AIDS-Related Lymphoma

Prognostic Significance of in situ Phenotypic Marker Expression in Diffuse Large B-cell Lymphomas

Diffuse large B-cell lymphomas (DLBCL) are the most common lymphoid malignancies, and encompass all malignant lymphomas characterized by large neoplastic cells and B-cell derivation. In the last decade, DLBCL has been subjected to intense clinical, phenotypic and molecular studies, and were found to represent a heterogeneous group of tumors. These studies suggested new disease subtypes and variants with distinct clinical characteristics, morphologies, immunophenotypes, genotypes or gene expression profiles, associated with distinct prognoses or unique sensitivities to particular therapy regimens. Unfortunately, the reliability and reproducibility of the molecular results remains unclear due to contradictory reports in the literature resulting from small sample sizes, referral and selection biases, and variable methodologies and cut-off levels used to determine positivity. Here, we review phenotypic studies on the prognostic significance of protein expression profiles in DLBCL and reconsider our own retrospective data on 301 primary DLBCL cases obtained on a previously validated tissue microarray in light of powerful statistical methods of determining optimal cut-off values of phenotypic factors for prediction of outcome.

Biomarkers of HIV-associated Cancer

Cancer biomarkers have provided great opportunities for improving the management of cancer patients by enhancing the efficiency of early detection, diagnosis, and efficacy of treatment. Every cell type has a unique molecular signature, referred to as biomarkers, which are identifiable characteristics such as levels or activities of a myriad of genes, proteins, or other molecular features. Biomarkers can facilitate the molecular definition of cancer, provide information about the course of cancer, and predict response to chemotherapy. They offer the hope of early detection as well as tracking disease progression and recurrence. Current progress in the characterization of molecular genetics of HIV-associated cancers may form the basis for improved patient stratification and future targeted or individualized therapies. Biomarker use for cancer staging and personalization of therapy at the time of diagnosis could improve patient care. This review focuses on the relevance of biomarkers in the most common HIV-associated malignancies, namely, Kaposi sarcoma, non-Hodgkin’s lymphoma, and invasive cervical cancer.

Plasmablastic lymphoma in pediatric patients: clinicopathologic study of three cases

Plasmablastic lymphoma (PBL) is an aggressive high grade non-Hodgkin lymphoma which occurs predominantly in adult patients who are concomitantly afflicted with HIV infection. In contrast to several reports and studies of PBL in adult patients, PBL has very rarely been reported in pediatric patients. This article hereby provides collaborative clinicopathologic information of de novo PBL diagnosed in 3 pediatric patients with concomitant HIV infection. Cognizance of this rare tumor in the pediatric population coupled with antiretroviral therapy and prompt initiation of multimodality treatment may, in the future, facilitate improved outcome in pediatric patients with PBL.

HMG-CoA reductase inhibitors (statins) use and risk of non-Hodgkin lymphoma in HIV-positive persons

OBJECTIVE

Experimental studies suggested that HMG-CoA reductase inhibitors ('statins') may have antilymphoma properties. We investigated whether statin use is associated with reduced risk of non-Hodgkin lymphoma (NHL) in HIV-positive persons.

DESIGN

A nested case-control study was conducted among HIV-positive members of Kaiser Permanente California, a large managed care organization.

METHODS

Cases were incident HIV+ NHL diagnosed from 1996 to 2008. Controls were HIV-positive members without NHL matched 5 : 1 to cases by age, sex, race, index year and known duration of HIV infection. Data were collected from Kaiser Permanente's electronic medical records. Conditional logistic regression was used to examine the effect of statin use on HIV + NHL risk, adjusting for potential confounders (matching factors, prior clinical AIDS diagnosis, antiretroviral use, baseline CD4 cell count, and history of selected co-morbidity) and use of nonstatin lipid-lowering therapy (LLT).

RESULTS

A total of 259 cases and 1295 controls were included. Eight percent of the cases and 14% of the controls had a history of statin use. Statin use was associated with lower risk of HIV + NHL; hazard ratio and 95% confidence intervals for ever use, less than 12, and at least 12 months cumulative use was 0.55 (0.31-0.95), 0.64 (0.31-1.28), and 0.50 (0.23-1.10), respectively. P value for trend for duration of statin use was 0.08. No association between nonstatin LLT use and risk of NHL was observed.

