic Burkitt's lymphomas (eBLs and sBLs, n = 10 each), and Burkitt-like lymphomas (BLLs, n-12), is reflected in divergent cytokinetics and related immunophenotypes. There was strong evidence that eBL and BLL grow markedly faster than sBL, as shown by differences in mitotic and apoptotic indices. Furthermore, in BLL, the median percentage of neoplastic cells immunoreactive for the bcl-2 protein was much higher than that observed in eBL and sBL. The reverse was true for the median fraction of cells containing c-myc protein. In eBL and sBL, the median fraction of bcl-6 protein-positive cells reached values above 50 per cent, while cells of 8/12 BLLs did not contain detectable amounts of this protein. This observation indicates that in this respect, eBL and sBL resemble normal germinal centres of lymphatic tissue much more than do BLL. Evidence for infection of neoplastic cells by the Epstein-Barr virus (EBV) was observed in 9/10 cases of eBL and in 3/10 of sBL, but not in BLL. EBV-positive lymphomas were associated with distinctly lower apoptotic indices and smaller median percentages of bcl-6-positive cells than EBV-negative tumours.

Morphologic patterns and molecular pathways of AIDS-related head and neck and other systemic lymphomas

Head and neck manifestations of human immunodeficiency virus (HIV) infection include lymph nodal and extranodal localization of non-Hodgkin's lymphoma (NHL). A histopathologic characteristic common to head and neck NHLs and to all the other systemic lymphomas in HIV patients is the frequent occurrence of cases displaying pleomorphic features and some overlap between established histologic subtypes. This article highlights the difficulties in defining HIV-related NHLs correctly, and proposes a specific pathologic categorization of these disorders accounting for their pathogenic aspects as gathered from molecular data.

Treatment of Burkitt's lymphoma in HIV-positive patients

Many Burkitt's-type non-Hodgkin lymphomas (NHL) in patients without HIV infection are curable with current brief high-dose combination chemotherapy regimens. Burkitt's-type lymphomas (BL) comprise 30-40% of HIV-associated NHL. Their morphologic, clinical, cytogenetic and molecular genetic characteristics are similar to those of sporadic BL unassociated with HIV infection. They often occur in less immunosuppressed HIV-infected individuals than the other types of NHL. Most patients with HIV-associated NHL benefit as much from low-dose as from standard or high-dose chemotherapy with less toxicity. However, there may be a subpopulation of HIV-infected patients with Burkitt's-type NHL and well preserved immune status who may benefit from high-dose chemotherapy programs that are effective for BL patients without HIV infection.