CONCLUSION

Our results suggested an inverse association between statin use and risk of NHL in HIV-positive persons. Potential limitations include the likelihood of residual confounding by indication and limited study power for some statin use subgroups.

Infectious agents and lymphoma

In the past 25 years revelations on the genesis of human cancer have come at an increasing pace. Research on oncogenic infectious agents, especially viruses, has helped us to understand the process of malignant transformation of cells because the cellular events in viral-driven transformation mirror, often brilliantly, basic cellular processes that culminate in cancer, even those not associated with viruses. Infectious agents, especially viruses, account for several of the most common malignancies-up to 20% of all cancers. Some of these cancers are endemic, with a high incidence in certain geographic locations, but sporadic/lower incidence in other parts of the world. Lymphomas arise frequently in association with infectious agents such as Epstein-Barr virus, human immunodeficiency virus, human herpes virus 8, Helicobacter pylori, and hepatitis C virus. In this review, we will focus on the association between infectious agents and lymphomas, with a look at the molecular mechanisms they use to disturb cell regulation and eventually result in cancer.

Interventions for previously untreated patients with AIDS-associated non-Hodgkin's lymphoma

BACKGROUND

Human immunodeficiency virus (HIV) infection is known to be associated with an increased risk of non-Hodgkin's lymphoma (NHL). The majority of lymphomas (>80%) occurring during immunosuppression are aggressive B-cell in origin and have a high-to-intermediate histology grade. Treatment of NHL is not standardized.

OBJECTIVES

To assess the clinical effectiveness and safety of single agent or combination chemotherapy with or without immunochemotherapy (rituximab) and with or without highly active antiretroviral therapy (HAART) on overall survival (OS) and disease-free survival (DFS) for previously untreated patients with AIDS-related NHL.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2009), MEDLINE (1966-March 6, 2009), EMBASE (1988-March 6, 2009), LlLACS (1982 to February 17, 2009), Gateway (March 6, 2009), and AIDSearch (2006 -February 2008) were used to identify published, potentially eligible trials. Further, we searched several electronic sources. For additional information see the Cochrane HIV/AIDS Group search strategy.

SELECTION CRITERIA

Randomized controlled trials (RCTs) assessing the effectiveness of systemic treatments for previously untreated AIDS-related NHL. There were no age or language restrictions.

DATA COLLECTION AND ANALYSIS

Authors independently assessed relevant studies for inclusion; four RCTs were selected. No meta-analysis was attempted due to clinical heterogeneity.

MAIN RESULTS

Four RCTs that included 857 patients (number range: 30 to 485) met the inclusion criteria. The studies have a high risk of bias; three RCTs were conducted in the United States and one was a multi-national, multi-centre RCT performed in France and Italy. One of the trials included only men. It was impossible to pool data for any of the outcomes due to the differences in the interventions assessed in these RCTs. Overall survival did not differ significantly between treatment groups. Disease free survival (DFS) was reported in two of the four RCTs, but it was not statistically significant between treatment groups.

AUTHORS' CONCLUSIONS

We found no evidence that the systemic interventions for untreated patients with AIDS-related NHL provide superior clinical effectiveness for improving OS, DSF, and tumour response rate; however, this conclusion is based on four RCTs with limited sample size and variable quality. More adequately powered RCTs that have low risk of bias are necessary to determine the real benefit or harm of interventions to treat this population. Overall survival (OS), DFS, and quality of life should be included as endpoints.

Minimum diagnostic criteria for plasmablastic lymphoma of oral/sinonasal region encountered in a tertiary cancer hospital of a developing country

BACKGROUND

Haematolymphoid tumours other than plasmablastic lymphoma (PBL) may reveal plasmablastic differentiation with overlapping immunoreactivity causing diagnostic dilemma. Elaborate ancillary diagnostic techniques can make the process expensive, tedious and out of reach for pathology laboratory in a developing country.

METHODS

Out of 98 total cases of primary non-Hodgkin's lymphoma and plasmacytoma of oral-sinonasal region recorded in our institute over 4 years, 39 cases showing varied plasmablastic differentiation were selected. Morphological and immunohistochemical criteria were applied to identify minimum diagnostic criteria for PBL. Human Immunodeficiency Virus (HIV) correlation and Epstein-Barr virus expressed RNA (EBER) in-situ hybridisation studies were also performed.

RESULTS

Minimum morphological criteria required to diagnose PBL were: (1) predominant population of plasmablasts which are large monomorphic cells with high nuclear-cytoplasmic ratio, moderate amount of amphophilic cytoplasm and round nucleus with prominent central nucleolus, (2) high mitotic and/or apoptotic index and (3) absence of neoplastic plasma cells in the background. Essential diagnostic immunophenotype consisted of CD20 negativity, LCA +/-, CD138/VS38c diffuse positivity, light chain restriction and high MIB-1 index (>60 %). Twenty-five of the total 32 PBL cases thus identified, involved oral cavity. Of these, 84% affected gingivo-buccal complex. Twenty-eight cases were HIV positive. EBER positivity confirmed the diagnosis in all the HIV-negative cases.

CONCLUSIONS

A triad of 'rapidly growing lesion with predilection for oral mucosa, classical plasmablastic morphology and limited immunohistochemical panel' can render a reliable diagnosis of PBL, irrespective of HIV and EBV status, especially in developing countries with limited resources.

Evaluation of evidence for infection as a mode of action for induction of rat lymphoma

The European Food Safety Authority (EFSA) released a 2006 report questioning the relationship of aspartame exposure with increased incidence of lymphomas/leukemias in a European Ramazzini Foundation (ERF) rat study. The EFSA report suggested that the lymphoma/leukemia findings were most likely explained by infection in the rat colony. The ERF has also conducted the only available long-term oral study of methyl tertiary-butyl ether (MTBE). Thus, using the EFSA report as support, some have now raised questions about the human relevance of MTBE-associated hemolymphoreticular tumors reported by the ERF in female rats as well as whether their incidence was elevated above background levels. In this report, we discuss the hypothesized mode of action (MOA) of infection-induced lymphoma and its relevance to MTBE-associated lymphomas. We address the relationship of rat strain and study duration to lymphoma susceptibility and review evidence of low background rates of this tumor in control animals at the ERF, similar survival rates for female rats at the ERF and National Toxicology Program (NTP), and chemical- and gender-specificity of tumor induction for this type of tumor in studies at the ERF. We find that the background incidence of hemolymphoreticular tumors in female rats in the MTBE study is consistent with contemporaneous studies at the ERF and that there is an exposure-related effect, which is unlikely to be due to infections. We examine more recent tumor classification schemes for lymphomas, which support the combination of lymphoblastic leukemias and lymphomas reported by Belpoggi et al. ([1995] Toxicol Ind Health 11:119-149; [1998] Eur J Oncol 3:201-206).

EBV-associated diseases in the AIDS patient

EBV-associated malignancies remain a considerable problem in HIV-infected individuals, even in the era of HAART. Although EBV is a common factor, each disease has a unique pathogenesis. Study of these diseases reveals the viral proteins expressed in the malignancies that might contribute to the development of the disease as well as the molecular basis for pathogenesis. It is likely that this knowledge will contribute to the development of novel therapeutics that will result in more favorable outcomes in the future.

Diffuse large B-cell lymphoma: a heterogeneous group of non-Hodgkin lymphomas comprising several distinct clinicopathological entities

Diffuse large B-cell lymphoma (DLBCL) as defined by the World Health Organization (WHO) classification is clinically, morphologically and genetically a heterogeneous group of malignant proliferations of large lymphoid B cells. Over the last 6 years, several studies have been published improving our understanding of these lymphomas. These studies analyzed DLBCL by their gene expression profile, provided further information on some of the variants of DLBCL listed in the WHO classification and stressed the impact of the site of origin of these tumors. This review summarizes these recent data and explores their impact on the recognition of new clinicopathological lymphoma entities.